Merge tag 'v3.5-rc4' into for-3.6

Linux 3.5-rc4 contains some bug fixes which overlap with new features.

18 files changed, 535 insertions, 231 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 3f75895c919b..7301cdb4b2cb 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -179,60 +179,74 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id,
 
 static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
 				struct ulist *parents, int level,
-				struct btrfs_key *key, u64 wanted_disk_byte,
+				struct btrfs_key *key_for_search, u64 time_seq,
+				u64 wanted_disk_byte,
 				const u64 *extent_item_pos)
 {
-	int ret;
-	int slot = path->slots[level];
-	struct extent_buffer *eb = path->nodes[level];
+	int ret = 0;
+	int slot;
+	struct extent_buffer *eb;
+	struct btrfs_key key;
 	struct btrfs_file_extent_item *fi;
 	struct extent_inode_elem *eie = NULL;
 	u64 disk_byte;
-	u64 wanted_objectid = key->objectid;
 
-add_parent:
-	if (level == 0 && extent_item_pos) {
-		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
-		ret = check_extent_in_eb(key, eb, fi, *extent_item_pos, &eie);
+	if (level != 0) {
+		eb = path->nodes[level];
+		ret = ulist_add(parents, eb->start, 0, GFP_NOFS);
 		if (ret < 0)
 			return ret;
-	}
-	ret = ulist_add(parents, eb->start, (unsigned long)eie, GFP_NOFS);
-	if (ret < 0)
-		return ret;
-
-	if (level != 0)
 		return 0;
+	}
 
 	/*
-	 * if the current leaf is full with EXTENT_DATA items, we must
-	 * check the next one if that holds a reference as well.
-	 * ref->count cannot be used to skip this check.
-	 * repeat this until we don't find any additional EXTENT_DATA items.
+	 * We normally enter this function with the path already pointing to
+	 * the first item to check. But sometimes, we may enter it with
+	 * slot==nritems. In that case, go to the next leaf before we continue.
 	 */
-	while (1) {
-		eie = NULL;
-		ret = btrfs_next_leaf(root, path);
-		if (ret < 0)
-			return ret;
-		if (ret)
-			return 0;
+	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
+		ret = btrfs_next_old_leaf(root, path, time_seq);
 
+	while (!ret) {
 		eb = path->nodes[0];
-		for (slot = 0; slot < btrfs_header_nritems(eb); ++slot) {
-			btrfs_item_key_to_cpu(eb, key, slot);
-			if (key->objectid != wanted_objectid ||
-			    key->type != BTRFS_EXTENT_DATA_KEY)
-				return 0;
-			fi = btrfs_item_ptr(eb, slot,
-						struct btrfs_file_extent_item);
-			disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
-			if (disk_byte == wanted_disk_byte)
-				goto add_parent;
+		slot = path->slots[0];
+
+		btrfs_item_key_to_cpu(eb, &key, slot);
+
+		if (key.objectid != key_for_search->objectid ||
+		    key.type != BTRFS_EXTENT_DATA_KEY)
+			break;
+
+		fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
+		disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
+
+		if (disk_byte == wanted_disk_byte) {
+			eie = NULL;
+			if (extent_item_pos) {
+				ret = check_extent_in_eb(&key, eb, fi,
+						*extent_item_pos,
+						&eie);
+				if (ret < 0)
+					break;
+			}
+			if (!ret) {
+				ret = ulist_add(parents, eb->start,
+						(unsigned long)eie, GFP_NOFS);
+				if (ret < 0)
+					break;
+				if (!extent_item_pos) {
+					ret = btrfs_next_old_leaf(root, path,
+							time_seq);
+					continue;
+				}
+			}
 		}
+		ret = btrfs_next_old_item(root, path, time_seq);
 	}
 
-	return 0;
+	if (ret > 0)
+		ret = 0;
+	return ret;
 }
 
 /*
@@ -249,7 +263,6 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 	struct btrfs_path *path;
 	struct btrfs_root *root;
 	struct btrfs_key root_key;
-	struct btrfs_key key = {0};
 	struct extent_buffer *eb;
 	int ret = 0;
 	int root_level;
@@ -294,19 +307,9 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 		goto out;
 	}
 
-	if (level == 0) {
-		if (ret == 1 && path->slots[0] >= btrfs_header_nritems(eb)) {
-			ret = btrfs_next_leaf(root, path);
-			if (ret)
-				goto out;
-			eb = path->nodes[0];
-		}
-
-		btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
-	}
-
-	ret = add_all_parents(root, path, parents, level, &key,
-				ref->wanted_disk_byte, extent_item_pos);
+	ret = add_all_parents(root, path, parents, level, &ref->key_for_search,
+				time_seq, ref->wanted_disk_byte,
+				extent_item_pos);
 out:
 	btrfs_free_path(path);
 	return ret;
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index e616f8872e69..12394a90d60f 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -37,6 +37,7 @@
 #define BTRFS_INODE_IN_DEFRAG			3
 #define BTRFS_INODE_DELALLOC_META_RESERVED	4
 #define BTRFS_INODE_HAS_ORPHAN_ITEM		5
+#define BTRFS_INODE_HAS_ASYNC_EXTENT		6
 
 /* in memory btrfs inode */
 struct btrfs_inode {
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 9cebb1fd6a3c..da6e9364a5e3 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -93,6 +93,7 @@
 #include "print-tree.h"
 #include "locking.h"
 #include "check-integrity.h"
+#include "rcu-string.h"
 
 #define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
 #define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
@@ -843,13 +844,14 @@ static int btrfsic_process_superblock_dev_mirror(
 		superblock_tmp->never_written = 0;
 		superblock_tmp->mirror_num = 1 + superblock_mirror_num;
 		if (state->print_mask & BTRFSIC_PRINT_MASK_SUPERBLOCK_WRITE)
-			printk(KERN_INFO "New initial S-block (bdev %p, %s)"
-			       " @%llu (%s/%llu/%d)\n",
-			       superblock_bdev, device->name,
-			       (unsigned long long)dev_bytenr,
-			       dev_state->name,
-			       (unsigned long long)dev_bytenr,
-			       superblock_mirror_num);
+			printk_in_rcu(KERN_INFO "New initial S-block (bdev %p, %s)"
+				     " @%llu (%s/%llu/%d)\n",
+				     superblock_bdev,
+				     rcu_str_deref(device->name),
+				     (unsigned long long)dev_bytenr,
+				     dev_state->name,
+				     (unsigned long long)dev_bytenr,
+				     superblock_mirror_num);
 		list_add(&superblock_tmp->all_blocks_node,
 			 &state->all_blocks_list);
 		btrfsic_block_hashtable_add(superblock_tmp,
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index d7a96cfdc50a..15cbc2bf4ff0 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -467,6 +467,15 @@ static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
+/*
+ * This allocates memory and gets a tree modification sequence number when
+ * needed.
+ *
+ * Returns 0 when no sequence number is needed, < 0 on error.
+ * Returns 1 when a sequence number was added. In this case,
+ * fs_info->tree_mod_seq_lock was acquired and must be released by the caller
+ * after inserting into the rb tree.
+ */
 static inline int tree_mod_alloc(struct btrfs_fs_info *fs_info, gfp_t flags,
 				 struct tree_mod_elem **tm_ret)
 {
@@ -491,11 +500,11 @@ static inline int tree_mod_alloc(struct btrfs_fs_info *fs_info, gfp_t flags,
 		 */
 		kfree(tm);
 		seq = 0;
+		spin_unlock(&fs_info->tree_mod_seq_lock);
 	} else {
 		__get_tree_mod_seq(fs_info, &tm->elem);
 		seq = tm->elem.seq;
 	}
-	spin_unlock(&fs_info->tree_mod_seq_lock);
 
 	return seq;
 }
@@ -521,7 +530,9 @@ tree_mod_log_insert_key_mask(struct btrfs_fs_info *fs_info,
 	tm->slot = slot;
 	tm->generation = btrfs_node_ptr_generation(eb, slot);
 
-	return __tree_mod_log_insert(fs_info, tm);
+	ret = __tree_mod_log_insert(fs_info, tm);
+	spin_unlock(&fs_info->tree_mod_seq_lock);
+	return ret;
 }
 
 static noinline int
@@ -559,7 +570,9 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info,
 	tm->move.nr_items = nr_items;
 	tm->op = MOD_LOG_MOVE_KEYS;
 
-	return __tree_mod_log_insert(fs_info, tm);
+	ret = __tree_mod_log_insert(fs_info, tm);
+	spin_unlock(&fs_info->tree_mod_seq_lock);
+	return ret;
 }
 
 static noinline int
@@ -580,7 +593,9 @@ tree_mod_log_insert_root(struct btrfs_fs_info *fs_info,
 	tm->generation = btrfs_header_generation(old_root);
 	tm->op = MOD_LOG_ROOT_REPLACE;
 
-	return __tree_mod_log_insert(fs_info, tm);
+	ret = __tree_mod_log_insert(fs_info, tm);
+	spin_unlock(&fs_info->tree_mod_seq_lock);
+	return ret;
 }
 
 static struct tree_mod_elem *
@@ -1023,6 +1038,10 @@ __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info,
 		looped = 1;
 	}
 
+	/* if there's no old root to return, return what we found instead */
+	if (!found)
+		found = tm;
+
 	return found;
 }
 
@@ -1143,22 +1162,36 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb,
 	return eb_rewin;
 }
 
+/*
+ * get_old_root() rewinds the state of @root's root node to the given @time_seq
+ * value. If there are no changes, the current root->root_node is returned. If
+ * anything changed in between, there's a fresh buffer allocated on which the
+ * rewind operations are done. In any case, the returned buffer is read locked.
+ * Returns NULL on error (with no locks held).
+ */
 static inline struct extent_buffer *
 get_old_root(struct btrfs_root *root, u64 time_seq)
 {
 	struct tree_mod_elem *tm;
 	struct extent_buffer *eb;
-	struct tree_mod_root *old_root;
-	u64 old_generation;
+	struct tree_mod_root *old_root = NULL;
+	u64 old_generation = 0;
+	u64 logical;
 
+	eb = btrfs_read_lock_root_node(root);
 	tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq);
 	if (!tm)
 		return root->node;
 
-	old_root = &tm->old_root;
-	old_generation = tm->generation;
+	if (tm->op == MOD_LOG_ROOT_REPLACE) {
+		old_root = &tm->old_root;
+		old_generation = tm->generation;
+		logical = old_root->logical;
+	} else {
+		logical = root->node->start;
+	}
 
-	tm = tree_mod_log_search(root->fs_info, old_root->logical, time_seq);
+	tm = tree_mod_log_search(root->fs_info, logical, time_seq);
 	/*
 	 * there was an item in the log when __tree_mod_log_oldest_root
 	 * returned. this one must not go away, because the time_seq passed to
@@ -1166,22 +1199,25 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
 	 */
 	BUG_ON(!tm);
 
-	if (old_root->logical == root->node->start) {
-		/* there are logged operations for the current root */
-		eb = btrfs_clone_extent_buffer(root->node);
-	} else {
-		/* there's a root replace operation for the current root */
+	if (old_root)
 		eb = alloc_dummy_extent_buffer(tm->index << PAGE_CACHE_SHIFT,
 					       root->nodesize);
+	else
+		eb = btrfs_clone_extent_buffer(root->node);
+	btrfs_tree_read_unlock(root->node);
+	free_extent_buffer(root->node);
+	if (!eb)
+		return NULL;
+	btrfs_tree_read_lock(eb);
+	if (old_root) {
 		btrfs_set_header_bytenr(eb, eb->start);
 		btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV);
 		btrfs_set_header_owner(eb, root->root_key.objectid);
+		btrfs_set_header_level(eb, old_root->level);
+		btrfs_set_header_generation(eb, old_generation);
 	}
-	if (!eb)
-		return NULL;
-	btrfs_set_header_level(eb, old_root->level);
-	btrfs_set_header_generation(eb, old_generation);
 	__tree_mod_log_rewind(eb, time_seq, tm);
+	extent_buffer_get(eb);
 
 	return eb;
 }
@@ -1650,8 +1686,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 	    BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
 		return 0;
 
-	btrfs_header_nritems(mid);
-
 	left = read_node_slot(root, parent, pslot - 1);
 	if (left) {
 		btrfs_tree_lock(left);
@@ -1681,7 +1715,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		wret = push_node_left(trans, root, left, mid, 1);
 		if (wret < 0)
 			ret = wret;
-		btrfs_header_nritems(mid);
 	}
 
 	/*
@@ -2615,9 +2648,7 @@ int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key,
 
 again:
 	b = get_old_root(root, time_seq);
-	extent_buffer_get(b);
 	level = btrfs_header_level(b);
-	btrfs_tree_read_lock(b);
 	p->locks[level] = BTRFS_READ_LOCK;
 
 	while (b) {
@@ -5001,6 +5032,12 @@ next:
  */
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 {
+	return btrfs_next_old_leaf(root, path, 0);
+}
+
+int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
+			u64 time_seq)
+{
 	int slot;
 	int level;
 	struct extent_buffer *c;
@@ -5025,7 +5062,10 @@ again:
 	path->keep_locks = 1;
 	path->leave_spinning = 1;
 
-	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+	if (time_seq)
+		ret = btrfs_search_old_slot(root, &key, path, time_seq);
+	else
+		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	path->keep_locks = 0;
 
 	if (ret < 0)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0236d03c6732..fa5c45b39075 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2753,13 +2753,20 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 }
 
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
-static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
+int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
+			u64 time_seq);
+static inline int btrfs_next_old_item(struct btrfs_root *root,
+				      struct btrfs_path *p, u64 time_seq)
 {
 	++p->slots[0];
 	if (p->slots[0] >= btrfs_header_nritems(p->nodes[0]))
-		return btrfs_next_leaf(root, p);
+		return btrfs_next_old_leaf(root, p, time_seq);
 	return 0;
 }
+static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
+{
+	return btrfs_next_old_item(root, p, 0);
+}
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
 int __must_check btrfs_drop_snapshot(struct btrfs_root *root,
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index c18d0442ae6d..2399f4086915 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -1879,3 +1879,21 @@ void btrfs_kill_all_delayed_nodes(struct btrfs_root *root)
 		}
 	}
 }
+
+void btrfs_destroy_delayed_inodes(struct btrfs_root *root)
+{
+	struct btrfs_delayed_root *delayed_root;
+	struct btrfs_delayed_node *curr_node, *prev_node;
+
+	delayed_root = btrfs_get_delayed_root(root);
+
+	curr_node = btrfs_first_delayed_node(delayed_root);
+	while (curr_node) {
+		__btrfs_kill_delayed_node(curr_node);
+
+		prev_node = curr_node;
+		curr_node = btrfs_next_delayed_node(curr_node);
+		btrfs_release_delayed_node(prev_node);
+	}
+}
+
diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h
index 7083d08b2a21..f5aa4023d3e1 100644
--- a/fs/btrfs/delayed-inode.h
+++ b/fs/btrfs/delayed-inode.h
@@ -124,6 +124,9 @@ int btrfs_fill_inode(struct inode *inode, u32 *rdev);
 /* Used for drop dead root */
 void btrfs_kill_all_delayed_nodes(struct btrfs_root *root);
 
+/* Used for clean the transaction */
+void btrfs_destroy_delayed_inodes(struct btrfs_root *root);
+
 /* Used for readdir() */
 void btrfs_get_delayed_items(struct inode *inode, struct list_head *ins_list,
 			     struct list_head *del_list);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 7ae51decf6d3..7b845ff4af99 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -44,6 +44,7 @@
 #include "free-space-cache.h"
 #include "inode-map.h"
 #include "check-integrity.h"
+#include "rcu-string.h"
 
 static struct extent_io_ops btree_extent_io_ops;
 static void end_workqueue_fn(struct btrfs_work *work);
@@ -2118,7 +2119,7 @@ int open_ctree(struct super_block *sb,
 
 	features = btrfs_super_incompat_flags(disk_super);
 	features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
-	if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
+	if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
 		features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
 
 	/*
@@ -2575,8 +2576,9 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 		struct btrfs_device *device = (struct btrfs_device *)
 			bh->b_private;
 
-		printk_ratelimited(KERN_WARNING "lost page write due to "
-				   "I/O error on %s\n", device->name);
+		printk_ratelimited_in_rcu(KERN_WARNING "lost page write due to "
+					  "I/O error on %s\n",
+					  rcu_str_deref(device->name));
 		/* note, we dont' set_buffer_write_io_error because we have
 		 * our own ways of dealing with the IO errors
 		 */
@@ -2749,8 +2751,8 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
 		wait_for_completion(&device->flush_wait);
 
 		if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
-			printk("btrfs: disabling barriers on dev %s\n",
-			       device->name);
+			printk_in_rcu("btrfs: disabling barriers on dev %s\n",
+				      rcu_str_deref(device->name));
 			device->nobarriers = 1;
 		}
 		if (!bio_flagged(bio, BIO_UPTODATE)) {
@@ -3400,7 +3402,6 @@ int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 
 	delayed_refs = &trans->delayed_refs;
 
-again:
 	spin_lock(&delayed_refs->lock);
 	if (delayed_refs->num_entries == 0) {
 		spin_unlock(&delayed_refs->lock);
@@ -3408,31 +3409,37 @@ again:
 		return ret;
 	}
 
-	node = rb_first(&delayed_refs->root);
-	while (node) {
+	while ((node = rb_first(&delayed_refs->root)) != NULL) {
 		ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-		node = rb_next(node);
-
-		ref->in_tree = 0;
-		rb_erase(&ref->rb_node, &delayed_refs->root);
-		delayed_refs->num_entries--;
 
 		atomic_set(&ref->refs, 1);
 		if (btrfs_delayed_ref_is_head(ref)) {
 			struct btrfs_delayed_ref_head *head;
 
 			head = btrfs_delayed_node_to_head(ref);
-			spin_unlock(&delayed_refs->lock);
-			mutex_lock(&head->mutex);
+			if (!mutex_trylock(&head->mutex)) {
+				atomic_inc(&ref->refs);
+				spin_unlock(&delayed_refs->lock);
+
+				/* Need to wait for the delayed ref to run */
+				mutex_lock(&head->mutex);
+				mutex_unlock(&head->mutex);
+				btrfs_put_delayed_ref(ref);
+
+				spin_lock(&delayed_refs->lock);
+				continue;
+			}
+
 			kfree(head->extent_op);
 			delayed_refs->num_heads--;
 			if (list_empty(&head->cluster))
 				delayed_refs->num_heads_ready--;
 			list_del_init(&head->cluster);
-			mutex_unlock(&head->mutex);
-			btrfs_put_delayed_ref(ref);
-			goto again;
 		}
+		ref->in_tree = 0;
+		rb_erase(&ref->rb_node, &delayed_refs->root);
+		delayed_refs->num_entries--;
+
 		spin_unlock(&delayed_refs->lock);
 		btrfs_put_delayed_ref(ref);
 
@@ -3520,11 +3527,9 @@ static int btrfs_destroy_marked_extents(struct btrfs_root *root,
 			     &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
 					       offset >> PAGE_CACHE_SHIFT);
 			spin_unlock(&dirty_pages->buffer_lock);
-			if (eb) {
+			if (eb)
 				ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
 							 &eb->bflags);
-				atomic_set(&eb->refs, 1);
-			}
 			if (PageWriteback(page))
 				end_page_writeback(page);
 
@@ -3538,8 +3543,8 @@ static int btrfs_destroy_marked_extents(struct btrfs_root *root,
 				spin_unlock_irq(&page->mapping->tree_lock);
 			}
 
-			page->mapping->a_ops->invalidatepage(page, 0);
 			unlock_page(page);
+			page_cache_release(page);
 		}
 	}
 
@@ -3553,8 +3558,10 @@ static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
 	u64 start;
 	u64 end;
 	int ret;
+	bool loop = true;
 
 	unpin = pinned_extents;
+again:
 	while (1) {
 		ret = find_first_extent_bit(unpin, 0, &start, &end,
 					    EXTENT_DIRTY);
@@ -3572,6 +3579,15 @@ static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
 		cond_resched();
 	}
 
+	if (loop) {
+		if (unpin == &root->fs_info->freed_extents[0])
+			unpin = &root->fs_info->freed_extents[1];
+		else
+			unpin = &root->fs_info->freed_extents[0];
+		loop = false;
+		goto again;
+	}
+
 	return 0;
 }
 
@@ -3585,21 +3601,23 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 	/* FIXME: cleanup wait for commit */
 	cur_trans->in_commit = 1;
 	cur_trans->blocked = 1;
-	if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
-		wake_up(&root->fs_info->transaction_blocked_wait);
+	wake_up(&root->fs_info->transaction_blocked_wait);
 
 	cur_trans->blocked = 0;
-	if (waitqueue_active(&root->fs_info->transaction_wait))
-		wake_up(&root->fs_info->transaction_wait);
+	wake_up(&root->fs_info->transaction_wait);
 
 	cur_trans->commit_done = 1;
-	if (waitqueue_active(&cur_trans->commit_wait))
-		wake_up(&cur_trans->commit_wait);
+	wake_up(&cur_trans->commit_wait);
+
+	btrfs_destroy_delayed_inodes(root);
+	btrfs_assert_delayed_root_empty(root);
 
 	btrfs_destroy_pending_snapshots(cur_trans);
 
 	btrfs_destroy_marked_extents(root, &cur_trans->dirty_pages,
 				     EXTENT_DIRTY);
+	btrfs_destroy_pinned_extent(root,
+				    root->fs_info->pinned_extents);
 
 	/*
 	memset(cur_trans, 0, sizeof(*cur_trans));
@@ -3648,6 +3666,9 @@ int btrfs_cleanup_transaction(struct btrfs_root *root)
 		if (waitqueue_active(&t->commit_wait))
 			wake_up(&t->commit_wait);
 
+		btrfs_destroy_delayed_inodes(root);
+		btrfs_assert_delayed_root_empty(root);
+
 		btrfs_destroy_pending_snapshots(t);
 
 		btrfs_destroy_delalloc_inodes(root);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 2c8f7b204617..aaa12c1eb348 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -20,6 +20,7 @@
 #include "volumes.h"
 #include "check-integrity.h"
 #include "locking.h"
+#include "rcu-string.h"
 
 static struct kmem_cache *extent_state_cache;
 static struct kmem_cache *extent_buffer_cache;
@@ -1917,9 +1918,9 @@ int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
 		return -EIO;
 	}
 
-	printk(KERN_INFO "btrfs read error corrected: ino %lu off %llu (dev %s "
-			"sector %llu)\n", page->mapping->host->i_ino, start,
-			dev->name, sector);
+	printk_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
+		      "(dev %s sector %llu)\n", page->mapping->host->i_ino,
+		      start, rcu_str_deref(dev->name), sector);
 
 	bio_put(bio);
 	return 0;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f6ab6f5e635a..d8bb0dbc4941 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -830,7 +830,7 @@ static noinline int cow_file_range(struct inode *inode,
 	if (IS_ERR(trans)) {
 		extent_clear_unlock_delalloc(inode,
 			     &BTRFS_I(inode)->io_tree,
-			     start, end, NULL,
+			     start, end, locked_page,
 			     EXTENT_CLEAR_UNLOCK_PAGE |
 			     EXTENT_CLEAR_UNLOCK |
 			     EXTENT_CLEAR_DELALLOC |
@@ -963,7 +963,7 @@ out:
 out_unlock:
 	extent_clear_unlock_delalloc(inode,
 		     &BTRFS_I(inode)->io_tree,
-		     start, end, NULL,
+		     start, end, locked_page,
 		     EXTENT_CLEAR_UNLOCK_PAGE |
 		     EXTENT_CLEAR_UNLOCK |
 		     EXTENT_CLEAR_DELALLOC |
@@ -986,8 +986,10 @@ static noinline void async_cow_start(struct btrfs_work *work)
 	compress_file_range(async_cow->inode, async_cow->locked_page,
 			    async_cow->start, async_cow->end, async_cow,
 			    &num_added);
-	if (num_added == 0)
+	if (num_added == 0) {
+		btrfs_add_delayed_iput(async_cow->inode);
 		async_cow->inode = NULL;
+	}
 }
 
 /*
@@ -1020,6 +1022,8 @@ static noinline void async_cow_free(struct btrfs_work *work)
 {
 	struct async_cow *async_cow;
 	async_cow = container_of(work, struct async_cow, work);
+	if (async_cow->inode)
+		btrfs_add_delayed_iput(async_cow->inode);
 	kfree(async_cow);
 }
 
@@ -1038,7 +1042,7 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page,
 	while (start < end) {
 		async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
 		BUG_ON(!async_cow); /* -ENOMEM */
-		async_cow->inode = inode;
+		async_cow->inode = igrab(inode);
 		async_cow->root = root;
 		async_cow->locked_page = locked_page;
 		async_cow->start = start;
@@ -1136,8 +1140,18 @@ static noinline int run_delalloc_nocow(struct inode *inode,
 	u64 ino = btrfs_ino(inode);
 
 	path = btrfs_alloc_path();
-	if (!path)
+	if (!path) {
+		extent_clear_unlock_delalloc(inode,
+			     &BTRFS_I(inode)->io_tree,
+			     start, end, locked_page,
+			     EXTENT_CLEAR_UNLOCK_PAGE |
+			     EXTENT_CLEAR_UNLOCK |
+			     EXTENT_CLEAR_DELALLOC |
+			     EXTENT_CLEAR_DIRTY |
+			     EXTENT_SET_WRITEBACK |
+			     EXTENT_END_WRITEBACK);
 		return -ENOMEM;
+	}
 
 	nolock = btrfs_is_free_space_inode(root, inode);
 
@@ -1147,6 +1161,15 @@ static noinline int run_delalloc_nocow(struct inode *inode,
 		trans = btrfs_join_transaction(root);
 
 	if (IS_ERR(trans)) {
+		extent_clear_unlock_delalloc(inode,
+			     &BTRFS_I(inode)->io_tree,
+			     start, end, locked_page,
+			     EXTENT_CLEAR_UNLOCK_PAGE |
+			     EXTENT_CLEAR_UNLOCK |
+			     EXTENT_CLEAR_DELALLOC |
+			     EXTENT_CLEAR_DIRTY |
+			     EXTENT_SET_WRITEBACK |
+			     EXTENT_END_WRITEBACK);
 		btrfs_free_path(path);
 		return PTR_ERR(trans);
 	}
@@ -1327,8 +1350,11 @@ out_check:
 	}
 	btrfs_release_path(path);
 
-	if (cur_offset <= end && cow_start == (u64)-1)
+	if (cur_offset <= end && cow_start == (u64)-1) {
 		cow_start = cur_offset;
+		cur_offset = end;
+	}
+
 	if (cow_start != (u64)-1) {
 		ret = cow_file_range(inode, locked_page, cow_start, end,
 				     page_started, nr_written, 1);
@@ -1347,6 +1373,17 @@ error:
 	if (!ret)
 		ret = err;
 
+	if (ret && cur_offset < end)
+		extent_clear_unlock_delalloc(inode,
+			     &BTRFS_I(inode)->io_tree,
+			     cur_offset, end, locked_page,
+			     EXTENT_CLEAR_UNLOCK_PAGE |
+			     EXTENT_CLEAR_UNLOCK |
+			     EXTENT_CLEAR_DELALLOC |
+			     EXTENT_CLEAR_DIRTY |
+			     EXTENT_SET_WRITEBACK |
+			     EXTENT_END_WRITEBACK);
+
 	btrfs_free_path(path);
 	return ret;
 }
@@ -1361,20 +1398,23 @@ static int run_delalloc_range(struct inode *inode, struct page *locked_page,
 	int ret;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 
-	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 1, nr_written);
-	else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
+	} else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
 					 page_started, 0, nr_written);
-	else if (!btrfs_test_opt(root, COMPRESS) &&
-		 !(BTRFS_I(inode)->force_compress) &&
-		 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))
+	} else if (!btrfs_test_opt(root, COMPRESS) &&
+		   !(BTRFS_I(inode)->force_compress) &&
+		   !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
 		ret = cow_file_range(inode, locked_page, start, end,
 				      page_started, nr_written, 1);
-	else
+	} else {
+		set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+			&BTRFS_I(inode)->runtime_flags);
 		ret = cow_file_range_async(inode, locked_page, start, end,
 					   page_started, nr_written);
+	}
 	return ret;
 }
 
@@ -7054,10 +7094,13 @@ static void fixup_inode_flags(struct inode *dir, struct inode *inode)
 	else
 		b_inode->flags &= ~BTRFS_INODE_NODATACOW;
 
-	if (b_dir->flags & BTRFS_INODE_COMPRESS)
+	if (b_dir->flags & BTRFS_INODE_COMPRESS) {
 		b_inode->flags |= BTRFS_INODE_COMPRESS;
-	else
-		b_inode->flags &= ~BTRFS_INODE_COMPRESS;
+		b_inode->flags &= ~BTRFS_INODE_NOCOMPRESS;
+	} else {
+		b_inode->flags &= ~(BTRFS_INODE_COMPRESS |
+				    BTRFS_INODE_NOCOMPRESS);
+	}
 }
 
 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 24b776c08d99..0e92e5763005 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -52,6 +52,7 @@
 #include "locking.h"
 #include "inode-map.h"
 #include "backref.h"
+#include "rcu-string.h"
 
 /* Mask out flags that are inappropriate for the given type of inode. */
 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
@@ -785,39 +786,57 @@ none:
 	return -ENOENT;
 }
 
-/*
- * Validaty check of prev em and next em:
- * 1) no prev/next em
- * 2) prev/next em is an hole/inline extent
- */
-static int check_adjacent_extents(struct inode *inode, struct extent_map *em)
+static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
 {
 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
-	struct extent_map *prev = NULL, *next = NULL;
-	int ret = 0;
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct extent_map *em;
+	u64 len = PAGE_CACHE_SIZE;
 
+	/*
+	 * hopefully we have this extent in the tree already, try without
+	 * the full extent lock
+	 */
 	read_lock(&em_tree->lock);
-	prev = lookup_extent_mapping(em_tree, em->start - 1, (u64)-1);
-	next = lookup_extent_mapping(em_tree, em->start + em->len, (u64)-1);
+	em = lookup_extent_mapping(em_tree, start, len);
 	read_unlock(&em_tree->lock);
 
-	if ((!prev || prev->block_start >= EXTENT_MAP_LAST_BYTE) &&
-	    (!next || next->block_start >= EXTENT_MAP_LAST_BYTE))
-		ret = 1;
-	free_extent_map(prev);
-	free_extent_map(next);
+	if (!em) {
+		/* get the big lock and read metadata off disk */
+		lock_extent(io_tree, start, start + len - 1);
+		em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
+		unlock_extent(io_tree, start, start + len - 1);
+
+		if (IS_ERR(em))
+			return NULL;
+	}
+
+	return em;
+}
+
+static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
+{
+	struct extent_map *next;
+	bool ret = true;
 
+	/* this is the last extent */
+	if (em->start + em->len >= i_size_read(inode))
+		return false;
+
+	next = defrag_lookup_extent(inode, em->start + em->len);
+	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
+		ret = false;
+
+	free_extent_map(next);
 	return ret;
 }
 
-static int should_defrag_range(struct inode *inode, u64 start, u64 len,
-			       int thresh, u64 *last_len, u64 *skip,
-			       u64 *defrag_end)
+static int should_defrag_range(struct inode *inode, u64 start, int thresh,
+			       u64 *last_len, u64 *skip, u64 *defrag_end)
 {
-	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
-	struct extent_map *em = NULL;
-	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+	struct extent_map *em;
 	int ret = 1;
+	bool next_mergeable = true;
 
 	/*
 	 * make sure that once we start defragging an extent, we keep on
@@ -828,23 +847,9 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 
 	*skip = 0;
 
-	/*
-	 * hopefully we have this extent in the tree already, try without
-	 * the full extent lock
-	 */
-	read_lock(&em_tree->lock);
-	em = lookup_extent_mapping(em_tree, start, len);
-	read_unlock(&em_tree->lock);
-
-	if (!em) {
-		/* get the big lock and read metadata off disk */
-		lock_extent(io_tree, start, start + len - 1);
-		em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
-		unlock_extent(io_tree, start, start + len - 1);
-
-		if (IS_ERR(em))
-			return 0;
-	}
+	em = defrag_lookup_extent(inode, start);
+	if (!em)
+		return 0;
 
 	/* this will cover holes, and inline extents */
 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
@@ -852,18 +857,15 @@ static int should_defrag_range(struct inode *inode, u64 start, u64 len,
 		goto out;
 	}
 
-	/* If we have nothing to merge with us, just skip. */
-	if (check_adjacent_extents(inode, em)) {
-		ret = 0;
-		goto out;
-	}
+	next_mergeable = defrag_check_next_extent(inode, em);
 
 	/*
-	 * we hit a real extent, if it is big don't bother defragging it again
+	 * we hit a real extent, if it is big or the next extent is not a
+	 * real extent, don't bother defragging it
 	 */
-	if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
+	if ((*last_len == 0 || *last_len >= thresh) &&
+	    (em->len >= thresh || !next_mergeable))
 		ret = 0;
-
 out:
 	/*
 	 * last_len ends up being a counter of how many bytes we've defragged.
@@ -1142,8 +1144,8 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 			break;
 
 		if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
-					 PAGE_CACHE_SIZE, extent_thresh,
-					 &last_len, &skip, &defrag_end)) {
+					 extent_thresh, &last_len, &skip,
+					 &defrag_end)) {
 			unsigned long next;
 			/*
 			 * the should_defrag function tells us how much to skip
@@ -1304,6 +1306,14 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 		ret = -EINVAL;
 		goto out_free;
 	}
+	if (device->fs_devices && device->fs_devices->seeding) {
+		printk(KERN_INFO "btrfs: resizer unable to apply on "
+		       "seeding device %llu\n",
+		       (unsigned long long)devid);
+		ret = -EINVAL;
+		goto out_free;
+	}
+
 	if (!strcmp(sizestr, "max"))
 		new_size = device->bdev->bd_inode->i_size;
 	else {
@@ -1345,8 +1355,9 @@ static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
 	do_div(new_size, root->sectorsize);
 	new_size *= root->sectorsize;
 
-	printk(KERN_INFO "btrfs: new size for %s is %llu\n",
-		device->name, (unsigned long long)new_size);
+	printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
+		      rcu_str_deref(device->name),
+		      (unsigned long long)new_size);
 
 	if (new_size > old_size) {
 		trans = btrfs_start_transaction(root, 0);
@@ -2264,7 +2275,12 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
 	di_args->total_bytes = dev->total_bytes;
 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
 	if (dev->name) {
-		strncpy(di_args->path, dev->name, sizeof(di_args->path));
+		struct rcu_string *name;
+
+		rcu_read_lock();
+		name = rcu_dereference(dev->name);
+		strncpy(di_args->path, name->str, sizeof(di_args->path));
+		rcu_read_unlock();
 		di_args->path[sizeof(di_args->path) - 1] = 0;
 	} else {
 		di_args->path[0] = '\0';
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 9e138cdc36c5..643335a4fe3c 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -627,7 +627,27 @@ void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 	/* start IO across the range first to instantiate any delalloc
 	 * extents
 	 */
-	filemap_write_and_wait_range(inode->i_mapping, start, orig_end);
+	filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
+
+	/*
+	 * So with compression we will find and lock a dirty page and clear the
+	 * first one as dirty, setup an async extent, and immediately return
+	 * with the entire range locked but with nobody actually marked with
+	 * writeback.  So we can't just filemap_write_and_wait_range() and
+	 * expect it to work since it will just kick off a thread to do the
+	 * actual work.  So we need to call filemap_fdatawrite_range _again_
+	 * since it will wait on the page lock, which won't be unlocked until
+	 * after the pages have been marked as writeback and so we're good to go
+	 * from there.  We have to do this otherwise we'll miss the ordered
+	 * extents and that results in badness.  Please Josef, do not think you
+	 * know better and pull this out at some point in the future, it is
+	 * right and you are wrong.
+	 */
+	if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+		     &BTRFS_I(inode)->runtime_flags))
+		filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
+
+	filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 
 	end = orig_end;
 	found = 0;
diff --git a/fs/btrfs/rcu-string.h b/fs/btrfs/rcu-string.h
new file mode 100644
index 000000000000..9e111e4576d4
--- /dev/null
+++ b/fs/btrfs/rcu-string.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2012 Red Hat.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+struct rcu_string {
+	struct rcu_head rcu;
+	char str[0];
+};
+
+static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
+{
+	size_t len = strlen(src) + 1;
+	struct rcu_string *ret = kzalloc(sizeof(struct rcu_string) +
+					 (len * sizeof(char)), mask);
+	if (!ret)
+		return ret;
+	strncpy(ret->str, src, len);
+	return ret;
+}
+
+static inline void rcu_string_free(struct rcu_string *str)
+{
+	if (str)
+		kfree_rcu(str, rcu);
+}
+
+#define printk_in_rcu(fmt, ...) do {	\
+	rcu_read_lock();		\
+	printk(fmt, __VA_ARGS__);	\
+	rcu_read_unlock();		\
+} while (0)
+
+#define printk_ratelimited_in_rcu(fmt, ...) do {	\
+	rcu_read_lock();				\
+	printk_ratelimited(fmt, __VA_ARGS__);		\
+	rcu_read_unlock();				\
+} while (0)
+
+#define rcu_str_deref(rcu_str) ({				\
+	struct rcu_string *__str = rcu_dereference(rcu_str);	\
+	__str->str;						\
+})
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index a38cfa4f251e..b223620cd5a6 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -26,6 +26,7 @@
 #include "backref.h"
 #include "extent_io.h"
 #include "check-integrity.h"
+#include "rcu-string.h"
 
 /*
  * This is only the first step towards a full-features scrub. It reads all
@@ -320,10 +321,10 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
 	 * hold all of the paths here
 	 */
 	for (i = 0; i < ipath->fspath->elem_cnt; ++i)
-		printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
+		printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
 			"%s, sector %llu, root %llu, inode %llu, offset %llu, "
 			"length %llu, links %u (path: %s)\n", swarn->errstr,
-			swarn->logical, swarn->dev->name,
+			swarn->logical, rcu_str_deref(swarn->dev->name),
 			(unsigned long long)swarn->sector, root, inum, offset,
 			min(isize - offset, (u64)PAGE_SIZE), nlink,
 			(char *)(unsigned long)ipath->fspath->val[i]);
@@ -332,10 +333,10 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root, void *ctx)
 	return 0;
 
 err:
-	printk(KERN_WARNING "btrfs: %s at logical %llu on dev "
+	printk_in_rcu(KERN_WARNING "btrfs: %s at logical %llu on dev "
 		"%s, sector %llu, root %llu, inode %llu, offset %llu: path "
 		"resolving failed with ret=%d\n", swarn->errstr,
-		swarn->logical, swarn->dev->name,
+		swarn->logical, rcu_str_deref(swarn->dev->name),
 		(unsigned long long)swarn->sector, root, inum, offset, ret);
 
 	free_ipath(ipath);
@@ -390,10 +391,11 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
 		do {
 			ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
 							&ref_root, &ref_level);
-			printk(KERN_WARNING
+			printk_in_rcu(KERN_WARNING
 				"btrfs: %s at logical %llu on dev %s, "
 				"sector %llu: metadata %s (level %d) in tree "
-				"%llu\n", errstr, swarn.logical, dev->name,
+				"%llu\n", errstr, swarn.logical,
+				rcu_str_deref(dev->name),
 				(unsigned long long)swarn.sector,
 				ref_level ? "node" : "leaf",
 				ret < 0 ? -1 : ref_level,
@@ -580,9 +582,11 @@ out:
 		spin_lock(&sdev->stat_lock);
 		++sdev->stat.uncorrectable_errors;
 		spin_unlock(&sdev->stat_lock);
-		printk_ratelimited(KERN_ERR
+
+		printk_ratelimited_in_rcu(KERN_ERR
 			"btrfs: unable to fixup (nodatasum) error at logical %llu on dev %s\n",
-			(unsigned long long)fixup->logical, sdev->dev->name);
+			(unsigned long long)fixup->logical,
+			rcu_str_deref(sdev->dev->name));
 	}
 
 	btrfs_free_path(path);
@@ -936,18 +940,20 @@ corrected_error:
 			spin_lock(&sdev->stat_lock);
 			sdev->stat.corrected_errors++;
 			spin_unlock(&sdev->stat_lock);
-			printk_ratelimited(KERN_ERR
+			printk_ratelimited_in_rcu(KERN_ERR
 				"btrfs: fixed up error at logical %llu on dev %s\n",
-				(unsigned long long)logical, sdev->dev->name);
+				(unsigned long long)logical,
+				rcu_str_deref(sdev->dev->name));
 		}
 	} else {
 did_not_correct_error:
 		spin_lock(&sdev->stat_lock);
 		sdev->stat.uncorrectable_errors++;
 		spin_unlock(&sdev->stat_lock);
-		printk_ratelimited(KERN_ERR
+		printk_ratelimited_in_rcu(KERN_ERR
 			"btrfs: unable to fixup (regular) error at logical %llu on dev %s\n",
-			(unsigned long long)logical, sdev->dev->name);
+			(unsigned long long)logical,
+			rcu_str_deref(sdev->dev->name));
 	}
 
 out:
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 96eb9fef7bd2..0eb9a4da069e 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -54,6 +54,7 @@
 #include "version.h"
 #include "export.h"
 #include "compression.h"
+#include "rcu-string.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/btrfs.h>
@@ -1482,12 +1483,44 @@ static void btrfs_fs_dirty_inode(struct inode *inode, int flags)
 				   "error %d\n", btrfs_ino(inode), ret);
 }
 
+static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
+	struct btrfs_fs_devices *cur_devices;
+	struct btrfs_device *dev, *first_dev = NULL;
+	struct list_head *head;
+	struct rcu_string *name;
+
+	mutex_lock(&fs_info->fs_devices->device_list_mutex);
+	cur_devices = fs_info->fs_devices;
+	while (cur_devices) {
+		head = &cur_devices->devices;
+		list_for_each_entry(dev, head, dev_list) {
+			if (!first_dev || dev->devid < first_dev->devid)
+				first_dev = dev;
+		}
+		cur_devices = cur_devices->seed;
+	}
+
+	if (first_dev) {
+		rcu_read_lock();
+		name = rcu_dereference(first_dev->name);
+		seq_escape(m, name->str, " \t\n\\");
+		rcu_read_unlock();
+	} else {
+		WARN_ON(1);
+	}
+	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+	return 0;
+}
+
 static const struct super_operations btrfs_super_ops = {
 	.drop_inode	= btrfs_drop_inode,
 	.evict_inode	= btrfs_evict_inode,
 	.put_super	= btrfs_put_super,
 	.sync_fs	= btrfs_sync_fs,
 	.show_options	= btrfs_show_options,
+	.show_devname	= btrfs_show_devname,
 	.write_inode	= btrfs_write_inode,
 	.dirty_inode	= btrfs_fs_dirty_inode,
 	.alloc_inode	= btrfs_alloc_inode,
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 1791c6e3d834..b72b068183ec 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -100,6 +100,10 @@ loop:
 		kmem_cache_free(btrfs_transaction_cachep, cur_trans);
 		cur_trans = fs_info->running_transaction;
 		goto loop;
+	} else if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+		spin_unlock(&root->fs_info->trans_lock);
+		kmem_cache_free(btrfs_transaction_cachep, cur_trans);
+		return -EROFS;
 	}
 
 	atomic_set(&cur_trans->num_writers, 1);
@@ -1213,14 +1217,20 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
 
 
 static void cleanup_transaction(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root)
+				struct btrfs_root *root, int err)
 {
 	struct btrfs_transaction *cur_trans = trans->transaction;
 
 	WARN_ON(trans->use_count > 1);
 
+	btrfs_abort_transaction(trans, root, err);
+
 	spin_lock(&root->fs_info->trans_lock);
 	list_del_init(&cur_trans->list);
+	if (cur_trans == root->fs_info->running_transaction) {
+		root->fs_info->running_transaction = NULL;
+		root->fs_info->trans_no_join = 0;
+	}
 	spin_unlock(&root->fs_info->trans_lock);
 
 	btrfs_cleanup_one_transaction(trans->transaction, root);
@@ -1526,7 +1536,7 @@ cleanup_transaction:
 //	WARN_ON(1);
 	if (current->journal_info == trans)
 		current->journal_info = NULL;
-	cleanup_transaction(trans, root);
+	cleanup_transaction(trans, root, ret);
 
 	return ret;
 }
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 7782020996fe..8a3d2594b807 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -35,6 +35,7 @@
 #include "volumes.h"
 #include "async-thread.h"
 #include "check-integrity.h"
+#include "rcu-string.h"
 
 static int init_first_rw_device(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root,
@@ -64,7 +65,7 @@ static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
 		device = list_entry(fs_devices->devices.next,
 				    struct btrfs_device, dev_list);
 		list_del(&device->dev_list);
-		kfree(device->name);
+		rcu_string_free(device->name);
 		kfree(device);
 	}
 	kfree(fs_devices);
@@ -334,8 +335,8 @@ static noinline int device_list_add(const char *path,
 {
 	struct btrfs_device *device;
 	struct btrfs_fs_devices *fs_devices;
+	struct rcu_string *name;
 	u64 found_transid = btrfs_super_generation(disk_super);
-	char *name;
 
 	fs_devices = find_fsid(disk_super->fsid);
 	if (!fs_devices) {
@@ -369,11 +370,13 @@ static noinline int device_list_add(const char *path,
 		memcpy(device->uuid, disk_super->dev_item.uuid,
 		       BTRFS_UUID_SIZE);
 		spin_lock_init(&device->io_lock);
-		device->name = kstrdup(path, GFP_NOFS);
-		if (!device->name) {
+
+		name = rcu_string_strdup(path, GFP_NOFS);
+		if (!name) {
 			kfree(device);
 			return -ENOMEM;
 		}
+		rcu_assign_pointer(device->name, name);
 		INIT_LIST_HEAD(&device->dev_alloc_list);
 
 		/* init readahead state */
@@ -390,12 +393,12 @@ static noinline int device_list_add(const char *path,
 
 		device->fs_devices = fs_devices;
 		fs_devices->num_devices++;
-	} else if (!device->name || strcmp(device->name, path)) {
-		name = kstrdup(path, GFP_NOFS);
+	} else if (!device->name || strcmp(device->name->str, path)) {
+		name = rcu_string_strdup(path, GFP_NOFS);
 		if (!name)
 			return -ENOMEM;
-		kfree(device->name);
-		device->name = name;
+		rcu_string_free(device->name);
+		rcu_assign_pointer(device->name, name);
 		if (device->missing) {
 			fs_devices->missing_devices--;
 			device->missing = 0;
@@ -430,15 +433,22 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
 
 	/* We have held the volume lock, it is safe to get the devices. */
 	list_for_each_entry(orig_dev, &orig->devices, dev_list) {
+		struct rcu_string *name;
+
 		device = kzalloc(sizeof(*device), GFP_NOFS);
 		if (!device)
 			goto error;
 
-		device->name = kstrdup(orig_dev->name, GFP_NOFS);
-		if (!device->name) {
+		/*
+		 * This is ok to do without rcu read locked because we hold the
+		 * uuid mutex so nothing we touch in here is going to disappear.
+		 */
+		name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
+		if (!name) {
 			kfree(device);
 			goto error;
 		}
+		rcu_assign_pointer(device->name, name);
 
 		device->devid = orig_dev->devid;
 		device->work.func = pending_bios_fn;
@@ -491,7 +501,7 @@ again:
 		}
 		list_del_init(&device->dev_list);
 		fs_devices->num_devices--;
-		kfree(device->name);
+		rcu_string_free(device->name);
 		kfree(device);
 	}
 
@@ -516,7 +526,7 @@ static void __free_device(struct work_struct *work)
 	if (device->bdev)
 		blkdev_put(device->bdev, device->mode);
 
-	kfree(device->name);
+	rcu_string_free(device->name);
 	kfree(device);
 }
 
@@ -540,6 +550,7 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 	mutex_lock(&fs_devices->device_list_mutex);
 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
 		struct btrfs_device *new_device;
+		struct rcu_string *name;
 
 		if (device->bdev)
 			fs_devices->open_devices--;
@@ -555,8 +566,11 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 		new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
 		BUG_ON(!new_device); /* -ENOMEM */
 		memcpy(new_device, device, sizeof(*new_device));
-		new_device->name = kstrdup(device->name, GFP_NOFS);
-		BUG_ON(device->name && !new_device->name); /* -ENOMEM */
+
+		/* Safe because we are under uuid_mutex */
+		name = rcu_string_strdup(device->name->str, GFP_NOFS);
+		BUG_ON(device->name && !name); /* -ENOMEM */
+		rcu_assign_pointer(new_device->name, name);
 		new_device->bdev = NULL;
 		new_device->writeable = 0;
 		new_device->in_fs_metadata = 0;
@@ -621,9 +635,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		if (!device->name)
 			continue;
 
-		bdev = blkdev_get_by_path(device->name, flags, holder);
+		bdev = blkdev_get_by_path(device->name->str, flags, holder);
 		if (IS_ERR(bdev)) {
-			printk(KERN_INFO "open %s failed\n", device->name);
+			printk(KERN_INFO "open %s failed\n", device->name->str);
 			goto error;
 		}
 		filemap_write_and_wait(bdev->bd_inode->i_mapping);
@@ -1632,6 +1646,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	struct block_device *bdev;
 	struct list_head *devices;
 	struct super_block *sb = root->fs_info->sb;
+	struct rcu_string *name;
 	u64 total_bytes;
 	int seeding_dev = 0;
 	int ret = 0;
@@ -1671,23 +1686,24 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 		goto error;
 	}
 
-	device->name = kstrdup(device_path, GFP_NOFS);
-	if (!device->name) {
+	name = rcu_string_strdup(device_path, GFP_NOFS);
+	if (!name) {
 		kfree(device);
 		ret = -ENOMEM;
 		goto error;
 	}
+	rcu_assign_pointer(device->name, name);
 
 	ret = find_next_devid(root, &device->devid);
 	if (ret) {
-		kfree(device->name);
+		rcu_string_free(device->name);
 		kfree(device);
 		goto error;
 	}
 
 	trans = btrfs_start_transaction(root, 0);
 	if (IS_ERR(trans)) {
-		kfree(device->name);
+		rcu_string_free(device->name);
 		kfree(device);
 		ret = PTR_ERR(trans);
 		goto error;
@@ -1796,7 +1812,7 @@ error_trans:
 	unlock_chunks(root);
 	btrfs_abort_transaction(trans, root, ret);
 	btrfs_end_transaction(trans, root);
-	kfree(device->name);
+	rcu_string_free(device->name);
 	kfree(device);
 error:
 	blkdev_put(bdev, FMODE_EXCL);
@@ -4204,10 +4220,17 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 		bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
 		dev = bbio->stripes[dev_nr].dev;
 		if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
+#ifdef DEBUG
+			struct rcu_string *name;
+
+			rcu_read_lock();
+			name = rcu_dereference(dev->name);
 			pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
 				 "(%s id %llu), size=%u\n", rw,
 				 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
-				 dev->name, dev->devid, bio->bi_size);
+				 name->str, dev->devid, bio->bi_size);
+			rcu_read_unlock();
+#endif
 			bio->bi_bdev = dev->bdev;
 			if (async_submit)
 				schedule_bio(root, dev, rw, bio);
@@ -4694,8 +4717,9 @@ int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
 		key.offset = device->devid;
 		ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
 		if (ret) {
-			printk(KERN_WARNING "btrfs: no dev_stats entry found for device %s (devid %llu) (OK on first mount after mkfs)\n",
-			       device->name, (unsigned long long)device->devid);
+			printk_in_rcu(KERN_WARNING "btrfs: no dev_stats entry found for device %s (devid %llu) (OK on first mount after mkfs)\n",
+				      rcu_str_deref(device->name),
+				      (unsigned long long)device->devid);
 			__btrfs_reset_dev_stats(device);
 			device->dev_stats_valid = 1;
 			btrfs_release_path(path);
@@ -4747,8 +4771,8 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
 	BUG_ON(!path);
 	ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
 	if (ret < 0) {
-		printk(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
-		       ret, device->name);
+		printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
+			      ret, rcu_str_deref(device->name));
 		goto out;
 	}
 
@@ -4757,8 +4781,8 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
 		/* need to delete old one and insert a new one */
 		ret = btrfs_del_item(trans, dev_root, path);
 		if (ret != 0) {
-			printk(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
-			       device->name, ret);
+			printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
+				      rcu_str_deref(device->name), ret);
 			goto out;
 		}
 		ret = 1;
@@ -4770,8 +4794,8 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
 		ret = btrfs_insert_empty_item(trans, dev_root, path,
 					      &key, sizeof(*ptr));
 		if (ret < 0) {
-			printk(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
-			       device->name, ret);
+			printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
+				      rcu_str_deref(device->name), ret);
 			goto out;
 		}
 	}
@@ -4823,9 +4847,9 @@ void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
 {
 	if (!dev->dev_stats_valid)
 		return;
-	printk_ratelimited(KERN_ERR
+	printk_ratelimited_in_rcu(KERN_ERR
 			   "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
-			   dev->name,
+			   rcu_str_deref(dev->name),
 			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
 			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
 			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
@@ -4837,8 +4861,8 @@ void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
 
 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
 {
-	printk(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
-	       dev->name,
+	printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
+	       rcu_str_deref(dev->name),
 	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
 	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
 	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 3406a88ca83e..74366f27a76b 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -58,7 +58,7 @@ struct btrfs_device {
 	/* the mode sent to blkdev_get */
 	fmode_t mode;
 
-	char *name;
+	struct rcu_string *name;
 
 	/* the internal btrfs device id */
 	u64 devid;