Merge tag 'for-5.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This contains feature updates, performance improvements, preparatory
  and core work and some related VFS updates:

  Features:

   - encoded read/write ioctls, allows user space to read or write raw
     data directly to extents (now compressed, encrypted in the future),
     will be used by send/receive v2 where it saves processing time

   - zoned mode now works with metadata DUP (the mkfs.btrfs default)

   - error message header updates:
      - print error state: transaction abort, other error, log tree
        errors
      - print transient filesystem state: remount, device replace,
        ignored checksum verifications

   - tree-checker: verify the transaction id of the to-be-written dirty
     extent buffer

  Performance improvements for fsync:

   - directory logging speedups (up to -90% run time)

   - avoid logging all directory changes during renames (up to -60% run
     time)

   - avoid inode logging during rename and link when possible (up to
     -60% run time)

   - prepare extents to be logged before locking a log tree path
     (throughput +7%)

   - stop copying old file extents when doing a full fsync()

   - improved logging of old extents after truncate

  Core, fixes:

   - improved stale device identification by dev_t and not just path
     (for devices that are behind other layers like device mapper)

   - continued extent tree v2 preparatory work
      - disable features that won't work yet
      - add wrappers and abstractions for new tree roots

   - improved error handling

   - add super block write annotations around background block group
     reclaim

   - fix device scanning messages potentially accessing stale pointer

   - cleanups and refactoring

  VFS:

   - allow reflinks/deduplication from two different mounts of the same
     filesystem

   - export and add helpers for read/write range verification, for the
     encoded ioctls"

* tag 'for-5.18-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (98 commits)
  btrfs: zoned: put block group after final usage
  btrfs: don't access possibly stale fs_info data in device_list_add
  btrfs: add lockdep_assert_held to need_preemptive_reclaim
  btrfs: verify the tranisd of the to-be-written dirty extent buffer
  btrfs: unify the error handling of btrfs_read_buffer()
  btrfs: unify the error handling pattern for read_tree_block()
  btrfs: factor out do_free_extent_accounting helper
  btrfs: remove last_ref from the extent freeing code
  btrfs: add a alloc_reserved_extent helper
  btrfs: remove BUG_ON(ret) in alloc_reserved_tree_block
  btrfs: add and use helper for unlinking inode during log replay
  btrfs: extend locking to all space_info members accesses
  btrfs: zoned: mark relocation as writing
  fs: allow cross-vfsmount reflink/dedupe
  btrfs: remove the cross file system checks from remap
  btrfs: pass btrfs_fs_info to btrfs_recover_relocation
  btrfs: pass btrfs_fs_info for deleting snapshots and cleaner
  btrfs: add filesystems state details to error messages
  btrfs: deal with unexpected extent type during reflinking
  btrfs: fix unexpected error path when reflinking an inline extent
  ...

46 files changed, 2970 insertions, 1331 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index c9ee579bc5a6..ebc392ea1d74 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -789,11 +789,13 @@ static int add_missing_keys(struct btrfs_fs_info *fs_info,
 		if (IS_ERR(eb)) {
 			free_pref(ref);
 			return PTR_ERR(eb);
-		} else if (!extent_buffer_uptodate(eb)) {
+		}
+		if (!extent_buffer_uptodate(eb)) {
 			free_pref(ref);
 			free_extent_buffer(eb);
 			return -EIO;
 		}
+
 		if (lock)
 			btrfs_tree_read_lock(eb);
 		if (btrfs_header_level(eb) == 0)
@@ -1335,7 +1337,8 @@ again:
 				if (IS_ERR(eb)) {
 					ret = PTR_ERR(eb);
 					goto out;
-				} else if (!extent_buffer_uptodate(eb)) {
+				}
+				if (!extent_buffer_uptodate(eb)) {
 					free_extent_buffer(eb);
 					ret = -EIO;
 					goto out;
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 8202ad6aa131..c22d287e020b 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1522,8 +1522,12 @@ void btrfs_reclaim_bgs_work(struct work_struct *work)
 	if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags))
 		return;
 
-	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE))
+	sb_start_write(fs_info->sb);
+
+	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
+		sb_end_write(fs_info->sb);
 		return;
+	}
 
 	/*
 	 * Long running balances can keep us blocked here for eternity, so
@@ -1531,6 +1535,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work)
 	 */
 	if (!mutex_trylock(&fs_info->reclaim_bgs_lock)) {
 		btrfs_exclop_finish(fs_info);
+		sb_end_write(fs_info->sb);
 		return;
 	}
 
@@ -1605,6 +1610,7 @@ next:
 	spin_unlock(&fs_info->unused_bgs_lock);
 	mutex_unlock(&fs_info->reclaim_bgs_lock);
 	btrfs_exclop_finish(fs_info);
+	sb_end_write(fs_info->sb);
 }
 
 void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info)
@@ -2006,6 +2012,7 @@ static int read_one_block_group(struct btrfs_fs_info *info,
 	cache->length = key->offset;
 	cache->used = btrfs_stack_block_group_used(bgi);
 	cache->flags = btrfs_stack_block_group_flags(bgi);
+	cache->global_root_id = btrfs_stack_block_group_chunk_objectid(bgi);
 
 	set_free_space_tree_thresholds(cache);
 
@@ -2288,7 +2295,7 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
 	spin_lock(&block_group->lock);
 	btrfs_set_stack_block_group_used(&bgi, block_group->used);
 	btrfs_set_stack_block_group_chunk_objectid(&bgi,
-				BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+						   block_group->global_root_id);
 	btrfs_set_stack_block_group_flags(&bgi, block_group->flags);
 	key.objectid = block_group->start;
 	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
@@ -2444,6 +2451,27 @@ next:
 	btrfs_trans_release_chunk_metadata(trans);
 }
 
+/*
+ * For extent tree v2 we use the block_group_item->chunk_offset to point at our
+ * global root id.  For v1 it's always set to BTRFS_FIRST_CHUNK_TREE_OBJECTID.
+ */
+static u64 calculate_global_root_id(struct btrfs_fs_info *fs_info, u64 offset)
+{
+	u64 div = SZ_1G;
+	u64 index;
+
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+
+	/* If we have a smaller fs index based on 128MiB. */
+	if (btrfs_super_total_bytes(fs_info->super_copy) <= (SZ_1G * 10ULL))
+		div = SZ_128M;
+
+	offset = div64_u64(offset, div);
+	div64_u64_rem(offset, fs_info->nr_global_roots, &index);
+	return index;
+}
+
 struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans,
 						 u64 bytes_used, u64 type,
 						 u64 chunk_offset, u64 size)
@@ -2464,6 +2492,8 @@ struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *tran
 	cache->flags = type;
 	cache->last_byte_to_unpin = (u64)-1;
 	cache->cached = BTRFS_CACHE_FINISHED;
+	cache->global_root_id = calculate_global_root_id(fs_info, cache->start);
+
 	if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
 		cache->needs_free_space = 1;
 
@@ -2693,7 +2723,7 @@ static int update_block_group_item(struct btrfs_trans_handle *trans,
 	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
 	btrfs_set_stack_block_group_used(&bgi, cache->used);
 	btrfs_set_stack_block_group_chunk_objectid(&bgi,
-			BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+						   cache->global_root_id);
 	btrfs_set_stack_block_group_flags(&bgi, cache->flags);
 	write_extent_buffer(leaf, &bgi, bi, sizeof(bgi));
 	btrfs_mark_buffer_dirty(leaf);
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 5878b7ce3b78..93aabc68bb6a 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -68,6 +68,7 @@ struct btrfs_block_group {
 	u64 bytes_super;
 	u64 flags;
 	u64 cache_generation;
+	u64 global_root_id;
 
 	/*
 	 * If the free space extent count exceeds this number, convert the block
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index b3e46aabc3d8..47e72d72f7d0 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -14,6 +14,13 @@
 #include "delayed-inode.h"
 
 /*
+ * Since we search a directory based on f_pos (struct dir_context::pos) we have
+ * to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so
+ * everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).
+ */
+#define BTRFS_DIR_START_INDEX 2
+
+/*
  * ordered_data_close is set by truncate when a file that used
  * to have good data has been truncated to zero.  When it is set
  * the btrfs file release call will add this inode to the
@@ -173,8 +180,9 @@ struct btrfs_inode {
 	u64 disk_i_size;
 
 	/*
-	 * if this is a directory then index_cnt is the counter for the index
-	 * number for new files that are created
+	 * If this is a directory then index_cnt is the counter for the index
+	 * number for new files that are created. For an empty directory, this
+	 * must be initialized to BTRFS_DIR_START_INDEX.
 	 */
 	u64 index_cnt;
 
@@ -333,6 +341,36 @@ static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
 	spin_unlock(&inode->lock);
 }
 
+/*
+ * Should be called while holding the inode's VFS lock in exclusive mode or in a
+ * context where no one else can access the inode concurrently (during inode
+ * creation or when loading an inode from disk).
+ */
+static inline void btrfs_set_inode_full_sync(struct btrfs_inode *inode)
+{
+	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
+	/*
+	 * The inode may have been part of a reflink operation in the last
+	 * transaction that modified it, and then a fsync has reset the
+	 * last_reflink_trans to avoid subsequent fsyncs in the same
+	 * transaction to do unnecessary work. So update last_reflink_trans
+	 * to the last_trans value (we have to be pessimistic and assume a
+	 * reflink happened).
+	 *
+	 * The ->last_trans is protected by the inode's spinlock and we can
+	 * have a concurrent ordered extent completion update it. Also set
+	 * last_reflink_trans to ->last_trans only if the former is less than
+	 * the later, because we can be called in a context where
+	 * last_reflink_trans was set to the current transaction generation
+	 * while ->last_trans was not yet updated in the current transaction,
+	 * and therefore has a lower value.
+	 */
+	spin_lock(&inode->lock);
+	if (inode->last_reflink_trans < inode->last_trans)
+		inode->last_reflink_trans = inode->last_trans;
+	spin_unlock(&inode->lock);
+}
+
 static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
 {
 	bool ret = false;
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 71e5b2e9a1ba..be476f094300 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -219,7 +219,7 @@ static bool dec_and_test_compressed_bio(struct compressed_bio *cb, struct bio *b
 		bi_size += bvec->bv_len;
 
 	if (bio->bi_status)
-		cb->errors = 1;
+		cb->status = bio->bi_status;
 
 	ASSERT(bi_size && bi_size <= cb->compressed_len);
 	last_io = refcount_sub_and_test(bi_size >> fs_info->sectorsize_bits,
@@ -234,7 +234,7 @@ static bool dec_and_test_compressed_bio(struct compressed_bio *cb, struct bio *b
 	return last_io;
 }
 
-static void finish_compressed_bio_read(struct compressed_bio *cb, struct bio *bio)
+static void finish_compressed_bio_read(struct compressed_bio *cb)
 {
 	unsigned int index;
 	struct page *page;
@@ -247,19 +247,18 @@ static void finish_compressed_bio_read(struct compressed_bio *cb, struct bio *bi
 	}
 
 	/* Do io completion on the original bio */
-	if (cb->errors) {
-		bio_io_error(cb->orig_bio);
+	if (cb->status != BLK_STS_OK) {
+		cb->orig_bio->bi_status = cb->status;
+		bio_endio(cb->orig_bio);
 	} else {
 		struct bio_vec *bvec;
 		struct bvec_iter_all iter_all;
 
-		ASSERT(bio);
-		ASSERT(!bio->bi_status);
 		/*
 		 * We have verified the checksum already, set page checked so
 		 * the end_io handlers know about it
 		 */
-		ASSERT(!bio_flagged(bio, BIO_CLONED));
+		ASSERT(!bio_flagged(cb->orig_bio, BIO_CLONED));
 		bio_for_each_segment_all(bvec, cb->orig_bio, iter_all) {
 			u64 bvec_start = page_offset(bvec->bv_page) +
 					 bvec->bv_offset;
@@ -308,7 +307,7 @@ static void end_compressed_bio_read(struct bio *bio)
 	 * Some IO in this cb have failed, just skip checksum as there
 	 * is no way it could be correct.
 	 */
-	if (cb->errors == 1)
+	if (cb->status != BLK_STS_OK)
 		goto csum_failed;
 
 	inode = cb->inode;
@@ -324,8 +323,8 @@ static void end_compressed_bio_read(struct bio *bio)
 
 csum_failed:
 	if (ret)
-		cb->errors = 1;
-	finish_compressed_bio_read(cb, bio);
+		cb->status = errno_to_blk_status(ret);
+	finish_compressed_bio_read(cb);
 out:
 	bio_put(bio);
 }
@@ -342,11 +341,12 @@ static noinline void end_compressed_writeback(struct inode *inode,
 	unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_SHIFT;
 	struct page *pages[16];
 	unsigned long nr_pages = end_index - index + 1;
+	const int errno = blk_status_to_errno(cb->status);
 	int i;
 	int ret;
 
-	if (cb->errors)
-		mapping_set_error(inode->i_mapping, -EIO);
+	if (errno)
+		mapping_set_error(inode->i_mapping, errno);
 
 	while (nr_pages > 0) {
 		ret = find_get_pages_contig(inode->i_mapping, index,
@@ -358,7 +358,7 @@ static noinline void end_compressed_writeback(struct inode *inode,
 			continue;
 		}
 		for (i = 0; i < ret; i++) {
-			if (cb->errors)
+			if (errno)
 				SetPageError(pages[i]);
 			btrfs_page_clamp_clear_writeback(fs_info, pages[i],
 							 cb->start, cb->len);
@@ -381,9 +381,10 @@ static void finish_compressed_bio_write(struct compressed_bio *cb)
 	 */
 	btrfs_writepage_endio_finish_ordered(BTRFS_I(inode), NULL,
 			cb->start, cb->start + cb->len - 1,
-			!cb->errors);
+			cb->status == BLK_STS_OK);
 
-	end_compressed_writeback(inode, cb);
+	if (cb->writeback)
+		end_compressed_writeback(inode, cb);
 	/* Note, our inode could be gone now */
 
 	/*
@@ -506,7 +507,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				 struct page **compressed_pages,
 				 unsigned int nr_pages,
 				 unsigned int write_flags,
-				 struct cgroup_subsys_state *blkcg_css)
+				 struct cgroup_subsys_state *blkcg_css,
+				 bool writeback)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct bio *bio = NULL;
@@ -524,13 +526,14 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 	if (!cb)
 		return BLK_STS_RESOURCE;
 	refcount_set(&cb->pending_sectors, compressed_len >> fs_info->sectorsize_bits);
-	cb->errors = 0;
+	cb->status = BLK_STS_OK;
 	cb->inode = &inode->vfs_inode;
 	cb->start = start;
 	cb->len = len;
 	cb->mirror_num = 0;
 	cb->compressed_pages = compressed_pages;
 	cb->compressed_len = compressed_len;
+	cb->writeback = writeback;
 	cb->orig_bio = NULL;
 	cb->nr_pages = nr_pages;
 
@@ -591,7 +594,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 
 		if (submit) {
 			if (!skip_sum) {
-				ret = btrfs_csum_one_bio(inode, bio, start, 1);
+				ret = btrfs_csum_one_bio(inode, bio, start, true);
 				if (ret)
 					goto finish_cb;
 			}
@@ -808,7 +811,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	u64 em_len;
 	u64 em_start;
 	struct extent_map *em;
-	blk_status_t ret = BLK_STS_RESOURCE;
+	blk_status_t ret;
 	int faili = 0;
 	u8 *sums;
 
@@ -821,17 +824,21 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, file_offset, fs_info->sectorsize);
 	read_unlock(&em_tree->lock);
-	if (!em)
-		return BLK_STS_IOERR;
+	if (!em) {
+		ret = BLK_STS_IOERR;
+		goto out;
+	}
 
 	ASSERT(em->compress_type != BTRFS_COMPRESS_NONE);
 	compressed_len = em->block_len;
 	cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS);
-	if (!cb)
+	if (!cb) {
+		ret = BLK_STS_RESOURCE;
 		goto out;
+	}
 
 	refcount_set(&cb->pending_sectors, compressed_len >> fs_info->sectorsize_bits);
-	cb->errors = 0;
+	cb->status = BLK_STS_OK;
 	cb->inode = inode;
 	cb->mirror_num = mirror_num;
 	sums = cb->sums;
@@ -851,8 +858,10 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	nr_pages = DIV_ROUND_UP(compressed_len, PAGE_SIZE);
 	cb->compressed_pages = kcalloc(nr_pages, sizeof(struct page *),
 				       GFP_NOFS);
-	if (!cb->compressed_pages)
+	if (!cb->compressed_pages) {
+		ret = BLK_STS_RESOURCE;
 		goto fail1;
+	}
 
 	for (pg_index = 0; pg_index < nr_pages; pg_index++) {
 		cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS);
@@ -938,7 +947,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 			comp_bio = NULL;
 		}
 	}
-	return 0;
+	return BLK_STS_OK;
 
 fail2:
 	while (faili >= 0) {
@@ -951,6 +960,8 @@ fail1:
 	kfree(cb);
 out:
 	free_extent_map(em);
+	bio->bi_status = ret;
+	bio_endio(bio);
 	return ret;
 finish_cb:
 	if (comp_bio) {
@@ -970,7 +981,7 @@ finish_cb:
 	 */
 	ASSERT(refcount_read(&cb->pending_sectors));
 	/* Now we are the only one referring @cb, can finish it safely. */
-	finish_compressed_bio_read(cb, NULL);
+	finish_compressed_bio_read(cb);
 	return ret;
 }
 
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 56eef0821e3e..ac5b20731d2a 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -22,6 +22,8 @@ struct btrfs_inode;
 
 /* Maximum length of compressed data stored on disk */
 #define BTRFS_MAX_COMPRESSED		(SZ_128K)
+static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
+
 /* Maximum size of data before compression */
 #define BTRFS_MAX_UNCOMPRESSED		(SZ_128K)
 
@@ -52,8 +54,11 @@ struct compressed_bio {
 	/* The compression algorithm for this bio */
 	u8 compress_type;
 
+	/* Whether this is a write for writeback. */
+	bool writeback;
+
 	/* IO errors */
-	u8 errors;
+	blk_status_t status;
 	int mirror_num;
 
 	/* for reads, this is the bio we are copying the data into */
@@ -95,7 +100,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				  struct page **compressed_pages,
 				  unsigned int nr_pages,
 				  unsigned int write_flags,
-				  struct cgroup_subsys_state *blkcg_css);
+				  struct cgroup_subsys_state *blkcg_css,
+				  bool writeback);
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags);
 
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index a7db3f6f1b7b..0eecf98d0abb 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -846,9 +846,11 @@ struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
 			     btrfs_header_owner(parent),
 			     btrfs_node_ptr_generation(parent, slot),
 			     level - 1, &first_key);
-	if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) {
+	if (IS_ERR(eb))
+		return eb;
+	if (!extent_buffer_uptodate(eb)) {
 		free_extent_buffer(eb);
-		eb = ERR_PTR(-EIO);
+		return ERR_PTR(-EIO);
 	}
 
 	return eb;
@@ -1436,13 +1438,13 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
 
 		/* now we're allowed to do a blocking uptodate check */
 		ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key);
-		if (!ret) {
-			*eb_ret = tmp;
-			return 0;
+		if (ret) {
+			free_extent_buffer(tmp);
+			btrfs_release_path(p);
+			return -EIO;
 		}
-		free_extent_buffer(tmp);
-		btrfs_release_path(p);
-		return -EIO;
+		*eb_ret = tmp;
+		return 0;
 	}
 
 	/*
@@ -1460,19 +1462,19 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
 	ret = -EAGAIN;
 	tmp = read_tree_block(fs_info, blocknr, root->root_key.objectid,
 			      gen, parent_level - 1, &first_key);
-	if (!IS_ERR(tmp)) {
-		/*
-		 * If the read above didn't mark this buffer up to date,
-		 * it will never end up being up to date.  Set ret to EIO now
-		 * and give up so that our caller doesn't loop forever
-		 * on our EAGAINs.
-		 */
-		if (!extent_buffer_uptodate(tmp))
-			ret = -EIO;
-		free_extent_buffer(tmp);
-	} else {
-		ret = PTR_ERR(tmp);
+	if (IS_ERR(tmp)) {
+		btrfs_release_path(p);
+		return PTR_ERR(tmp);
 	}
+	/*
+	 * If the read above didn't mark this buffer up to date,
+	 * it will never end up being up to date.  Set ret to EIO now
+	 * and give up so that our caller doesn't loop forever
+	 * on our EAGAINs.
+	 */
+	if (!extent_buffer_uptodate(tmp))
+		ret = -EIO;
+	free_extent_buffer(tmp);
 
 	btrfs_release_path(p);
 	return ret;
@@ -2990,16 +2992,11 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (free_space < data_size)
 		goto out_unlock;
 
-	/* cow and double check */
 	ret = btrfs_cow_block(trans, root, right, upper,
 			      slot + 1, &right, BTRFS_NESTING_RIGHT_COW);
 	if (ret)
 		goto out_unlock;
 
-	free_space = btrfs_leaf_free_space(right);
-	if (free_space < data_size)
-		goto out_unlock;
-
 	left_nritems = btrfs_header_nritems(left);
 	if (left_nritems == 0)
 		goto out_unlock;
@@ -3224,7 +3221,6 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 		goto out;
 	}
 
-	/* cow and double check */
 	ret = btrfs_cow_block(trans, root, left,
 			      path->nodes[1], slot - 1, &left,
 			      BTRFS_NESTING_LEFT_COW);
@@ -3235,12 +3231,6 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 		goto out;
 	}
 
-	free_space = btrfs_leaf_free_space(left);
-	if (free_space < data_size) {
-		ret = 1;
-		goto out;
-	}
-
 	if (check_sibling_keys(left, right)) {
 		ret = -EUCLEAN;
 		goto out;
@@ -4170,24 +4160,22 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct extent_buffer *leaf;
-	u32 last_off;
-	u32 dsize = 0;
 	int ret = 0;
 	int wret;
-	int i;
 	u32 nritems;
 
 	leaf = path->nodes[0];
-	last_off = btrfs_item_offset(leaf, slot + nr - 1);
-
-	for (i = 0; i < nr; i++)
-		dsize += btrfs_item_size(leaf, slot + i);
-
 	nritems = btrfs_header_nritems(leaf);
 
 	if (slot + nr != nritems) {
-		int data_end = leaf_data_end(leaf);
+		const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1);
+		const int data_end = leaf_data_end(leaf);
 		struct btrfs_map_token token;
+		u32 dsize = 0;
+		int i;
+
+		for (i = 0; i < nr; i++)
+			dsize += btrfs_item_size(leaf, slot + i);
 
 		memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET +
 			      data_end + dsize,
@@ -4227,24 +4215,50 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			fixup_low_keys(path, &disk_key, 1);
 		}
 
-		/* delete the leaf if it is mostly empty */
+		/*
+		 * Try to delete the leaf if it is mostly empty. We do this by
+		 * trying to move all its items into its left and right neighbours.
+		 * If we can't move all the items, then we don't delete it - it's
+		 * not ideal, but future insertions might fill the leaf with more
+		 * items, or items from other leaves might be moved later into our
+		 * leaf due to deletions on those leaves.
+		 */
 		if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) {
+			u32 min_push_space;
+
 			/* push_leaf_left fixes the path.
 			 * make sure the path still points to our leaf
 			 * for possible call to del_ptr below
 			 */
 			slot = path->slots[1];
 			atomic_inc(&leaf->refs);
-
-			wret = push_leaf_left(trans, root, path, 1, 1,
-					      1, (u32)-1);
+			/*
+			 * We want to be able to at least push one item to the
+			 * left neighbour leaf, and that's the first item.
+			 */
+			min_push_space = sizeof(struct btrfs_item) +
+				btrfs_item_size(leaf, 0);
+			wret = push_leaf_left(trans, root, path, 0,
+					      min_push_space, 1, (u32)-1);
 			if (wret < 0 && wret != -ENOSPC)
 				ret = wret;
 
 			if (path->nodes[0] == leaf &&
 			    btrfs_header_nritems(leaf)) {
-				wret = push_leaf_right(trans, root, path, 1,
-						       1, 1, 0);
+				/*
+				 * If we were not able to push all items from our
+				 * leaf to its left neighbour, then attempt to
+				 * either push all the remaining items to the
+				 * right neighbour or none. There's no advantage
+				 * in pushing only some items, instead of all, as
+				 * it's pointless to end up with a leaf having
+				 * too few items while the neighbours can be full
+				 * or nearly full.
+				 */
+				nritems = btrfs_header_nritems(leaf);
+				min_push_space = leaf_space_used(leaf, 0, nritems);
+				wret = push_leaf_right(trans, root, path, 0,
+						       min_push_space, 1, 0);
 				if (wret < 0 && wret != -ENOSPC)
 					ret = wret;
 			}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index ebb2d109e8bb..4db17bd05a21 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -49,6 +49,7 @@ extern struct kmem_cache *btrfs_free_space_bitmap_cachep;
 struct btrfs_ordered_sum;
 struct btrfs_ref;
 struct btrfs_bio;
+struct btrfs_ioctl_encoded_io_args;
 
 #define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
 
@@ -148,6 +149,8 @@ enum {
 
 	/* Indicates there was an error cleaning up a log tree. */
 	BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
+
+	BTRFS_FS_STATE_COUNT
 };
 
 #define BTRFS_BACKREF_REV_MAX		256
@@ -274,8 +277,14 @@ struct btrfs_super_block {
 	/* the UUID written into btree blocks */
 	u8 metadata_uuid[BTRFS_FSID_SIZE];
 
+	/* Extent tree v2 */
+	__le64 block_group_root;
+	__le64 block_group_root_generation;
+	u8 block_group_root_level;
+
 	/* future expansion */
-	__le64 reserved[28];
+	u8 reserved8[7];
+	__le64 reserved[25];
 	u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
 	struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
 
@@ -300,6 +309,26 @@ static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE);
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_SET	0ULL
 #define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR	0ULL
 
+#ifdef CONFIG_BTRFS_DEBUG
+/*
+ * Extent tree v2 supported only with CONFIG_BTRFS_DEBUG
+ */
+#define BTRFS_FEATURE_INCOMPAT_SUPP			\
+	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
+	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
+	 BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS |		\
+	 BTRFS_FEATURE_INCOMPAT_BIG_METADATA |		\
+	 BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |		\
+	 BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD |		\
+	 BTRFS_FEATURE_INCOMPAT_RAID56 |		\
+	 BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |		\
+	 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA |	\
+	 BTRFS_FEATURE_INCOMPAT_NO_HOLES	|	\
+	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID	|	\
+	 BTRFS_FEATURE_INCOMPAT_RAID1C34	|	\
+	 BTRFS_FEATURE_INCOMPAT_ZONED		|	\
+	 BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2)
+#else
 #define BTRFS_FEATURE_INCOMPAT_SUPP			\
 	(BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |		\
 	 BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |	\
@@ -314,6 +343,7 @@ static_assert(sizeof(struct btrfs_super_block) == BTRFS_SUPER_INFO_SIZE);
 	 BTRFS_FEATURE_INCOMPAT_METADATA_UUID	|	\
 	 BTRFS_FEATURE_INCOMPAT_RAID1C34	|	\
 	 BTRFS_FEATURE_INCOMPAT_ZONED)
+#endif
 
 #define BTRFS_FEATURE_INCOMPAT_SAFE_SET			\
 	(BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
@@ -636,6 +666,7 @@ struct btrfs_fs_info {
 	struct btrfs_root *quota_root;
 	struct btrfs_root *uuid_root;
 	struct btrfs_root *data_reloc_root;
+	struct btrfs_root *block_group_root;
 
 	/* the log root tree is a directory of all the other log roots */
 	struct btrfs_root *log_root_tree;
@@ -1030,6 +1061,8 @@ struct btrfs_fs_info {
 	spinlock_t relocation_bg_lock;
 	u64 data_reloc_bg;
 
+	u64 nr_global_roots;
+
 	spinlock_t zone_active_bgs_lock;
 	struct list_head zone_active_bgs;
 
@@ -1609,25 +1642,25 @@ DECLARE_BTRFS_SETGET_BITS(64)
 static inline u##bits btrfs_##name(const struct extent_buffer *eb,	\
 				   const type *s)			\
 {									\
-	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\
+	static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);	\
 	return btrfs_get_##bits(eb, s, offsetof(type, member));		\
 }									\
 static inline void btrfs_set_##name(const struct extent_buffer *eb, type *s, \
 				    u##bits val)			\
 {									\
-	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\
+	static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);	\
 	btrfs_set_##bits(eb, s, offsetof(type, member), val);		\
 }									\
 static inline u##bits btrfs_token_##name(struct btrfs_map_token *token,	\
 					 const type *s)			\
 {									\
-	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\
+	static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);	\
 	return btrfs_get_token_##bits(token, s, offsetof(type, member));\
 }									\
 static inline void btrfs_set_token_##name(struct btrfs_map_token *token,\
 					  type *s, u##bits val)		\
 {									\
-	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\
+	static_assert(sizeof(u##bits) == sizeof(((type *)0))->member);	\
 	btrfs_set_token_##bits(token, s, offsetof(type, member), val);	\
 }
 
@@ -1658,8 +1691,8 @@ static inline void btrfs_set_##name(type *s, u##bits val)		\
 static inline u64 btrfs_device_total_bytes(const struct extent_buffer *eb,
 					   struct btrfs_dev_item *s)
 {
-	BUILD_BUG_ON(sizeof(u64) !=
-		     sizeof(((struct btrfs_dev_item *)0))->total_bytes);
+	static_assert(sizeof(u64) ==
+		      sizeof(((struct btrfs_dev_item *)0))->total_bytes);
 	return btrfs_get_64(eb, s, offsetof(struct btrfs_dev_item,
 					    total_bytes));
 }
@@ -1667,8 +1700,8 @@ static inline void btrfs_set_device_total_bytes(const struct extent_buffer *eb,
 						struct btrfs_dev_item *s,
 						u64 val)
 {
-	BUILD_BUG_ON(sizeof(u64) !=
-		     sizeof(((struct btrfs_dev_item *)0))->total_bytes);
+	static_assert(sizeof(u64) ==
+		      sizeof(((struct btrfs_dev_item *)0))->total_bytes);
 	WARN_ON(!IS_ALIGNED(val, eb->fs_info->sectorsize));
 	btrfs_set_64(eb, s, offsetof(struct btrfs_dev_item, total_bytes), val);
 }
@@ -2328,6 +2361,17 @@ BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
 BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
 		   num_devices, 64);
 
+/*
+ * For extent tree v2 we overload the extent root with the block group root, as
+ * we will have multiple extent roots.
+ */
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root, struct btrfs_root_backup,
+			 extent_root, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_gen, struct btrfs_root_backup,
+			 extent_root_gen, 64);
+BTRFS_SETGET_STACK_FUNCS(backup_block_group_root_level,
+			 struct btrfs_root_backup, extent_root_level, 8);
+
 /* struct btrfs_balance_item */
 BTRFS_SETGET_FUNCS(balance_flags, struct btrfs_balance_item, flags, 64);
 
@@ -2462,6 +2506,13 @@ BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
 BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64);
 BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,
 			 uuid_tree_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root, struct btrfs_super_block,
+			 block_group_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root_generation,
+			 struct btrfs_super_block,
+			 block_group_root_generation, 64);
+BTRFS_SETGET_STACK_FUNCS(super_block_group_root_level, struct btrfs_super_block,
+			 block_group_root_level, 8);
 
 int btrfs_super_csum_size(const struct btrfs_super_block *s);
 const char *btrfs_super_csum_name(u16 csum_type);
@@ -2839,7 +2890,8 @@ void btrfs_subvolume_release_metadata(struct btrfs_root *root,
 				      struct btrfs_block_rsv *rsv);
 void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
 
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end);
@@ -3155,7 +3207,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct btrfs_ordered_sum *sums);
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
-				u64 file_start, int contig);
+				u64 offset, bool one_ordered);
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
 			     struct list_head *list, int search_commit);
 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
@@ -3256,6 +3308,11 @@ int btrfs_writepage_cow_fixup(struct page *page);
 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
 					  struct page *page, u64 start,
 					  u64 end, bool uptodate);
+ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
+			   struct btrfs_ioctl_encoded_io_args *encoded);
+ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			     const struct btrfs_ioctl_encoded_io_args *encoded);
+
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
 extern const struct iomap_dio_ops btrfs_dio_ops;
@@ -3318,6 +3375,8 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
 			   struct btrfs_trans_handle **trans_out);
 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
 			      struct btrfs_inode *inode, u64 start, u64 end);
+ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from,
+			    const struct btrfs_ioctl_encoded_io_args *encoded);
 int btrfs_release_file(struct inode *inode, struct file *file);
 int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
 		      size_t num_pages, loff_t pos, size_t write_bytes,
@@ -3774,7 +3833,7 @@ int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root);
 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root);
-int btrfs_recover_relocation(struct btrfs_root *root);
+int btrfs_recover_relocation(struct btrfs_fs_info *fs_info);
 int btrfs_reloc_clone_csums(struct btrfs_inode *inode, u64 file_pos, u64 len);
 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, struct extent_buffer *buf,
diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index fb46a28f5065..bd8267c4687d 100644
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -270,11 +270,11 @@ static void btrfs_calculate_inode_block_rsv_size(struct btrfs_fs_info *fs_info,
 }
 
 static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
-				    u64 num_bytes, u64 *meta_reserve,
-				    u64 *qgroup_reserve)
+				    u64 num_bytes, u64 disk_num_bytes,
+				    u64 *meta_reserve, u64 *qgroup_reserve)
 {
 	u64 nr_extents = count_max_extents(num_bytes);
-	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, num_bytes);
+	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, disk_num_bytes);
 	u64 inode_update = btrfs_calc_metadata_size(fs_info, 1);
 
 	*meta_reserve = btrfs_calc_insert_metadata_size(fs_info,
@@ -288,7 +288,8 @@ static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
 	*qgroup_reserve = nr_extents * fs_info->nodesize;
 }
 
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -318,6 +319,7 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	}
 
 	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
+	disk_num_bytes = ALIGN(disk_num_bytes, fs_info->sectorsize);
 
 	/*
 	 * We always want to do it this way, every other way is wrong and ends
@@ -329,8 +331,8 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	 * everything out and try again, which is bad.  This way we just
 	 * over-reserve slightly, and clean up the mess when we are done.
 	 */
-	calc_inode_reservations(fs_info, num_bytes, &meta_reserve,
-				&qgroup_reserve);
+	calc_inode_reservations(fs_info, num_bytes, disk_num_bytes,
+				&meta_reserve, &qgroup_reserve);
 	ret = btrfs_qgroup_reserve_meta_prealloc(root, qgroup_reserve, true);
 	if (ret)
 		return ret;
@@ -349,7 +351,7 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	spin_lock(&inode->lock);
 	nr_extents = count_max_extents(num_bytes);
 	btrfs_mod_outstanding_extents(inode, nr_extents);
-	inode->csum_bytes += num_bytes;
+	inode->csum_bytes += disk_num_bytes;
 	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
 	spin_unlock(&inode->lock);
 
@@ -454,7 +456,7 @@ int btrfs_delalloc_reserve_space(struct btrfs_inode *inode,
 	ret = btrfs_check_data_free_space(inode, reserved, start, len);
 	if (ret < 0)
 		return ret;
-	ret = btrfs_delalloc_reserve_metadata(inode, len);
+	ret = btrfs_delalloc_reserve_metadata(inode, len, len);
 	if (ret < 0) {
 		btrfs_free_reserved_data_space(inode, *reserved, start, len);
 		extent_changeset_free(*reserved);
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 62b9651ea662..71fd99b48283 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -243,6 +243,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 				  struct btrfs_device *srcdev,
 				  struct btrfs_device **device_out)
 {
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *device;
 	struct block_device *bdev;
 	struct rcu_string *name;
@@ -271,7 +272,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
 	sync_blockdev(bdev);
 
-	list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
+	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 		if (device->bdev == bdev) {
 			btrfs_err(fs_info,
 				  "target device is in the filesystem!");
@@ -302,6 +303,9 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 		goto error;
 	}
 	rcu_assign_pointer(device->name, name);
+	ret = lookup_bdev(device_path, &device->devt);
+	if (ret)
+		goto error;
 
 	set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
 	device->generation = 0;
@@ -320,17 +324,17 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 	device->mode = FMODE_EXCL;
 	device->dev_stats_valid = 1;
 	set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
-	device->fs_devices = fs_info->fs_devices;
+	device->fs_devices = fs_devices;
 
 	ret = btrfs_get_dev_zone_info(device, false);
 	if (ret)
 		goto error;
 
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	list_add(&device->dev_list, &fs_info->fs_devices->devices);
-	fs_info->fs_devices->num_devices++;
-	fs_info->fs_devices->open_devices++;
-	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+	mutex_lock(&fs_devices->device_list_mutex);
+	list_add(&device->dev_list, &fs_devices->devices);
+	fs_devices->num_devices++;
+	fs_devices->open_devices++;
+	mutex_unlock(&fs_devices->device_list_mutex);
 
 	*device_out = device;
 	return 0;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b3e9cf3fd1dd..62565ee00b97 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -441,17 +441,31 @@ static int csum_one_extent_buffer(struct extent_buffer *eb)
 	else
 		ret = btrfs_check_leaf_full(eb);
 
-	if (ret < 0) {
-		btrfs_print_tree(eb, 0);
+	if (ret < 0)
+		goto error;
+
+	/*
+	 * Also check the generation, the eb reached here must be newer than
+	 * last committed. Or something seriously wrong happened.
+	 */
+	if (unlikely(btrfs_header_generation(eb) <= fs_info->last_trans_committed)) {
+		ret = -EUCLEAN;
 		btrfs_err(fs_info,
-			"block=%llu write time tree block corruption detected",
-			eb->start);
-		WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
-		return ret;
+			"block=%llu bad generation, have %llu expect > %llu",
+			  eb->start, btrfs_header_generation(eb),
+			  fs_info->last_trans_committed);
+		goto error;
 	}
 	write_extent_buffer(eb, result, 0, fs_info->csum_size);
 
 	return 0;
+
+error:
+	btrfs_print_tree(eb, 0);
+	btrfs_err(fs_info, "block=%llu write time tree block corruption detected",
+		  eb->start);
+	WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
+	return ret;
 }
 
 /* Checksum all dirty extent buffers in one bio_vec */
@@ -1289,12 +1303,33 @@ struct btrfs_root *btrfs_global_root(struct btrfs_fs_info *fs_info,
 	return root;
 }
 
+static u64 btrfs_global_root_id(struct btrfs_fs_info *fs_info, u64 bytenr)
+{
+	struct btrfs_block_group *block_group;
+	u64 ret;
+
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return 0;
+
+	if (bytenr)
+		block_group = btrfs_lookup_block_group(fs_info, bytenr);
+	else
+		block_group = btrfs_lookup_first_block_group(fs_info, bytenr);
+	ASSERT(block_group);
+	if (!block_group)
+		return 0;
+	ret = block_group->global_root_id;
+	btrfs_put_block_group(block_group);
+
+	return ret;
+}
+
 struct btrfs_root *btrfs_csum_root(struct btrfs_fs_info *fs_info, u64 bytenr)
 {
 	struct btrfs_key key = {
 		.objectid = BTRFS_CSUM_TREE_OBJECTID,
 		.type = BTRFS_ROOT_ITEM_KEY,
-		.offset = 0,
+		.offset = btrfs_global_root_id(fs_info, bytenr),
 	};
 
 	return btrfs_global_root(fs_info, &key);
@@ -1305,7 +1340,7 @@ struct btrfs_root *btrfs_extent_root(struct btrfs_fs_info *fs_info, u64 bytenr)
 	struct btrfs_key key = {
 		.objectid = BTRFS_EXTENT_TREE_OBJECTID,
 		.type = BTRFS_ROOT_ITEM_KEY,
-		.offset = 0,
+		.offset = btrfs_global_root_id(fs_info, bytenr),
 	};
 
 	return btrfs_global_root(fs_info, &key);
@@ -1522,7 +1557,8 @@ static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
 		ret = PTR_ERR(root->node);
 		root->node = NULL;
 		goto fail;
-	} else if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
+	}
+	if (!btrfs_buffer_uptodate(root->node, generation, 0)) {
 		ret = -EIO;
 		goto fail;
 	}
@@ -1727,6 +1763,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
 	btrfs_put_root(fs_info->uuid_root);
 	btrfs_put_root(fs_info->fs_root);
 	btrfs_put_root(fs_info->data_reloc_root);
+	btrfs_put_root(fs_info->block_group_root);
 	btrfs_check_leaked_roots(fs_info);
 	btrfs_extent_buffer_leak_debug_check(fs_info);
 	kfree(fs_info->super_copy);
@@ -1925,8 +1962,7 @@ static void end_workqueue_fn(struct btrfs_work *work)
 
 static int cleaner_kthread(void *arg)
 {
-	struct btrfs_root *root = arg;
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)arg;
 	int again;
 
 	while (1) {
@@ -1959,7 +1995,7 @@ static int cleaner_kthread(void *arg)
 
 		btrfs_run_delayed_iputs(fs_info);
 
-		again = btrfs_clean_one_deleted_snapshot(root);
+		again = btrfs_clean_one_deleted_snapshot(fs_info);
 		mutex_unlock(&fs_info->cleaner_mutex);
 
 		/*
@@ -2095,8 +2131,6 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 {
 	const int next_backup = info->backup_root_index;
 	struct btrfs_root_backup *root_backup;
-	struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
-	struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
 
 	root_backup = info->super_for_commit->super_roots + next_backup;
 
@@ -2121,11 +2155,30 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 	btrfs_set_backup_chunk_root_level(root_backup,
 			       btrfs_header_level(info->chunk_root->node));
 
-	btrfs_set_backup_extent_root(root_backup, extent_root->node->start);
-	btrfs_set_backup_extent_root_gen(root_backup,
-			       btrfs_header_generation(extent_root->node));
-	btrfs_set_backup_extent_root_level(root_backup,
-			       btrfs_header_level(extent_root->node));
+	if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) {
+		btrfs_set_backup_block_group_root(root_backup,
+					info->block_group_root->node->start);
+		btrfs_set_backup_block_group_root_gen(root_backup,
+			btrfs_header_generation(info->block_group_root->node));
+		btrfs_set_backup_block_group_root_level(root_backup,
+			btrfs_header_level(info->block_group_root->node));
+	} else {
+		struct btrfs_root *extent_root = btrfs_extent_root(info, 0);
+		struct btrfs_root *csum_root = btrfs_csum_root(info, 0);
+
+		btrfs_set_backup_extent_root(root_backup,
+					     extent_root->node->start);
+		btrfs_set_backup_extent_root_gen(root_backup,
+				btrfs_header_generation(extent_root->node));
+		btrfs_set_backup_extent_root_level(root_backup,
+					btrfs_header_level(extent_root->node));
+
+		btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
+		btrfs_set_backup_csum_root_gen(root_backup,
+					       btrfs_header_generation(csum_root->node));
+		btrfs_set_backup_csum_root_level(root_backup,
+						 btrfs_header_level(csum_root->node));
+	}
 
 	/*
 	 * we might commit during log recovery, which happens before we set
@@ -2146,12 +2199,6 @@ static void backup_super_roots(struct btrfs_fs_info *info)
 	btrfs_set_backup_dev_root_level(root_backup,
 				       btrfs_header_level(info->dev_root->node));
 
-	btrfs_set_backup_csum_root(root_backup, csum_root->node->start);
-	btrfs_set_backup_csum_root_gen(root_backup,
-				       btrfs_header_generation(csum_root->node));
-	btrfs_set_backup_csum_root_level(root_backup,
-					 btrfs_header_level(csum_root->node));
-
 	btrfs_set_backup_total_bytes(root_backup,
 			     btrfs_super_total_bytes(info->super_copy));
 	btrfs_set_backup_bytes_used(root_backup,
@@ -2269,6 +2316,7 @@ static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
 	free_root_extent_buffers(info->uuid_root);
 	free_root_extent_buffers(info->fs_root);
 	free_root_extent_buffers(info->data_reloc_root);
+	free_root_extent_buffers(info->block_group_root);
 	if (free_chunk_root)
 		free_root_extent_buffers(info->chunk_root);
 }
@@ -2504,11 +2552,13 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 		log_tree_root->node = NULL;
 		btrfs_put_root(log_tree_root);
 		return ret;
-	} else if (!extent_buffer_uptodate(log_tree_root->node)) {
+	}
+	if (!extent_buffer_uptodate(log_tree_root->node)) {
 		btrfs_err(fs_info, "failed to read log tree");
 		btrfs_put_root(log_tree_root);
 		return -EIO;
 	}
+
 	/* returns with log_tree_root freed on success */
 	ret = btrfs_recover_log_trees(log_tree_root);
 	if (ret) {
@@ -2533,6 +2583,7 @@ static int load_global_roots_objectid(struct btrfs_root *tree_root,
 {
 	struct btrfs_fs_info *fs_info = tree_root->fs_info;
 	struct btrfs_root *root;
+	u64 max_global_id = 0;
 	int ret;
 	struct btrfs_key key = {
 		.objectid = objectid,
@@ -2568,6 +2619,13 @@ static int load_global_roots_objectid(struct btrfs_root *tree_root,
 			break;
 		btrfs_release_path(path);
 
+		/*
+		 * Just worry about this for extent tree, it'll be the same for
+		 * everybody.
+		 */
+		if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
+			max_global_id = max(max_global_id, key.offset);
+
 		found = true;
 		root = read_tree_root_path(tree_root, path, &key);
 		if (IS_ERR(root)) {
@@ -2585,6 +2643,9 @@ static int load_global_roots_objectid(struct btrfs_root *tree_root,
 	}
 	btrfs_release_path(path);
 
+	if (objectid == BTRFS_EXTENT_TREE_OBJECTID)
+		fs_info->nr_global_roots = max_global_id + 1;
+
 	if (!found || ret) {
 		if (objectid == BTRFS_CSUM_TREE_OBJECTID)
 			set_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state);
@@ -2930,6 +2991,56 @@ out:
 	return ret;
 }
 
+static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int level)
+{
+	int ret = 0;
+
+	root->node = read_tree_block(root->fs_info, bytenr,
+				     root->root_key.objectid, gen, level, NULL);
+	if (IS_ERR(root->node)) {
+		ret = PTR_ERR(root->node);
+		root->node = NULL;
+		return ret;
+	}
+	if (!extent_buffer_uptodate(root->node)) {
+		free_extent_buffer(root->node);
+		root->node = NULL;
+		return -EIO;
+	}
+
+	btrfs_set_root_node(&root->root_item, root->node);
+	root->commit_root = btrfs_root_node(root);
+	btrfs_set_root_refs(&root->root_item, 1);
+	return ret;
+}
+
+static int load_important_roots(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_super_block *sb = fs_info->super_copy;
+	u64 gen, bytenr;
+	int level, ret;
+
+	bytenr = btrfs_super_root(sb);
+	gen = btrfs_super_generation(sb);
+	level = btrfs_super_root_level(sb);
+	ret = load_super_root(fs_info->tree_root, bytenr, gen, level);
+	if (ret) {
+		btrfs_warn(fs_info, "couldn't read tree root");
+		return ret;
+	}
+
+	if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return 0;
+
+	bytenr = btrfs_super_block_group_root(sb);
+	gen = btrfs_super_block_group_root_generation(sb);
+	level = btrfs_super_block_group_root_level(sb);
+	ret = load_super_root(fs_info->block_group_root, bytenr, gen, level);
+	if (ret)
+		btrfs_warn(fs_info, "couldn't read block group root");
+	return ret;
+}
+
 static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
 {
 	int backup_index = find_newest_super_backup(fs_info);
@@ -2939,10 +3050,17 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
 	int ret = 0;
 	int i;
 
-	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
-		u64 generation;
-		int level;
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		struct btrfs_root *root;
+
+		root = btrfs_alloc_root(fs_info, BTRFS_BLOCK_GROUP_TREE_OBJECTID,
+					GFP_KERNEL);
+		if (!root)
+			return -ENOMEM;
+		fs_info->block_group_root = root;
+	}
 
+	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
 		if (handle_error) {
 			if (!IS_ERR(tree_root->node))
 				free_extent_buffer(tree_root->node);
@@ -2967,29 +3085,13 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
 			if (ret < 0)
 				return ret;
 		}
-		generation = btrfs_super_generation(sb);
-		level = btrfs_super_root_level(sb);
-		tree_root->node = read_tree_block(fs_info, btrfs_super_root(sb),
-						  BTRFS_ROOT_TREE_OBJECTID,
-						  generation, level, NULL);
-		if (IS_ERR(tree_root->node)) {
-			handle_error = true;
-			ret = PTR_ERR(tree_root->node);
-			tree_root->node = NULL;
-			btrfs_warn(fs_info, "couldn't read tree root");
-			continue;
 
-		} else if (!extent_buffer_uptodate(tree_root->node)) {
+		ret = load_important_roots(fs_info);
+		if (ret) {
 			handle_error = true;
-			ret = -EIO;
-			btrfs_warn(fs_info, "error while reading tree root");
 			continue;
 		}
 
-		btrfs_set_root_node(&tree_root->root_item, tree_root->node);
-		tree_root->commit_root = btrfs_root_node(tree_root);
-		btrfs_set_root_refs(&tree_root->root_item, 1);
-
 		/*
 		 * No need to hold btrfs_root::objectid_mutex since the fs
 		 * hasn't been fully initialised and we are the only user
@@ -3009,8 +3111,8 @@ static int __cold init_tree_roots(struct btrfs_fs_info *fs_info)
 		}
 
 		/* All successful */
-		fs_info->generation = generation;
-		fs_info->last_trans_committed = generation;
+		fs_info->generation = btrfs_header_generation(tree_root->node);
+		fs_info->last_trans_committed = fs_info->generation;
 		fs_info->last_reloc_trans = 0;
 
 		/* Always begin writing backup roots after the one being used */
@@ -3293,7 +3395,7 @@ int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info)
 	up_read(&fs_info->cleanup_work_sem);
 
 	mutex_lock(&fs_info->cleaner_mutex);
-	ret = btrfs_recover_relocation(fs_info->tree_root);
+	ret = btrfs_recover_relocation(fs_info);
 	mutex_unlock(&fs_info->cleaner_mutex);
 	if (ret < 0) {
 		btrfs_warn(fs_info, "failed to recover relocation: %d", ret);
@@ -3594,21 +3696,12 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 
 	generation = btrfs_super_chunk_root_generation(disk_super);
 	level = btrfs_super_chunk_root_level(disk_super);
-
-	chunk_root->node = read_tree_block(fs_info,
-					   btrfs_super_chunk_root(disk_super),
-					   BTRFS_CHUNK_TREE_OBJECTID,
-					   generation, level, NULL);
-	if (IS_ERR(chunk_root->node) ||
-	    !extent_buffer_uptodate(chunk_root->node)) {
+	ret = load_super_root(chunk_root, btrfs_super_chunk_root(disk_super),
+			      generation, level);
+	if (ret) {
 		btrfs_err(fs_info, "failed to read chunk root");
-		if (!IS_ERR(chunk_root->node))
-			free_extent_buffer(chunk_root->node);
-		chunk_root->node = NULL;
 		goto fail_tree_roots;
 	}
-	btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
-	chunk_root->commit_root = btrfs_root_node(chunk_root);
 
 	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
 			   offsetof(struct btrfs_header, chunk_tree_uuid),
@@ -3728,7 +3821,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 		goto fail_sysfs;
 	}
 
-	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
+	fs_info->cleaner_kthread = kthread_run(cleaner_kthread, fs_info,
 					       "btrfs-cleaner");
 	if (IS_ERR(fs_info->cleaner_kthread))
 		goto fail_sysfs;
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 5e8bef4b7563..2e10514ecda8 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -111,6 +111,8 @@ static inline struct btrfs_root *btrfs_grab_root(struct btrfs_root *root)
 
 static inline struct btrfs_root *btrfs_block_group_root(struct btrfs_fs_info *fs_info)
 {
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+		return fs_info->block_group_root;
 	return btrfs_extent_root(fs_info, 0);
 }
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 96427b1ecac3..f477035a2ac2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -598,7 +598,7 @@ fail:
 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
 					   struct btrfs_root *root,
 					   struct btrfs_path *path,
-					   int refs_to_drop, int *last_ref)
+					   int refs_to_drop)
 {
 	struct btrfs_key key;
 	struct btrfs_extent_data_ref *ref1 = NULL;
@@ -631,7 +631,6 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
 
 	if (num_refs == 0) {
 		ret = btrfs_del_item(trans, root, path);
-		*last_ref = 1;
 	} else {
 		if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
 			btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
@@ -1072,8 +1071,7 @@ static noinline_for_stack
 void update_inline_extent_backref(struct btrfs_path *path,
 				  struct btrfs_extent_inline_ref *iref,
 				  int refs_to_mod,
-				  struct btrfs_delayed_extent_op *extent_op,
-				  int *last_ref)
+				  struct btrfs_delayed_extent_op *extent_op)
 {
 	struct extent_buffer *leaf = path->nodes[0];
 	struct btrfs_extent_item *ei;
@@ -1121,7 +1119,6 @@ void update_inline_extent_backref(struct btrfs_path *path,
 		else
 			btrfs_set_shared_data_ref_count(leaf, sref, refs);
 	} else {
-		*last_ref = 1;
 		size =  btrfs_extent_inline_ref_size(type);
 		item_size = btrfs_item_size(leaf, path->slots[0]);
 		ptr = (unsigned long)iref;
@@ -1166,8 +1163,7 @@ int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
 			}
 			return -EUCLEAN;
 		}
-		update_inline_extent_backref(path, iref, refs_to_add,
-					     extent_op, NULL);
+		update_inline_extent_backref(path, iref, refs_to_add, extent_op);
 	} else if (ret == -ENOENT) {
 		setup_inline_extent_backref(trans->fs_info, path, iref, parent,
 					    root_objectid, owner, offset,
@@ -1181,21 +1177,17 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans,
 				 struct btrfs_root *root,
 				 struct btrfs_path *path,
 				 struct btrfs_extent_inline_ref *iref,
-				 int refs_to_drop, int is_data, int *last_ref)
+				 int refs_to_drop, int is_data)
 {
 	int ret = 0;
 
 	BUG_ON(!is_data && refs_to_drop != 1);
-	if (iref) {
-		update_inline_extent_backref(path, iref, -refs_to_drop, NULL,
-					     last_ref);
-	} else if (is_data) {
-		ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
-					     last_ref);
-	} else {
-		*last_ref = 1;
+	if (iref)
+		update_inline_extent_backref(path, iref, -refs_to_drop, NULL);
+	else if (is_data)
+		ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
+	else
 		ret = btrfs_del_item(trans, root, path);
-	}
 	return ret;
 }
 
@@ -2766,12 +2758,11 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
 		spin_unlock(&cache->lock);
 		if (!readonly && return_free_space &&
 		    global_rsv->space_info == space_info) {
-			u64 to_add = len;
-
 			spin_lock(&global_rsv->lock);
 			if (!global_rsv->full) {
-				to_add = min(len, global_rsv->size -
-					     global_rsv->reserved);
+				u64 to_add = min(len, global_rsv->size -
+						      global_rsv->reserved);
+
 				global_rsv->reserved += to_add;
 				btrfs_space_info_update_bytes_may_use(fs_info,
 						space_info, to_add);
@@ -2862,6 +2853,35 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
 	return 0;
 }
 
+static int do_free_extent_accounting(struct btrfs_trans_handle *trans,
+				     u64 bytenr, u64 num_bytes, bool is_data)
+{
+	int ret;
+
+	if (is_data) {
+		struct btrfs_root *csum_root;
+
+		csum_root = btrfs_csum_root(trans->fs_info, bytenr);
+		ret = btrfs_del_csums(trans, csum_root, bytenr, num_bytes);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			return ret;
+		}
+	}
+
+	ret = add_to_free_space_tree(trans, bytenr, num_bytes);
+	if (ret) {
+		btrfs_abort_transaction(trans, ret);
+		return ret;
+	}
+
+	ret = btrfs_update_block_group(trans, bytenr, num_bytes, false);
+	if (ret)
+		btrfs_abort_transaction(trans, ret);
+
+	return ret;
+}
+
 /*
  * Drop one or more refs of @node.
  *
@@ -2943,7 +2963,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 	u64 refs;
 	u64 bytenr = node->bytenr;
 	u64 num_bytes = node->num_bytes;
-	int last_ref = 0;
 	bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA);
 
 	extent_root = btrfs_extent_root(info, bytenr);
@@ -3010,8 +3029,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			}
 			/* Must be SHARED_* item, remove the backref first */
 			ret = remove_extent_backref(trans, extent_root, path,
-						    NULL, refs_to_drop, is_data,
-						    &last_ref);
+						    NULL, refs_to_drop, is_data);
 			if (ret) {
 				btrfs_abort_transaction(trans, ret);
 				goto out;
@@ -3136,8 +3154,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 		}
 		if (found_extent) {
 			ret = remove_extent_backref(trans, extent_root, path,
-						    iref, refs_to_drop, is_data,
-						    &last_ref);
+						    iref, refs_to_drop, is_data);
 			if (ret) {
 				btrfs_abort_transaction(trans, ret);
 				goto out;
@@ -3182,7 +3199,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			}
 		}
 
-		last_ref = 1;
 		ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
 				      num_to_del);
 		if (ret) {
@@ -3191,28 +3207,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 		}
 		btrfs_release_path(path);
 
-		if (is_data) {
-			struct btrfs_root *csum_root;
-			csum_root = btrfs_csum_root(info, bytenr);
-			ret = btrfs_del_csums(trans, csum_root, bytenr,
-					      num_bytes);
-			if (ret) {
-				btrfs_abort_transaction(trans, ret);
-				goto out;
-			}
-		}
-
-		ret = add_to_free_space_tree(trans, bytenr, num_bytes);
-		if (ret) {
-			btrfs_abort_transaction(trans, ret);
-			goto out;
-		}
-
-		ret = btrfs_update_block_group(trans, bytenr, num_bytes, false);
-		if (ret) {
-			btrfs_abort_transaction(trans, ret);
-			goto out;
-		}
+		ret = do_free_extent_accounting(trans, bytenr, num_bytes, is_data);
 	}
 	btrfs_release_path(path);
 
@@ -4605,6 +4600,28 @@ int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans, u64 start,
 	return ret;
 }
 
+static int alloc_reserved_extent(struct btrfs_trans_handle *trans, u64 bytenr,
+				 u64 num_bytes)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	int ret;
+
+	ret = remove_from_free_space_tree(trans, bytenr, num_bytes);
+	if (ret)
+		return ret;
+
+	ret = btrfs_update_block_group(trans, bytenr, num_bytes, true);
+	if (ret) {
+		ASSERT(!ret);
+		btrfs_err(fs_info, "update block group failed for %llu %llu",
+			  bytenr, num_bytes);
+		return ret;
+	}
+
+	trace_btrfs_reserved_extent_alloc(fs_info, bytenr, num_bytes);
+	return 0;
+}
+
 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 				      u64 parent, u64 root_objectid,
 				      u64 flags, u64 owner, u64 offset,
@@ -4665,18 +4682,7 @@ static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 	btrfs_free_path(path);
 
-	ret = remove_from_free_space_tree(trans, ins->objectid, ins->offset);
-	if (ret)
-		return ret;
-
-	ret = btrfs_update_block_group(trans, ins->objectid, ins->offset, true);
-	if (ret) { /* -ENOENT, logic error */
-		btrfs_err(fs_info, "update block group failed for %llu %llu",
-			ins->objectid, ins->offset);
-		BUG();
-	}
-	trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid, ins->offset);
-	return ret;
+	return alloc_reserved_extent(trans, ins->objectid, ins->offset);
 }
 
 static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
@@ -4694,7 +4700,6 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 	struct btrfs_delayed_tree_ref *ref;
 	u32 size = sizeof(*extent_item) + sizeof(*iref);
-	u64 num_bytes;
 	u64 flags = extent_op->flags_to_set;
 	bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
 
@@ -4704,12 +4709,10 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	if (skinny_metadata) {
 		extent_key.offset = ref->level;
 		extent_key.type = BTRFS_METADATA_ITEM_KEY;
-		num_bytes = fs_info->nodesize;
 	} else {
 		extent_key.offset = node->num_bytes;
 		extent_key.type = BTRFS_EXTENT_ITEM_KEY;
 		size += sizeof(*block_info);
-		num_bytes = node->num_bytes;
 	}
 
 	path = btrfs_alloc_path();
@@ -4754,22 +4757,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	btrfs_mark_buffer_dirty(leaf);
 	btrfs_free_path(path);
 
-	ret = remove_from_free_space_tree(trans, extent_key.objectid,
-					  num_bytes);
-	if (ret)
-		return ret;
-
-	ret = btrfs_update_block_group(trans, extent_key.objectid,
-				       fs_info->nodesize, true);
-	if (ret) { /* -ENOENT, logic error */
-		btrfs_err(fs_info, "update block group failed for %llu %llu",
-			extent_key.objectid, extent_key.offset);
-		BUG();
-	}
-
-	trace_btrfs_reserved_extent_alloc(fs_info, extent_key.objectid,
-					  fs_info->nodesize);
-	return ret;
+	return alloc_reserved_extent(trans, node->bytenr, fs_info->nodesize);
 }
 
 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 5923eec8caa8..df7c81255964 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2610,6 +2610,7 @@ static bool btrfs_check_repairable(struct inode *inode,
 	 * a good copy of the failed sector and if we succeed, we have setup
 	 * everything for repair_io_failure to do the rest for us.
 	 */
+	ASSERT(failed_mirror);
 	failrec->failed_mirror = failed_mirror;
 	failrec->this_mirror++;
 	if (failrec->this_mirror == failed_mirror)
@@ -2639,7 +2640,6 @@ int btrfs_repair_one_sector(struct inode *inode,
 	const int icsum = bio_offset >> fs_info->sectorsize_bits;
 	struct bio *repair_bio;
 	struct btrfs_bio *repair_bbio;
-	blk_status_t status;
 
 	btrfs_debug(fs_info,
 		   "repair read error: read error at %llu", start);
@@ -2678,13 +2678,13 @@ int btrfs_repair_one_sector(struct inode *inode,
 		    "repair read error: submitting new read to mirror %d",
 		    failrec->this_mirror);
 
-	status = submit_bio_hook(inode, repair_bio, failrec->this_mirror,
-				 failrec->bio_flags);
-	if (status) {
-		free_io_failure(failure_tree, tree, failrec);
-		bio_put(repair_bio);
-	}
-	return blk_status_to_errno(status);
+	/*
+	 * At this point we have a bio, so any errors from submit_bio_hook()
+	 * will be handled by the endio on the repair_bio, so we can't return an
+	 * error here.
+	 */
+	submit_bio_hook(inode, repair_bio, failrec->this_mirror, failrec->bio_flags);
+	return BLK_STS_OK;
 }
 
 static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len)
@@ -3068,6 +3068,14 @@ static void end_bio_extent_readpage(struct bio *bio)
 
 		if (is_data_inode(inode)) {
 			/*
+			 * If we failed to submit the IO at all we'll have a
+			 * mirror_num == 0, in which case we need to just mark
+			 * the page with an error and unlock it and carry on.
+			 */
+			if (mirror == 0)
+				goto readpage_ok;
+
+			/*
 			 * btrfs_submit_read_repair() will handle all the good
 			 * and bad sectors, we just continue to the next bvec.
 			 */
@@ -3534,7 +3542,7 @@ __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
 	}
 
 	em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, start, len);
-	if (em_cached && !IS_ERR_OR_NULL(em)) {
+	if (em_cached && !IS_ERR(em)) {
 		BUG_ON(*em_cached);
 		refcount_inc(&em->refs);
 		*em_cached = em;
@@ -3563,7 +3571,6 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 	u64 cur_end;
 	struct extent_map *em;
 	int ret = 0;
-	int nr = 0;
 	size_t pg_offset = 0;
 	size_t iosize;
 	size_t blocksize = inode->i_sb->s_blocksize;
@@ -3608,9 +3615,10 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 		}
 		em = __get_extent_map(inode, page, pg_offset, cur,
 				      end - cur + 1, em_cached);
-		if (IS_ERR_OR_NULL(em)) {
+		if (IS_ERR(em)) {
 			unlock_extent(tree, cur, end);
 			end_page_read(page, false, cur, end + 1 - cur);
+			ret = PTR_ERR(em);
 			break;
 		}
 		extent_offset = cur - em->start;
@@ -3721,9 +3729,7 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
 					 end_bio_extent_readpage, 0,
 					 this_bio_flag,
 					 force_bio_submit);
-		if (!ret) {
-			nr++;
-		} else {
+		if (ret) {
 			unlock_extent(tree, cur, cur + iosize - 1);
 			end_page_read(page, false, cur, iosize);
 			goto out;
@@ -3951,7 +3957,7 @@ static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
 		}
 
 		em = btrfs_get_extent(inode, NULL, 0, cur, end - cur + 1);
-		if (IS_ERR_OR_NULL(em)) {
+		if (IS_ERR(em)) {
 			btrfs_page_set_error(fs_info, page, cur, end - cur + 1);
 			ret = PTR_ERR_OR_ZERO(em);
 			break;
@@ -4780,11 +4786,12 @@ static int submit_eb_page(struct page *page, struct writeback_control *wbc,
 		return ret;
 	}
 	if (cache) {
-		/* Impiles write in zoned mode */
-		btrfs_put_block_group(cache);
-		/* Mark the last eb in a block group */
+		/*
+		 * Implies write in zoned mode. Mark the last eb in a block group.
+		 */
 		if (cache->seq_zone && eb->start + eb->len == cache->zone_capacity)
 			set_bit(EXTENT_BUFFER_ZONE_FINISH, &eb->bflags);
+		btrfs_put_block_group(cache);
 	}
 	ret = write_one_eb(eb, wbc, epd);
 	free_extent_buffer(eb);
@@ -5390,7 +5397,7 @@ static struct extent_map *get_extent_skip_holes(struct btrfs_inode *inode,
 			break;
 		len = ALIGN(len, sectorsize);
 		em = btrfs_get_extent_fiemap(inode, offset, len);
-		if (IS_ERR_OR_NULL(em))
+		if (IS_ERR(em))
 			return em;
 
 		/* if this isn't a hole return it */
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index c28ceddefae4..6fee14ce2e6b 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -492,6 +492,8 @@ struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
  */
 void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
 {
+	lockdep_assert_held_write(&tree->lock);
+
 	WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
 	rb_erase_cached(&em->rb_node, &tree->map);
 	if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
@@ -506,6 +508,8 @@ void replace_extent_mapping(struct extent_map_tree *tree,
 			    struct extent_map *new,
 			    int modified)
 {
+	lockdep_assert_held_write(&tree->lock);
+
 	WARN_ON(test_bit(EXTENT_FLAG_PINNED, &cur->flags));
 	ASSERT(extent_map_in_tree(cur));
 	if (!test_bit(EXTENT_FLAG_LOGGING, &cur->flags))
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 90c5c38836ab..c828f971a346 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -305,7 +305,7 @@ found:
 	read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
 			ret * csum_size);
 out:
-	if (ret == -ENOENT)
+	if (ret == -ENOENT || ret == -EFBIG)
 		ret = 0;
 	return ret;
 }
@@ -368,6 +368,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct btrfs_bio *bbio = NULL;
 	struct btrfs_path *path;
 	const u32 sectorsize = fs_info->sectorsize;
 	const u32 csum_size = fs_info->csum_size;
@@ -377,6 +378,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
 	u8 *csum;
 	const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
 	int count = 0;
+	blk_status_t ret = BLK_STS_OK;
 
 	if ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) ||
 	    test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state))
@@ -400,7 +402,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
 		return BLK_STS_RESOURCE;
 
 	if (!dst) {
-		struct btrfs_bio *bbio = btrfs_bio(bio);
+		bbio = btrfs_bio(bio);
 
 		if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
 			bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
@@ -456,21 +458,27 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
 
 		count = search_csum_tree(fs_info, path, cur_disk_bytenr,
 					 search_len, csum_dst);
-		if (count <= 0) {
-			/*
-			 * Either we hit a critical error or we didn't find
-			 * the csum.
-			 * Either way, we put zero into the csums dst, and skip
-			 * to the next sector.
-			 */
+		if (count < 0) {
+			ret = errno_to_blk_status(count);
+			if (bbio)
+				btrfs_bio_free_csum(bbio);
+			break;
+		}
+
+		/*
+		 * We didn't find a csum for this range.  We need to make sure
+		 * we complain loudly about this, because we are not NODATASUM.
+		 *
+		 * However for the DATA_RELOC inode we could potentially be
+		 * relocating data extents for a NODATASUM inode, so the inode
+		 * itself won't be marked with NODATASUM, but the extent we're
+		 * copying is in fact NODATASUM.  If we don't find a csum we
+		 * assume this is the case.
+		 */
+		if (count == 0) {
 			memset(csum_dst, 0, csum_size);
 			count = 1;
 
-			/*
-			 * For data reloc inode, we need to mark the range
-			 * NODATASUM so that balance won't report false csum
-			 * error.
-			 */
 			if (BTRFS_I(inode)->root->root_key.objectid ==
 			    BTRFS_DATA_RELOC_TREE_OBJECTID) {
 				u64 file_offset;
@@ -491,7 +499,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
 	}
 
 	btrfs_free_path(path);
-	return BLK_STS_OK;
+	return ret;
 }
 
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
@@ -612,32 +620,33 @@ fail:
 	return ret;
 }
 
-/*
- * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
+/**
+ * Calculate checksums of the data contained inside a bio
+ *
  * @inode:	 Owner of the data inside the bio
  * @bio:	 Contains the data to be checksummed
- * @file_start:  offset in file this bio begins to describe
- * @contig:	 Boolean. If true/1 means all bio vecs in this bio are
- *		 contiguous and they begin at @file_start in the file. False/0
- *		 means this bio can contain potentially discontiguous bio vecs
- *		 so the logical offset of each should be calculated separately.
+ * @offset:      If (u64)-1, @bio may contain discontiguous bio vecs, so the
+ *               file offsets are determined from the page offsets in the bio.
+ *               Otherwise, this is the starting file offset of the bio vecs in
+ *               @bio, which must be contiguous.
+ * @one_ordered: If true, @bio only refers to one ordered extent.
  */
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
-		       u64 file_start, int contig)
+				u64 offset, bool one_ordered)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	struct btrfs_ordered_sum *sums;
 	struct btrfs_ordered_extent *ordered = NULL;
+	const bool use_page_offsets = (offset == (u64)-1);
 	char *data;
 	struct bvec_iter iter;
 	struct bio_vec bvec;
 	int index;
-	int nr_sectors;
+	unsigned int blockcount;
 	unsigned long total_bytes = 0;
 	unsigned long this_sum_bytes = 0;
 	int i;
-	u64 offset;
 	unsigned nofs_flag;
 
 	nofs_flag = memalloc_nofs_save();
@@ -651,18 +660,13 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 	sums->len = bio->bi_iter.bi_size;
 	INIT_LIST_HEAD(&sums->list);
 
-	if (contig)
-		offset = file_start;
-	else
-		offset = 0; /* shut up gcc */
-
 	sums->bytenr = bio->bi_iter.bi_sector << 9;
 	index = 0;
 
 	shash->tfm = fs_info->csum_shash;
 
 	bio_for_each_segment(bvec, bio, iter) {
-		if (!contig)
+		if (use_page_offsets)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
 
 		if (!ordered) {
@@ -681,13 +685,14 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 			}
 		}
 
-		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
+		blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
 						 bvec.bv_len + fs_info->sectorsize
 						 - 1);
 
-		for (i = 0; i < nr_sectors; i++) {
-			if (offset >= ordered->file_offset + ordered->num_bytes ||
-			    offset < ordered->file_offset) {
+		for (i = 0; i < blockcount; i++) {
+			if (!one_ordered &&
+			    !in_range(offset, ordered->file_offset,
+				      ordered->num_bytes)) {
 				unsigned long bytes_left;
 
 				sums->len = this_sum_bytes;
@@ -1211,6 +1216,7 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
 	extent_start = key.offset;
 	extent_end = btrfs_file_extent_end(path);
 	em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
+	em->generation = btrfs_file_extent_generation(leaf, fi);
 	if (type == BTRFS_FILE_EXTENT_REG ||
 	    type == BTRFS_FILE_EXTENT_PREALLOC) {
 		em->start = extent_start;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index a0179cc62913..9f455c96c974 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -691,7 +691,6 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 	int modify_tree = -1;
 	int update_refs;
 	int found = 0;
-	int leafs_visited = 0;
 	struct btrfs_path *path = args->path;
 
 	args->bytes_found = 0;
@@ -729,7 +728,6 @@ int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 				path->slots[0]--;
 		}
 		ret = 0;
-		leafs_visited++;
 next_slot:
 		leaf = path->nodes[0];
 		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
@@ -741,7 +739,6 @@ next_slot:
 				ret = 0;
 				break;
 			}
-			leafs_visited++;
 			leaf = path->nodes[0];
 			recow = 1;
 		}
@@ -987,7 +984,7 @@ delete_extent_item:
 	 * which case it unlocked our path, so check path->locks[0] matches a
 	 * write lock.
 	 */
-	if (!ret && args->replace_extent && leafs_visited == 1 &&
+	if (!ret && args->replace_extent &&
 	    path->locks[0] == BTRFS_WRITE_LOCK &&
 	    btrfs_leaf_free_space(leaf) >=
 	    sizeof(struct btrfs_item) + args->extent_item_size) {
@@ -1722,7 +1719,8 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 					 fs_info->sectorsize);
 		WARN_ON(reserve_bytes == 0);
 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-				reserve_bytes);
+						      reserve_bytes,
+						      reserve_bytes);
 		if (ret) {
 			if (!only_release_metadata)
 				btrfs_free_reserved_data_space(BTRFS_I(inode),
@@ -2039,12 +2037,43 @@ out:
 	return err < 0 ? err : written;
 }
 
-static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
-				    struct iov_iter *from)
+static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			const struct btrfs_ioctl_encoded_io_args *encoded)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	loff_t count;
+	ssize_t ret;
+
+	btrfs_inode_lock(inode, 0);
+	count = encoded->len;
+	ret = generic_write_checks_count(iocb, &count);
+	if (ret == 0 && count != encoded->len) {
+		/*
+		 * The write got truncated by generic_write_checks_count(). We
+		 * can't do a partial encoded write.
+		 */
+		ret = -EFBIG;
+	}
+	if (ret || encoded->len == 0)
+		goto out;
+
+	ret = btrfs_write_check(iocb, from, encoded->len);
+	if (ret < 0)
+		goto out;
+
+	ret = btrfs_do_encoded_write(iocb, from, encoded);
+out:
+	btrfs_inode_unlock(inode, 0);
+	return ret;
+}
+
+ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from,
+			    const struct btrfs_ioctl_encoded_io_args *encoded)
 {
 	struct file *file = iocb->ki_filp;
 	struct btrfs_inode *inode = BTRFS_I(file_inode(file));
-	ssize_t num_written = 0;
+	ssize_t num_written, num_sync;
 	const bool sync = iocb->ki_flags & IOCB_DSYNC;
 
 	/*
@@ -2055,22 +2084,28 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	if (BTRFS_FS_ERROR(inode->root->fs_info))
 		return -EROFS;
 
-	if (!(iocb->ki_flags & IOCB_DIRECT) &&
-	    (iocb->ki_flags & IOCB_NOWAIT))
+	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
 		return -EOPNOTSUPP;
 
 	if (sync)
 		atomic_inc(&inode->sync_writers);
 
-	if (iocb->ki_flags & IOCB_DIRECT)
-		num_written = btrfs_direct_write(iocb, from);
-	else
-		num_written = btrfs_buffered_write(iocb, from);
+	if (encoded) {
+		num_written = btrfs_encoded_write(iocb, from, encoded);
+		num_sync = encoded->len;
+	} else if (iocb->ki_flags & IOCB_DIRECT) {
+		num_written = num_sync = btrfs_direct_write(iocb, from);
+	} else {
+		num_written = num_sync = btrfs_buffered_write(iocb, from);
+	}
 
 	btrfs_set_inode_last_sub_trans(inode);
 
-	if (num_written > 0)
-		num_written = generic_write_sync(iocb, num_written);
+	if (num_sync > 0) {
+		num_sync = generic_write_sync(iocb, num_sync);
+		if (num_sync < 0)
+			num_written = num_sync;
+	}
 
 	if (sync)
 		atomic_dec(&inode->sync_writers);
@@ -2079,6 +2114,11 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	return num_written;
 }
 
+static ssize_t btrfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	return btrfs_do_write_iter(iocb, from, NULL);
+}
+
 int btrfs_release_file(struct inode *inode, struct file *filp)
 {
 	struct btrfs_file_private *private = filp->private_data;
@@ -2474,7 +2514,7 @@ out:
 	hole_em = alloc_extent_map();
 	if (!hole_em) {
 		btrfs_drop_extent_cache(inode, offset, end - 1, 0);
-		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
+		btrfs_set_inode_full_sync(inode);
 	} else {
 		hole_em->start = offset;
 		hole_em->len = end - offset;
@@ -2495,8 +2535,7 @@ out:
 		} while (ret == -EEXIST);
 		free_extent_map(hole_em);
 		if (ret)
-			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
-					&inode->runtime_flags);
+			btrfs_set_inode_full_sync(inode);
 	}
 
 	return 0;
@@ -2850,7 +2889,7 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
 	 * maps for the replacement extents (or holes).
 	 */
 	if (extent_info && !extent_info->is_new_extent)
-		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
+		btrfs_set_inode_full_sync(inode);
 
 	if (ret)
 		goto out_trans;
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index 655aad0f9e1c..0ae54d8c10d6 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -25,6 +25,8 @@ static struct btrfs_root *btrfs_free_space_root(
 		.offset = 0,
 	};
 
+	if (btrfs_fs_incompat(block_group->fs_info, EXTENT_TREE_V2))
+		key.offset = block_group->global_root_id;
 	return btrfs_global_root(block_group->fs_info, &key);
 }
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5bbea5ec31fc..2e7143ff5523 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -66,6 +66,11 @@ struct btrfs_dio_data {
 	struct extent_changeset *data_reserved;
 };
 
+struct btrfs_rename_ctx {
+	/* Output field. Stores the index number of the old directory entry. */
+	u64 index;
+};
+
 static const struct inode_operations btrfs_dir_inode_operations;
 static const struct inode_operations btrfs_symlink_inode_operations;
 static const struct inode_operations btrfs_special_inode_operations;
@@ -234,12 +239,14 @@ static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
  * no overlapping inline items exist in the btree
  */
 static int insert_inline_extent(struct btrfs_trans_handle *trans,
-				struct btrfs_path *path, bool extent_inserted,
-				struct btrfs_root *root, struct inode *inode,
-				u64 start, size_t size, size_t compressed_size,
+				struct btrfs_path *path,
+				struct btrfs_inode *inode, bool extent_inserted,
+				size_t size, size_t compressed_size,
 				int compress_type,
-				struct page **compressed_pages)
+				struct page **compressed_pages,
+				bool update_i_size)
 {
+	struct btrfs_root *root = inode->root;
 	struct extent_buffer *leaf;
 	struct page *page = NULL;
 	char *kaddr;
@@ -247,7 +254,7 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_file_extent_item *ei;
 	int ret;
 	size_t cur_size = size;
-	unsigned long offset;
+	u64 i_size;
 
 	ASSERT((compressed_size > 0 && compressed_pages) ||
 	       (compressed_size == 0 && !compressed_pages));
@@ -259,8 +266,8 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		struct btrfs_key key;
 		size_t datasize;
 
-		key.objectid = btrfs_ino(BTRFS_I(inode));
-		key.offset = start;
+		key.objectid = btrfs_ino(inode);
+		key.offset = 0;
 		key.type = BTRFS_EXTENT_DATA_KEY;
 
 		datasize = btrfs_file_extent_calc_inline_size(cur_size);
@@ -298,12 +305,10 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		btrfs_set_file_extent_compression(leaf, ei,
 						  compress_type);
 	} else {
-		page = find_get_page(inode->i_mapping,
-				     start >> PAGE_SHIFT);
+		page = find_get_page(inode->vfs_inode.i_mapping, 0);
 		btrfs_set_file_extent_compression(leaf, ei, 0);
 		kaddr = kmap_atomic(page);
-		offset = offset_in_page(start);
-		write_extent_buffer(leaf, kaddr + offset, ptr, size);
+		write_extent_buffer(leaf, kaddr, ptr, size);
 		kunmap_atomic(kaddr);
 		put_page(page);
 	}
@@ -314,21 +319,25 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	 * We align size to sectorsize for inline extents just for simplicity
 	 * sake.
 	 */
-	size = ALIGN(size, root->fs_info->sectorsize);
-	ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, size);
+	ret = btrfs_inode_set_file_extent_range(inode, 0,
+					ALIGN(size, root->fs_info->sectorsize));
 	if (ret)
 		goto fail;
 
 	/*
-	 * we're an inline extent, so nobody can
-	 * extend the file past i_size without locking
-	 * a page we already have locked.
+	 * We're an inline extent, so nobody can extend the file past i_size
+	 * without locking a page we already have locked.
 	 *
-	 * We must do any isize and inode updates
-	 * before we unlock the pages.  Otherwise we
-	 * could end up racing with unlink.
+	 * We must do any i_size and inode updates before we unlock the pages.
+	 * Otherwise we could end up racing with unlink.
 	 */
-	BTRFS_I(inode)->disk_i_size = inode->i_size;
+	i_size = i_size_read(&inode->vfs_inode);
+	if (update_i_size && size > i_size) {
+		i_size_write(&inode->vfs_inode, size);
+		i_size = size;
+	}
+	inode->disk_i_size = i_size;
+
 fail:
 	return ret;
 }
@@ -339,35 +348,31 @@ fail:
  * does the checks required to make sure the data is small enough
  * to fit as an inline extent.
  */
-static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
-					  u64 end, size_t compressed_size,
+static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
+					  size_t compressed_size,
 					  int compress_type,
-					  struct page **compressed_pages)
+					  struct page **compressed_pages,
+					  bool update_i_size)
 {
 	struct btrfs_drop_extents_args drop_args = { 0 };
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_trans_handle *trans;
-	u64 isize = i_size_read(&inode->vfs_inode);
-	u64 actual_end = min(end + 1, isize);
-	u64 inline_len = actual_end - start;
-	u64 aligned_end = ALIGN(end, fs_info->sectorsize);
-	u64 data_len = inline_len;
+	u64 data_len = (compressed_size ?: size);
 	int ret;
 	struct btrfs_path *path;
 
-	if (compressed_size)
-		data_len = compressed_size;
-
-	if (start > 0 ||
-	    actual_end > fs_info->sectorsize ||
+	/*
+	 * We can create an inline extent if it ends at or beyond the current
+	 * i_size, is no larger than a sector (decompressed), and the (possibly
+	 * compressed) data fits in a leaf and the configured maximum inline
+	 * size.
+	 */
+	if (size < i_size_read(&inode->vfs_inode) ||
+	    size > fs_info->sectorsize ||
 	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
-	    (!compressed_size &&
-	    (actual_end & (fs_info->sectorsize - 1)) == 0) ||
-	    end + 1 < isize ||
-	    data_len > fs_info->max_inline) {
+	    data_len > fs_info->max_inline)
 		return 1;
-	}
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -381,30 +386,20 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 	trans->block_rsv = &inode->block_rsv;
 
 	drop_args.path = path;
-	drop_args.start = start;
-	drop_args.end = aligned_end;
+	drop_args.start = 0;
+	drop_args.end = fs_info->sectorsize;
 	drop_args.drop_cache = true;
 	drop_args.replace_extent = true;
-
-	if (compressed_size && compressed_pages)
-		drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
-		   compressed_size);
-	else
-		drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
-		    inline_len);
-
+	drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(data_len);
 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;
 	}
 
-	if (isize > actual_end)
-		inline_len = min_t(u64, isize, actual_end);
-	ret = insert_inline_extent(trans, path, drop_args.extent_inserted,
-				   root, &inode->vfs_inode, start,
-				   inline_len, compressed_size,
-				   compress_type, compressed_pages);
+	ret = insert_inline_extent(trans, path, inode, drop_args.extent_inserted,
+				   size, compressed_size, compress_type,
+				   compressed_pages, update_i_size);
 	if (ret && ret != -ENOSPC) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;
@@ -413,7 +408,7 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 		goto out;
 	}
 
-	btrfs_update_inode_bytes(inode, inline_len, drop_args.bytes_found);
+	btrfs_update_inode_bytes(inode, size, drop_args.bytes_found);
 	ret = btrfs_update_inode(trans, root, inode);
 	if (ret && ret != -ENOSPC) {
 		btrfs_abort_transaction(trans, ret);
@@ -423,7 +418,7 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 		goto out;
 	}
 
-	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
+	btrfs_set_inode_full_sync(inode);
 out:
 	/*
 	 * Don't forget to free the reserved space, as for inlined extent
@@ -624,7 +619,6 @@ static noinline int compress_file_range(struct async_chunk *async_chunk)
 again:
 	will_compress = 0;
 	nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
-	BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
 	nr_pages = min_t(unsigned long, nr_pages,
 			BTRFS_MAX_COMPRESSED / PAGE_SIZE);
 
@@ -735,14 +729,15 @@ cont:
 			/* we didn't compress the entire range, try
 			 * to make an uncompressed inline extent.
 			 */
-			ret = cow_file_range_inline(BTRFS_I(inode), start, end,
+			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
 						    0, BTRFS_COMPRESS_NONE,
-						    NULL);
+						    NULL, false);
 		} else {
 			/* try making a compressed inline extent */
-			ret = cow_file_range_inline(BTRFS_I(inode), start, end,
+			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
 						    total_compressed,
-						    compress_type, pages);
+						    compress_type, pages,
+						    false);
 		}
 		if (ret <= 0) {
 			unsigned long clear_flags = EXTENT_DELALLOC |
@@ -981,11 +976,14 @@ static int submit_one_async_extent(struct btrfs_inode *inode,
 	}
 	free_extent_map(em);
 
-	ret = btrfs_add_ordered_extent_compress(inode, start,	/* file_offset */
-					ins.objectid,		/* disk_bytenr */
-					async_extent->ram_size, /* num_bytes */
-					ins.offset,		/* disk_num_bytes */
-					async_extent->compress_type);
+	ret = btrfs_add_ordered_extent(inode, start,		/* file_offset */
+				       async_extent->ram_size,	/* num_bytes */
+				       async_extent->ram_size,	/* ram_bytes */
+				       ins.objectid,		/* disk_bytenr */
+				       ins.offset,		/* disk_num_bytes */
+				       0,			/* offset */
+				       1 << BTRFS_ORDERED_COMPRESSED,
+				       async_extent->compress_type);
 	if (ret) {
 		btrfs_drop_extent_cache(inode, start, end, 0);
 		goto out_free_reserve;
@@ -1003,7 +1001,7 @@ static int submit_one_async_extent(struct btrfs_inode *inode,
 			    async_extent->pages,	/* compressed_pages */
 			    async_extent->nr_pages,
 			    async_chunk->write_flags,
-			    async_chunk->blkcg_css)) {
+			    async_chunk->blkcg_css, true)) {
 		const u64 start = async_extent->start;
 		const u64 end = start + async_extent->ram_size - 1;
 
@@ -1152,9 +1150,12 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 	 * So here we skip inline extent creation completely.
 	 */
 	if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
+		u64 actual_end = min_t(u64, i_size_read(&inode->vfs_inode),
+				       end + 1);
+
 		/* lets try to make an inline extent */
-		ret = cow_file_range_inline(inode, start, end, 0,
-					    BTRFS_COMPRESS_NONE, NULL);
+		ret = cow_file_range_inline(inode, actual_end, 0,
+					    BTRFS_COMPRESS_NONE, NULL, false);
 		if (ret == 0) {
 			/*
 			 * We use DO_ACCOUNTING here because we need the
@@ -1234,9 +1235,10 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 		}
 		free_extent_map(em);
 
-		ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
-					       ram_size, cur_alloc_size,
-					       BTRFS_ORDERED_REGULAR);
+		ret = btrfs_add_ordered_extent(inode, start, ram_size, ram_size,
+					       ins.objectid, cur_alloc_size, 0,
+					       1 << BTRFS_ORDERED_REGULAR,
+					       BTRFS_COMPRESS_NONE);
 		if (ret)
 			goto out_drop_extent_cache;
 
@@ -1895,10 +1897,11 @@ out_check:
 				goto error;
 			}
 			free_extent_map(em);
-			ret = btrfs_add_ordered_extent(inode, cur_offset,
-						       disk_bytenr, num_bytes,
-						       num_bytes,
-						       BTRFS_ORDERED_PREALLOC);
+			ret = btrfs_add_ordered_extent(inode,
+					cur_offset, num_bytes, num_bytes,
+					disk_bytenr, num_bytes, 0,
+					1 << BTRFS_ORDERED_PREALLOC,
+					BTRFS_COMPRESS_NONE);
 			if (ret) {
 				btrfs_drop_extent_cache(inode, cur_offset,
 							cur_offset + num_bytes - 1,
@@ -1907,9 +1910,11 @@ out_check:
 			}
 		} else {
 			ret = btrfs_add_ordered_extent(inode, cur_offset,
+						       num_bytes, num_bytes,
 						       disk_bytenr, num_bytes,
-						       num_bytes,
-						       BTRFS_ORDERED_NOCOW);
+						       0,
+						       1 << BTRFS_ORDERED_NOCOW,
+						       BTRFS_COMPRESS_NONE);
 			if (ret)
 				goto error;
 		}
@@ -2310,7 +2315,7 @@ void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
 static blk_status_t btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
 					   u64 dio_file_offset)
 {
-	return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
+	return btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
 }
 
 /*
@@ -2538,10 +2543,15 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
 			goto out;
 
 		if (bio_flags & EXTENT_BIO_COMPRESSED) {
+			/*
+			 * btrfs_submit_compressed_read will handle completing
+			 * the bio if there were any errors, so just return
+			 * here.
+			 */
 			ret = btrfs_submit_compressed_read(inode, bio,
 							   mirror_num,
 							   bio_flags);
-			goto out;
+			goto out_no_endio;
 		} else {
 			/*
 			 * Lookup bio sums does extra checks around whether we
@@ -2562,7 +2572,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
 					  0, btrfs_submit_bio_start);
 		goto out;
 	} else if (!skip_sum) {
-		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
+		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
 		if (ret)
 			goto out;
 	}
@@ -2575,6 +2585,7 @@ out:
 		bio->bi_status = ret;
 		bio_endio(bio);
 	}
+out_no_endio:
 	return ret;
 }
 
@@ -2870,6 +2881,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_key ins;
 	u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi);
 	u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi);
+	u64 offset = btrfs_stack_file_extent_offset(stack_fi);
 	u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
 	u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
 	struct btrfs_drop_extents_args drop_args = { 0 };
@@ -2944,7 +2956,8 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 		goto out;
 
 	ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode),
-					       file_pos, qgroup_reserved, &ins);
+					       file_pos - offset,
+					       qgroup_reserved, &ins);
 out:
 	btrfs_free_path(path);
 
@@ -2970,20 +2983,20 @@ static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
 					     struct btrfs_ordered_extent *oe)
 {
 	struct btrfs_file_extent_item stack_fi;
-	u64 logical_len;
 	bool update_inode_bytes;
+	u64 num_bytes = oe->num_bytes;
+	u64 ram_bytes = oe->ram_bytes;
 
 	memset(&stack_fi, 0, sizeof(stack_fi));
 	btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG);
 	btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr);
 	btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi,
 						   oe->disk_num_bytes);
+	btrfs_set_stack_file_extent_offset(&stack_fi, oe->offset);
 	if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags))
-		logical_len = oe->truncated_len;
-	else
-		logical_len = oe->num_bytes;
-	btrfs_set_stack_file_extent_num_bytes(&stack_fi, logical_len);
-	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, logical_len);
+		num_bytes = ram_bytes = oe->truncated_len;
+	btrfs_set_stack_file_extent_num_bytes(&stack_fi, num_bytes);
+	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, ram_bytes);
 	btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type);
 	/* Encryption and other encoding is reserved and all 0 */
 
@@ -2994,6 +3007,7 @@ static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
 	 * except if the ordered extent was truncated.
 	 */
 	update_inode_bytes = test_bit(BTRFS_ORDERED_DIRECT, &oe->flags) ||
+			     test_bit(BTRFS_ORDERED_ENCODED, &oe->flags) ||
 			     test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags);
 
 	return insert_reserved_file_extent(trans, BTRFS_I(oe->inode),
@@ -3028,7 +3042,8 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 
 	if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
 	    !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
-	    !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
+	    !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags) &&
+	    !test_bit(BTRFS_ORDERED_ENCODED, &ordered_extent->flags))
 		clear_bits |= EXTENT_DELALLOC_NEW;
 
 	freespace_inode = btrfs_is_free_space_inode(inode);
@@ -4062,7 +4077,8 @@ int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 				struct btrfs_inode *dir,
 				struct btrfs_inode *inode,
-				const char *name, int name_len)
+				const char *name, int name_len,
+				struct btrfs_rename_ctx *rename_ctx)
 {
 	struct btrfs_root *root = dir->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -4118,15 +4134,27 @@ static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		goto err;
 	}
 skip_backref:
+	if (rename_ctx)
+		rename_ctx->index = index;
+
 	ret = btrfs_delete_delayed_dir_index(trans, dir, index);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto err;
 	}
 
-	btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
-				   dir_ino);
-	btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir, index);
+	/*
+	 * If we are in a rename context, we don't need to update anything in the
+	 * log. That will be done later during the rename by btrfs_log_new_name().
+	 * Besides that, doing it here would only cause extra unncessary btree
+	 * operations on the log tree, increasing latency for applications.
+	 */
+	if (!rename_ctx) {
+		btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
+					   dir_ino);
+		btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
+					     index);
+	}
 
 	/*
 	 * If we have a pending delayed iput we could end up with the final iput
@@ -4158,7 +4186,7 @@ int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		       const char *name, int name_len)
 {
 	int ret;
-	ret = __btrfs_unlink_inode(trans, dir, inode, name, name_len);
+	ret = __btrfs_unlink_inode(trans, dir, inode, name, name_len, NULL);
 	if (!ret) {
 		drop_nlink(&inode->vfs_inode);
 		ret = btrfs_update_inode(trans, inode->root, inode);
@@ -4565,14 +4593,21 @@ out_up_write:
 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	struct inode *inode = d_inode(dentry);
+	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
 	int err = 0;
 	struct btrfs_trans_handle *trans;
 	u64 last_unlink_trans;
 
 	if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
 		return -ENOTEMPTY;
-	if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
+	if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID) {
+		if (unlikely(btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))) {
+			btrfs_err(fs_info,
+			"extent tree v2 doesn't support snapshot deletion yet");
+			return -EOPNOTSUPP;
+		}
 		return btrfs_delete_subvolume(dir, dentry);
+	}
 
 	trans = __unlink_start_trans(dir);
 	if (IS_ERR(trans))
@@ -4611,7 +4646,7 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 	}
 out:
 	btrfs_end_transaction(trans);
-	btrfs_btree_balance_dirty(BTRFS_I(dir)->root->fs_info);
+	btrfs_btree_balance_dirty(fs_info);
 
 	return err;
 }
@@ -4664,7 +4699,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
 			goto out;
 		}
 	}
-	ret = btrfs_delalloc_reserve_metadata(inode, blocksize);
+	ret = btrfs_delalloc_reserve_metadata(inode, blocksize, blocksize);
 	if (ret < 0) {
 		if (!only_release_metadata)
 			btrfs_free_reserved_data_space(inode, data_reserved,
@@ -4876,8 +4911,7 @@ int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size)
 						cur_offset + hole_size - 1, 0);
 			hole_em = alloc_extent_map();
 			if (!hole_em) {
-				set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
-					&inode->runtime_flags);
+				btrfs_set_inode_full_sync(inode);
 				goto next;
 			}
 			hole_em->start = cur_offset;
@@ -5584,21 +5618,17 @@ static struct inode *new_simple_dir(struct super_block *s,
 	return inode;
 }
 
+static_assert(BTRFS_FT_UNKNOWN == FT_UNKNOWN);
+static_assert(BTRFS_FT_REG_FILE == FT_REG_FILE);
+static_assert(BTRFS_FT_DIR == FT_DIR);
+static_assert(BTRFS_FT_CHRDEV == FT_CHRDEV);
+static_assert(BTRFS_FT_BLKDEV == FT_BLKDEV);
+static_assert(BTRFS_FT_FIFO == FT_FIFO);
+static_assert(BTRFS_FT_SOCK == FT_SOCK);
+static_assert(BTRFS_FT_SYMLINK == FT_SYMLINK);
+
 static inline u8 btrfs_inode_type(struct inode *inode)
 {
-	/*
-	 * Compile-time asserts that generic FT_* types still match
-	 * BTRFS_FT_* types
-	 */
-	BUILD_BUG_ON(BTRFS_FT_UNKNOWN != FT_UNKNOWN);
-	BUILD_BUG_ON(BTRFS_FT_REG_FILE != FT_REG_FILE);
-	BUILD_BUG_ON(BTRFS_FT_DIR != FT_DIR);
-	BUILD_BUG_ON(BTRFS_FT_CHRDEV != FT_CHRDEV);
-	BUILD_BUG_ON(BTRFS_FT_BLKDEV != FT_BLKDEV);
-	BUILD_BUG_ON(BTRFS_FT_FIFO != FT_FIFO);
-	BUILD_BUG_ON(BTRFS_FT_SOCK != FT_SOCK);
-	BUILD_BUG_ON(BTRFS_FT_SYMLINK != FT_SYMLINK);
-
 	return fs_umode_to_ftype(inode->i_mode);
 }
 
@@ -5971,14 +6001,8 @@ static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
 		goto out;
 	ret = 0;
 
-	/*
-	 * MAGIC NUMBER EXPLANATION:
-	 * since we search a directory based on f_pos we have to start at 2
-	 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
-	 * else has to start at 2
-	 */
 	if (path->slots[0] == 0) {
-		inode->index_cnt = 2;
+		inode->index_cnt = BTRFS_DIR_START_INDEX;
 		goto out;
 	}
 
@@ -5989,7 +6013,7 @@ static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
 
 	if (found_key.objectid != btrfs_ino(inode) ||
 	    found_key.type != BTRFS_DIR_INDEX_KEY) {
-		inode->index_cnt = 2;
+		inode->index_cnt = BTRFS_DIR_START_INDEX;
 		goto out;
 	}
 
@@ -6140,7 +6164,7 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	 * sync since it will be a full sync anyway and this will blow away the
 	 * old info in the log.
 	 */
-	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
+	btrfs_set_inode_full_sync(BTRFS_I(inode));
 
 	key[0].objectid = objectid;
 	key[0].type = BTRFS_INODE_ITEM_KEY;
@@ -6537,7 +6561,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 				goto fail;
 		}
 		d_instantiate(dentry, inode);
-		btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
+		btrfs_log_new_name(trans, old_dentry, NULL, 0, parent);
 	}
 
 fail:
@@ -7040,8 +7064,11 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 		if (IS_ERR(em))
 			goto out;
 	}
-	ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len,
-					   block_len, type);
+	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,
+				       block_len, 0,
+				       (1 << type) |
+				       (1 << BTRFS_ORDERED_DIRECT),
+				       BTRFS_COMPRESS_NONE);
 	if (ret) {
 		if (em) {
 			free_extent_map(em);
@@ -7441,7 +7468,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
 		struct extent_map *em2;
 
 		/* We can NOCOW, so only need to reserve metadata space. */
-		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len);
+		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), len, len);
 		if (ret < 0) {
 			/* Our caller expects us to free the input extent map. */
 			free_extent_map(em);
@@ -7831,7 +7858,7 @@ static blk_status_t btrfs_submit_bio_start_direct_io(struct inode *inode,
 						     struct bio *bio,
 						     u64 dio_file_offset)
 {
-	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, 1);
+	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, false);
 }
 
 static void btrfs_end_dio_bio(struct bio *bio)
@@ -7888,7 +7915,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
 		 * If we aren't doing async submit, calculate the csum of the
 		 * bio now.
 		 */
-		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, 1);
+		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, false);
 		if (ret)
 			goto err;
 	} else {
@@ -8104,8 +8131,13 @@ int btrfs_readpage(struct file *file, struct page *page)
 	btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
 
 	ret = btrfs_do_readpage(page, NULL, &bio_ctrl, 0, NULL);
-	if (bio_ctrl.bio)
-		ret = submit_one_bio(bio_ctrl.bio, 0, bio_ctrl.bio_flags);
+	if (bio_ctrl.bio) {
+		int ret2;
+
+		ret2 = submit_one_bio(bio_ctrl.bio, 0, bio_ctrl.bio_flags);
+		if (ret == 0)
+			ret = ret2;
+	}
 	return ret;
 }
 
@@ -8734,7 +8766,7 @@ out:
 	 * extents beyond i_size to drop.
 	 */
 	if (control.extents_found > 0)
-		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
+		btrfs_set_inode_full_sync(BTRFS_I(inode));
 
 	return ret;
 }
@@ -9030,14 +9062,14 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 	struct inode *new_inode = new_dentry->d_inode;
 	struct inode *old_inode = old_dentry->d_inode;
 	struct timespec64 ctime = current_time(old_inode);
+	struct btrfs_rename_ctx old_rename_ctx;
+	struct btrfs_rename_ctx new_rename_ctx;
 	u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
 	u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
 	u64 old_idx = 0;
 	u64 new_idx = 0;
 	int ret;
 	int ret2;
-	bool root_log_pinned = false;
-	bool dest_log_pinned = false;
 	bool need_abort = false;
 
 	/*
@@ -9140,29 +9172,6 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 				BTRFS_I(new_inode), 1);
 	}
 
-	/*
-	 * Now pin the logs of the roots. We do it to ensure that no other task
-	 * can sync the logs while we are in progress with the rename, because
-	 * that could result in an inconsistency in case any of the inodes that
-	 * are part of this rename operation were logged before.
-	 *
-	 * We pin the logs even if at this precise moment none of the inodes was
-	 * logged before. This is because right after we checked for that, some
-	 * other task fsyncing some other inode not involved with this rename
-	 * operation could log that one of our inodes exists.
-	 *
-	 * We don't need to pin the logs before the above calls to
-	 * btrfs_insert_inode_ref(), since those don't ever need to change a log.
-	 */
-	if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
-		btrfs_pin_log_trans(root);
-		root_log_pinned = true;
-	}
-	if (new_ino != BTRFS_FIRST_FREE_OBJECTID) {
-		btrfs_pin_log_trans(dest);
-		dest_log_pinned = true;
-	}
-
 	/* src is a subvolume */
 	if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
@@ -9170,7 +9179,8 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 		ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
 					   BTRFS_I(old_dentry->d_inode),
 					   old_dentry->d_name.name,
-					   old_dentry->d_name.len);
+					   old_dentry->d_name.len,
+					   &old_rename_ctx);
 		if (!ret)
 			ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
 	}
@@ -9186,7 +9196,8 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 		ret = __btrfs_unlink_inode(trans, BTRFS_I(new_dir),
 					   BTRFS_I(new_dentry->d_inode),
 					   new_dentry->d_name.name,
-					   new_dentry->d_name.len);
+					   new_dentry->d_name.len,
+					   &new_rename_ctx);
 		if (!ret)
 			ret = btrfs_update_inode(trans, dest, BTRFS_I(new_inode));
 	}
@@ -9216,46 +9227,31 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 	if (new_inode->i_nlink == 1)
 		BTRFS_I(new_inode)->dir_index = new_idx;
 
-	if (root_log_pinned) {
-		btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
-				   new_dentry->d_parent);
-		btrfs_end_log_trans(root);
-		root_log_pinned = false;
-	}
-	if (dest_log_pinned) {
-		btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
-				   old_dentry->d_parent);
-		btrfs_end_log_trans(dest);
-		dest_log_pinned = false;
-	}
-out_fail:
 	/*
-	 * If we have pinned a log and an error happened, we unpin tasks
-	 * trying to sync the log and force them to fallback to a transaction
-	 * commit if the log currently contains any of the inodes involved in
-	 * this rename operation (to ensure we do not persist a log with an
-	 * inconsistent state for any of these inodes or leading to any
-	 * inconsistencies when replayed). If the transaction was aborted, the
-	 * abortion reason is propagated to userspace when attempting to commit
-	 * the transaction. If the log does not contain any of these inodes, we
-	 * allow the tasks to sync it.
+	 * Now pin the logs of the roots. We do it to ensure that no other task
+	 * can sync the logs while we are in progress with the rename, because
+	 * that could result in an inconsistency in case any of the inodes that
+	 * are part of this rename operation were logged before.
 	 */
-	if (ret && (root_log_pinned || dest_log_pinned)) {
-		if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
-		    btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
-		    btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
-		    btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))
-			btrfs_set_log_full_commit(trans);
+	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_pin_log_trans(root);
+	if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_pin_log_trans(dest);
 
-		if (root_log_pinned) {
-			btrfs_end_log_trans(root);
-			root_log_pinned = false;
-		}
-		if (dest_log_pinned) {
-			btrfs_end_log_trans(dest);
-			dest_log_pinned = false;
-		}
-	}
+	/* Do the log updates for all inodes. */
+	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
+				   old_rename_ctx.index, new_dentry->d_parent);
+	if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_log_new_name(trans, new_dentry, BTRFS_I(new_dir),
+				   new_rename_ctx.index, old_dentry->d_parent);
+
+	/* Now unpin the logs. */
+	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_end_log_trans(root);
+	if (new_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_end_log_trans(dest);
+out_fail:
 	ret2 = btrfs_end_transaction(trans);
 	ret = ret ? ret : ret2;
 out_notrans:
@@ -9330,11 +9326,11 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 	struct btrfs_root *dest = BTRFS_I(new_dir)->root;
 	struct inode *new_inode = d_inode(new_dentry);
 	struct inode *old_inode = d_inode(old_dentry);
+	struct btrfs_rename_ctx rename_ctx;
 	u64 index = 0;
 	int ret;
 	int ret2;
 	u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
-	bool log_pinned = false;
 
 	if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
 		return -EPERM;
@@ -9439,29 +9435,11 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 	if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
 	} else {
-		/*
-		 * Now pin the log. We do it to ensure that no other task can
-		 * sync the log while we are in progress with the rename, as
-		 * that could result in an inconsistency in case any of the
-		 * inodes that are part of this rename operation were logged
-		 * before.
-		 *
-		 * We pin the log even if at this precise moment none of the
-		 * inodes was logged before. This is because right after we
-		 * checked for that, some other task fsyncing some other inode
-		 * not involved with this rename operation could log that one of
-		 * our inodes exists.
-		 *
-		 * We don't need to pin the logs before the above call to
-		 * btrfs_insert_inode_ref(), since that does not need to change
-		 * a log.
-		 */
-		btrfs_pin_log_trans(root);
-		log_pinned = true;
 		ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
 					BTRFS_I(d_inode(old_dentry)),
 					old_dentry->d_name.name,
-					old_dentry->d_name.len);
+					old_dentry->d_name.len,
+					&rename_ctx);
 		if (!ret)
 			ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
 	}
@@ -9503,12 +9481,9 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 	if (old_inode->i_nlink == 1)
 		BTRFS_I(old_inode)->dir_index = index;
 
-	if (log_pinned) {
-		btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
-				   new_dentry->d_parent);
-		btrfs_end_log_trans(root);
-		log_pinned = false;
-	}
+	if (old_ino != BTRFS_FIRST_FREE_OBJECTID)
+		btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
+				   rename_ctx.index, new_dentry->d_parent);
 
 	if (flags & RENAME_WHITEOUT) {
 		ret = btrfs_whiteout_for_rename(trans, root, mnt_userns,
@@ -9520,28 +9495,6 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 		}
 	}
 out_fail:
-	/*
-	 * If we have pinned the log and an error happened, we unpin tasks
-	 * trying to sync the log and force them to fallback to a transaction
-	 * commit if the log currently contains any of the inodes involved in
-	 * this rename operation (to ensure we do not persist a log with an
-	 * inconsistent state for any of these inodes or leading to any
-	 * inconsistencies when replayed). If the transaction was aborted, the
-	 * abortion reason is propagated to userspace when attempting to commit
-	 * the transaction. If the log does not contain any of these inodes, we
-	 * allow the tasks to sync it.
-	 */
-	if (ret && log_pinned) {
-		if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
-		    btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
-		    btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
-		    (new_inode &&
-		     btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
-			btrfs_set_log_full_commit(trans);
-
-		btrfs_end_log_trans(root);
-		log_pinned = false;
-	}
 	ret2 = btrfs_end_transaction(trans);
 	ret = ret ? ret : ret2;
 out_notrans:
@@ -10021,8 +9974,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
 
 		em = alloc_extent_map();
 		if (!em) {
-			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
-				&BTRFS_I(inode)->runtime_flags);
+			btrfs_set_inode_full_sync(BTRFS_I(inode));
 			goto next;
 		}
 
@@ -10210,6 +10162,747 @@ void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
 	}
 }
 
+static int btrfs_encoded_io_compression_from_extent(
+				struct btrfs_fs_info *fs_info,
+				int compress_type)
+{
+	switch (compress_type) {
+	case BTRFS_COMPRESS_NONE:
+		return BTRFS_ENCODED_IO_COMPRESSION_NONE;
+	case BTRFS_COMPRESS_ZLIB:
+		return BTRFS_ENCODED_IO_COMPRESSION_ZLIB;
+	case BTRFS_COMPRESS_LZO:
+		/*
+		 * The LZO format depends on the sector size. 64K is the maximum
+		 * sector size that we support.
+		 */
+		if (fs_info->sectorsize < SZ_4K || fs_info->sectorsize > SZ_64K)
+			return -EINVAL;
+		return BTRFS_ENCODED_IO_COMPRESSION_LZO_4K +
+		       (fs_info->sectorsize_bits - 12);
+	case BTRFS_COMPRESS_ZSTD:
+		return BTRFS_ENCODED_IO_COMPRESSION_ZSTD;
+	default:
+		return -EUCLEAN;
+	}
+}
+
+static ssize_t btrfs_encoded_read_inline(
+				struct kiocb *iocb,
+				struct iov_iter *iter, u64 start,
+				u64 lockend,
+				struct extent_state **cached_state,
+				u64 extent_start, size_t count,
+				struct btrfs_ioctl_encoded_io_args *encoded,
+				bool *unlocked)
+{
+	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct extent_io_tree *io_tree = &inode->io_tree;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_file_extent_item *item;
+	u64 ram_bytes;
+	unsigned long ptr;
+	void *tmp;
+	ssize_t ret;
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
+				       extent_start, 0);
+	if (ret) {
+		if (ret > 0) {
+			/* The extent item disappeared? */
+			ret = -EIO;
+		}
+		goto out;
+	}
+	leaf = path->nodes[0];
+	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
+
+	ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
+	ptr = btrfs_file_extent_inline_start(item);
+
+	encoded->len = min_t(u64, extent_start + ram_bytes,
+			     inode->vfs_inode.i_size) - iocb->ki_pos;
+	ret = btrfs_encoded_io_compression_from_extent(fs_info,
+				 btrfs_file_extent_compression(leaf, item));
+	if (ret < 0)
+		goto out;
+	encoded->compression = ret;
+	if (encoded->compression) {
+		size_t inline_size;
+
+		inline_size = btrfs_file_extent_inline_item_len(leaf,
+								path->slots[0]);
+		if (inline_size > count) {
+			ret = -ENOBUFS;
+			goto out;
+		}
+		count = inline_size;
+		encoded->unencoded_len = ram_bytes;
+		encoded->unencoded_offset = iocb->ki_pos - extent_start;
+	} else {
+		count = min_t(u64, count, encoded->len);
+		encoded->len = count;
+		encoded->unencoded_len = count;
+		ptr += iocb->ki_pos - extent_start;
+	}
+
+	tmp = kmalloc(count, GFP_NOFS);
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	read_extent_buffer(leaf, tmp, ptr, count);
+	btrfs_release_path(path);
+	unlock_extent_cached(io_tree, start, lockend, cached_state);
+	btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
+	*unlocked = true;
+
+	ret = copy_to_iter(tmp, count, iter);
+	if (ret != count)
+		ret = -EFAULT;
+	kfree(tmp);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+struct btrfs_encoded_read_private {
+	struct btrfs_inode *inode;
+	u64 file_offset;
+	wait_queue_head_t wait;
+	atomic_t pending;
+	blk_status_t status;
+	bool skip_csum;
+};
+
+static blk_status_t submit_encoded_read_bio(struct btrfs_inode *inode,
+					    struct bio *bio, int mirror_num)
+{
+	struct btrfs_encoded_read_private *priv = bio->bi_private;
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	blk_status_t ret;
+
+	if (!priv->skip_csum) {
+		ret = btrfs_lookup_bio_sums(&inode->vfs_inode, bio, NULL);
+		if (ret)
+			return ret;
+	}
+
+	ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
+	if (ret) {
+		btrfs_bio_free_csum(bbio);
+		return ret;
+	}
+
+	atomic_inc(&priv->pending);
+	ret = btrfs_map_bio(fs_info, bio, mirror_num);
+	if (ret) {
+		atomic_dec(&priv->pending);
+		btrfs_bio_free_csum(bbio);
+	}
+	return ret;
+}
+
+static blk_status_t btrfs_encoded_read_verify_csum(struct btrfs_bio *bbio)
+{
+	const bool uptodate = (bbio->bio.bi_status == BLK_STS_OK);
+	struct btrfs_encoded_read_private *priv = bbio->bio.bi_private;
+	struct btrfs_inode *inode = priv->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	u32 sectorsize = fs_info->sectorsize;
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
+	u64 start = priv->file_offset;
+	u32 bio_offset = 0;
+
+	if (priv->skip_csum || !uptodate)
+		return bbio->bio.bi_status;
+
+	bio_for_each_segment_all(bvec, &bbio->bio, iter_all) {
+		unsigned int i, nr_sectors, pgoff;
+
+		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
+		pgoff = bvec->bv_offset;
+		for (i = 0; i < nr_sectors; i++) {
+			ASSERT(pgoff < PAGE_SIZE);
+			if (check_data_csum(&inode->vfs_inode, bbio, bio_offset,
+					    bvec->bv_page, pgoff, start))
+				return BLK_STS_IOERR;
+			start += sectorsize;
+			bio_offset += sectorsize;
+			pgoff += sectorsize;
+		}
+	}
+	return BLK_STS_OK;
+}
+
+static void btrfs_encoded_read_endio(struct bio *bio)
+{
+	struct btrfs_encoded_read_private *priv = bio->bi_private;
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+	blk_status_t status;
+
+	status = btrfs_encoded_read_verify_csum(bbio);
+	if (status) {
+		/*
+		 * The memory barrier implied by the atomic_dec_return() here
+		 * pairs with the memory barrier implied by the
+		 * atomic_dec_return() or io_wait_event() in
+		 * btrfs_encoded_read_regular_fill_pages() to ensure that this
+		 * write is observed before the load of status in
+		 * btrfs_encoded_read_regular_fill_pages().
+		 */
+		WRITE_ONCE(priv->status, status);
+	}
+	if (!atomic_dec_return(&priv->pending))
+		wake_up(&priv->wait);
+	btrfs_bio_free_csum(bbio);
+	bio_put(bio);
+}
+
+static int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
+						 u64 file_offset,
+						 u64 disk_bytenr,
+						 u64 disk_io_size,
+						 struct page **pages)
+{
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct btrfs_encoded_read_private priv = {
+		.inode = inode,
+		.file_offset = file_offset,
+		.pending = ATOMIC_INIT(1),
+		.skip_csum = (inode->flags & BTRFS_INODE_NODATASUM),
+	};
+	unsigned long i = 0;
+	u64 cur = 0;
+	int ret;
+
+	init_waitqueue_head(&priv.wait);
+	/*
+	 * Submit bios for the extent, splitting due to bio or stripe limits as
+	 * necessary.
+	 */
+	while (cur < disk_io_size) {
+		struct extent_map *em;
+		struct btrfs_io_geometry geom;
+		struct bio *bio = NULL;
+		u64 remaining;
+
+		em = btrfs_get_chunk_map(fs_info, disk_bytenr + cur,
+					 disk_io_size - cur);
+		if (IS_ERR(em)) {
+			ret = PTR_ERR(em);
+		} else {
+			ret = btrfs_get_io_geometry(fs_info, em, BTRFS_MAP_READ,
+						    disk_bytenr + cur, &geom);
+			free_extent_map(em);
+		}
+		if (ret) {
+			WRITE_ONCE(priv.status, errno_to_blk_status(ret));
+			break;
+		}
+		remaining = min(geom.len, disk_io_size - cur);
+		while (bio || remaining) {
+			size_t bytes = min_t(u64, remaining, PAGE_SIZE);
+
+			if (!bio) {
+				bio = btrfs_bio_alloc(BIO_MAX_VECS);
+				bio->bi_iter.bi_sector =
+					(disk_bytenr + cur) >> SECTOR_SHIFT;
+				bio->bi_end_io = btrfs_encoded_read_endio;
+				bio->bi_private = &priv;
+				bio->bi_opf = REQ_OP_READ;
+			}
+
+			if (!bytes ||
+			    bio_add_page(bio, pages[i], bytes, 0) < bytes) {
+				blk_status_t status;
+
+				status = submit_encoded_read_bio(inode, bio, 0);
+				if (status) {
+					WRITE_ONCE(priv.status, status);
+					bio_put(bio);
+					goto out;
+				}
+				bio = NULL;
+				continue;
+			}
+
+			i++;
+			cur += bytes;
+			remaining -= bytes;
+		}
+	}
+
+out:
+	if (atomic_dec_return(&priv.pending))
+		io_wait_event(priv.wait, !atomic_read(&priv.pending));
+	/* See btrfs_encoded_read_endio() for ordering. */
+	return blk_status_to_errno(READ_ONCE(priv.status));
+}
+
+static ssize_t btrfs_encoded_read_regular(struct kiocb *iocb,
+					  struct iov_iter *iter,
+					  u64 start, u64 lockend,
+					  struct extent_state **cached_state,
+					  u64 disk_bytenr, u64 disk_io_size,
+					  size_t count, bool compressed,
+					  bool *unlocked)
+{
+	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
+	struct extent_io_tree *io_tree = &inode->io_tree;
+	struct page **pages;
+	unsigned long nr_pages, i;
+	u64 cur;
+	size_t page_offset;
+	ssize_t ret;
+
+	nr_pages = DIV_ROUND_UP(disk_io_size, PAGE_SIZE);
+	pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
+	if (!pages)
+		return -ENOMEM;
+	for (i = 0; i < nr_pages; i++) {
+		pages[i] = alloc_page(GFP_NOFS);
+		if (!pages[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
+
+	ret = btrfs_encoded_read_regular_fill_pages(inode, start, disk_bytenr,
+						    disk_io_size, pages);
+	if (ret)
+		goto out;
+
+	unlock_extent_cached(io_tree, start, lockend, cached_state);
+	btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
+	*unlocked = true;
+
+	if (compressed) {
+		i = 0;
+		page_offset = 0;
+	} else {
+		i = (iocb->ki_pos - start) >> PAGE_SHIFT;
+		page_offset = (iocb->ki_pos - start) & (PAGE_SIZE - 1);
+	}
+	cur = 0;
+	while (cur < count) {
+		size_t bytes = min_t(size_t, count - cur,
+				     PAGE_SIZE - page_offset);
+
+		if (copy_page_to_iter(pages[i], page_offset, bytes,
+				      iter) != bytes) {
+			ret = -EFAULT;
+			goto out;
+		}
+		i++;
+		cur += bytes;
+		page_offset = 0;
+	}
+	ret = count;
+out:
+	for (i = 0; i < nr_pages; i++) {
+		if (pages[i])
+			__free_page(pages[i]);
+	}
+	kfree(pages);
+	return ret;
+}
+
+ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
+			   struct btrfs_ioctl_encoded_io_args *encoded)
+{
+	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct extent_io_tree *io_tree = &inode->io_tree;
+	ssize_t ret;
+	size_t count = iov_iter_count(iter);
+	u64 start, lockend, disk_bytenr, disk_io_size;
+	struct extent_state *cached_state = NULL;
+	struct extent_map *em;
+	bool unlocked = false;
+
+	file_accessed(iocb->ki_filp);
+
+	btrfs_inode_lock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
+
+	if (iocb->ki_pos >= inode->vfs_inode.i_size) {
+		btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
+		return 0;
+	}
+	start = ALIGN_DOWN(iocb->ki_pos, fs_info->sectorsize);
+	/*
+	 * We don't know how long the extent containing iocb->ki_pos is, but if
+	 * it's compressed we know that it won't be longer than this.
+	 */
+	lockend = start + BTRFS_MAX_UNCOMPRESSED - 1;
+
+	for (;;) {
+		struct btrfs_ordered_extent *ordered;
+
+		ret = btrfs_wait_ordered_range(&inode->vfs_inode, start,
+					       lockend - start + 1);
+		if (ret)
+			goto out_unlock_inode;
+		lock_extent_bits(io_tree, start, lockend, &cached_state);
+		ordered = btrfs_lookup_ordered_range(inode, start,
+						     lockend - start + 1);
+		if (!ordered)
+			break;
+		btrfs_put_ordered_extent(ordered);
+		unlock_extent_cached(io_tree, start, lockend, &cached_state);
+		cond_resched();
+	}
+
+	em = btrfs_get_extent(inode, NULL, 0, start, lockend - start + 1);
+	if (IS_ERR(em)) {
+		ret = PTR_ERR(em);
+		goto out_unlock_extent;
+	}
+
+	if (em->block_start == EXTENT_MAP_INLINE) {
+		u64 extent_start = em->start;
+
+		/*
+		 * For inline extents we get everything we need out of the
+		 * extent item.
+		 */
+		free_extent_map(em);
+		em = NULL;
+		ret = btrfs_encoded_read_inline(iocb, iter, start, lockend,
+						&cached_state, extent_start,
+						count, encoded, &unlocked);
+		goto out;
+	}
+
+	/*
+	 * We only want to return up to EOF even if the extent extends beyond
+	 * that.
+	 */
+	encoded->len = min_t(u64, extent_map_end(em),
+			     inode->vfs_inode.i_size) - iocb->ki_pos;
+	if (em->block_start == EXTENT_MAP_HOLE ||
+	    test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
+		disk_bytenr = EXTENT_MAP_HOLE;
+		count = min_t(u64, count, encoded->len);
+		encoded->len = count;
+		encoded->unencoded_len = count;
+	} else if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+		disk_bytenr = em->block_start;
+		/*
+		 * Bail if the buffer isn't large enough to return the whole
+		 * compressed extent.
+		 */
+		if (em->block_len > count) {
+			ret = -ENOBUFS;
+			goto out_em;
+		}
+		disk_io_size = count = em->block_len;
+		encoded->unencoded_len = em->ram_bytes;
+		encoded->unencoded_offset = iocb->ki_pos - em->orig_start;
+		ret = btrfs_encoded_io_compression_from_extent(fs_info,
+							     em->compress_type);
+		if (ret < 0)
+			goto out_em;
+		encoded->compression = ret;
+	} else {
+		disk_bytenr = em->block_start + (start - em->start);
+		if (encoded->len > count)
+			encoded->len = count;
+		/*
+		 * Don't read beyond what we locked. This also limits the page
+		 * allocations that we'll do.
+		 */
+		disk_io_size = min(lockend + 1, iocb->ki_pos + encoded->len) - start;
+		count = start + disk_io_size - iocb->ki_pos;
+		encoded->len = count;
+		encoded->unencoded_len = count;
+		disk_io_size = ALIGN(disk_io_size, fs_info->sectorsize);
+	}
+	free_extent_map(em);
+	em = NULL;
+
+	if (disk_bytenr == EXTENT_MAP_HOLE) {
+		unlock_extent_cached(io_tree, start, lockend, &cached_state);
+		btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
+		unlocked = true;
+		ret = iov_iter_zero(count, iter);
+		if (ret != count)
+			ret = -EFAULT;
+	} else {
+		ret = btrfs_encoded_read_regular(iocb, iter, start, lockend,
+						 &cached_state, disk_bytenr,
+						 disk_io_size, count,
+						 encoded->compression,
+						 &unlocked);
+	}
+
+out:
+	if (ret >= 0)
+		iocb->ki_pos += encoded->len;
+out_em:
+	free_extent_map(em);
+out_unlock_extent:
+	if (!unlocked)
+		unlock_extent_cached(io_tree, start, lockend, &cached_state);
+out_unlock_inode:
+	if (!unlocked)
+		btrfs_inode_unlock(&inode->vfs_inode, BTRFS_ILOCK_SHARED);
+	return ret;
+}
+
+ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			       const struct btrfs_ioctl_encoded_io_args *encoded)
+{
+	struct btrfs_inode *inode = BTRFS_I(file_inode(iocb->ki_filp));
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct extent_io_tree *io_tree = &inode->io_tree;
+	struct extent_changeset *data_reserved = NULL;
+	struct extent_state *cached_state = NULL;
+	int compression;
+	size_t orig_count;
+	u64 start, end;
+	u64 num_bytes, ram_bytes, disk_num_bytes;
+	unsigned long nr_pages, i;
+	struct page **pages;
+	struct btrfs_key ins;
+	bool extent_reserved = false;
+	struct extent_map *em;
+	ssize_t ret;
+
+	switch (encoded->compression) {
+	case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
+		compression = BTRFS_COMPRESS_ZLIB;
+		break;
+	case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
+		compression = BTRFS_COMPRESS_ZSTD;
+		break;
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
+		/* The sector size must match for LZO. */
+		if (encoded->compression -
+		    BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12 !=
+		    fs_info->sectorsize_bits)
+			return -EINVAL;
+		compression = BTRFS_COMPRESS_LZO;
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (encoded->encryption != BTRFS_ENCODED_IO_ENCRYPTION_NONE)
+		return -EINVAL;
+
+	orig_count = iov_iter_count(from);
+
+	/* The extent size must be sane. */
+	if (encoded->unencoded_len > BTRFS_MAX_UNCOMPRESSED ||
+	    orig_count > BTRFS_MAX_COMPRESSED || orig_count == 0)
+		return -EINVAL;
+
+	/*
+	 * The compressed data must be smaller than the decompressed data.
+	 *
+	 * It's of course possible for data to compress to larger or the same
+	 * size, but the buffered I/O path falls back to no compression for such
+	 * data, and we don't want to break any assumptions by creating these
+	 * extents.
+	 *
+	 * Note that this is less strict than the current check we have that the
+	 * compressed data must be at least one sector smaller than the
+	 * decompressed data. We only want to enforce the weaker requirement
+	 * from old kernels that it is at least one byte smaller.
+	 */
+	if (orig_count >= encoded->unencoded_len)
+		return -EINVAL;
+
+	/* The extent must start on a sector boundary. */
+	start = iocb->ki_pos;
+	if (!IS_ALIGNED(start, fs_info->sectorsize))
+		return -EINVAL;
+
+	/*
+	 * The extent must end on a sector boundary. However, we allow a write
+	 * which ends at or extends i_size to have an unaligned length; we round
+	 * up the extent size and set i_size to the unaligned end.
+	 */
+	if (start + encoded->len < inode->vfs_inode.i_size &&
+	    !IS_ALIGNED(start + encoded->len, fs_info->sectorsize))
+		return -EINVAL;
+
+	/* Finally, the offset in the unencoded data must be sector-aligned. */
+	if (!IS_ALIGNED(encoded->unencoded_offset, fs_info->sectorsize))
+		return -EINVAL;
+
+	num_bytes = ALIGN(encoded->len, fs_info->sectorsize);
+	ram_bytes = ALIGN(encoded->unencoded_len, fs_info->sectorsize);
+	end = start + num_bytes - 1;
+
+	/*
+	 * If the extent cannot be inline, the compressed data on disk must be
+	 * sector-aligned. For convenience, we extend it with zeroes if it
+	 * isn't.
+	 */
+	disk_num_bytes = ALIGN(orig_count, fs_info->sectorsize);
+	nr_pages = DIV_ROUND_UP(disk_num_bytes, PAGE_SIZE);
+	pages = kvcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL_ACCOUNT);
+	if (!pages)
+		return -ENOMEM;
+	for (i = 0; i < nr_pages; i++) {
+		size_t bytes = min_t(size_t, PAGE_SIZE, iov_iter_count(from));
+		char *kaddr;
+
+		pages[i] = alloc_page(GFP_KERNEL_ACCOUNT);
+		if (!pages[i]) {
+			ret = -ENOMEM;
+			goto out_pages;
+		}
+		kaddr = kmap(pages[i]);
+		if (copy_from_iter(kaddr, bytes, from) != bytes) {
+			kunmap(pages[i]);
+			ret = -EFAULT;
+			goto out_pages;
+		}
+		if (bytes < PAGE_SIZE)
+			memset(kaddr + bytes, 0, PAGE_SIZE - bytes);
+		kunmap(pages[i]);
+	}
+
+	for (;;) {
+		struct btrfs_ordered_extent *ordered;
+
+		ret = btrfs_wait_ordered_range(&inode->vfs_inode, start, num_bytes);
+		if (ret)
+			goto out_pages;
+		ret = invalidate_inode_pages2_range(inode->vfs_inode.i_mapping,
+						    start >> PAGE_SHIFT,
+						    end >> PAGE_SHIFT);
+		if (ret)
+			goto out_pages;
+		lock_extent_bits(io_tree, start, end, &cached_state);
+		ordered = btrfs_lookup_ordered_range(inode, start, num_bytes);
+		if (!ordered &&
+		    !filemap_range_has_page(inode->vfs_inode.i_mapping, start, end))
+			break;
+		if (ordered)
+			btrfs_put_ordered_extent(ordered);
+		unlock_extent_cached(io_tree, start, end, &cached_state);
+		cond_resched();
+	}
+
+	/*
+	 * We don't use the higher-level delalloc space functions because our
+	 * num_bytes and disk_num_bytes are different.
+	 */
+	ret = btrfs_alloc_data_chunk_ondemand(inode, disk_num_bytes);
+	if (ret)
+		goto out_unlock;
+	ret = btrfs_qgroup_reserve_data(inode, &data_reserved, start, num_bytes);
+	if (ret)
+		goto out_free_data_space;
+	ret = btrfs_delalloc_reserve_metadata(inode, num_bytes, disk_num_bytes);
+	if (ret)
+		goto out_qgroup_free_data;
+
+	/* Try an inline extent first. */
+	if (start == 0 && encoded->unencoded_len == encoded->len &&
+	    encoded->unencoded_offset == 0) {
+		ret = cow_file_range_inline(inode, encoded->len, orig_count,
+					    compression, pages, true);
+		if (ret <= 0) {
+			if (ret == 0)
+				ret = orig_count;
+			goto out_delalloc_release;
+		}
+	}
+
+	ret = btrfs_reserve_extent(root, disk_num_bytes, disk_num_bytes,
+				   disk_num_bytes, 0, 0, &ins, 1, 1);
+	if (ret)
+		goto out_delalloc_release;
+	extent_reserved = true;
+
+	em = create_io_em(inode, start, num_bytes,
+			  start - encoded->unencoded_offset, ins.objectid,
+			  ins.offset, ins.offset, ram_bytes, compression,
+			  BTRFS_ORDERED_COMPRESSED);
+	if (IS_ERR(em)) {
+		ret = PTR_ERR(em);
+		goto out_free_reserved;
+	}
+	free_extent_map(em);
+
+	ret = btrfs_add_ordered_extent(inode, start, num_bytes, ram_bytes,
+				       ins.objectid, ins.offset,
+				       encoded->unencoded_offset,
+				       (1 << BTRFS_ORDERED_ENCODED) |
+				       (1 << BTRFS_ORDERED_COMPRESSED),
+				       compression);
+	if (ret) {
+		btrfs_drop_extent_cache(inode, start, end, 0);
+		goto out_free_reserved;
+	}
+	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
+
+	if (start + encoded->len > inode->vfs_inode.i_size)
+		i_size_write(&inode->vfs_inode, start + encoded->len);
+
+	unlock_extent_cached(io_tree, start, end, &cached_state);
+
+	btrfs_delalloc_release_extents(inode, num_bytes);
+
+	if (btrfs_submit_compressed_write(inode, start, num_bytes, ins.objectid,
+					  ins.offset, pages, nr_pages, 0, NULL,
+					  false)) {
+		btrfs_writepage_endio_finish_ordered(inode, pages[0], start, end, 0);
+		ret = -EIO;
+		goto out_pages;
+	}
+	ret = orig_count;
+	goto out;
+
+out_free_reserved:
+	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
+	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
+out_delalloc_release:
+	btrfs_delalloc_release_extents(inode, num_bytes);
+	btrfs_delalloc_release_metadata(inode, disk_num_bytes, ret < 0);
+out_qgroup_free_data:
+	if (ret < 0)
+		btrfs_qgroup_free_data(inode, data_reserved, start, num_bytes);
+out_free_data_space:
+	/*
+	 * If btrfs_reserve_extent() succeeded, then we already decremented
+	 * bytes_may_use.
+	 */
+	if (!extent_reserved)
+		btrfs_free_reserved_data_space_noquota(fs_info, disk_num_bytes);
+out_unlock:
+	unlock_extent_cached(io_tree, start, end, &cached_state);
+out_pages:
+	for (i = 0; i < nr_pages; i++) {
+		if (pages[i])
+			__free_page(pages[i]);
+	}
+	kvfree(pages);
+out:
+	if (ret >= 0)
+		iocb->ki_pos += encoded->len;
+	return ret;
+}
+
 #ifdef CONFIG_SWAP
 /*
  * Add an entry indicating a block group or device which is pinned by a
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8d47ec5fc4f4..238cee5b5254 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -28,6 +28,7 @@
 #include <linux/iversion.h>
 #include <linux/fileattr.h>
 #include <linux/fsverity.h>
+#include <linux/sched/xacct.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "export.h"
@@ -88,6 +89,24 @@ struct btrfs_ioctl_send_args_32 {
 
 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
 			       struct btrfs_ioctl_send_args_32)
+
+struct btrfs_ioctl_encoded_io_args_32 {
+	compat_uptr_t iov;
+	compat_ulong_t iovcnt;
+	__s64 offset;
+	__u64 flags;
+	__u64 len;
+	__u64 unencoded_len;
+	__u64 unencoded_offset;
+	__u32 compression;
+	__u32 encryption;
+	__u8 reserved[64];
+};
+
+#define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
+				       struct btrfs_ioctl_encoded_io_args_32)
+#define BTRFS_IOC_ENCODED_WRITE_32 _IOW(BTRFS_IOCTL_MAGIC, 64, \
+					struct btrfs_ioctl_encoded_io_args_32)
 #endif
 
 /* Mask out flags that are inappropriate for the given type of inode. */
@@ -440,10 +459,8 @@ void btrfs_exclop_balance(struct btrfs_fs_info *fs_info,
 	}
 }
 
-static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
+static int btrfs_ioctl_getversion(struct inode *inode, int __user *arg)
 {
-	struct inode *inode = file_inode(file);
-
 	return put_user(inode->i_generation, arg);
 }
 
@@ -753,6 +770,13 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
 	struct btrfs_trans_handle *trans;
 	int ret;
 
+	/* We do not support snapshotting right now. */
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_warn(fs_info,
+			   "extent tree v2 doesn't support snapshotting yet");
+		return -EOPNOTSUPP;
+	}
+
 	if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
 		return -EINVAL;
 
@@ -1522,6 +1546,7 @@ next:
 }
 
 #define CLUSTER_SIZE	(SZ_256K)
+static_assert(IS_ALIGNED(CLUSTER_SIZE, PAGE_SIZE));
 
 /*
  * Defrag one contiguous target range.
@@ -1667,7 +1692,6 @@ static int defrag_one_cluster(struct btrfs_inode *inode,
 	LIST_HEAD(target_list);
 	int ret;
 
-	BUILD_BUG_ON(!IS_ALIGNED(CLUSTER_SIZE, PAGE_SIZE));
 	ret = defrag_collect_targets(inode, start, len, extent_thresh,
 				     newer_than, do_compress, false,
 				     &target_list, NULL);
@@ -1810,9 +1834,6 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra,
 		u64 last_scanned = cur;
 		u64 cluster_end;
 
-		/* The cluster size 256K should always be page aligned */
-		BUILD_BUG_ON(!IS_ALIGNED(CLUSTER_SIZE, PAGE_SIZE));
-
 		if (btrfs_defrag_cancelled(fs_info)) {
 			ret = -EAGAIN;
 			break;
@@ -2229,10 +2250,9 @@ free_args:
 	return ret;
 }
 
-static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
+static noinline int btrfs_ioctl_subvol_getflags(struct inode *inode,
 						void __user *arg)
 {
-	struct inode *inode = file_inode(file);
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	int ret = 0;
@@ -2562,12 +2582,11 @@ err:
 	return ret;
 }
 
-static noinline int btrfs_ioctl_tree_search(struct file *file,
-					   void __user *argp)
+static noinline int btrfs_ioctl_tree_search(struct inode *inode,
+					    void __user *argp)
 {
 	struct btrfs_ioctl_search_args __user *uargs;
 	struct btrfs_ioctl_search_key sk;
-	struct inode *inode;
 	int ret;
 	size_t buf_size;
 
@@ -2581,7 +2600,6 @@ static noinline int btrfs_ioctl_tree_search(struct file *file,
 
 	buf_size = sizeof(uargs->buf);
 
-	inode = file_inode(file);
 	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
 
 	/*
@@ -2596,12 +2614,11 @@ static noinline int btrfs_ioctl_tree_search(struct file *file,
 	return ret;
 }
 
-static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
+static noinline int btrfs_ioctl_tree_search_v2(struct inode *inode,
 					       void __user *argp)
 {
 	struct btrfs_ioctl_search_args_v2 __user *uarg;
 	struct btrfs_ioctl_search_args_v2 args;
-	struct inode *inode;
 	int ret;
 	size_t buf_size;
 	const size_t buf_limit = SZ_16M;
@@ -2620,7 +2637,6 @@ static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
 	if (buf_size > buf_limit)
 		buf_size = buf_limit;
 
-	inode = file_inode(file);
 	ret = search_ioctl(inode, &args.key, &buf_size,
 			   (char __user *)(&uarg->buf[0]));
 	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
@@ -2871,25 +2887,22 @@ out:
 	return ret;
 }
 
-static noinline int btrfs_ioctl_ino_lookup(struct file *file,
+static noinline int btrfs_ioctl_ino_lookup(struct btrfs_root *root,
 					   void __user *argp)
 {
 	struct btrfs_ioctl_ino_lookup_args *args;
-	struct inode *inode;
 	int ret = 0;
 
 	args = memdup_user(argp, sizeof(*args));
 	if (IS_ERR(args))
 		return PTR_ERR(args);
 
-	inode = file_inode(file);
-
 	/*
 	 * Unprivileged query to obtain the containing subvolume root id. The
 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
 	 */
 	if (args->treeid == 0)
-		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
+		args->treeid = root->root_key.objectid;
 
 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
 		args->name[0] = 0;
@@ -2901,7 +2914,7 @@ static noinline int btrfs_ioctl_ino_lookup(struct file *file,
 		goto out;
 	}
 
-	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
+	ret = btrfs_search_path_in_tree(root->fs_info,
 					args->treeid, args->objectid,
 					args->name);
 
@@ -2957,7 +2970,7 @@ static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
 }
 
 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
-static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
+static int btrfs_ioctl_get_subvol_info(struct inode *inode, void __user *argp)
 {
 	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
 	struct btrfs_fs_info *fs_info;
@@ -2969,7 +2982,6 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
 	struct extent_buffer *leaf;
 	unsigned long item_off;
 	unsigned long item_len;
-	struct inode *inode;
 	int slot;
 	int ret = 0;
 
@@ -2983,7 +2995,6 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
 		return -ENOMEM;
 	}
 
-	inode = file_inode(file);
 	fs_info = BTRFS_I(inode)->root->fs_info;
 
 	/* Get root_item of inode's subvolume */
@@ -3077,15 +3088,14 @@ out_free:
  * Return ROOT_REF information of the subvolume containing this inode
  * except the subvolume name.
  */
-static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
+static int btrfs_ioctl_get_subvol_rootref(struct btrfs_root *root,
+					  void __user *argp)
 {
 	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
 	struct btrfs_root_ref *rref;
-	struct btrfs_root *root;
 	struct btrfs_path *path;
 	struct btrfs_key key;
 	struct extent_buffer *leaf;
-	struct inode *inode;
 	u64 objectid;
 	int slot;
 	int ret;
@@ -3101,15 +3111,13 @@ static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
 		return PTR_ERR(rootrefs);
 	}
 
-	inode = file_inode(file);
-	root = BTRFS_I(inode)->root->fs_info->tree_root;
-	objectid = BTRFS_I(inode)->root->root_key.objectid;
-
+	objectid = root->root_key.objectid;
 	key.objectid = objectid;
 	key.type = BTRFS_ROOT_REF_KEY;
 	key.offset = rootrefs->min_treeid;
 	found = 0;
 
+	root = root->fs_info->tree_root;
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0) {
 		goto out;
@@ -3189,6 +3197,13 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
 	int err = 0;
 	bool destroy_parent = false;
 
+	/* We don't support snapshots with extent tree v2 yet. */
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info,
+			  "extent tree v2 doesn't support snapshot deletion yet");
+		return -EOPNOTSUPP;
+	}
+
 	if (destroy_v2) {
 		vol_args2 = memdup_user(arg, sizeof(*vol_args2));
 		if (IS_ERR(vol_args2))
@@ -3464,6 +3479,11 @@ static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info, "device add not supported on extent tree v2 yet");
+		return -EINVAL;
+	}
+
 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD)) {
 		if (!btrfs_exclop_start_try_lock(fs_info, BTRFS_EXCLOP_DEV_ADD))
 			return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
@@ -3989,6 +4009,11 @@ static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info, "scrub is not supported on extent tree v2 yet");
+		return -EINVAL;
+	}
+
 	sa = memdup_user(arg, sizeof(*sa));
 	if (IS_ERR(sa))
 		return PTR_ERR(sa);
@@ -4088,6 +4113,11 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info, "device replace not supported on extent tree v2 yet");
+		return -EINVAL;
+	}
+
 	p = memdup_user(arg, sizeof(*p));
 	if (IS_ERR(p))
 		return PTR_ERR(p);
@@ -5149,7 +5179,7 @@ out_drop_write:
 	return ret;
 }
 
-static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
+static int _btrfs_ioctl_send(struct inode *inode, void __user *argp, bool compat)
 {
 	struct btrfs_ioctl_send_args *arg;
 	int ret;
@@ -5179,11 +5209,194 @@ static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
 		if (IS_ERR(arg))
 			return PTR_ERR(arg);
 	}
-	ret = btrfs_ioctl_send(file, arg);
+	ret = btrfs_ioctl_send(inode, arg);
 	kfree(arg);
 	return ret;
 }
 
+static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp,
+				    bool compat)
+{
+	struct btrfs_ioctl_encoded_io_args args = { 0 };
+	size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args,
+					     flags);
+	size_t copy_end;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	loff_t pos;
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		ret = -EPERM;
+		goto out_acct;
+	}
+
+	if (compat) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+		struct btrfs_ioctl_encoded_io_args_32 args32;
+
+		copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32,
+				       flags);
+		if (copy_from_user(&args32, argp, copy_end)) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+		args.iov = compat_ptr(args32.iov);
+		args.iovcnt = args32.iovcnt;
+		args.offset = args32.offset;
+		args.flags = args32.flags;
+#else
+		return -ENOTTY;
+#endif
+	} else {
+		copy_end = copy_end_kernel;
+		if (copy_from_user(&args, argp, copy_end)) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+	}
+	if (args.flags != 0) {
+		ret = -EINVAL;
+		goto out_acct;
+	}
+
+	ret = import_iovec(READ, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
+			   &iov, &iter);
+	if (ret < 0)
+		goto out_acct;
+
+	if (iov_iter_count(&iter) == 0) {
+		ret = 0;
+		goto out_iov;
+	}
+	pos = args.offset;
+	ret = rw_verify_area(READ, file, &pos, args.len);
+	if (ret < 0)
+		goto out_iov;
+
+	init_sync_kiocb(&kiocb, file);
+	kiocb.ki_pos = pos;
+
+	ret = btrfs_encoded_read(&kiocb, &iter, &args);
+	if (ret >= 0) {
+		fsnotify_access(file);
+		if (copy_to_user(argp + copy_end,
+				 (char *)&args + copy_end_kernel,
+				 sizeof(args) - copy_end_kernel))
+			ret = -EFAULT;
+	}
+
+out_iov:
+	kfree(iov);
+out_acct:
+	if (ret > 0)
+		add_rchar(current, ret);
+	inc_syscr(current);
+	return ret;
+}
+
+static int btrfs_ioctl_encoded_write(struct file *file, void __user *argp, bool compat)
+{
+	struct btrfs_ioctl_encoded_io_args args;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	loff_t pos;
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		ret = -EPERM;
+		goto out_acct;
+	}
+
+	if (!(file->f_mode & FMODE_WRITE)) {
+		ret = -EBADF;
+		goto out_acct;
+	}
+
+	if (compat) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+		struct btrfs_ioctl_encoded_io_args_32 args32;
+
+		if (copy_from_user(&args32, argp, sizeof(args32))) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+		args.iov = compat_ptr(args32.iov);
+		args.iovcnt = args32.iovcnt;
+		args.offset = args32.offset;
+		args.flags = args32.flags;
+		args.len = args32.len;
+		args.unencoded_len = args32.unencoded_len;
+		args.unencoded_offset = args32.unencoded_offset;
+		args.compression = args32.compression;
+		args.encryption = args32.encryption;
+		memcpy(args.reserved, args32.reserved, sizeof(args.reserved));
+#else
+		return -ENOTTY;
+#endif
+	} else {
+		if (copy_from_user(&args, argp, sizeof(args))) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+	}
+
+	ret = -EINVAL;
+	if (args.flags != 0)
+		goto out_acct;
+	if (memchr_inv(args.reserved, 0, sizeof(args.reserved)))
+		goto out_acct;
+	if (args.compression == BTRFS_ENCODED_IO_COMPRESSION_NONE &&
+	    args.encryption == BTRFS_ENCODED_IO_ENCRYPTION_NONE)
+		goto out_acct;
+	if (args.compression >= BTRFS_ENCODED_IO_COMPRESSION_TYPES ||
+	    args.encryption >= BTRFS_ENCODED_IO_ENCRYPTION_TYPES)
+		goto out_acct;
+	if (args.unencoded_offset > args.unencoded_len)
+		goto out_acct;
+	if (args.len > args.unencoded_len - args.unencoded_offset)
+		goto out_acct;
+
+	ret = import_iovec(WRITE, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
+			   &iov, &iter);
+	if (ret < 0)
+		goto out_acct;
+
+	file_start_write(file);
+
+	if (iov_iter_count(&iter) == 0) {
+		ret = 0;
+		goto out_end_write;
+	}
+	pos = args.offset;
+	ret = rw_verify_area(WRITE, file, &pos, args.len);
+	if (ret < 0)
+		goto out_end_write;
+
+	init_sync_kiocb(&kiocb, file);
+	ret = kiocb_set_rw_flags(&kiocb, 0);
+	if (ret)
+		goto out_end_write;
+	kiocb.ki_pos = pos;
+
+	ret = btrfs_do_write_iter(&kiocb, &iter, &args);
+	if (ret > 0)
+		fsnotify_modify(file);
+
+out_end_write:
+	file_end_write(file);
+	kfree(iov);
+out_acct:
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -5194,7 +5407,7 @@ long btrfs_ioctl(struct file *file, unsigned int
 
 	switch (cmd) {
 	case FS_IOC_GETVERSION:
-		return btrfs_ioctl_getversion(file, argp);
+		return btrfs_ioctl_getversion(inode, argp);
 	case FS_IOC_GETFSLABEL:
 		return btrfs_ioctl_get_fslabel(fs_info, argp);
 	case FS_IOC_SETFSLABEL:
@@ -5214,7 +5427,7 @@ long btrfs_ioctl(struct file *file, unsigned int
 	case BTRFS_IOC_SNAP_DESTROY_V2:
 		return btrfs_ioctl_snap_destroy(file, argp, true);
 	case BTRFS_IOC_SUBVOL_GETFLAGS:
-		return btrfs_ioctl_subvol_getflags(file, argp);
+		return btrfs_ioctl_subvol_getflags(inode, argp);
 	case BTRFS_IOC_SUBVOL_SETFLAGS:
 		return btrfs_ioctl_subvol_setflags(file, argp);
 	case BTRFS_IOC_DEFAULT_SUBVOL:
@@ -5238,11 +5451,11 @@ long btrfs_ioctl(struct file *file, unsigned int
 	case BTRFS_IOC_BALANCE:
 		return btrfs_ioctl_balance(file, NULL);
 	case BTRFS_IOC_TREE_SEARCH:
-		return btrfs_ioctl_tree_search(file, argp);
+		return btrfs_ioctl_tree_search(inode, argp);
 	case BTRFS_IOC_TREE_SEARCH_V2:
-		return btrfs_ioctl_tree_search_v2(file, argp);
+		return btrfs_ioctl_tree_search_v2(inode, argp);
 	case BTRFS_IOC_INO_LOOKUP:
-		return btrfs_ioctl_ino_lookup(file, argp);
+		return btrfs_ioctl_ino_lookup(root, argp);
 	case BTRFS_IOC_INO_PATHS:
 		return btrfs_ioctl_ino_to_path(root, argp);
 	case BTRFS_IOC_LOGICAL_INO:
@@ -5289,10 +5502,10 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_set_received_subvol_32(file, argp);
 #endif
 	case BTRFS_IOC_SEND:
-		return _btrfs_ioctl_send(file, argp, false);
+		return _btrfs_ioctl_send(inode, argp, false);
 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
 	case BTRFS_IOC_SEND_32:
-		return _btrfs_ioctl_send(file, argp, true);
+		return _btrfs_ioctl_send(inode, argp, true);
 #endif
 	case BTRFS_IOC_GET_DEV_STATS:
 		return btrfs_ioctl_get_dev_stats(fs_info, argp);
@@ -5319,15 +5532,25 @@ long btrfs_ioctl(struct file *file, unsigned int
 	case BTRFS_IOC_SET_FEATURES:
 		return btrfs_ioctl_set_features(file, argp);
 	case BTRFS_IOC_GET_SUBVOL_INFO:
-		return btrfs_ioctl_get_subvol_info(file, argp);
+		return btrfs_ioctl_get_subvol_info(inode, argp);
 	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
-		return btrfs_ioctl_get_subvol_rootref(file, argp);
+		return btrfs_ioctl_get_subvol_rootref(root, argp);
 	case BTRFS_IOC_INO_LOOKUP_USER:
 		return btrfs_ioctl_ino_lookup_user(file, argp);
 	case FS_IOC_ENABLE_VERITY:
 		return fsverity_ioctl_enable(file, (const void __user *)argp);
 	case FS_IOC_MEASURE_VERITY:
 		return fsverity_ioctl_measure(file, argp);
+	case BTRFS_IOC_ENCODED_READ:
+		return btrfs_ioctl_encoded_read(file, argp, false);
+	case BTRFS_IOC_ENCODED_WRITE:
+		return btrfs_ioctl_encoded_write(file, argp, false);
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+	case BTRFS_IOC_ENCODED_READ_32:
+		return btrfs_ioctl_encoded_read(file, argp, true);
+	case BTRFS_IOC_ENCODED_WRITE_32:
+		return btrfs_ioctl_encoded_write(file, argp, true);
+#endif
 	}
 
 	return -ENOTTY;
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index e6e28a9c7987..430ad36b8b08 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -55,6 +55,9 @@
  * 0x1000   | SegHdr N+1| Data payload N+1 ...                |
  */
 
+#define WORKSPACE_BUF_LENGTH	(lzo1x_worst_compress(PAGE_SIZE))
+#define WORKSPACE_CBUF_LENGTH	(lzo1x_worst_compress(PAGE_SIZE))
+
 struct workspace {
 	void *mem;
 	void *buf;	/* where decompressed data goes */
@@ -83,8 +86,8 @@ struct list_head *lzo_alloc_workspace(unsigned int level)
 		return ERR_PTR(-ENOMEM);
 
 	workspace->mem = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
-	workspace->buf = kvmalloc(lzo1x_worst_compress(PAGE_SIZE), GFP_KERNEL);
-	workspace->cbuf = kvmalloc(lzo1x_worst_compress(PAGE_SIZE), GFP_KERNEL);
+	workspace->buf = kvmalloc(WORKSPACE_BUF_LENGTH, GFP_KERNEL);
+	workspace->cbuf = kvmalloc(WORKSPACE_CBUF_LENGTH, GFP_KERNEL);
 	if (!workspace->mem || !workspace->buf || !workspace->cbuf)
 		goto fail;
 
@@ -380,7 +383,7 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 		kunmap(cur_page);
 		cur_in += LZO_LEN;
 
-		if (seg_len > lzo1x_worst_compress(PAGE_SIZE)) {
+		if (seg_len > WORKSPACE_CBUF_LENGTH) {
 			/*
 			 * seg_len shouldn't be larger than we have allocated
 			 * for workspace->cbuf
@@ -433,7 +436,7 @@ int lzo_decompress(struct list_head *ws, unsigned char *data_in,
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
 	size_t in_len;
 	size_t out_len;
-	size_t max_segment_len = lzo1x_worst_compress(PAGE_SIZE);
+	size_t max_segment_len = WORKSPACE_BUF_LENGTH;
 	int ret = 0;
 	char *kaddr;
 	unsigned long bytes;
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 6b51fd2ec5ac..1957b14b329a 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -143,16 +143,28 @@ static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 	return ret;
 }
 
-/*
- * Allocate and add a new ordered_extent into the per-inode tree.
+/**
+ * Add an ordered extent to the per-inode tree.
+ *
+ * @inode:           Inode that this extent is for.
+ * @file_offset:     Logical offset in file where the extent starts.
+ * @num_bytes:       Logical length of extent in file.
+ * @ram_bytes:       Full length of unencoded data.
+ * @disk_bytenr:     Offset of extent on disk.
+ * @disk_num_bytes:  Size of extent on disk.
+ * @offset:          Offset into unencoded data where file data starts.
+ * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
+ * @compress_type:   Compression algorithm used for data.
  *
- * The tree is given a single reference on the ordered extent that was
- * inserted.
+ * Most of these parameters correspond to &struct btrfs_file_extent_item. The
+ * tree is given a single reference on the ordered extent that was inserted.
+ *
+ * Return: 0 or -ENOMEM.
  */
-static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int type, int dio,
-				      int compress_type)
+int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
+			     u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
+			     u64 disk_num_bytes, u64 offset, unsigned flags,
+			     int compress_type)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -161,7 +173,8 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	struct btrfs_ordered_extent *entry;
 	int ret;
 
-	if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) {
+	if (flags &
+	    ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 		/* For nocow write, we can release the qgroup rsv right now */
 		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 		if (ret < 0)
@@ -181,9 +194,11 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 		return -ENOMEM;
 
 	entry->file_offset = file_offset;
-	entry->disk_bytenr = disk_bytenr;
 	entry->num_bytes = num_bytes;
+	entry->ram_bytes = ram_bytes;
+	entry->disk_bytenr = disk_bytenr;
 	entry->disk_num_bytes = disk_num_bytes;
+	entry->offset = offset;
 	entry->bytes_left = num_bytes;
 	entry->inode = igrab(&inode->vfs_inode);
 	entry->compress_type = compress_type;
@@ -191,18 +206,12 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	entry->qgroup_rsv = ret;
 	entry->physical = (u64)-1;
 
-	ASSERT(type == BTRFS_ORDERED_REGULAR ||
-	       type == BTRFS_ORDERED_NOCOW ||
-	       type == BTRFS_ORDERED_PREALLOC ||
-	       type == BTRFS_ORDERED_COMPRESSED);
-	set_bit(type, &entry->flags);
+	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
+	entry->flags = flags;
 
 	percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 				 fs_info->delalloc_batch);
 
-	if (dio)
-		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
-
 	/* one ref for the tree */
 	refcount_set(&entry->refs, 1);
 	init_waitqueue_head(&entry->wait);
@@ -247,41 +256,6 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	return 0;
 }
 
-int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
-			     int type)
-{
-	ASSERT(type == BTRFS_ORDERED_REGULAR ||
-	       type == BTRFS_ORDERED_NOCOW ||
-	       type == BTRFS_ORDERED_PREALLOC);
-	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
-					  num_bytes, disk_num_bytes, type, 0,
-					  BTRFS_COMPRESS_NONE);
-}
-
-int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
-				 u64 disk_bytenr, u64 num_bytes,
-				 u64 disk_num_bytes, int type)
-{
-	ASSERT(type == BTRFS_ORDERED_REGULAR ||
-	       type == BTRFS_ORDERED_NOCOW ||
-	       type == BTRFS_ORDERED_PREALLOC);
-	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
-					  num_bytes, disk_num_bytes, type, 1,
-					  BTRFS_COMPRESS_NONE);
-}
-
-int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int compress_type)
-{
-	ASSERT(compress_type != BTRFS_COMPRESS_NONE);
-	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
-					  num_bytes, disk_num_bytes,
-					  BTRFS_ORDERED_COMPRESSED, 0,
-					  compress_type);
-}
-
 /*
  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
  * when an ordered extent is finished.  If the list covers more than one
@@ -548,9 +522,15 @@ void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 	spin_lock(&btrfs_inode->lock);
 	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 	spin_unlock(&btrfs_inode->lock);
-	if (root != fs_info->tree_root)
-		btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
-						false);
+	if (root != fs_info->tree_root) {
+		u64 release;
+
+		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
+			release = entry->disk_num_bytes;
+		else
+			release = entry->num_bytes;
+		btrfs_delalloc_release_metadata(btrfs_inode, release, false);
+	}
 
 	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 				 fs_info->delalloc_batch);
@@ -1052,42 +1032,18 @@ static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
 	u64 file_offset = ordered->file_offset + pos;
 	u64 disk_bytenr = ordered->disk_bytenr + pos;
-	u64 num_bytes = len;
-	u64 disk_num_bytes = len;
-	int type;
-	unsigned long flags_masked = ordered->flags & ~(1 << BTRFS_ORDERED_DIRECT);
-	int compress_type = ordered->compress_type;
-	unsigned long weight;
-	int ret;
-
-	weight = hweight_long(flags_masked);
-	WARN_ON_ONCE(weight > 1);
-	if (!weight)
-		type = 0;
-	else
-		type = __ffs(flags_masked);
+	unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
 
 	/*
-	 * The splitting extent is already counted and will be added again
-	 * in btrfs_add_ordered_extent_*(). Subtract num_bytes to avoid
-	 * double counting.
+	 * The splitting extent is already counted and will be added again in
+	 * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
 	 */
-	percpu_counter_add_batch(&fs_info->ordered_bytes, -num_bytes,
+	percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
 				 fs_info->delalloc_batch);
-	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) {
-		WARN_ON_ONCE(1);
-		ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode),
-				file_offset, disk_bytenr, num_bytes,
-				disk_num_bytes, compress_type);
-	} else if (test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
-		ret = btrfs_add_ordered_extent_dio(BTRFS_I(inode), file_offset,
-				disk_bytenr, num_bytes, disk_num_bytes, type);
-	} else {
-		ret = btrfs_add_ordered_extent(BTRFS_I(inode), file_offset,
-				disk_bytenr, num_bytes, disk_num_bytes, type);
-	}
-
-	return ret;
+	WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
+	return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
+					disk_bytenr, len, 0, flags,
+					ordered->compress_type);
 }
 
 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 4194e960ff61..ecad67a2c745 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -74,8 +74,18 @@ enum {
 	BTRFS_ORDERED_LOGGED_CSUM,
 	/* We wait for this extent to complete in the current transaction */
 	BTRFS_ORDERED_PENDING,
+	/* BTRFS_IOC_ENCODED_WRITE */
+	BTRFS_ORDERED_ENCODED,
 };
 
+/* BTRFS_ORDERED_* flags that specify the type of the extent. */
+#define BTRFS_ORDERED_TYPE_FLAGS ((1UL << BTRFS_ORDERED_REGULAR) |	\
+				  (1UL << BTRFS_ORDERED_NOCOW) |	\
+				  (1UL << BTRFS_ORDERED_PREALLOC) |	\
+				  (1UL << BTRFS_ORDERED_COMPRESSED) |	\
+				  (1UL << BTRFS_ORDERED_DIRECT) |	\
+				  (1UL << BTRFS_ORDERED_ENCODED))
+
 struct btrfs_ordered_extent {
 	/* logical offset in the file */
 	u64 file_offset;
@@ -84,9 +94,11 @@ struct btrfs_ordered_extent {
 	 * These fields directly correspond to the same fields in
 	 * btrfs_file_extent_item.
 	 */
-	u64 disk_bytenr;
 	u64 num_bytes;
+	u64 ram_bytes;
+	u64 disk_bytenr;
 	u64 disk_num_bytes;
+	u64 offset;
 
 	/* number of bytes that still need writing */
 	u64 bytes_left;
@@ -179,14 +191,9 @@ bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 				    struct btrfs_ordered_extent **cached,
 				    u64 file_offset, u64 io_size);
 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
-			     int type);
-int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
-				 u64 disk_bytenr, u64 num_bytes,
-				 u64 disk_num_bytes, int type);
-int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int compress_type);
+			     u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
+			     u64 disk_num_bytes, u64 offset, unsigned flags,
+			     int compress_type);
 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 			   struct btrfs_ordered_sum *sum);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
index 0775ae9f4419..dd8777872143 100644
--- a/fs/btrfs/print-tree.c
+++ b/fs/btrfs/print-tree.c
@@ -23,6 +23,7 @@ static const struct root_name_map root_map[] = {
 	{ BTRFS_QUOTA_TREE_OBJECTID,		"QUOTA_TREE"		},
 	{ BTRFS_UUID_TREE_OBJECTID,		"UUID_TREE"		},
 	{ BTRFS_FREE_SPACE_TREE_OBJECTID,	"FREE_SPACE_TREE"	},
+	{ BTRFS_BLOCK_GROUP_TREE_OBJECTID,	"BLOCK_GROUP_TREE"	},
 	{ BTRFS_DATA_RELOC_TREE_OBJECTID,	"DATA_RELOC_TREE"	},
 };
 
@@ -391,9 +392,9 @@ void btrfs_print_tree(struct extent_buffer *c, bool follow)
 				       btrfs_header_owner(c),
 				       btrfs_node_ptr_generation(c, i),
 				       level - 1, &first_key);
-		if (IS_ERR(next)) {
+		if (IS_ERR(next))
 			continue;
-		} else if (!extent_buffer_uptodate(next)) {
+		if (!extent_buffer_uptodate(next)) {
 			free_extent_buffer(next);
 			continue;
 		}
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 30d42ea655ce..1866b1f0da01 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -25,18 +25,6 @@
 #include "sysfs.h"
 #include "tree-mod-log.h"
 
-/* TODO XXX FIXME
- *  - subvol delete -> delete when ref goes to 0? delete limits also?
- *  - reorganize keys
- *  - compressed
- *  - sync
- *  - copy also limits on subvol creation
- *  - limit
- *  - caches for ulists
- *  - performance benchmarks
- *  - check all ioctl parameters
- */
-
 /*
  * Helpers to access qgroup reservation
  *
@@ -258,16 +246,19 @@ static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid)
 	return 0;
 }
 
-/* must be called with qgroup_lock held */
-static int add_relation_rb(struct btrfs_fs_info *fs_info,
-			   u64 memberid, u64 parentid)
+/*
+ * Add relation specified by two qgroups.
+ *
+ * Must be called with qgroup_lock held.
+ *
+ * Return: 0        on success
+ *         -ENOENT  if one of the qgroups is NULL
+ *         <0       other errors
+ */
+static int __add_relation_rb(struct btrfs_qgroup *member, struct btrfs_qgroup *parent)
 {
-	struct btrfs_qgroup *member;
-	struct btrfs_qgroup *parent;
 	struct btrfs_qgroup_list *list;
 
-	member = find_qgroup_rb(fs_info, memberid);
-	parent = find_qgroup_rb(fs_info, parentid);
 	if (!member || !parent)
 		return -ENOENT;
 
@@ -283,7 +274,27 @@ static int add_relation_rb(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-/* must be called with qgroup_lock held */
+/*
+ * Add relation specified by two qgoup ids.
+ *
+ * Must be called with qgroup_lock held.
+ *
+ * Return: 0        on success
+ *         -ENOENT  if one of the ids does not exist
+ *         <0       other errors
+ */
+static int add_relation_rb(struct btrfs_fs_info *fs_info, u64 memberid, u64 parentid)
+{
+	struct btrfs_qgroup *member;
+	struct btrfs_qgroup *parent;
+
+	member = find_qgroup_rb(fs_info, memberid);
+	parent = find_qgroup_rb(fs_info, parentid);
+
+	return __add_relation_rb(member, parent);
+}
+
+/* Must be called with qgroup_lock held */
 static int del_relation_rb(struct btrfs_fs_info *fs_info,
 			   u64 memberid, u64 parentid)
 {
@@ -948,6 +959,12 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
 	 */
 	lockdep_assert_held_write(&fs_info->subvol_sem);
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info,
+			  "qgroups are currently unsupported in extent tree v2");
+		return -EINVAL;
+	}
+
 	mutex_lock(&fs_info->qgroup_ioctl_lock);
 	if (fs_info->quota_root)
 		goto out;
@@ -1451,7 +1468,7 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
 	}
 
 	spin_lock(&fs_info->qgroup_lock);
-	ret = add_relation_rb(fs_info, src, dst);
+	ret = __add_relation_rb(member, parent);
 	if (ret < 0) {
 		spin_unlock(&fs_info->qgroup_lock);
 		goto out;
@@ -3268,7 +3285,8 @@ out:
 static bool rescan_should_stop(struct btrfs_fs_info *fs_info)
 {
 	return btrfs_fs_closing(fs_info) ||
-		test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
+		test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state) ||
+		!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 }
 
 static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
@@ -3298,11 +3316,9 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
 			err = PTR_ERR(trans);
 			break;
 		}
-		if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
-			err = -EINTR;
-		} else {
-			err = qgroup_rescan_leaf(trans, path);
-		}
+
+		err = qgroup_rescan_leaf(trans, path);
+
 		if (err > 0)
 			btrfs_commit_transaction(trans);
 		else
@@ -3316,7 +3332,7 @@ out:
 	if (err > 0 &&
 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) {
 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
-	} else if (err < 0) {
+	} else if (err < 0 || stopped) {
 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 	}
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index a3930da4eb3f..04a88bfe4fcf 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -277,7 +277,7 @@ copy_inline_extent:
 						  path->slots[0]),
 			    size);
 	btrfs_update_inode_bytes(BTRFS_I(dst), datal, drop_args.bytes_found);
-	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(dst)->runtime_flags);
+	btrfs_set_inode_full_sync(BTRFS_I(dst));
 	ret = btrfs_inode_set_file_extent_range(BTRFS_I(dst), 0, aligned_end);
 out:
 	if (!ret && !trans) {
@@ -494,7 +494,8 @@ process_slot:
 					&clone_info, &trans);
 			if (ret)
 				goto out;
-		} else if (type == BTRFS_FILE_EXTENT_INLINE) {
+		} else {
+			ASSERT(type == BTRFS_FILE_EXTENT_INLINE);
 			/*
 			 * Inline extents always have to start at file offset 0
 			 * and can never be bigger then the sector size. We can
@@ -505,8 +506,12 @@ process_slot:
 			 */
 			ASSERT(key.offset == 0);
 			ASSERT(datal <= fs_info->sectorsize);
-			if (key.offset != 0 || datal > fs_info->sectorsize)
-				return -EUCLEAN;
+			if (WARN_ON(type != BTRFS_FILE_EXTENT_INLINE) ||
+			    WARN_ON(key.offset != 0) ||
+			    WARN_ON(datal > fs_info->sectorsize)) {
+				ret = -EUCLEAN;
+				goto out;
+			}
 
 			ret = clone_copy_inline_extent(inode, path, &new_key,
 						       drop_start, datal, size,
@@ -518,17 +523,22 @@ process_slot:
 		btrfs_release_path(path);
 
 		/*
-		 * If this is a new extent update the last_reflink_trans of both
-		 * inodes. This is used by fsync to make sure it does not log
-		 * multiple checksum items with overlapping ranges. For older
-		 * extents we don't need to do it since inode logging skips the
-		 * checksums for older extents. Also ignore holes and inline
-		 * extents because they don't have checksums in the csum tree.
+		 * Whenever we share an extent we update the last_reflink_trans
+		 * of each inode to the current transaction. This is needed to
+		 * make sure fsync does not log multiple checksum items with
+		 * overlapping ranges (because some extent items might refer
+		 * only to sections of the original extent). For the destination
+		 * inode we do this regardless of the generation of the extents
+		 * or even if they are inline extents or explicit holes, to make
+		 * sure a full fsync does not skip them. For the source inode,
+		 * we only need to update last_reflink_trans in case it's a new
+		 * extent that is not a hole or an inline extent, to deal with
+		 * the checksums problem on fsync.
 		 */
-		if (extent_gen == trans->transid && disko > 0) {
+		if (extent_gen == trans->transid && disko > 0)
 			BTRFS_I(src)->last_reflink_trans = trans->transid;
-			BTRFS_I(inode)->last_reflink_trans = trans->transid;
-		}
+
+		BTRFS_I(inode)->last_reflink_trans = trans->transid;
 
 		last_dest_end = ALIGN(new_key.offset + datal,
 				      fs_info->sectorsize);
@@ -575,8 +585,7 @@ process_slot:
 		 * replaced file extent items.
 		 */
 		if (last_dest_end >= i_size_read(inode))
-			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
-				&BTRFS_I(inode)->runtime_flags);
+			btrfs_set_inode_full_sync(BTRFS_I(inode));
 
 		ret = btrfs_replace_file_extents(BTRFS_I(inode), path,
 				last_dest_end, destoff + len - 1, NULL, &trans);
@@ -772,9 +781,7 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
 		if (btrfs_root_readonly(root_out))
 			return -EROFS;
 
-		if (file_in->f_path.mnt != file_out->f_path.mnt ||
-		    inode_in->i_sb != inode_out->i_sb)
-			return -EXDEV;
+		ASSERT(inode_in->i_sb == inode_out->i_sb);
 	}
 
 	/* Don't make the dst file partly checksummed */
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 9d8054839782..fdc2c4b411f0 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2599,9 +2599,9 @@ static int get_tree_block_key(struct btrfs_fs_info *fs_info,
 
 	eb = read_tree_block(fs_info, block->bytenr, block->owner,
 			     block->key.offset, block->level, NULL);
-	if (IS_ERR(eb)) {
+	if (IS_ERR(eb))
 		return PTR_ERR(eb);
-	} else if (!extent_buffer_uptodate(eb)) {
+	if (!extent_buffer_uptodate(eb)) {
 		free_extent_buffer(eb);
 		return -EIO;
 	}
@@ -2997,7 +2997,7 @@ static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
 
 		/* Reserve metadata for this range */
 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-						      clamped_len);
+						      clamped_len, clamped_len);
 		if (ret)
 			goto release_page;
 
@@ -4123,9 +4123,8 @@ static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
  * this function resumes merging reloc trees with corresponding fs trees.
  * this is important for keeping the sharing of tree blocks
  */
-int btrfs_recover_relocation(struct btrfs_root *root)
+int btrfs_recover_relocation(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	LIST_HEAD(reloc_roots);
 	struct btrfs_key key;
 	struct btrfs_root *fs_root;
@@ -4166,7 +4165,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
 		    key.type != BTRFS_ROOT_ITEM_KEY)
 			break;
 
-		reloc_root = btrfs_read_tree_root(root, &key);
+		reloc_root = btrfs_read_tree_root(fs_info->tree_root, &key);
 		if (IS_ERR(reloc_root)) {
 			err = PTR_ERR(reloc_root);
 			goto out;
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 2e9a322773f2..11089568b287 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3190,7 +3190,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	u64 generation;
 	int mirror_num;
 	struct btrfs_key key;
-	u64 increment = map->stripe_len;
+	u64 increment;
 	u64 offset;
 	u64 extent_logical;
 	u64 extent_physical;
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 201eb2628aea..7d1642937274 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -528,17 +528,12 @@ out:
 
 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
 {
-	int ret;
-
 	p->reversed = from->reversed;
 	fs_path_reset(p);
 
-	ret = fs_path_add_path(p, from);
-
-	return ret;
+	return fs_path_add_path(p, from);
 }
 
-
 static void fs_path_unreverse(struct fs_path *p)
 {
 	char *tmp;
@@ -7477,10 +7472,10 @@ static void dedupe_in_progress_warn(const struct btrfs_root *root)
 		      root->root_key.objectid, root->dedupe_in_progress);
 }
 
-long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
+long btrfs_ioctl_send(struct inode *inode, struct btrfs_ioctl_send_args *arg)
 {
 	int ret = 0;
-	struct btrfs_root *send_root = BTRFS_I(file_inode(mnt_file))->root;
+	struct btrfs_root *send_root = BTRFS_I(inode)->root;
 	struct btrfs_fs_info *fs_info = send_root->fs_info;
 	struct btrfs_root *clone_root;
 	struct send_ctx *sctx = NULL;
diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
index 23bcefc84e49..08602fdd600a 100644
--- a/fs/btrfs/send.h
+++ b/fs/btrfs/send.h
@@ -126,7 +126,7 @@ enum {
 #define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1)
 
 #ifdef __KERNEL__
-long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg);
+long btrfs_ioctl_send(struct inode *inode, struct btrfs_ioctl_send_args *arg);
 #endif
 
 #endif
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 294242c194d8..b87931a458eb 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -737,6 +737,8 @@ static bool need_preemptive_reclaim(struct btrfs_fs_info *fs_info,
 	u64 thresh = div_factor_fine(space_info->total_bytes, 90);
 	u64 used;
 
+	lockdep_assert_held(&space_info->lock);
+
 	/* If we're just plain full then async reclaim just slows us down. */
 	if ((space_info->bytes_used + space_info->bytes_reserved +
 	     global_rsv_size) >= thresh)
@@ -1061,7 +1063,6 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work)
 			trans_rsv->reserved;
 		if (block_rsv_size < space_info->bytes_may_use)
 			delalloc_size = space_info->bytes_may_use - block_rsv_size;
-		spin_unlock(&space_info->lock);
 
 		/*
 		 * We don't want to include the global_rsv in our calculation,
@@ -1092,6 +1093,8 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work)
 			flush = FLUSH_DELAYED_REFS_NR;
 		}
 
+		spin_unlock(&space_info->lock);
+
 		/*
 		 * We don't want to reclaim everything, just a portion, so scale
 		 * down the to_reclaim by 1/4.  If it takes us down to 0,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4d947ba32da9..b228efe8ab6e 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -66,6 +66,52 @@ static struct file_system_type btrfs_root_fs_type;
 
 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
 
+#ifdef CONFIG_PRINTK
+
+#define STATE_STRING_PREFACE	": state "
+#define STATE_STRING_BUF_LEN	(sizeof(STATE_STRING_PREFACE) + BTRFS_FS_STATE_COUNT)
+
+/*
+ * Characters to print to indicate error conditions or uncommon filesystem sate.
+ * RO is not an error.
+ */
+static const char fs_state_chars[] = {
+	[BTRFS_FS_STATE_ERROR]			= 'E',
+	[BTRFS_FS_STATE_REMOUNTING]		= 'M',
+	[BTRFS_FS_STATE_RO]			= 0,
+	[BTRFS_FS_STATE_TRANS_ABORTED]		= 'A',
+	[BTRFS_FS_STATE_DEV_REPLACING]		= 'R',
+	[BTRFS_FS_STATE_DUMMY_FS_INFO]		= 0,
+	[BTRFS_FS_STATE_NO_CSUMS]		= 'C',
+	[BTRFS_FS_STATE_LOG_CLEANUP_ERROR]	= 'L',
+};
+
+static void btrfs_state_to_string(const struct btrfs_fs_info *info, char *buf)
+{
+	unsigned int bit;
+	bool states_printed = false;
+	unsigned long fs_state = READ_ONCE(info->fs_state);
+	char *curr = buf;
+
+	memcpy(curr, STATE_STRING_PREFACE, sizeof(STATE_STRING_PREFACE));
+	curr += sizeof(STATE_STRING_PREFACE) - 1;
+
+	for_each_set_bit(bit, &fs_state, sizeof(fs_state)) {
+		WARN_ON_ONCE(bit >= BTRFS_FS_STATE_COUNT);
+		if ((bit < BTRFS_FS_STATE_COUNT) && fs_state_chars[bit]) {
+			*curr++ = fs_state_chars[bit];
+			states_printed = true;
+		}
+	}
+
+	/* If no states were printed, reset the buffer */
+	if (!states_printed)
+		curr = buf;
+
+	*curr++ = 0;
+}
+#endif
+
 /*
  * Generally the error codes correspond to their respective errors, but there
  * are a few special cases.
@@ -128,6 +174,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function
 {
 	struct super_block *sb = fs_info->sb;
 #ifdef CONFIG_PRINTK
+	char statestr[STATE_STRING_BUF_LEN];
 	const char *errstr;
 #endif
 
@@ -140,6 +187,7 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function
 
 #ifdef CONFIG_PRINTK
 	errstr = btrfs_decode_error(errno);
+	btrfs_state_to_string(fs_info, statestr);
 	if (fmt) {
 		struct va_format vaf;
 		va_list args;
@@ -148,12 +196,12 @@ void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function
 		vaf.fmt = fmt;
 		vaf.va = &args;
 
-		pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
-			sb->s_id, function, line, errno, errstr, &vaf);
+		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s (%pV)\n",
+			sb->s_id, statestr, function, line, errno, errstr, &vaf);
 		va_end(args);
 	} else {
-		pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
-			sb->s_id, function, line, errno, errstr);
+		pr_crit("BTRFS: error (device %s%s) in %s:%d: errno=%d %s\n",
+			sb->s_id, statestr, function, line, errno, errstr);
 	}
 #endif
 
@@ -240,11 +288,15 @@ void __cold btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, .
 	vaf.va = &args;
 
 	if (__ratelimit(ratelimit)) {
-		if (fs_info)
-			printk("%sBTRFS %s (device %s): %pV\n", lvl, type,
-				fs_info->sb->s_id, &vaf);
-		else
+		if (fs_info) {
+			char statestr[STATE_STRING_BUF_LEN];
+
+			btrfs_state_to_string(fs_info, statestr);
+			printk("%sBTRFS %s (device %s%s): %pV\n", lvl, type,
+				fs_info->sb->s_id, statestr, &vaf);
+		} else {
 			printk("%sBTRFS %s: %pV\n", lvl, type, &vaf);
+		}
 	}
 
 	va_end(args);
@@ -861,6 +913,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 			break;
 		case Opt_space_cache:
 		case Opt_space_cache_version:
+			/*
+			 * We already set FREE_SPACE_TREE above because we have
+			 * compat_ro(FREE_SPACE_TREE) set, and we aren't going
+			 * to allow v1 to be set for extent tree v2, simply
+			 * ignore this setting if we're extent tree v2.
+			 */
+			if (btrfs_fs_incompat(info, EXTENT_TREE_V2))
+				break;
 			if (token == Opt_space_cache ||
 			    strcmp(args[0].from, "v1") == 0) {
 				btrfs_clear_opt(info->mount_opt,
@@ -881,6 +941,12 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 			btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 			break;
 		case Opt_no_space_cache:
+			/*
+			 * We cannot operate without the free space tree with
+			 * extent tree v2, ignore this option.
+			 */
+			if (btrfs_fs_incompat(info, EXTENT_TREE_V2))
+				break;
 			if (btrfs_test_opt(info, SPACE_CACHE)) {
 				btrfs_clear_and_info(info, SPACE_CACHE,
 					     "disabling disk space caching");
@@ -896,6 +962,12 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 	"the 'inode_cache' option is deprecated and has no effect since 5.11");
 			break;
 		case Opt_clear_cache:
+			/*
+			 * We cannot clear the free space tree with extent tree
+			 * v2, ignore this option.
+			 */
+			if (btrfs_fs_incompat(info, EXTENT_TREE_V2))
+				break;
 			btrfs_set_and_info(info, CLEAR_CACHE,
 					   "force clearing of disk cache");
 			break;
@@ -2383,6 +2455,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
 {
 	struct btrfs_ioctl_vol_args *vol;
 	struct btrfs_device *device = NULL;
+	dev_t devt = 0;
 	int ret = -ENOTTY;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -2402,7 +2475,12 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
 		mutex_unlock(&uuid_mutex);
 		break;
 	case BTRFS_IOC_FORGET_DEV:
-		ret = btrfs_forget_devices(vol->name);
+		if (vol->name[0] != 0) {
+			ret = lookup_bdev(vol->name, &devt);
+			if (ret)
+				break;
+		}
+		ret = btrfs_forget_devices(devt);
 		break;
 	case BTRFS_IOC_DEVICES_READY:
 		mutex_lock(&uuid_mutex);
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index beb7f72d50b8..17389a42a3ab 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -283,9 +283,11 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
-/* Remove once support for zoned allocation is feature complete */
 #ifdef CONFIG_BTRFS_DEBUG
+/* Remove once support for zoned allocation is feature complete */
 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
+/* Remove once support for extent tree v2 is feature complete */
+BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
 #endif
 #ifdef CONFIG_FS_VERITY
 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
@@ -314,6 +316,7 @@ static struct attribute *btrfs_supported_feature_attrs[] = {
 	BTRFS_FEAT_ATTR_PTR(raid1c34),
 #ifdef CONFIG_BTRFS_DEBUG
 	BTRFS_FEAT_ATTR_PTR(zoned),
+	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
 #endif
 #ifdef CONFIG_FS_VERITY
 	BTRFS_FEAT_ATTR_PTR(verity),
@@ -1104,6 +1107,11 @@ static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
 
+static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
+	      ARRAY_SIZE(btrfs_feature_attrs));
+static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
+	      ARRAY_SIZE(btrfs_feature_attrs[0]));
+
 static const u64 supported_feature_masks[FEAT_MAX] = {
 	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
 	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
@@ -1272,11 +1280,6 @@ static void init_feature_attrs(void)
 	struct btrfs_feature_attr *fa;
 	int set, i;
 
-	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
-		     ARRAY_SIZE(btrfs_feature_attrs));
-	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
-		     ARRAY_SIZE(btrfs_feature_attrs[0]));
-
 	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
 	memset(btrfs_unknown_feature_names, 0,
 	       sizeof(btrfs_unknown_feature_names));
diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c
index 319fed82d741..c5b3a631bf4f 100644
--- a/fs/btrfs/tests/extent-map-tests.c
+++ b/fs/btrfs/tests/extent-map-tests.c
@@ -15,6 +15,7 @@ static void free_extent_map_tree(struct extent_map_tree *em_tree)
 	struct extent_map *em;
 	struct rb_node *node;
 
+	write_lock(&em_tree->lock);
 	while (!RB_EMPTY_ROOT(&em_tree->map.rb_root)) {
 		node = rb_first_cached(&em_tree->map);
 		em = rb_entry(node, struct extent_map, rb_node);
@@ -32,6 +33,7 @@ static void free_extent_map_tree(struct extent_map_tree *em_tree)
 #endif
 		free_extent_map(em);
 	}
+	write_unlock(&em_tree->lock);
 }
 
 /*
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 1f1c25db6f6b..b008c5110958 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1911,6 +1911,14 @@ static void update_super_roots(struct btrfs_fs_info *fs_info)
 		super->cache_generation = 0;
 	if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags))
 		super->uuid_tree_generation = root_item->generation;
+
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		root_item = &fs_info->block_group_root->root_item;
+
+		super->block_group_root = root_item->bytenr;
+		super->block_group_root_generation = root_item->generation;
+		super->block_group_root_level = root_item->level;
+	}
 }
 
 int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
@@ -2362,6 +2370,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
 	list_add_tail(&fs_info->chunk_root->dirty_list,
 		      &cur_trans->switch_commits);
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_set_root_node(&fs_info->block_group_root->root_item,
+				    fs_info->block_group_root->node);
+		list_add_tail(&fs_info->block_group_root->dirty_list,
+			      &cur_trans->switch_commits);
+	}
+
 	switch_commit_roots(trans);
 
 	ASSERT(list_empty(&cur_trans->dirty_bgs));
@@ -2490,10 +2505,10 @@ cleanup_transaction:
  * because btrfs_commit_super will poke cleaner thread and it will process it a
  * few seconds later.
  */
-int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
+int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info)
 {
+	struct btrfs_root *root;
 	int ret;
-	struct btrfs_fs_info *fs_info = root->fs_info;
 
 	spin_lock(&fs_info->trans_lock);
 	if (list_empty(&fs_info->dead_roots)) {
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index ba8a9826eb37..970ff316069d 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -217,7 +217,7 @@ int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid);
 void btrfs_add_dead_root(struct btrfs_root *root);
 int btrfs_defrag_root(struct btrfs_root *root);
 void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info);
-int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
+int btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info);
 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans);
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index aae5697dde32..e56c0107eea3 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -639,8 +639,10 @@ static void block_group_err(const struct extent_buffer *eb, int slot,
 static int check_block_group_item(struct extent_buffer *leaf,
 				  struct btrfs_key *key, int slot)
 {
+	struct btrfs_fs_info *fs_info = leaf->fs_info;
 	struct btrfs_block_group_item bgi;
 	u32 item_size = btrfs_item_size(leaf, slot);
+	u64 chunk_objectid;
 	u64 flags;
 	u64 type;
 
@@ -663,8 +665,23 @@ static int check_block_group_item(struct extent_buffer *leaf,
 
 	read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot),
 			   sizeof(bgi));
-	if (unlikely(btrfs_stack_block_group_chunk_objectid(&bgi) !=
-		     BTRFS_FIRST_CHUNK_TREE_OBJECTID)) {
+	chunk_objectid = btrfs_stack_block_group_chunk_objectid(&bgi);
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		/*
+		 * We don't init the nr_global_roots until we load the global
+		 * roots, so this could be 0 at mount time.  If it's 0 we'll
+		 * just assume we're fine, and later we'll check against our
+		 * actual value.
+		 */
+		if (unlikely(fs_info->nr_global_roots &&
+			     chunk_objectid >= fs_info->nr_global_roots)) {
+			block_group_err(leaf, slot,
+	"invalid block group global root id, have %llu, needs to be <= %llu",
+					chunk_objectid,
+					fs_info->nr_global_roots);
+			return -EUCLEAN;
+		}
+	} else if (unlikely(chunk_objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID)) {
 		block_group_err(leaf, slot,
 		"invalid block group chunk objectid, have %llu expect %llu",
 				btrfs_stack_block_group_chunk_objectid(&bgi),
@@ -1648,7 +1665,6 @@ static int check_leaf(struct extent_buffer *leaf, bool check_item_data)
 		/* These trees must never be empty */
 		if (unlikely(owner == BTRFS_ROOT_TREE_OBJECTID ||
 			     owner == BTRFS_CHUNK_TREE_OBJECTID ||
-			     owner == BTRFS_EXTENT_TREE_OBJECTID ||
 			     owner == BTRFS_DEV_TREE_OBJECTID ||
 			     owner == BTRFS_FS_TREE_OBJECTID ||
 			     owner == BTRFS_DATA_RELOC_TREE_OBJECTID)) {
@@ -1657,12 +1673,25 @@ static int check_leaf(struct extent_buffer *leaf, bool check_item_data)
 				    owner);
 			return -EUCLEAN;
 		}
+
 		/* Unknown tree */
 		if (unlikely(owner == 0)) {
 			generic_err(leaf, 0,
 				"invalid owner, root 0 is not defined");
 			return -EUCLEAN;
 		}
+
+		/* EXTENT_TREE_V2 can have empty extent trees. */
+		if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
+			return 0;
+
+		if (unlikely(owner == BTRFS_EXTENT_TREE_OBJECTID)) {
+			generic_err(leaf, 0,
+			"invalid root, root %llu must never be empty",
+				    owner);
+			return -EUCLEAN;
+		}
+
 		return 0;
 	}
 
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 6bc8834ac8f7..571dae8ad65e 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -270,12 +270,6 @@ void btrfs_end_log_trans(struct btrfs_root *root)
 	}
 }
 
-static int btrfs_write_tree_block(struct extent_buffer *buf)
-{
-	return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
-					buf->start + buf->len - 1);
-}
-
 static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
 {
 	filemap_fdatawait_range(buf->pages[0]->mapping,
@@ -294,16 +288,6 @@ struct walk_control {
 	 */
 	int free;
 
-	/* should we write out the extent buffer?  This is used
-	 * while flushing the log tree to disk during a sync
-	 */
-	int write;
-
-	/* should we wait for the extent buffer io to finish?  Also used
-	 * while flushing the log tree to disk for a sync
-	 */
-	int wait;
-
 	/* pin only walk, we record which extents on disk belong to the
 	 * log trees
 	 */
@@ -354,17 +338,15 @@ static int process_one_buffer(struct btrfs_root *log,
 			return ret;
 	}
 
-	if (wc->pin)
+	if (wc->pin) {
 		ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start,
 						      eb->len);
+		if (ret)
+			return ret;
 
-	if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
-		if (wc->pin && btrfs_header_level(eb) == 0)
+		if (btrfs_buffer_uptodate(eb, gen, 0) &&
+		    btrfs_header_level(eb) == 0)
 			ret = btrfs_exclude_logged_extents(eb);
-		if (wc->write)
-			btrfs_write_tree_block(eb);
-		if (wc->wait)
-			btrfs_wait_tree_block_writeback(eb);
 	}
 	return ret;
 }
@@ -917,6 +899,26 @@ out:
 	return ret;
 }
 
+static int unlink_inode_for_log_replay(struct btrfs_trans_handle *trans,
+				       struct btrfs_inode *dir,
+				       struct btrfs_inode *inode,
+				       const char *name,
+				       int name_len)
+{
+	int ret;
+
+	ret = btrfs_unlink_inode(trans, dir, inode, name, name_len);
+	if (ret)
+		return ret;
+	/*
+	 * Whenever we need to check if a name exists or not, we check the
+	 * fs/subvolume tree. So after an unlink we must run delayed items, so
+	 * that future checks for a name during log replay see that the name
+	 * does not exists anymore.
+	 */
+	return btrfs_run_delayed_items(trans);
+}
+
 /*
  * when cleaning up conflicts between the directory names in the
  * subvolume, directory names in the log and directory names in the
@@ -959,12 +961,8 @@ static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
 	if (ret)
 		goto out;
 
-	ret = btrfs_unlink_inode(trans, dir, BTRFS_I(inode), name,
+	ret = unlink_inode_for_log_replay(trans, dir, BTRFS_I(inode), name,
 			name_len);
-	if (ret)
-		goto out;
-	else
-		ret = btrfs_run_delayed_items(trans);
 out:
 	kfree(name);
 	iput(inode);
@@ -1124,14 +1122,11 @@ again:
 				inc_nlink(&inode->vfs_inode);
 				btrfs_release_path(path);
 
-				ret = btrfs_unlink_inode(trans, dir, inode,
+				ret = unlink_inode_for_log_replay(trans, dir, inode,
 						victim_name, victim_name_len);
 				kfree(victim_name);
 				if (ret)
 					return ret;
-				ret = btrfs_run_delayed_items(trans);
-				if (ret)
-					return ret;
 				*search_done = 1;
 				goto again;
 			}
@@ -1196,14 +1191,11 @@ again:
 					inc_nlink(&inode->vfs_inode);
 					btrfs_release_path(path);
 
-					ret = btrfs_unlink_inode(trans,
+					ret = unlink_inode_for_log_replay(trans,
 							BTRFS_I(victim_parent),
 							inode,
 							victim_name,
 							victim_name_len);
-					if (!ret)
-						ret = btrfs_run_delayed_items(
-								  trans);
 				}
 				iput(victim_parent);
 				kfree(victim_name);
@@ -1358,19 +1350,10 @@ again:
 				kfree(name);
 				goto out;
 			}
-			ret = btrfs_unlink_inode(trans, BTRFS_I(dir),
+			ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir),
 						 inode, name, namelen);
 			kfree(name);
 			iput(dir);
-			/*
-			 * Whenever we need to check if a name exists or not, we
-			 * check the subvolume tree. So after an unlink we must
-			 * run delayed items, so that future checks for a name
-			 * during log replay see that the name does not exists
-			 * anymore.
-			 */
-			if (!ret)
-				ret = btrfs_run_delayed_items(trans);
 			if (ret)
 				goto out;
 			goto again;
@@ -1466,8 +1449,8 @@ static int add_link(struct btrfs_trans_handle *trans,
 		ret = -ENOENT;
 		goto out;
 	}
-	ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(other_inode),
-				 name, namelen);
+	ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(other_inode),
+					  name, namelen);
 	if (ret)
 		goto out;
 	/*
@@ -1476,10 +1459,6 @@ static int add_link(struct btrfs_trans_handle *trans,
 	 */
 	if (other_inode->i_nlink == 0)
 		inc_nlink(other_inode);
-
-	ret = btrfs_run_delayed_items(trans);
-	if (ret)
-		goto out;
 add_link:
 	ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
 			     name, namelen, 0, ref_index);
@@ -1612,7 +1591,7 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
 			ret = btrfs_inode_ref_exists(inode, dir, key->type,
 						     name, namelen);
 			if (ret > 0) {
-				ret = btrfs_unlink_inode(trans,
+				ret = unlink_inode_for_log_replay(trans,
 							 BTRFS_I(dir),
 							 BTRFS_I(inode),
 							 name, namelen);
@@ -1623,15 +1602,6 @@ static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
 				 */
 				if (!ret && inode->i_nlink == 0)
 					inc_nlink(inode);
-				/*
-				 * Whenever we need to check if a name exists or
-				 * not, we check the subvolume tree. So after an
-				 * unlink we must run delayed items, so that future
-				 * checks for a name during log replay see that the
-				 * name does not exists anymore.
-				 */
-				if (!ret)
-					ret = btrfs_run_delayed_items(trans);
 			}
 			if (ret < 0)
 				goto out;
@@ -2368,15 +2338,8 @@ static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
 		goto out;
 
 	inc_nlink(inode);
-	ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(inode), name,
-				 name_len);
-	if (ret)
-		goto out;
-
-	ret = btrfs_run_delayed_items(trans);
-	if (ret)
-		goto out;
-
+	ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(inode),
+					  name, name_len);
 	/*
 	 * Unlike dir item keys, dir index keys can only have one name (entry) in
 	 * them, as there are no key collisions since each key has a unique offset
@@ -3495,35 +3458,156 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
 }
 
 /*
- * Check if an inode was logged in the current transaction. This may often
- * return some false positives, because logged_trans is an in memory only field,
- * not persisted anywhere. This is meant to be used in contexts where a false
- * positive has no functional consequences.
+ * Check if an inode was logged in the current transaction. This correctly deals
+ * with the case where the inode was logged but has a logged_trans of 0, which
+ * happens if the inode is evicted and loaded again, as logged_trans is an in
+ * memory only field (not persisted).
+ *
+ * Returns 1 if the inode was logged before in the transaction, 0 if it was not,
+ * and < 0 on error.
  */
-static bool inode_logged(struct btrfs_trans_handle *trans,
-			 struct btrfs_inode *inode)
+static int inode_logged(struct btrfs_trans_handle *trans,
+			struct btrfs_inode *inode,
+			struct btrfs_path *path_in)
 {
+	struct btrfs_path *path = path_in;
+	struct btrfs_key key;
+	int ret;
+
 	if (inode->logged_trans == trans->transid)
-		return true;
+		return 1;
 
-	if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state))
-		return false;
+	/*
+	 * If logged_trans is not 0, then we know the inode logged was not logged
+	 * in this transaction, so we can return false right away.
+	 */
+	if (inode->logged_trans > 0)
+		return 0;
 
 	/*
-	 * The inode's logged_trans is always 0 when we load it (because it is
-	 * not persisted in the inode item or elsewhere). So if it is 0, the
-	 * inode was last modified in the current transaction then the inode may
-	 * have been logged before in the current transaction, then evicted and
-	 * loaded again in the current transaction - or may have never been logged
-	 * in the current transaction, but since we can not be sure, we have to
-	 * assume it was, otherwise our callers can leave an inconsistent log.
+	 * If no log tree was created for this root in this transaction, then
+	 * the inode can not have been logged in this transaction. In that case
+	 * set logged_trans to anything greater than 0 and less than the current
+	 * transaction's ID, to avoid the search below in a future call in case
+	 * a log tree gets created after this.
 	 */
-	if (inode->logged_trans == 0 &&
-	    inode->last_trans == trans->transid &&
-	    !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
-		return true;
+	if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) {
+		inode->logged_trans = trans->transid - 1;
+		return 0;
+	}
+
+	/*
+	 * We have a log tree and the inode's logged_trans is 0. We can't tell
+	 * for sure if the inode was logged before in this transaction by looking
+	 * only at logged_trans. We could be pessimistic and assume it was, but
+	 * that can lead to unnecessarily logging an inode during rename and link
+	 * operations, and then further updating the log in followup rename and
+	 * link operations, specially if it's a directory, which adds latency
+	 * visible to applications doing a series of rename or link operations.
+	 *
+	 * A logged_trans of 0 here can mean several things:
+	 *
+	 * 1) The inode was never logged since the filesystem was mounted, and may
+	 *    or may have not been evicted and loaded again;
+	 *
+	 * 2) The inode was logged in a previous transaction, then evicted and
+	 *    then loaded again;
+	 *
+	 * 3) The inode was logged in the current transaction, then evicted and
+	 *    then loaded again.
+	 *
+	 * For cases 1) and 2) we don't want to return true, but we need to detect
+	 * case 3) and return true. So we do a search in the log root for the inode
+	 * item.
+	 */
+	key.objectid = btrfs_ino(inode);
+	key.type = BTRFS_INODE_ITEM_KEY;
+	key.offset = 0;
 
-	return false;
+	if (!path) {
+		path = btrfs_alloc_path();
+		if (!path)
+			return -ENOMEM;
+	}
+
+	ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
+
+	if (path_in)
+		btrfs_release_path(path);
+	else
+		btrfs_free_path(path);
+
+	/*
+	 * Logging an inode always results in logging its inode item. So if we
+	 * did not find the item we know the inode was not logged for sure.
+	 */
+	if (ret < 0) {
+		return ret;
+	} else if (ret > 0) {
+		/*
+		 * Set logged_trans to a value greater than 0 and less then the
+		 * current transaction to avoid doing the search in future calls.
+		 */
+		inode->logged_trans = trans->transid - 1;
+		return 0;
+	}
+
+	/*
+	 * The inode was previously logged and then evicted, set logged_trans to
+	 * the current transacion's ID, to avoid future tree searches as long as
+	 * the inode is not evicted again.
+	 */
+	inode->logged_trans = trans->transid;
+
+	/*
+	 * If it's a directory, then we must set last_dir_index_offset to the
+	 * maximum possible value, so that the next attempt to log the inode does
+	 * not skip checking if dir index keys found in modified subvolume tree
+	 * leaves have been logged before, otherwise it would result in attempts
+	 * to insert duplicate dir index keys in the log tree. This must be done
+	 * because last_dir_index_offset is an in-memory only field, not persisted
+	 * in the inode item or any other on-disk structure, so its value is lost
+	 * once the inode is evicted.
+	 */
+	if (S_ISDIR(inode->vfs_inode.i_mode))
+		inode->last_dir_index_offset = (u64)-1;
+
+	return 1;
+}
+
+/*
+ * Delete a directory entry from the log if it exists.
+ *
+ * Returns < 0 on error
+ *           1 if the entry does not exists
+ *           0 if the entry existed and was successfully deleted
+ */
+static int del_logged_dentry(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *log,
+			     struct btrfs_path *path,
+			     u64 dir_ino,
+			     const char *name, int name_len,
+			     u64 index)
+{
+	struct btrfs_dir_item *di;
+
+	/*
+	 * We only log dir index items of a directory, so we don't need to look
+	 * for dir item keys.
+	 */
+	di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
+					 index, name, name_len, -1);
+	if (IS_ERR(di))
+		return PTR_ERR(di);
+	else if (!di)
+		return 1;
+
+	/*
+	 * We do not need to update the size field of the directory's
+	 * inode item because on log replay we update the field to reflect
+	 * all existing entries in the directory (see overwrite_item()).
+	 */
+	return btrfs_delete_one_dir_name(trans, log, path, di);
 }
 
 /*
@@ -3552,15 +3636,16 @@ void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
 				  const char *name, int name_len,
 				  struct btrfs_inode *dir, u64 index)
 {
-	struct btrfs_root *log;
-	struct btrfs_dir_item *di;
 	struct btrfs_path *path;
 	int ret;
-	int err = 0;
-	u64 dir_ino = btrfs_ino(dir);
 
-	if (!inode_logged(trans, dir))
+	ret = inode_logged(trans, dir, NULL);
+	if (ret == 0)
+		return;
+	else if (ret < 0) {
+		btrfs_set_log_full_commit(trans);
 		return;
+	}
 
 	ret = join_running_log_trans(root);
 	if (ret)
@@ -3568,41 +3653,18 @@ void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
 
 	mutex_lock(&dir->log_mutex);
 
-	log = root->log_root;
 	path = btrfs_alloc_path();
 	if (!path) {
-		err = -ENOMEM;
+		ret = -ENOMEM;
 		goto out_unlock;
 	}
 
-	/*
-	 * We only log dir index items of a directory, so we don't need to look
-	 * for dir item keys.
-	 */
-	di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
-					 index, name, name_len, -1);
-	if (IS_ERR(di)) {
-		err = PTR_ERR(di);
-		goto fail;
-	}
-	if (di) {
-		ret = btrfs_delete_one_dir_name(trans, log, path, di);
-		if (ret) {
-			err = ret;
-			goto fail;
-		}
-	}
-
-	/*
-	 * We do not need to update the size field of the directory's inode item
-	 * because on log replay we update the field to reflect all existing
-	 * entries in the directory (see overwrite_item()).
-	 */
-fail:
+	ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
+				name, name_len, index);
 	btrfs_free_path(path);
 out_unlock:
 	mutex_unlock(&dir->log_mutex);
-	if (err < 0)
+	if (ret < 0)
 		btrfs_set_log_full_commit(trans);
 	btrfs_end_log_trans(root);
 }
@@ -3617,8 +3679,13 @@ void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
 	u64 index;
 	int ret;
 
-	if (!inode_logged(trans, inode))
+	ret = inode_logged(trans, inode, NULL);
+	if (ret == 0)
+		return;
+	else if (ret < 0) {
+		btrfs_set_log_full_commit(trans);
 		return;
+	}
 
 	ret = join_running_log_trans(root);
 	if (ret)
@@ -3743,19 +3810,20 @@ static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
 				  struct btrfs_inode *inode,
 				  struct btrfs_path *path,
 				  struct btrfs_path *dst_path,
-				  struct btrfs_log_ctx *ctx)
+				  struct btrfs_log_ctx *ctx,
+				  u64 *last_old_dentry_offset)
 {
 	struct btrfs_root *log = inode->root->log_root;
 	struct extent_buffer *src = path->nodes[0];
 	const int nritems = btrfs_header_nritems(src);
 	const u64 ino = btrfs_ino(inode);
-	const bool inode_logged_before = inode_logged(trans, inode);
 	bool last_found = false;
 	int batch_start = 0;
 	int batch_size = 0;
 	int i;
 
 	for (i = path->slots[0]; i < nritems; i++) {
+		struct btrfs_dir_item *di;
 		struct btrfs_key key;
 		int ret;
 
@@ -3766,7 +3834,34 @@ static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
 			break;
 		}
 
+		di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
 		ctx->last_dir_item_offset = key.offset;
+
+		/*
+		 * Skip ranges of items that consist only of dir item keys created
+		 * in past transactions. However if we find a gap, we must log a
+		 * dir index range item for that gap, so that index keys in that
+		 * gap are deleted during log replay.
+		 */
+		if (btrfs_dir_transid(src, di) < trans->transid) {
+			if (key.offset > *last_old_dentry_offset + 1) {
+				ret = insert_dir_log_key(trans, log, dst_path,
+						 ino, *last_old_dentry_offset + 1,
+						 key.offset - 1);
+				/*
+				 * -EEXIST should never happen because when we
+				 * log a directory in full mode (LOG_INODE_ALL)
+				 * we drop all BTRFS_DIR_LOG_INDEX_KEY keys from
+				 * the log tree.
+				 */
+				ASSERT(ret != -EEXIST);
+				if (ret < 0)
+					return ret;
+			}
+
+			*last_old_dentry_offset = key.offset;
+			continue;
+		}
 		/*
 		 * We must make sure that when we log a directory entry, the
 		 * corresponding inode, after log replay, has a matching link
@@ -3790,25 +3885,23 @@ static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
 		 * resulting in -ENOTEMPTY errors.
 		 */
 		if (!ctx->log_new_dentries) {
-			struct btrfs_dir_item *di;
 			struct btrfs_key di_key;
 
-			di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
 			btrfs_dir_item_key_to_cpu(src, di, &di_key);
-			if ((btrfs_dir_transid(src, di) == trans->transid ||
-			     btrfs_dir_type(src, di) == BTRFS_FT_DIR) &&
-			    di_key.type != BTRFS_ROOT_ITEM_KEY)
+			if (di_key.type != BTRFS_ROOT_ITEM_KEY)
 				ctx->log_new_dentries = true;
 		}
 
-		if (!inode_logged_before)
+		if (!ctx->logged_before)
 			goto add_to_batch;
 
 		/*
 		 * If we were logged before and have logged dir items, we can skip
 		 * checking if any item with a key offset larger than the last one
 		 * we logged is in the log tree, saving time and avoiding adding
-		 * contention on the log tree.
+		 * contention on the log tree. We can only rely on the value of
+		 * last_dir_index_offset when we know for sure that the inode was
+		 * previously logged in the current transaction.
 		 */
 		if (key.offset > inode->last_dir_index_offset)
 			goto add_to_batch;
@@ -3878,7 +3971,7 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
 	struct btrfs_root *log = root->log_root;
 	int err = 0;
 	int ret;
-	u64 first_offset = min_offset;
+	u64 last_old_dentry_offset = min_offset - 1;
 	u64 last_offset = (u64)-1;
 	u64 ino = btrfs_ino(inode);
 
@@ -3912,10 +4005,11 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
 		 */
 		if (ret == 0) {
 			struct btrfs_key tmp;
+
 			btrfs_item_key_to_cpu(path->nodes[0], &tmp,
 					      path->slots[0]);
 			if (tmp.type == BTRFS_DIR_INDEX_KEY)
-				first_offset = max(min_offset, tmp.offset) + 1;
+				last_old_dentry_offset = tmp.offset;
 		}
 		goto done;
 	}
@@ -3924,17 +4018,18 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
 	ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
 	if (ret == 0) {
 		struct btrfs_key tmp;
+
 		btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
-		if (tmp.type == BTRFS_DIR_INDEX_KEY) {
-			first_offset = tmp.offset;
-			ret = overwrite_item(trans, log, dst_path,
-					     path->nodes[0], path->slots[0],
-					     &tmp);
-			if (ret) {
-				err = ret;
-				goto done;
-			}
-		}
+		/*
+		 * The dir index key before the first one we found that needs to
+		 * be logged might be in a previous leaf, and there might be a
+		 * gap between these keys, meaning that we had deletions that
+		 * happened. So the key range item we log (key type
+		 * BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the
+		 * previous key's offset plus 1, so that those deletes are replayed.
+		 */
+		if (tmp.type == BTRFS_DIR_INDEX_KEY)
+			last_old_dentry_offset = tmp.offset;
 	}
 	btrfs_release_path(path);
 
@@ -3956,7 +4051,8 @@ search:
 	 * from our directory
 	 */
 	while (1) {
-		ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx);
+		ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx,
+					     &last_old_dentry_offset);
 		if (ret != 0) {
 			if (ret < 0)
 				err = ret;
@@ -3982,14 +4078,16 @@ search:
 			goto done;
 		}
 		if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
-			ctx->last_dir_item_offset = min_key.offset;
-			ret = overwrite_item(trans, log, dst_path,
-					     path->nodes[0], path->slots[0],
-					     &min_key);
-			if (ret)
-				err = ret;
-			else
-				last_offset = min_key.offset;
+			/*
+			 * The next leaf was not changed in the current transaction
+			 * and has at least one dir index key.
+			 * We check for the next key because there might have been
+			 * one or more deletions between the last key we logged and
+			 * that next key. So the key range item we log (key type
+			 * BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's
+			 * offset minus 1, so that those deletes are replayed.
+			 */
+			last_offset = min_key.offset - 1;
 			goto done;
 		}
 		if (need_resched()) {
@@ -4005,13 +4103,21 @@ done:
 	if (err == 0) {
 		*last_offset_ret = last_offset;
 		/*
-		 * insert the log range keys to indicate where the log
-		 * is valid
+		 * In case the leaf was changed in the current transaction but
+		 * all its dir items are from a past transaction, the last item
+		 * in the leaf is a dir item and there's no gap between that last
+		 * dir item and the first one on the next leaf (which did not
+		 * change in the current transaction), then we don't need to log
+		 * a range, last_old_dentry_offset is == to last_offset.
 		 */
-		ret = insert_dir_log_key(trans, log, path, ino, first_offset,
-					 last_offset);
-		if (ret)
-			err = ret;
+		ASSERT(last_old_dentry_offset <= last_offset);
+		if (last_old_dentry_offset < last_offset) {
+			ret = insert_dir_log_key(trans, log, path, ino,
+						 last_old_dentry_offset + 1,
+						 last_offset);
+			if (ret)
+				err = ret;
+		}
 	}
 	return err;
 }
@@ -4038,22 +4144,7 @@ static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
 	u64 max_key;
 	int ret;
 
-	/*
-	 * If this is the first time we are being logged in the current
-	 * transaction, or we were logged before but the inode was evicted and
-	 * reloaded later, in which case its logged_trans is 0, reset the value
-	 * of the last logged key offset. Note that we don't use the helper
-	 * function inode_logged() here - that is because the function returns
-	 * true after an inode eviction, assuming the worst case as it can not
-	 * know for sure if the inode was logged before. So we can not skip key
-	 * searches in the case the inode was evicted, because it may not have
-	 * been logged in this transaction and may have been logged in a past
-	 * transaction, so we need to reset the last dir index offset to (u64)-1.
-	 */
-	if (inode->logged_trans != trans->transid)
-		inode->last_dir_index_offset = (u64)-1;
-
-	min_key = 0;
+	min_key = BTRFS_DIR_START_INDEX;
 	max_key = 0;
 	ctx->last_dir_item_offset = inode->last_dir_index_offset;
 
@@ -4089,9 +4180,6 @@ static int drop_inode_items(struct btrfs_trans_handle *trans,
 	struct btrfs_key found_key;
 	int start_slot;
 
-	if (!inode_logged(trans, inode))
-		return 0;
-
 	key.objectid = btrfs_ino(inode);
 	key.type = max_key_type;
 	key.offset = (u64)-1;
@@ -4311,23 +4399,18 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 			       int start_slot, int nr, int inode_only,
 			       u64 logged_isize)
 {
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	unsigned long src_offset;
-	unsigned long dst_offset;
 	struct btrfs_root *log = inode->root->log_root;
 	struct btrfs_file_extent_item *extent;
-	struct btrfs_inode_item *inode_item;
 	struct extent_buffer *src = src_path->nodes[0];
-	int ret;
+	int ret = 0;
 	struct btrfs_key *ins_keys;
 	u32 *ins_sizes;
 	struct btrfs_item_batch batch;
 	char *ins_data;
 	int i;
-	struct list_head ordered_sums;
-	int skip_csum = inode->flags & BTRFS_INODE_NODATASUM;
-
-	INIT_LIST_HEAD(&ordered_sums);
+	int dst_index;
+	const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
+	const u64 i_size = i_size_read(&inode->vfs_inode);
 
 	ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
 			   nr * sizeof(u32), GFP_NOFS);
@@ -4339,28 +4422,152 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 	batch.keys = ins_keys;
 	batch.data_sizes = ins_sizes;
 	batch.total_data_size = 0;
-	batch.nr = nr;
+	batch.nr = 0;
 
+	dst_index = 0;
 	for (i = 0; i < nr; i++) {
-		ins_sizes[i] = btrfs_item_size(src, i + start_slot);
-		batch.total_data_size += ins_sizes[i];
-		btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
+		const int src_slot = start_slot + i;
+		struct btrfs_root *csum_root;
+		struct btrfs_ordered_sum *sums;
+		struct btrfs_ordered_sum *sums_next;
+		LIST_HEAD(ordered_sums);
+		u64 disk_bytenr;
+		u64 disk_num_bytes;
+		u64 extent_offset;
+		u64 extent_num_bytes;
+		bool is_old_extent;
+
+		btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot);
+
+		if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY)
+			goto add_to_batch;
+
+		extent = btrfs_item_ptr(src, src_slot,
+					struct btrfs_file_extent_item);
+
+		is_old_extent = (btrfs_file_extent_generation(src, extent) <
+				 trans->transid);
+
+		/*
+		 * Don't copy extents from past generations. That would make us
+		 * log a lot more metadata for common cases like doing only a
+		 * few random writes into a file and then fsync it for the first
+		 * time or after the full sync flag is set on the inode. We can
+		 * get leaves full of extent items, most of which are from past
+		 * generations, so we can skip them - as long as the inode has
+		 * not been the target of a reflink operation in this transaction,
+		 * as in that case it might have had file extent items with old
+		 * generations copied into it. We also must always log prealloc
+		 * extents that start at or beyond eof, otherwise we would lose
+		 * them on log replay.
+		 */
+		if (is_old_extent &&
+		    ins_keys[dst_index].offset < i_size &&
+		    inode->last_reflink_trans < trans->transid)
+			continue;
+
+		if (skip_csum)
+			goto add_to_batch;
+
+		/* Only regular extents have checksums. */
+		if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG)
+			goto add_to_batch;
+
+		/*
+		 * If it's an extent created in a past transaction, then its
+		 * checksums are already accessible from the committed csum tree,
+		 * no need to log them.
+		 */
+		if (is_old_extent)
+			goto add_to_batch;
+
+		disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent);
+		/* If it's an explicit hole, there are no checksums. */
+		if (disk_bytenr == 0)
+			goto add_to_batch;
+
+		disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent);
+
+		if (btrfs_file_extent_compression(src, extent)) {
+			extent_offset = 0;
+			extent_num_bytes = disk_num_bytes;
+		} else {
+			extent_offset = btrfs_file_extent_offset(src, extent);
+			extent_num_bytes = btrfs_file_extent_num_bytes(src, extent);
+		}
+
+		csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr);
+		disk_bytenr += extent_offset;
+		ret = btrfs_lookup_csums_range(csum_root, disk_bytenr,
+					       disk_bytenr + extent_num_bytes - 1,
+					       &ordered_sums, 0);
+		if (ret)
+			goto out;
+
+		list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
+			if (!ret)
+				ret = log_csums(trans, inode, log, sums);
+			list_del(&sums->list);
+			kfree(sums);
+		}
+		if (ret)
+			goto out;
+
+add_to_batch:
+		ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
+		batch.total_data_size += ins_sizes[dst_index];
+		batch.nr++;
+		dst_index++;
 	}
+
+	/*
+	 * We have a leaf full of old extent items that don't need to be logged,
+	 * so we don't need to do anything.
+	 */
+	if (batch.nr == 0)
+		goto out;
+
 	ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
-	if (ret) {
-		kfree(ins_data);
-		return ret;
-	}
+	if (ret)
+		goto out;
+
+	dst_index = 0;
+	for (i = 0; i < nr; i++) {
+		const int src_slot = start_slot + i;
+		const int dst_slot = dst_path->slots[0] + dst_index;
+		struct btrfs_key key;
+		unsigned long src_offset;
+		unsigned long dst_offset;
+
+		/*
+		 * We're done, all the remaining items in the source leaf
+		 * correspond to old file extent items.
+		 */
+		if (dst_index >= batch.nr)
+			break;
+
+		btrfs_item_key_to_cpu(src, &key, src_slot);
 
-	for (i = 0; i < nr; i++, dst_path->slots[0]++) {
-		dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
-						   dst_path->slots[0]);
+		if (key.type != BTRFS_EXTENT_DATA_KEY)
+			goto copy_item;
+
+		extent = btrfs_item_ptr(src, src_slot,
+					struct btrfs_file_extent_item);
+
+		/* See the comment in the previous loop, same logic. */
+		if (btrfs_file_extent_generation(src, extent) < trans->transid &&
+		    key.offset < i_size &&
+		    inode->last_reflink_trans < trans->transid)
+			continue;
 
-		src_offset = btrfs_item_ptr_offset(src, start_slot + i);
+copy_item:
+		dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot);
+		src_offset = btrfs_item_ptr_offset(src, src_slot);
 
-		if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
-			inode_item = btrfs_item_ptr(dst_path->nodes[0],
-						    dst_path->slots[0],
+		if (key.type == BTRFS_INODE_ITEM_KEY) {
+			struct btrfs_inode_item *inode_item;
+
+			inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot,
 						    struct btrfs_inode_item);
 			fill_inode_item(trans, dst_path->nodes[0], inode_item,
 					&inode->vfs_inode,
@@ -4368,71 +4575,17 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
 					logged_isize);
 		} else {
 			copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
-					   src_offset, ins_sizes[i]);
+					   src_offset, ins_sizes[dst_index]);
 		}
 
-		/* take a reference on file data extents so that truncates
-		 * or deletes of this inode don't have to relog the inode
-		 * again
-		 */
-		if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY &&
-		    !skip_csum) {
-			int found_type;
-			extent = btrfs_item_ptr(src, start_slot + i,
-						struct btrfs_file_extent_item);
-
-			if (btrfs_file_extent_generation(src, extent) < trans->transid)
-				continue;
-
-			found_type = btrfs_file_extent_type(src, extent);
-			if (found_type == BTRFS_FILE_EXTENT_REG) {
-				struct btrfs_root *csum_root;
-				u64 ds, dl, cs, cl;
-				ds = btrfs_file_extent_disk_bytenr(src,
-								extent);
-				/* ds == 0 is a hole */
-				if (ds == 0)
-					continue;
-
-				dl = btrfs_file_extent_disk_num_bytes(src,
-								extent);
-				cs = btrfs_file_extent_offset(src, extent);
-				cl = btrfs_file_extent_num_bytes(src,
-								extent);
-				if (btrfs_file_extent_compression(src,
-								  extent)) {
-					cs = 0;
-					cl = dl;
-				}
-
-				csum_root = btrfs_csum_root(fs_info, ds);
-				ret = btrfs_lookup_csums_range(csum_root,
-						ds + cs, ds + cs + cl - 1,
-						&ordered_sums, 0);
-				if (ret)
-					break;
-			}
-		}
+		dst_index++;
 	}
 
 	btrfs_mark_buffer_dirty(dst_path->nodes[0]);
 	btrfs_release_path(dst_path);
+out:
 	kfree(ins_data);
 
-	/*
-	 * we have to do this after the loop above to avoid changing the
-	 * log tree while trying to change the log tree.
-	 */
-	while (!list_empty(&ordered_sums)) {
-		struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
-						   struct btrfs_ordered_sum,
-						   list);
-		if (!ret)
-			ret = log_csums(trans, inode, log, sums);
-		list_del(&sums->list);
-		kfree(sums);
-	}
-
 	return ret;
 }
 
@@ -4568,14 +4721,34 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_drop_extents_args drop_args = { 0 };
 	struct btrfs_root *log = inode->root->log_root;
-	struct btrfs_file_extent_item *fi;
+	struct btrfs_file_extent_item fi = { 0 };
 	struct extent_buffer *leaf;
-	struct btrfs_map_token token;
 	struct btrfs_key key;
 	u64 extent_offset = em->start - em->orig_start;
 	u64 block_len;
 	int ret;
 
+	btrfs_set_stack_file_extent_generation(&fi, trans->transid);
+	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+		btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC);
+	else
+		btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG);
+
+	block_len = max(em->block_len, em->orig_block_len);
+	if (em->compress_type != BTRFS_COMPRESS_NONE) {
+		btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start);
+		btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
+	} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
+		btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start -
+							extent_offset);
+		btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
+	}
+
+	btrfs_set_stack_file_extent_offset(&fi, extent_offset);
+	btrfs_set_stack_file_extent_num_bytes(&fi, em->len);
+	btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes);
+	btrfs_set_stack_file_extent_compression(&fi, em->compress_type);
+
 	ret = log_extent_csums(trans, inode, log, em, ctx);
 	if (ret)
 		return ret;
@@ -4589,12 +4762,12 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 	 * are small, with a root at level 2 or 3 at most, due to their short
 	 * life span.
 	 */
-	if (inode_logged(trans, inode)) {
+	if (ctx->logged_before) {
 		drop_args.path = path;
 		drop_args.start = em->start;
 		drop_args.end = em->start + em->len;
 		drop_args.replace_extent = true;
-		drop_args.extent_item_size = sizeof(*fi);
+		drop_args.extent_item_size = sizeof(fi);
 		ret = btrfs_drop_extents(trans, log, inode, &drop_args);
 		if (ret)
 			return ret;
@@ -4606,44 +4779,14 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 		key.offset = em->start;
 
 		ret = btrfs_insert_empty_item(trans, log, path, &key,
-					      sizeof(*fi));
+					      sizeof(fi));
 		if (ret)
 			return ret;
 	}
 	leaf = path->nodes[0];
-	btrfs_init_map_token(&token, leaf);
-	fi = btrfs_item_ptr(leaf, path->slots[0],
-			    struct btrfs_file_extent_item);
-
-	btrfs_set_token_file_extent_generation(&token, fi, trans->transid);
-	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
-		btrfs_set_token_file_extent_type(&token, fi,
-						 BTRFS_FILE_EXTENT_PREALLOC);
-	else
-		btrfs_set_token_file_extent_type(&token, fi,
-						 BTRFS_FILE_EXTENT_REG);
-
-	block_len = max(em->block_len, em->orig_block_len);
-	if (em->compress_type != BTRFS_COMPRESS_NONE) {
-		btrfs_set_token_file_extent_disk_bytenr(&token, fi,
-							em->block_start);
-		btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len);
-	} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
-		btrfs_set_token_file_extent_disk_bytenr(&token, fi,
-							em->block_start -
-							extent_offset);
-		btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len);
-	} else {
-		btrfs_set_token_file_extent_disk_bytenr(&token, fi, 0);
-		btrfs_set_token_file_extent_disk_num_bytes(&token, fi, 0);
-	}
-
-	btrfs_set_token_file_extent_offset(&token, fi, extent_offset);
-	btrfs_set_token_file_extent_num_bytes(&token, fi, em->len);
-	btrfs_set_token_file_extent_ram_bytes(&token, fi, em->ram_bytes);
-	btrfs_set_token_file_extent_compression(&token, fi, em->compress_type);
-	btrfs_set_token_file_extent_encryption(&token, fi, 0);
-	btrfs_set_token_file_extent_other_encoding(&token, fi, 0);
+	write_extent_buffer(leaf, &fi,
+			    btrfs_item_ptr_offset(leaf, path->slots[0]),
+			    sizeof(fi));
 	btrfs_mark_buffer_dirty(leaf);
 
 	btrfs_release_path(path);
@@ -4857,7 +5000,6 @@ process:
 	WARN_ON(!list_empty(&extents));
 	write_unlock(&tree->lock);
 
-	btrfs_release_path(path);
 	if (!ret)
 		ret = btrfs_log_prealloc_extents(trans, inode, path);
 	if (ret)
@@ -5551,6 +5693,13 @@ next_key:
 		} else {
 			break;
 		}
+
+		/*
+		 * We may process many leaves full of items for our inode, so
+		 * avoid monopolizing a cpu for too long by rescheduling while
+		 * not holding locks on any tree.
+		 */
+		cond_resched();
 	}
 	if (ins_nr) {
 		ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
@@ -5595,8 +5744,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 	struct btrfs_key min_key;
 	struct btrfs_key max_key;
 	struct btrfs_root *log = inode->root->log_root;
-	int err = 0;
-	int ret = 0;
+	int ret;
 	bool fast_search = false;
 	u64 ino = btrfs_ino(inode);
 	struct extent_map_tree *em_tree = &inode->extent_tree;
@@ -5605,6 +5753,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 	bool xattrs_logged = false;
 	bool recursive_logging = false;
 	bool inode_item_dropped = true;
+	const bool orig_logged_before = ctx->logged_before;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -5638,8 +5787,8 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 	 * and figure out which index ranges have to be logged.
 	 */
 	if (S_ISDIR(inode->vfs_inode.i_mode)) {
-		err = btrfs_commit_inode_delayed_items(trans, inode);
-		if (err)
+		ret = btrfs_commit_inode_delayed_items(trans, inode);
+		if (ret)
 			goto out;
 	}
 
@@ -5655,6 +5804,17 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 	}
 
 	/*
+	 * Before logging the inode item, cache the value returned by
+	 * inode_logged(), because after that we have the need to figure out if
+	 * the inode was previously logged in this transaction.
+	 */
+	ret = inode_logged(trans, inode, path);
+	if (ret < 0)
+		goto out_unlock;
+	ctx->logged_before = (ret == 1);
+	ret = 0;
+
+	/*
 	 * This is for cases where logging a directory could result in losing a
 	 * a file after replaying the log. For example, if we move a file from a
 	 * directory A to a directory B, then fsync directory A, we have no way
@@ -5665,7 +5825,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 	    inode_only == LOG_INODE_ALL &&
 	    inode->last_unlink_trans >= trans->transid) {
 		btrfs_set_log_full_commit(trans);
-		err = 1;
+		ret = 1;
 		goto out_unlock;
 	}
 
@@ -5679,9 +5839,11 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 		clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
 		if (inode_only == LOG_INODE_EXISTS)
 			max_key_type = BTRFS_XATTR_ITEM_KEY;
-		ret = drop_inode_items(trans, log, path, inode, max_key_type);
+		if (ctx->logged_before)
+			ret = drop_inode_items(trans, log, path, inode,
+					       max_key_type);
 	} else {
-		if (inode_only == LOG_INODE_EXISTS && inode_logged(trans, inode)) {
+		if (inode_only == LOG_INODE_EXISTS && ctx->logged_before) {
 			/*
 			 * Make sure the new inode item we write to the log has
 			 * the same isize as the current one (if it exists).
@@ -5695,22 +5857,23 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 			 * (zeroes), as if an expanding truncate happened,
 			 * instead of getting a file of 4Kb only.
 			 */
-			err = logged_inode_size(log, inode, path, &logged_isize);
-			if (err)
+			ret = logged_inode_size(log, inode, path, &logged_isize);
+			if (ret)
 				goto out_unlock;
 		}
 		if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
 			     &inode->runtime_flags)) {
 			if (inode_only == LOG_INODE_EXISTS) {
 				max_key.type = BTRFS_XATTR_ITEM_KEY;
-				ret = drop_inode_items(trans, log, path, inode,
-						       max_key.type);
+				if (ctx->logged_before)
+					ret = drop_inode_items(trans, log, path,
+							       inode, max_key.type);
 			} else {
 				clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
 					  &inode->runtime_flags);
 				clear_bit(BTRFS_INODE_COPY_EVERYTHING,
 					  &inode->runtime_flags);
-				if (inode_logged(trans, inode))
+				if (ctx->logged_before)
 					ret = truncate_inode_items(trans, log,
 								   inode, 0, 0);
 			}
@@ -5720,8 +5883,9 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 			if (inode_only == LOG_INODE_ALL)
 				fast_search = true;
 			max_key.type = BTRFS_XATTR_ITEM_KEY;
-			ret = drop_inode_items(trans, log, path, inode,
-					       max_key.type);
+			if (ctx->logged_before)
+				ret = drop_inode_items(trans, log, path, inode,
+						       max_key.type);
 		} else {
 			if (inode_only == LOG_INODE_ALL)
 				fast_search = true;
@@ -5730,37 +5894,35 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 		}
 
 	}
-	if (ret) {
-		err = ret;
+	if (ret)
 		goto out_unlock;
-	}
 
-	err = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
+	ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
 				      path, dst_path, logged_isize,
 				      recursive_logging, inode_only, ctx,
 				      &need_log_inode_item);
-	if (err)
+	if (ret)
 		goto out_unlock;
 
 	btrfs_release_path(path);
 	btrfs_release_path(dst_path);
-	err = btrfs_log_all_xattrs(trans, inode, path, dst_path);
-	if (err)
+	ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
+	if (ret)
 		goto out_unlock;
 	xattrs_logged = true;
 	if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
 		btrfs_release_path(path);
 		btrfs_release_path(dst_path);
-		err = btrfs_log_holes(trans, inode, path);
-		if (err)
+		ret = btrfs_log_holes(trans, inode, path);
+		if (ret)
 			goto out_unlock;
 	}
 log_extents:
 	btrfs_release_path(path);
 	btrfs_release_path(dst_path);
 	if (need_log_inode_item) {
-		err = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
-		if (err)
+		ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
+		if (ret)
 			goto out_unlock;
 		/*
 		 * If we are doing a fast fsync and the inode was logged before
@@ -5771,18 +5933,16 @@ log_extents:
 		 * BTRFS_INODE_COPY_EVERYTHING set.
 		 */
 		if (!xattrs_logged && inode->logged_trans < trans->transid) {
-			err = btrfs_log_all_xattrs(trans, inode, path, dst_path);
-			if (err)
+			ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
+			if (ret)
 				goto out_unlock;
 			btrfs_release_path(path);
 		}
 	}
 	if (fast_search) {
 		ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx);
-		if (ret) {
-			err = ret;
+		if (ret)
 			goto out_unlock;
-		}
 	} else if (inode_only == LOG_INODE_ALL) {
 		struct extent_map *em, *n;
 
@@ -5794,10 +5954,8 @@ log_extents:
 
 	if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) {
 		ret = log_directory_changes(trans, inode, path, dst_path, ctx);
-		if (ret) {
-			err = ret;
+		if (ret)
 			goto out_unlock;
-		}
 	}
 
 	spin_lock(&inode->lock);
@@ -5836,12 +5994,24 @@ log_extents:
 	if (inode_only != LOG_INODE_EXISTS)
 		inode->last_log_commit = inode->last_sub_trans;
 	spin_unlock(&inode->lock);
+
+	/*
+	 * Reset the last_reflink_trans so that the next fsync does not need to
+	 * go through the slower path when logging extents and their checksums.
+	 */
+	if (inode_only == LOG_INODE_ALL)
+		inode->last_reflink_trans = 0;
+
 out_unlock:
 	mutex_unlock(&inode->log_mutex);
 out:
 	btrfs_free_path(path);
 	btrfs_free_path(dst_path);
-	return err;
+
+	if (recursive_logging)
+		ctx->logged_before = orig_logged_before;
+
+	return ret;
 }
 
 /*
@@ -5926,7 +6096,6 @@ static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
 				struct btrfs_log_ctx *ctx)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_root *log = root->log_root;
 	struct btrfs_path *path;
 	LIST_HEAD(dir_list);
 	struct btrfs_dir_list *dir_elem;
@@ -5968,7 +6137,7 @@ static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
 		min_key.offset = 0;
 again:
 		btrfs_release_path(path);
-		ret = btrfs_search_forward(log, &min_key, path, trans->transid);
+		ret = btrfs_search_forward(root, &min_key, path, trans->transid);
 		if (ret < 0) {
 			goto next_dir_inode;
 		} else if (ret > 0) {
@@ -5976,7 +6145,6 @@ again:
 			goto next_dir_inode;
 		}
 
-process_leaf:
 		leaf = path->nodes[0];
 		nritems = btrfs_header_nritems(leaf);
 		for (i = path->slots[0]; i < nritems; i++) {
@@ -5994,8 +6162,7 @@ process_leaf:
 
 			di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
 			type = btrfs_dir_type(leaf, di);
-			if (btrfs_dir_transid(leaf, di) < trans->transid &&
-			    type != BTRFS_FT_DIR)
+			if (btrfs_dir_transid(leaf, di) < trans->transid)
 				continue;
 			btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
 			if (di_key.type == BTRFS_ROOT_ITEM_KEY)
@@ -6033,16 +6200,6 @@ process_leaf:
 			}
 			break;
 		}
-		if (i == nritems) {
-			ret = btrfs_next_leaf(log, path);
-			if (ret < 0) {
-				goto next_dir_inode;
-			} else if (ret > 0) {
-				ret = 0;
-				goto next_dir_inode;
-			}
-			goto process_leaf;
-		}
 		if (min_key.offset < (u64)-1) {
 			min_key.offset++;
 			goto again;
@@ -6773,15 +6930,32 @@ void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
 	mutex_unlock(&dir->log_mutex);
 }
 
-/*
- * Call this after adding a new name for a file and it will properly
- * update the log to reflect the new name.
+/**
+ * Update the log after adding a new name for an inode.
+ *
+ * @trans:              Transaction handle.
+ * @old_dentry:         The dentry associated with the old name and the old
+ *                      parent directory.
+ * @old_dir:            The inode of the previous parent directory for the case
+ *                      of a rename. For a link operation, it must be NULL.
+ * @old_dir_index:      The index number associated with the old name, meaningful
+ *                      only for rename operations (when @old_dir is not NULL).
+ *                      Ignored for link operations.
+ * @parent:             The dentry associated with the directory under which the
+ *                      new name is located.
+ *
+ * Call this after adding a new name for an inode, as a result of a link or
+ * rename operation, and it will properly update the log to reflect the new name.
  */
 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
-			struct btrfs_inode *inode, struct btrfs_inode *old_dir,
-			struct dentry *parent)
+			struct dentry *old_dentry, struct btrfs_inode *old_dir,
+			u64 old_dir_index, struct dentry *parent)
 {
+	struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
+	struct btrfs_root *root = inode->root;
 	struct btrfs_log_ctx ctx;
+	bool log_pinned = false;
+	int ret;
 
 	/*
 	 * this will force the logging code to walk the dentry chain
@@ -6794,26 +6968,83 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 	 * if this inode hasn't been logged and directory we're renaming it
 	 * from hasn't been logged, we don't need to log it
 	 */
-	if (!inode_logged(trans, inode) &&
-	    (!old_dir || !inode_logged(trans, old_dir)))
-		return;
+	ret = inode_logged(trans, inode, NULL);
+	if (ret < 0) {
+		goto out;
+	} else if (ret == 0) {
+		if (!old_dir)
+			return;
+		/*
+		 * If the inode was not logged and we are doing a rename (old_dir is not
+		 * NULL), check if old_dir was logged - if it was not we can return and
+		 * do nothing.
+		 */
+		ret = inode_logged(trans, old_dir, NULL);
+		if (ret < 0)
+			goto out;
+		else if (ret == 0)
+			return;
+	}
+	ret = 0;
 
 	/*
 	 * If we are doing a rename (old_dir is not NULL) from a directory that
-	 * was previously logged, make sure the next log attempt on the directory
-	 * is not skipped and logs the inode again. This is because the log may
-	 * not currently be authoritative for a range including the old
-	 * BTRFS_DIR_INDEX_KEY key, so we want to make sure after a log replay we
-	 * do not end up with both the new and old dentries around (in case the
-	 * inode is a directory we would have a directory with two hard links and
-	 * 2 inode references for different parents). The next log attempt of
-	 * old_dir will happen at btrfs_log_all_parents(), called through
-	 * btrfs_log_inode_parent() below, because we have previously set
-	 * inode->last_unlink_trans to the current transaction ID, either here or
-	 * at btrfs_record_unlink_dir() in case the inode is a directory.
+	 * was previously logged, make sure that on log replay we get the old
+	 * dir entry deleted. This is needed because we will also log the new
+	 * name of the renamed inode, so we need to make sure that after log
+	 * replay we don't end up with both the new and old dir entries existing.
 	 */
-	if (old_dir)
-		old_dir->logged_trans = 0;
+	if (old_dir && old_dir->logged_trans == trans->transid) {
+		struct btrfs_root *log = old_dir->root->log_root;
+		struct btrfs_path *path;
+
+		ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX);
+
+		/*
+		 * We have two inodes to update in the log, the old directory and
+		 * the inode that got renamed, so we must pin the log to prevent
+		 * anyone from syncing the log until we have updated both inodes
+		 * in the log.
+		 */
+		log_pinned = true;
+		btrfs_pin_log_trans(root);
+
+		path = btrfs_alloc_path();
+		if (!path) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		/*
+		 * Other concurrent task might be logging the old directory,
+		 * as it can be triggered when logging other inode that had or
+		 * still has a dentry in the old directory. So take the old
+		 * directory's log_mutex to prevent getting an -EEXIST when
+		 * logging a key to record the deletion, or having that other
+		 * task logging the old directory get an -EEXIST if it attempts
+		 * to log the same key after we just did it. In both cases that
+		 * would result in falling back to a transaction commit.
+		 */
+		mutex_lock(&old_dir->log_mutex);
+		ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir),
+					old_dentry->d_name.name,
+					old_dentry->d_name.len, old_dir_index);
+		if (ret > 0) {
+			/*
+			 * The dentry does not exist in the log, so record its
+			 * deletion.
+			 */
+			btrfs_release_path(path);
+			ret = insert_dir_log_key(trans, log, path,
+						 btrfs_ino(old_dir),
+						 old_dir_index, old_dir_index);
+		}
+		mutex_unlock(&old_dir->log_mutex);
+
+		btrfs_free_path(path);
+		if (ret < 0)
+			goto out;
+	}
 
 	btrfs_init_log_ctx(&ctx, &inode->vfs_inode);
 	ctx.logging_new_name = true;
@@ -6825,5 +7056,16 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 	 * inconsistent state after a rename operation.
 	 */
 	btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
+out:
+	/*
+	 * If an error happened mark the log for a full commit because it's not
+	 * consistent and up to date or we couldn't find out if one of the
+	 * inodes was logged before in this transaction. Do it before unpinning
+	 * the log, to avoid any races with someone else trying to commit it.
+	 */
+	if (ret < 0)
+		btrfs_set_log_full_commit(trans);
+	if (log_pinned)
+		btrfs_end_log_trans(root);
 }
 
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index f6811c3df38a..1620f8170629 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -17,6 +17,8 @@ struct btrfs_log_ctx {
 	int log_transid;
 	bool log_new_dentries;
 	bool logging_new_name;
+	/* Indicate if the inode being logged was logged before. */
+	bool logged_before;
 	/* Tracks the last logged dir item/index key offset. */
 	u64 last_dir_item_offset;
 	struct inode *inode;
@@ -32,6 +34,7 @@ static inline void btrfs_init_log_ctx(struct btrfs_log_ctx *ctx,
 	ctx->log_transid = 0;
 	ctx->log_new_dentries = false;
 	ctx->logging_new_name = false;
+	ctx->logged_before = false;
 	ctx->inode = inode;
 	INIT_LIST_HEAD(&ctx->list);
 	INIT_LIST_HEAD(&ctx->ordered_extents);
@@ -86,7 +89,7 @@ void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
 void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
 				   struct btrfs_inode *dir);
 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
-			struct btrfs_inode *inode, struct btrfs_inode *old_dir,
-			struct dentry *parent);
+			struct dentry *old_dentry, struct btrfs_inode *old_dir,
+			u64 old_dir_index, struct dentry *parent);
 
 #endif
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index b07d382d53a8..1be7cb2f955f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -534,30 +534,20 @@ error:
 	return ret;
 }
 
-static bool device_path_matched(const char *path, struct btrfs_device *device)
-{
-	int found;
-
-	rcu_read_lock();
-	found = strcmp(rcu_str_deref(device->name), path);
-	rcu_read_unlock();
-
-	return found == 0;
-}
-
-/*
- *  Search and remove all stale (devices which are not mounted) devices.
+/**
+ *  Search and remove all stale devices (which are not mounted).
  *  When both inputs are NULL, it will search and release all stale devices.
- *  path:	Optional. When provided will it release all unmounted devices
- *		matching this path only.
- *  skip_dev:	Optional. Will skip this device when searching for the stale
+ *
+ *  @devt:	Optional. When provided will it release all unmounted devices
+ *		matching this devt only.
+ *  @skip_device:  Optional. Will skip this device when searching for the stale
  *		devices.
- *  Return:	0 for success or if @path is NULL.
- * 		-EBUSY if @path is a mounted device.
- * 		-ENOENT if @path does not match any device in the list.
+ *
+ *  Return:	0 for success or if @devt is 0.
+ *		-EBUSY if @devt is a mounted device.
+ *		-ENOENT if @devt does not match any device in the list.
  */
-static int btrfs_free_stale_devices(const char *path,
-				     struct btrfs_device *skip_device)
+static int btrfs_free_stale_devices(dev_t devt, struct btrfs_device *skip_device)
 {
 	struct btrfs_fs_devices *fs_devices, *tmp_fs_devices;
 	struct btrfs_device *device, *tmp_device;
@@ -565,7 +555,7 @@ static int btrfs_free_stale_devices(const char *path,
 
 	lockdep_assert_held(&uuid_mutex);
 
-	if (path)
+	if (devt)
 		ret = -ENOENT;
 
 	list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) {
@@ -575,13 +565,11 @@ static int btrfs_free_stale_devices(const char *path,
 					 &fs_devices->devices, dev_list) {
 			if (skip_device && skip_device == device)
 				continue;
-			if (path && !device->name)
-				continue;
-			if (path && !device_path_matched(path, device))
+			if (devt && devt != device->devt)
 				continue;
 			if (fs_devices->opened) {
 				/* for an already deleted device return 0 */
-				if (path && ret != 0)
+				if (devt && ret != 0)
 					ret = -EBUSY;
 				break;
 			}
@@ -614,7 +602,6 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 			struct btrfs_device *device, fmode_t flags,
 			void *holder)
 {
-	struct request_queue *q;
 	struct block_device *bdev;
 	struct btrfs_super_block *disk_super;
 	u64 devid;
@@ -656,8 +643,7 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 			set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
 	}
 
-	q = bdev_get_queue(bdev);
-	if (!blk_queue_nonrot(q))
+	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
 		fs_devices->rotating = true;
 
 	device->bdev = bdev;
@@ -781,11 +767,17 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 	struct rcu_string *name;
 	u64 found_transid = btrfs_super_generation(disk_super);
 	u64 devid = btrfs_stack_device_id(&disk_super->dev_item);
+	dev_t path_devt;
+	int error;
 	bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) &
 		BTRFS_FEATURE_INCOMPAT_METADATA_UUID);
 	bool fsid_change_in_progress = (btrfs_super_flags(disk_super) &
 					BTRFS_SUPER_FLAG_CHANGING_FSID_V2);
 
+	error = lookup_bdev(path, &path_devt);
+	if (error)
+		return ERR_PTR(error);
+
 	if (fsid_change_in_progress) {
 		if (!has_metadata_uuid)
 			fs_devices = find_fsid_inprogress(disk_super);
@@ -868,6 +860,7 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 			return ERR_PTR(-ENOMEM);
 		}
 		rcu_assign_pointer(device->name, name);
+		device->devt = path_devt;
 
 		list_add_rcu(&device->dev_list, &fs_devices->devices);
 		fs_devices->num_devices++;
@@ -928,25 +921,15 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 		/*
 		 * We are going to replace the device path for a given devid,
 		 * make sure it's the same device if the device is mounted
+		 *
+		 * NOTE: the device->fs_info may not be reliable here so pass
+		 * in a NULL to message helpers instead. This avoids a possible
+		 * use-after-free when the fs_info and fs_info->sb are already
+		 * torn down.
 		 */
 		if (device->bdev) {
-			int error;
-			dev_t path_dev;
-
-			error = lookup_bdev(path, &path_dev);
-			if (error) {
-				mutex_unlock(&fs_devices->device_list_mutex);
-				return ERR_PTR(error);
-			}
-
-			if (device->bdev->bd_dev != path_dev) {
+			if (device->devt != path_devt) {
 				mutex_unlock(&fs_devices->device_list_mutex);
-				/*
-				 * device->fs_info may not be reliable here, so
-				 * pass in a NULL instead. This avoids a
-				 * possible use-after-free when the fs_info and
-				 * fs_info->sb are already torn down.
-				 */
 				btrfs_warn_in_rcu(NULL,
 	"duplicate device %s devid %llu generation %llu scanned by %s (%d)",
 						  path, devid, found_transid,
@@ -954,7 +937,7 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 						  task_pid_nr(current));
 				return ERR_PTR(-EEXIST);
 			}
-			btrfs_info_in_rcu(device->fs_info,
+			btrfs_info_in_rcu(NULL,
 	"devid %llu device path %s changed to %s scanned by %s (%d)",
 					  devid, rcu_str_deref(device->name),
 					  path, current->comm,
@@ -972,6 +955,7 @@ static noinline struct btrfs_device *device_list_add(const char *path,
 			fs_devices->missing_devices--;
 			clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
 		}
+		device->devt = path_devt;
 	}
 
 	/*
@@ -1331,12 +1315,12 @@ static struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev
 	return disk_super;
 }
 
-int btrfs_forget_devices(const char *path)
+int btrfs_forget_devices(dev_t devt)
 {
 	int ret;
 
 	mutex_lock(&uuid_mutex);
-	ret = btrfs_free_stale_devices(strlen(path) ? path : NULL, NULL);
+	ret = btrfs_free_stale_devices(devt, NULL);
 	mutex_unlock(&uuid_mutex);
 
 	return ret;
@@ -1385,10 +1369,8 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
 	}
 
 	device = device_list_add(path, disk_super, &new_device_added);
-	if (!IS_ERR(device)) {
-		if (new_device_added)
-			btrfs_free_stale_devices(path, device);
-	}
+	if (!IS_ERR(device) && new_device_added)
+		btrfs_free_stale_devices(device->devt, device);
 
 	btrfs_release_disk_super(disk_super);
 
@@ -2102,6 +2084,11 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info,
 	u64 num_devices;
 	int ret = 0;
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info, "device remove not supported on extent tree v2 yet");
+		return -EINVAL;
+	}
+
 	/*
 	 * The device list in fs_devices is accessed without locks (neither
 	 * uuid_mutex nor device_list_mutex) as it won't change on a mounted
@@ -2606,7 +2593,6 @@ error:
 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path)
 {
 	struct btrfs_root *root = fs_info->dev_root;
-	struct request_queue *q;
 	struct btrfs_trans_handle *trans;
 	struct btrfs_device *device;
 	struct block_device *bdev;
@@ -2668,6 +2654,9 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 
 	device->fs_info = fs_info;
 	device->bdev = bdev;
+	ret = lookup_bdev(device_path, &device->devt);
+	if (ret)
+		goto error_free_device;
 
 	ret = btrfs_get_dev_zone_info(device, false);
 	if (ret)
@@ -2679,7 +2668,6 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 		goto error_free_zone;
 	}
 
-	q = bdev_get_queue(bdev);
 	set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
 	device->generation = trans->transid;
 	device->io_width = fs_info->sectorsize;
@@ -2727,7 +2715,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 
 	atomic64_add(device->total_bytes, &fs_info->free_chunk_space);
 
-	if (!blk_queue_nonrot(q))
+	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
 		fs_devices->rotating = true;
 
 	orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
@@ -2814,7 +2802,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
 	 * We can ignore the return value as it typically returns -EINVAL and
 	 * only succeeds if the device was an alien.
 	 */
-	btrfs_forget_devices(device_path);
+	btrfs_forget_devices(device->devt);
 
 	/* Update ctime/mtime for blkid or udev */
 	update_dev_time(device_path);
@@ -3251,6 +3239,12 @@ int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset)
 	u64 length;
 	int ret;
 
+	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) {
+		btrfs_err(fs_info,
+			  "relocate: not supported on extent tree v2 yet");
+		return -EINVAL;
+	}
+
 	/*
 	 * Prevent races with automatic removal of unused block groups.
 	 * After we relocate and before we remove the chunk with offset
@@ -7060,6 +7054,27 @@ static void warn_32bit_meta_chunk(struct btrfs_fs_info *fs_info,
 }
 #endif
 
+static struct btrfs_device *handle_missing_device(struct btrfs_fs_info *fs_info,
+						  u64 devid, u8 *uuid)
+{
+	struct btrfs_device *dev;
+
+	if (!btrfs_test_opt(fs_info, DEGRADED)) {
+		btrfs_report_missing_device(fs_info, devid, uuid, true);
+		return ERR_PTR(-ENOENT);
+	}
+
+	dev = add_missing_dev(fs_info->fs_devices, devid, uuid);
+	if (IS_ERR(dev)) {
+		btrfs_err(fs_info, "failed to init missing device %llu: %ld",
+			  devid, PTR_ERR(dev));
+		return dev;
+	}
+	btrfs_report_missing_device(fs_info, devid, uuid, false);
+
+	return dev;
+}
+
 static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
 			  struct btrfs_chunk *chunk)
 {
@@ -7147,28 +7162,17 @@ static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
 				   BTRFS_UUID_SIZE);
 		args.uuid = uuid;
 		map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices, &args);
-		if (!map->stripes[i].dev &&
-		    !btrfs_test_opt(fs_info, DEGRADED)) {
-			free_extent_map(em);
-			btrfs_report_missing_device(fs_info, devid, uuid, true);
-			return -ENOENT;
-		}
 		if (!map->stripes[i].dev) {
-			map->stripes[i].dev =
-				add_missing_dev(fs_info->fs_devices, devid,
-						uuid);
+			map->stripes[i].dev = handle_missing_device(fs_info,
+								    devid, uuid);
 			if (IS_ERR(map->stripes[i].dev)) {
 				free_extent_map(em);
-				btrfs_err(fs_info,
-					"failed to init missing dev %llu: %ld",
-					devid, PTR_ERR(map->stripes[i].dev));
 				return PTR_ERR(map->stripes[i].dev);
 			}
-			btrfs_report_missing_device(fs_info, devid, uuid, false);
 		}
+
 		set_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
 				&(map->stripes[i].dev->dev_state));
-
 	}
 
 	write_lock(&map_tree->lock);
@@ -8299,10 +8303,12 @@ static int relocating_repair_kthread(void *data)
 	target = cache->start;
 	btrfs_put_block_group(cache);
 
+	sb_start_write(fs_info->sb);
 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
 		btrfs_info(fs_info,
 			   "zoned: skip relocating block group %llu to repair: EBUSY",
 			   target);
+		sb_end_write(fs_info->sb);
 		return -EBUSY;
 	}
 
@@ -8330,6 +8336,7 @@ out:
 		btrfs_put_block_group(cache);
 	mutex_unlock(&fs_info->reclaim_bgs_lock);
 	btrfs_exclop_finish(fs_info);
+	sb_end_write(fs_info->sb);
 
 	return ret;
 }
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 005c9e2a491a..bd297f23d19e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -72,6 +72,11 @@ struct btrfs_device {
 	/* the mode sent to blkdev_get */
 	fmode_t mode;
 
+	/*
+	 * Device's major-minor number. Must be set even if the device is not
+	 * opened (bdev == NULL), unless the device is missing.
+	 */
+	dev_t devt;
 	unsigned long dev_state;
 	blk_status_t last_flush_error;
 
@@ -505,7 +510,7 @@ int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		       fmode_t flags, void *holder);
 struct btrfs_device *btrfs_scan_one_device(const char *path,
 					   fmode_t flags, void *holder);
-int btrfs_forget_devices(const char *path);
+int btrfs_forget_devices(dev_t devt);
 void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
 void btrfs_assign_next_active_device(struct btrfs_device *device,
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index f559d517c7c4..b7b5fac1c779 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -652,8 +652,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 		if (model == BLK_ZONED_HM ||
 		    (model == BLK_ZONED_HA && incompat_zoned) ||
 		    (model == BLK_ZONED_NONE && incompat_zoned)) {
-			struct btrfs_zoned_device_info *zone_info =
-				device->zone_info;
+			struct btrfs_zoned_device_info *zone_info;
 
 			zone_info = device->zone_info;
 			zoned_devices++;
@@ -1215,12 +1214,12 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 	struct btrfs_device *device;
 	u64 logical = cache->start;
 	u64 length = cache->length;
-	u64 physical = 0;
 	int ret;
 	int i;
 	unsigned int nofs_flag;
 	u64 *alloc_offsets = NULL;
 	u64 *caps = NULL;
+	u64 *physical = NULL;
 	unsigned long *active = NULL;
 	u64 last_alloc = 0;
 	u32 num_sequential = 0, num_conventional = 0;
@@ -1264,6 +1263,12 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		goto out;
 	}
 
+	physical = kcalloc(map->num_stripes, sizeof(*physical), GFP_NOFS);
+	if (!physical) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
 	active = bitmap_zalloc(map->num_stripes, GFP_NOFS);
 	if (!active) {
 		ret = -ENOMEM;
@@ -1277,14 +1282,14 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		int dev_replace_is_ongoing = 0;
 
 		device = map->stripes[i].dev;
-		physical = map->stripes[i].physical;
+		physical[i] = map->stripes[i].physical;
 
 		if (device->bdev == NULL) {
 			alloc_offsets[i] = WP_MISSING_DEV;
 			continue;
 		}
 
-		is_sequential = btrfs_dev_is_sequential(device, physical);
+		is_sequential = btrfs_dev_is_sequential(device, physical[i]);
 		if (is_sequential)
 			num_sequential++;
 		else
@@ -1299,21 +1304,21 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		 * This zone will be used for allocation, so mark this zone
 		 * non-empty.
 		 */
-		btrfs_dev_clear_zone_empty(device, physical);
+		btrfs_dev_clear_zone_empty(device, physical[i]);
 
 		down_read(&dev_replace->rwsem);
 		dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
 		if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL)
-			btrfs_dev_clear_zone_empty(dev_replace->tgtdev, physical);
+			btrfs_dev_clear_zone_empty(dev_replace->tgtdev, physical[i]);
 		up_read(&dev_replace->rwsem);
 
 		/*
 		 * The group is mapped to a sequential zone. Get the zone write
 		 * pointer to determine the allocation offset within the zone.
 		 */
-		WARN_ON(!IS_ALIGNED(physical, fs_info->zone_size));
+		WARN_ON(!IS_ALIGNED(physical[i], fs_info->zone_size));
 		nofs_flag = memalloc_nofs_save();
-		ret = btrfs_get_dev_zone(device, physical, &zone);
+		ret = btrfs_get_dev_zone(device, physical[i], &zone);
 		memalloc_nofs_restore(nofs_flag);
 		if (ret == -EIO || ret == -EOPNOTSUPP) {
 			ret = 0;
@@ -1339,7 +1344,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		case BLK_ZONE_COND_READONLY:
 			btrfs_err(fs_info,
 		"zoned: offline/readonly zone %llu on device %s (devid %llu)",
-				  physical >> device->zone_info->zone_size_shift,
+				  physical[i] >> device->zone_info->zone_size_shift,
 				  rcu_str_deref(device->name), device->devid);
 			alloc_offsets[i] = WP_MISSING_DEV;
 			break;
@@ -1404,7 +1409,7 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		if (alloc_offsets[0] == WP_MISSING_DEV) {
 			btrfs_err(fs_info,
 			"zoned: cannot recover write pointer for zone %llu",
-				physical);
+				physical[0]);
 			ret = -EIO;
 			goto out;
 		}
@@ -1413,6 +1418,42 @@ int btrfs_load_block_group_zone_info(struct btrfs_block_group *cache, bool new)
 		cache->zone_is_active = test_bit(0, active);
 		break;
 	case BTRFS_BLOCK_GROUP_DUP:
+		if (map->type & BTRFS_BLOCK_GROUP_DATA) {
+			btrfs_err(fs_info, "zoned: profile DUP not yet supported on data bg");
+			ret = -EINVAL;
+			goto out;
+		}
+		if (alloc_offsets[0] == WP_MISSING_DEV) {
+			btrfs_err(fs_info,
+			"zoned: cannot recover write pointer for zone %llu",
+				physical[0]);
+			ret = -EIO;
+			goto out;
+		}
+		if (alloc_offsets[1] == WP_MISSING_DEV) {
+			btrfs_err(fs_info,
+			"zoned: cannot recover write pointer for zone %llu",
+				physical[1]);
+			ret = -EIO;
+			goto out;
+		}
+		if (alloc_offsets[0] != alloc_offsets[1]) {
+			btrfs_err(fs_info,
+			"zoned: write pointer offset mismatch of zones in DUP profile");
+			ret = -EIO;
+			goto out;
+		}
+		if (test_bit(0, active) != test_bit(1, active)) {
+			if (!btrfs_zone_activate(cache)) {
+				ret = -EIO;
+				goto out;
+			}
+		} else {
+			cache->zone_is_active = test_bit(0, active);
+		}
+		cache->alloc_offset = alloc_offsets[0];
+		cache->zone_capacity = min(caps[0], caps[1]);
+		break;
 	case BTRFS_BLOCK_GROUP_RAID1:
 	case BTRFS_BLOCK_GROUP_RAID0:
 	case BTRFS_BLOCK_GROUP_RAID10:
@@ -1465,6 +1506,7 @@ out:
 		cache->physical_map = NULL;
 	}
 	bitmap_free(active);
+	kfree(physical);
 	kfree(caps);
 	kfree(alloc_offsets);
 	free_extent_map(em);
@@ -1781,50 +1823,55 @@ bool btrfs_zone_activate(struct btrfs_block_group *block_group)
 	struct btrfs_device *device;
 	u64 physical;
 	bool ret;
+	int i;
 
 	if (!btrfs_is_zoned(block_group->fs_info))
 		return true;
 
 	map = block_group->physical_map;
-	/* Currently support SINGLE profile only */
-	ASSERT(map->num_stripes == 1);
-	device = map->stripes[0].dev;
-	physical = map->stripes[0].physical;
-
-	if (device->zone_info->max_active_zones == 0)
-		return true;
 
 	spin_lock(&block_group->lock);
-
 	if (block_group->zone_is_active) {
 		ret = true;
 		goto out_unlock;
 	}
 
-	/* No space left */
-	if (block_group->alloc_offset == block_group->zone_capacity) {
-		ret = false;
-		goto out_unlock;
-	}
+	for (i = 0; i < map->num_stripes; i++) {
+		device = map->stripes[i].dev;
+		physical = map->stripes[i].physical;
 
-	if (!btrfs_dev_set_active_zone(device, physical)) {
-		/* Cannot activate the zone */
-		ret = false;
-		goto out_unlock;
-	}
+		if (device->zone_info->max_active_zones == 0)
+			continue;
+
+		/* No space left */
+		if (block_group->alloc_offset == block_group->zone_capacity) {
+			ret = false;
+			goto out_unlock;
+		}
+
+		if (!btrfs_dev_set_active_zone(device, physical)) {
+			/* Cannot activate the zone */
+			ret = false;
+			goto out_unlock;
+		}
+
+		/* Successfully activated all the zones */
+		if (i == map->num_stripes - 1)
+			block_group->zone_is_active = 1;
 
-	/* Successfully activated all the zones */
-	block_group->zone_is_active = 1;
 
+	}
 	spin_unlock(&block_group->lock);
 
-	/* For the active block group list */
-	btrfs_get_block_group(block_group);
+	if (block_group->zone_is_active) {
+		/* For the active block group list */
+		btrfs_get_block_group(block_group);
 
-	spin_lock(&fs_info->zone_active_bgs_lock);
-	ASSERT(list_empty(&block_group->active_bg_list));
-	list_add_tail(&block_group->active_bg_list, &fs_info->zone_active_bgs);
-	spin_unlock(&fs_info->zone_active_bgs_lock);
+		spin_lock(&fs_info->zone_active_bgs_lock);
+		list_add_tail(&block_group->active_bg_list,
+			      &fs_info->zone_active_bgs);
+		spin_unlock(&fs_info->zone_active_bgs_lock);
+	}
 
 	return true;
 
@@ -1840,19 +1887,12 @@ int btrfs_zone_finish(struct btrfs_block_group *block_group)
 	struct btrfs_device *device;
 	u64 physical;
 	int ret = 0;
+	int i;
 
 	if (!btrfs_is_zoned(fs_info))
 		return 0;
 
 	map = block_group->physical_map;
-	/* Currently support SINGLE profile only */
-	ASSERT(map->num_stripes == 1);
-
-	device = map->stripes[0].dev;
-	physical = map->stripes[0].physical;
-
-	if (device->zone_info->max_active_zones == 0)
-		return 0;
 
 	spin_lock(&block_group->lock);
 	if (!block_group->zone_is_active) {
@@ -1904,25 +1944,34 @@ int btrfs_zone_finish(struct btrfs_block_group *block_group)
 	btrfs_clear_data_reloc_bg(block_group);
 	spin_unlock(&block_group->lock);
 
-	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
-			       physical >> SECTOR_SHIFT,
-			       device->zone_info->zone_size >> SECTOR_SHIFT,
-			       GFP_NOFS);
-	btrfs_dec_block_group_ro(block_group);
+	for (i = 0; i < map->num_stripes; i++) {
+		device = map->stripes[i].dev;
+		physical = map->stripes[i].physical;
 
-	if (!ret) {
-		btrfs_dev_clear_active_zone(device, physical);
+		if (device->zone_info->max_active_zones == 0)
+			continue;
 
-		spin_lock(&fs_info->zone_active_bgs_lock);
-		ASSERT(!list_empty(&block_group->active_bg_list));
-		list_del_init(&block_group->active_bg_list);
-		spin_unlock(&fs_info->zone_active_bgs_lock);
+		ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
+				       physical >> SECTOR_SHIFT,
+				       device->zone_info->zone_size >> SECTOR_SHIFT,
+				       GFP_NOFS);
 
-		/* For active_bg_list */
-		btrfs_put_block_group(block_group);
+		if (ret)
+			return ret;
+
+		btrfs_dev_clear_active_zone(device, physical);
 	}
+	btrfs_dec_block_group_ro(block_group);
 
-	return ret;
+	spin_lock(&fs_info->zone_active_bgs_lock);
+	ASSERT(!list_empty(&block_group->active_bg_list));
+	list_del_init(&block_group->active_bg_list);
+	spin_unlock(&fs_info->zone_active_bgs_lock);
+
+	/* For active_bg_list */
+	btrfs_put_block_group(block_group);
+
+	return 0;
 }
 
 bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, u64 flags)
diff --git a/fs/internal.h b/fs/internal.h
index 56c0477f4215..fb2c2ea807d7 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -158,11 +158,6 @@ extern void dput_to_list(struct dentry *, struct list_head *);
 extern void shrink_dentry_list(struct list_head *);
 
 /*
- * read_write.c
- */
-extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
-
-/*
  * pipe.c
  */
 extern const struct file_operations pipefifo_fops;
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 1ed097e94af2..090bf47606ab 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -236,9 +236,6 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 
 	if (!src_file.file)
 		return -EBADF;
-	ret = -EXDEV;
-	if (src_file.file->f_path.mnt != dst_file->f_path.mnt)
-		goto fdput;
 	cloned = vfs_clone_file_range(src_file.file, off, dst_file, destoff,
 				      olen, 0);
 	if (cloned < 0)
@@ -247,7 +244,6 @@ static long ioctl_file_clone(struct file *dst_file, unsigned long srcfd,
 		ret = -EINVAL;
 	else
 		ret = 0;
-fdput:
 	fdput(src_file);
 	return ret;
 }
diff --git a/fs/read_write.c b/fs/read_write.c
index 0074afa7ecb3..dc5000173b80 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -385,6 +385,7 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
 	return security_file_permission(file,
 				read_write == READ ? MAY_READ : MAY_WRITE);
 }
+EXPORT_SYMBOL(rw_verify_area);
 
 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
@@ -1617,24 +1618,16 @@ int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count)
 	return 0;
 }
 
-/*
- * Performs necessary checks before doing a write
- *
- * Can adjust writing position or amount of bytes to write.
- * Returns appropriate error code that caller should return or
- * zero in case that write should be allowed.
- */
-ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
+/* Like generic_write_checks(), but takes size of write instead of iter. */
+int generic_write_checks_count(struct kiocb *iocb, loff_t *count)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
-	loff_t count;
-	int ret;
 
 	if (IS_SWAPFILE(inode))
 		return -ETXTBSY;
 
-	if (!iov_iter_count(from))
+	if (!*count)
 		return 0;
 
 	/* FIXME: this is for backwards compatibility with 2.4 */
@@ -1644,8 +1637,23 @@ ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
 	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
 		return -EINVAL;
 
-	count = iov_iter_count(from);
-	ret = generic_write_check_limits(file, iocb->ki_pos, &count);
+	return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count);
+}
+EXPORT_SYMBOL(generic_write_checks_count);
+
+/*
+ * Performs necessary checks before doing a write
+ *
+ * Can adjust writing position or amount of bytes to write.
+ * Returns appropriate error code that caller should return or
+ * zero in case that write should be allowed.
+ */
+ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
+{
+	loff_t count = iov_iter_count(from);
+	int ret;
+
+	ret = generic_write_checks_count(iocb, &count);
 	if (ret)
 		return ret;
 
diff --git a/fs/remap_range.c b/fs/remap_range.c
index 231159682907..bc5fb006dc79 100644
--- a/fs/remap_range.c
+++ b/fs/remap_range.c
@@ -362,11 +362,6 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
 
 	WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP);
 
-	/*
-	 * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on
-	 * the same mount. Practically, they only need to be on the same file
-	 * system.
-	 */
 	if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
 		return -EXDEV;
 
@@ -458,7 +453,7 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
 		goto out_drop_write;
 
 	ret = -EXDEV;
-	if (src_file->f_path.mnt != dst_file->f_path.mnt)
+	if (file_inode(src_file)->i_sb != file_inode(dst_file)->i_sb)
 		goto out_drop_write;
 
 	ret = -EISDIR;