Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs updates from Chris Mason:
 "The largest set of changes here come from Miao Xie.  He's cleaning up
  and improving read recovery/repair for raid, and has a number of
  related fixes.

  I've merged another set of fsync fixes from Filipe, and he's also
  improved the way we handle metadata write errors to make sure we force
  the FS readonly if things go wrong.

  Otherwise we have a collection of fixes and cleanups.  Dave Sterba
  gets a cookie for removing the most lines (thanks Dave)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (139 commits)
  btrfs: Fix compile error when CONFIG_SECURITY is not set.
  Btrfs: fix compiles when CONFIG_BTRFS_FS_RUN_SANITY_TESTS is off
  btrfs: Make btrfs handle security mount options internally to avoid losing security label.
  Btrfs: send, don't delay dir move if there's a new parent inode
  btrfs: add more superblock checks
  Btrfs: fix race in WAIT_SYNC ioctl
  Btrfs: be aware of btree inode write errors to avoid fs corruption
  Btrfs: remove redundant btrfs_verify_qgroup_counts declaration.
  btrfs: fix shadow warning on cmp
  Btrfs: fix compilation errors under DEBUG
  Btrfs: fix crash of btrfs_release_extent_buffer_page
  Btrfs: add missing end_page_writeback on submit_extent_page failure
  btrfs: Fix the wrong condition judgment about subset extent map
  Btrfs: fix build_backref_tree issue with multiple shared blocks
  Btrfs: cleanup error handling in build_backref_tree
  btrfs: move checks for DUMMY_ROOT into a helper
  btrfs: new define for the inline extent data start
  btrfs: kill extent_buffer_page helper
  btrfs: drop constant param from btrfs_release_extent_buffer_page
  btrfs: hide typecast to definition of BTRFS_SEND_TRANS_STUB
  ...

1 files changed, 426 insertions, 250 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2c2d6d1d8eee..d47289c715c8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -50,7 +50,7 @@ static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
 
-static DEFINE_MUTEX(uuid_mutex);
+DEFINE_MUTEX(uuid_mutex);
 static LIST_HEAD(fs_uuids);
 
 static void lock_chunks(struct btrfs_root *root)
@@ -74,6 +74,7 @@ static struct btrfs_fs_devices *__alloc_fs_devices(void)
 	mutex_init(&fs_devs->device_list_mutex);
 
 	INIT_LIST_HEAD(&fs_devs->devices);
+	INIT_LIST_HEAD(&fs_devs->resized_devices);
 	INIT_LIST_HEAD(&fs_devs->alloc_list);
 	INIT_LIST_HEAD(&fs_devs->list);
 
@@ -154,11 +155,13 @@ static struct btrfs_device *__alloc_device(void)
 
 	INIT_LIST_HEAD(&dev->dev_list);
 	INIT_LIST_HEAD(&dev->dev_alloc_list);
+	INIT_LIST_HEAD(&dev->resized_list);
 
 	spin_lock_init(&dev->io_lock);
 
 	spin_lock_init(&dev->reada_lock);
 	atomic_set(&dev->reada_in_flight, 0);
+	atomic_set(&dev->dev_stats_ccnt, 0);
 	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
 	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
 
@@ -474,14 +477,13 @@ static noinline int device_list_add(const char *path,
 			return PTR_ERR(fs_devices);
 
 		list_add(&fs_devices->list, &fs_uuids);
-		fs_devices->latest_devid = devid;
-		fs_devices->latest_trans = found_transid;
 
 		device = NULL;
 	} else {
 		device = __find_device(&fs_devices->devices, devid,
 				       disk_super->dev_item.uuid);
 	}
+
 	if (!device) {
 		if (fs_devices->opened)
 			return -EBUSY;
@@ -565,10 +567,6 @@ static noinline int device_list_add(const char *path,
 	if (!fs_devices->opened)
 		device->generation = found_transid;
 
-	if (found_transid > fs_devices->latest_trans) {
-		fs_devices->latest_devid = devid;
-		fs_devices->latest_trans = found_transid;
-	}
 	*fs_devices_ret = fs_devices;
 
 	return ret;
@@ -584,8 +582,7 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
 	if (IS_ERR(fs_devices))
 		return fs_devices;
 
-	fs_devices->latest_devid = orig->latest_devid;
-	fs_devices->latest_trans = orig->latest_trans;
+	mutex_lock(&orig->device_list_mutex);
 	fs_devices->total_devices = orig->total_devices;
 
 	/* We have held the volume lock, it is safe to get the devices. */
@@ -614,8 +611,10 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
 		device->fs_devices = fs_devices;
 		fs_devices->num_devices++;
 	}
+	mutex_unlock(&orig->device_list_mutex);
 	return fs_devices;
 error:
+	mutex_unlock(&orig->device_list_mutex);
 	free_fs_devices(fs_devices);
 	return ERR_PTR(-ENOMEM);
 }
@@ -624,10 +623,7 @@ void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
 			       struct btrfs_fs_devices *fs_devices, int step)
 {
 	struct btrfs_device *device, *next;
-
-	struct block_device *latest_bdev = NULL;
-	u64 latest_devid = 0;
-	u64 latest_transid = 0;
+	struct btrfs_device *latest_dev = NULL;
 
 	mutex_lock(&uuid_mutex);
 again:
@@ -635,11 +631,9 @@ again:
 	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
 		if (device->in_fs_metadata) {
 			if (!device->is_tgtdev_for_dev_replace &&
-			    (!latest_transid ||
-			     device->generation > latest_transid)) {
-				latest_devid = device->devid;
-				latest_transid = device->generation;
-				latest_bdev = device->bdev;
+			    (!latest_dev ||
+			     device->generation > latest_dev->generation)) {
+				latest_dev = device;
 			}
 			continue;
 		}
@@ -681,9 +675,7 @@ again:
 		goto again;
 	}
 
-	fs_devices->latest_bdev = latest_bdev;
-	fs_devices->latest_devid = latest_devid;
-	fs_devices->latest_trans = latest_transid;
+	fs_devices->latest_bdev = latest_dev->bdev;
 
 	mutex_unlock(&uuid_mutex);
 }
@@ -732,8 +724,6 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 			fs_devices->rw_devices--;
 		}
 
-		if (device->can_discard)
-			fs_devices->num_can_discard--;
 		if (device->missing)
 			fs_devices->missing_devices--;
 
@@ -798,11 +788,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 	struct block_device *bdev;
 	struct list_head *head = &fs_devices->devices;
 	struct btrfs_device *device;
-	struct block_device *latest_bdev = NULL;
+	struct btrfs_device *latest_dev = NULL;
 	struct buffer_head *bh;
 	struct btrfs_super_block *disk_super;
-	u64 latest_devid = 0;
-	u64 latest_transid = 0;
 	u64 devid;
 	int seeding = 1;
 	int ret = 0;
@@ -830,11 +818,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 			goto error_brelse;
 
 		device->generation = btrfs_super_generation(disk_super);
-		if (!latest_transid || device->generation > latest_transid) {
-			latest_devid = devid;
-			latest_transid = device->generation;
-			latest_bdev = bdev;
-		}
+		if (!latest_dev ||
+		    device->generation > latest_dev->generation)
+			latest_dev = device;
 
 		if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
 			device->writeable = 0;
@@ -844,10 +830,8 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		}
 
 		q = bdev_get_queue(bdev);
-		if (blk_queue_discard(q)) {
+		if (blk_queue_discard(q))
 			device->can_discard = 1;
-			fs_devices->num_can_discard++;
-		}
 
 		device->bdev = bdev;
 		device->in_fs_metadata = 0;
@@ -877,9 +861,7 @@ error_brelse:
 	}
 	fs_devices->seeding = seeding;
 	fs_devices->opened = 1;
-	fs_devices->latest_bdev = latest_bdev;
-	fs_devices->latest_devid = latest_devid;
-	fs_devices->latest_trans = latest_transid;
+	fs_devices->latest_bdev = latest_dev->bdev;
 	fs_devices->total_rw_bytes = 0;
 out:
 	return ret;
@@ -1053,7 +1035,7 @@ int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 		if (key.objectid > device->devid)
 			break;
 
-		if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
+		if (key.type != BTRFS_DEV_EXTENT_KEY)
 			goto next;
 
 		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
@@ -1205,7 +1187,7 @@ again:
 		if (key.objectid > device->devid)
 			break;
 
-		if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
+		if (key.type != BTRFS_DEV_EXTENT_KEY)
 			goto next;
 
 		if (key.offset > search_start) {
@@ -1284,7 +1266,7 @@ out:
 
 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
 			  struct btrfs_device *device,
-			  u64 start)
+			  u64 start, u64 *dev_extent_len)
 {
 	int ret;
 	struct btrfs_path *path;
@@ -1326,13 +1308,8 @@ again:
 		goto out;
 	}
 
-	if (device->bytes_used > 0) {
-		u64 len = btrfs_dev_extent_length(leaf, extent);
-		device->bytes_used -= len;
-		spin_lock(&root->fs_info->free_chunk_lock);
-		root->fs_info->free_chunk_space += len;
-		spin_unlock(&root->fs_info->free_chunk_lock);
-	}
+	*dev_extent_len = btrfs_dev_extent_length(leaf, extent);
+
 	ret = btrfs_del_item(trans, root, path);
 	if (ret) {
 		btrfs_error(root->fs_info, ret,
@@ -1482,8 +1459,10 @@ static int btrfs_add_device(struct btrfs_trans_handle *trans,
 	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
 	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
 	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-	btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
-	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
+	btrfs_set_device_total_bytes(leaf, dev_item,
+				     btrfs_device_get_disk_total_bytes(device));
+	btrfs_set_device_bytes_used(leaf, dev_item,
+				    btrfs_device_get_bytes_used(device));
 	btrfs_set_device_group(leaf, dev_item, 0);
 	btrfs_set_device_seek_speed(leaf, dev_item, 0);
 	btrfs_set_device_bandwidth(leaf, dev_item, 0);
@@ -1539,7 +1518,6 @@ static int btrfs_rm_dev_item(struct btrfs_root *root,
 	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
 	key.type = BTRFS_DEV_ITEM_KEY;
 	key.offset = device->devid;
-	lock_chunks(root);
 
 	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
 	if (ret < 0)
@@ -1555,7 +1533,6 @@ static int btrfs_rm_dev_item(struct btrfs_root *root,
 		goto out;
 out:
 	btrfs_free_path(path);
-	unlock_chunks(root);
 	btrfs_commit_transaction(trans, root);
 	return ret;
 }
@@ -1671,8 +1648,8 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (device->writeable) {
 		lock_chunks(root);
 		list_del_init(&device->dev_alloc_list);
+		device->fs_devices->rw_devices--;
 		unlock_chunks(root);
-		root->fs_info->fs_devices->rw_devices--;
 		clear_super = true;
 	}
 
@@ -1691,11 +1668,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 	if (ret)
 		goto error_undo;
 
-	spin_lock(&root->fs_info->free_chunk_lock);
-	root->fs_info->free_chunk_space = device->total_bytes -
-		device->bytes_used;
-	spin_unlock(&root->fs_info->free_chunk_lock);
-
 	device->in_fs_metadata = 0;
 	btrfs_scrub_cancel_dev(root->fs_info, device);
 
@@ -1749,9 +1721,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 			fs_devices = fs_devices->seed;
 		}
 		cur_devices->seed = NULL;
-		lock_chunks(root);
 		__btrfs_close_devices(cur_devices);
-		unlock_chunks(root);
 		free_fs_devices(cur_devices);
 	}
 
@@ -1824,8 +1794,8 @@ error_undo:
 		lock_chunks(root);
 		list_add(&device->dev_alloc_list,
 			 &root->fs_info->fs_devices->alloc_list);
+		device->fs_devices->rw_devices++;
 		unlock_chunks(root);
-		root->fs_info->fs_devices->rw_devices++;
 	}
 	goto error_brelse;
 }
@@ -1833,29 +1803,57 @@ error_undo:
 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
 				 struct btrfs_device *srcdev)
 {
+	struct btrfs_fs_devices *fs_devices;
+
 	WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
 
+	/*
+	 * in case of fs with no seed, srcdev->fs_devices will point
+	 * to fs_devices of fs_info. However when the dev being replaced is
+	 * a seed dev it will point to the seed's local fs_devices. In short
+	 * srcdev will have its correct fs_devices in both the cases.
+	 */
+	fs_devices = srcdev->fs_devices;
+
 	list_del_rcu(&srcdev->dev_list);
 	list_del_rcu(&srcdev->dev_alloc_list);
-	fs_info->fs_devices->num_devices--;
-	if (srcdev->missing) {
-		fs_info->fs_devices->missing_devices--;
-		fs_info->fs_devices->rw_devices++;
-	}
-	if (srcdev->can_discard)
-		fs_info->fs_devices->num_can_discard--;
-	if (srcdev->bdev) {
-		fs_info->fs_devices->open_devices--;
+	fs_devices->num_devices--;
+	if (srcdev->missing)
+		fs_devices->missing_devices--;
 
-		/*
-		 * zero out the old super if it is not writable
-		 * (e.g. seed device)
-		 */
-		if (srcdev->writeable)
-			btrfs_scratch_superblock(srcdev);
+	if (srcdev->writeable) {
+		fs_devices->rw_devices--;
+		/* zero out the old super if it is writable */
+		btrfs_scratch_superblock(srcdev);
 	}
 
+	if (srcdev->bdev)
+		fs_devices->open_devices--;
+
 	call_rcu(&srcdev->rcu, free_device);
+
+	/*
+	 * unless fs_devices is seed fs, num_devices shouldn't go
+	 * zero
+	 */
+	BUG_ON(!fs_devices->num_devices && !fs_devices->seeding);
+
+	/* if this is no devs we rather delete the fs_devices */
+	if (!fs_devices->num_devices) {
+		struct btrfs_fs_devices *tmp_fs_devices;
+
+		tmp_fs_devices = fs_info->fs_devices;
+		while (tmp_fs_devices) {
+			if (tmp_fs_devices->seed == fs_devices) {
+				tmp_fs_devices->seed = fs_devices->seed;
+				break;
+			}
+			tmp_fs_devices = tmp_fs_devices->seed;
+		}
+		fs_devices->seed = NULL;
+		__btrfs_close_devices(fs_devices);
+		free_fs_devices(fs_devices);
+	}
 }
 
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
@@ -1863,6 +1861,7 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 {
 	struct btrfs_device *next_device;
 
+	mutex_lock(&uuid_mutex);
 	WARN_ON(!tgtdev);
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
 	if (tgtdev->bdev) {
@@ -1870,8 +1869,6 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 		fs_info->fs_devices->open_devices--;
 	}
 	fs_info->fs_devices->num_devices--;
-	if (tgtdev->can_discard)
-		fs_info->fs_devices->num_can_discard++;
 
 	next_device = list_entry(fs_info->fs_devices->devices.next,
 				 struct btrfs_device, dev_list);
@@ -1884,6 +1881,7 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 	call_rcu(&tgtdev->rcu, free_device);
 
 	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+	mutex_unlock(&uuid_mutex);
 }
 
 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
@@ -1982,17 +1980,17 @@ static int btrfs_prepare_sprout(struct btrfs_root *root)
 	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 	list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
 			      synchronize_rcu);
+	list_for_each_entry(device, &seed_devices->devices, dev_list)
+		device->fs_devices = seed_devices;
 
+	lock_chunks(root);
 	list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
-	list_for_each_entry(device, &seed_devices->devices, dev_list) {
-		device->fs_devices = seed_devices;
-	}
+	unlock_chunks(root);
 
 	fs_devices->seeding = 0;
 	fs_devices->num_devices = 0;
 	fs_devices->open_devices = 0;
 	fs_devices->missing_devices = 0;
-	fs_devices->num_can_discard = 0;
 	fs_devices->rotating = 0;
 	fs_devices->seed = seed_devices;
 
@@ -2092,7 +2090,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	struct list_head *devices;
 	struct super_block *sb = root->fs_info->sb;
 	struct rcu_string *name;
-	u64 total_bytes;
+	u64 tmp;
 	int seeding_dev = 0;
 	int ret = 0;
 
@@ -2148,8 +2146,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 		goto error;
 	}
 
-	lock_chunks(root);
-
 	q = bdev_get_queue(bdev);
 	if (blk_queue_discard(q))
 		device->can_discard = 1;
@@ -2160,6 +2156,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	device->sector_size = root->sectorsize;
 	device->total_bytes = i_size_read(bdev->bd_inode);
 	device->disk_total_bytes = device->total_bytes;
+	device->commit_total_bytes = device->total_bytes;
 	device->dev_root = root->fs_info->dev_root;
 	device->bdev = bdev;
 	device->in_fs_metadata = 1;
@@ -2177,6 +2174,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	device->fs_devices = root->fs_info->fs_devices;
 
 	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+	lock_chunks(root);
 	list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
 	list_add(&device->dev_alloc_list,
 		 &root->fs_info->fs_devices->alloc_list);
@@ -2184,8 +2182,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	root->fs_info->fs_devices->open_devices++;
 	root->fs_info->fs_devices->rw_devices++;
 	root->fs_info->fs_devices->total_devices++;
-	if (device->can_discard)
-		root->fs_info->fs_devices->num_can_discard++;
 	root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
 
 	spin_lock(&root->fs_info->free_chunk_lock);
@@ -2195,26 +2191,45 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
 		root->fs_info->fs_devices->rotating = 1;
 
-	total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
+	tmp = btrfs_super_total_bytes(root->fs_info->super_copy);
 	btrfs_set_super_total_bytes(root->fs_info->super_copy,
-				    total_bytes + device->total_bytes);
+				    tmp + device->total_bytes);
 
-	total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
+	tmp = btrfs_super_num_devices(root->fs_info->super_copy);
 	btrfs_set_super_num_devices(root->fs_info->super_copy,
-				    total_bytes + 1);
+				    tmp + 1);
 
 	/* add sysfs device entry */
 	btrfs_kobj_add_device(root->fs_info, device);
 
+	/*
+	 * we've got more storage, clear any full flags on the space
+	 * infos
+	 */
+	btrfs_clear_space_info_full(root->fs_info);
+
+	unlock_chunks(root);
 	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
 	if (seeding_dev) {
-		char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+		lock_chunks(root);
 		ret = init_first_rw_device(trans, root, device);
+		unlock_chunks(root);
 		if (ret) {
 			btrfs_abort_transaction(trans, root, ret);
 			goto error_trans;
 		}
+	}
+
+	ret = btrfs_add_device(trans, root, device);
+	if (ret) {
+		btrfs_abort_transaction(trans, root, ret);
+		goto error_trans;
+	}
+
+	if (seeding_dev) {
+		char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+
 		ret = btrfs_finish_sprout(trans, root);
 		if (ret) {
 			btrfs_abort_transaction(trans, root, ret);
@@ -2228,21 +2243,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 						root->fs_info->fsid);
 		if (kobject_rename(&root->fs_info->super_kobj, fsid_buf))
 			goto error_trans;
-	} else {
-		ret = btrfs_add_device(trans, root, device);
-		if (ret) {
-			btrfs_abort_transaction(trans, root, ret);
-			goto error_trans;
-		}
 	}
 
-	/*
-	 * we've got more storage, clear any full flags on the space
-	 * infos
-	 */
-	btrfs_clear_space_info_full(root->fs_info);
-
-	unlock_chunks(root);
 	root->fs_info->num_tolerated_disk_barrier_failures =
 		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
 	ret = btrfs_commit_transaction(trans, root);
@@ -2274,7 +2276,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
 	return ret;
 
 error_trans:
-	unlock_chunks(root);
 	btrfs_end_transaction(trans, root);
 	rcu_string_free(device->name);
 	btrfs_kobj_rm_device(root->fs_info, device);
@@ -2289,6 +2290,7 @@ error:
 }
 
 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
+				  struct btrfs_device *srcdev,
 				  struct btrfs_device **device_out)
 {
 	struct request_queue *q;
@@ -2301,24 +2303,38 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
 	int ret = 0;
 
 	*device_out = NULL;
-	if (fs_info->fs_devices->seeding)
+	if (fs_info->fs_devices->seeding) {
+		btrfs_err(fs_info, "the filesystem is a seed filesystem!");
 		return -EINVAL;
+	}
 
 	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
 				  fs_info->bdev_holder);
-	if (IS_ERR(bdev))
+	if (IS_ERR(bdev)) {
+		btrfs_err(fs_info, "target device %s is invalid!", device_path);
 		return PTR_ERR(bdev);
+	}
 
 	filemap_write_and_wait(bdev->bd_inode->i_mapping);
 
 	devices = &fs_info->fs_devices->devices;
 	list_for_each_entry(device, devices, dev_list) {
 		if (device->bdev == bdev) {
+			btrfs_err(fs_info, "target device is in the filesystem!");
 			ret = -EEXIST;
 			goto error;
 		}
 	}
 
+
+	if (i_size_read(bdev->bd_inode) <
+	    btrfs_device_get_total_bytes(srcdev)) {
+		btrfs_err(fs_info, "target device is smaller than source device!");
+		ret = -EINVAL;
+		goto error;
+	}
+
+
 	device = btrfs_alloc_device(NULL, &devid, NULL);
 	if (IS_ERR(device)) {
 		ret = PTR_ERR(device);
@@ -2342,8 +2358,12 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
 	device->io_width = root->sectorsize;
 	device->io_align = root->sectorsize;
 	device->sector_size = root->sectorsize;
-	device->total_bytes = i_size_read(bdev->bd_inode);
-	device->disk_total_bytes = device->total_bytes;
+	device->total_bytes = btrfs_device_get_total_bytes(srcdev);
+	device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev);
+	device->bytes_used = btrfs_device_get_bytes_used(srcdev);
+	ASSERT(list_empty(&srcdev->resized_list));
+	device->commit_total_bytes = srcdev->commit_total_bytes;
+	device->commit_bytes_used = device->bytes_used;
 	device->dev_root = fs_info->dev_root;
 	device->bdev = bdev;
 	device->in_fs_metadata = 1;
@@ -2355,8 +2375,6 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
 	list_add(&device->dev_list, &fs_info->fs_devices->devices);
 	fs_info->fs_devices->num_devices++;
 	fs_info->fs_devices->open_devices++;
-	if (device->can_discard)
-		fs_info->fs_devices->num_can_discard++;
 	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
 	*device_out = device;
@@ -2415,8 +2433,10 @@ static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
 	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
 	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
 	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
-	btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
-	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
+	btrfs_set_device_total_bytes(leaf, dev_item,
+				     btrfs_device_get_disk_total_bytes(device));
+	btrfs_set_device_bytes_used(leaf, dev_item,
+				    btrfs_device_get_bytes_used(device));
 	btrfs_mark_buffer_dirty(leaf);
 
 out:
@@ -2424,40 +2444,44 @@ out:
 	return ret;
 }
 
-static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
+int btrfs_grow_device(struct btrfs_trans_handle *trans,
 		      struct btrfs_device *device, u64 new_size)
 {
 	struct btrfs_super_block *super_copy =
 		device->dev_root->fs_info->super_copy;
-	u64 old_total = btrfs_super_total_bytes(super_copy);
-	u64 diff = new_size - device->total_bytes;
+	struct btrfs_fs_devices *fs_devices;
+	u64 old_total;
+	u64 diff;
 
 	if (!device->writeable)
 		return -EACCES;
+
+	lock_chunks(device->dev_root);
+	old_total = btrfs_super_total_bytes(super_copy);
+	diff = new_size - device->total_bytes;
+
 	if (new_size <= device->total_bytes ||
-	    device->is_tgtdev_for_dev_replace)
+	    device->is_tgtdev_for_dev_replace) {
+		unlock_chunks(device->dev_root);
 		return -EINVAL;
+	}
+
+	fs_devices = device->dev_root->fs_info->fs_devices;
 
 	btrfs_set_super_total_bytes(super_copy, old_total + diff);
 	device->fs_devices->total_rw_bytes += diff;
 
-	device->total_bytes = new_size;
-	device->disk_total_bytes = new_size;
+	btrfs_device_set_total_bytes(device, new_size);
+	btrfs_device_set_disk_total_bytes(device, new_size);
 	btrfs_clear_space_info_full(device->dev_root->fs_info);
+	if (list_empty(&device->resized_list))
+		list_add_tail(&device->resized_list,
+			      &fs_devices->resized_devices);
+	unlock_chunks(device->dev_root);
 
 	return btrfs_update_device(trans, device);
 }
 
-int btrfs_grow_device(struct btrfs_trans_handle *trans,
-		      struct btrfs_device *device, u64 new_size)
-{
-	int ret;
-	lock_chunks(device->dev_root);
-	ret = __btrfs_grow_device(trans, device, new_size);
-	unlock_chunks(device->dev_root);
-	return ret;
-}
-
 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    u64 chunk_tree, u64 chunk_objectid,
@@ -2509,6 +2533,7 @@ static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
 	u32 cur;
 	struct btrfs_key key;
 
+	lock_chunks(root);
 	array_size = btrfs_super_sys_array_size(super_copy);
 
 	ptr = super_copy->sys_chunk_array;
@@ -2538,79 +2563,95 @@ static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
 			cur += len;
 		}
 	}
+	unlock_chunks(root);
 	return ret;
 }
 
-static int btrfs_relocate_chunk(struct btrfs_root *root,
-			 u64 chunk_tree, u64 chunk_objectid,
-			 u64 chunk_offset)
+int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *root, u64 chunk_offset)
 {
 	struct extent_map_tree *em_tree;
-	struct btrfs_root *extent_root;
-	struct btrfs_trans_handle *trans;
 	struct extent_map *em;
+	struct btrfs_root *extent_root = root->fs_info->extent_root;
 	struct map_lookup *map;
-	int ret;
-	int i;
+	u64 dev_extent_len = 0;
+	u64 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+	u64 chunk_tree = root->fs_info->chunk_root->objectid;
+	int i, ret = 0;
 
+	/* Just in case */
 	root = root->fs_info->chunk_root;
-	extent_root = root->fs_info->extent_root;
 	em_tree = &root->fs_info->mapping_tree.map_tree;
 
-	ret = btrfs_can_relocate(extent_root, chunk_offset);
-	if (ret)
-		return -ENOSPC;
-
-	/* step one, relocate all the extents inside this chunk */
-	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
-	if (ret)
-		return ret;
-
-	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans)) {
-		ret = PTR_ERR(trans);
-		btrfs_std_error(root->fs_info, ret);
-		return ret;
-	}
-
-	lock_chunks(root);
-
-	/*
-	 * step two, delete the device extents and the
-	 * chunk tree entries
-	 */
 	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
 	read_unlock(&em_tree->lock);
 
-	BUG_ON(!em || em->start > chunk_offset ||
-	       em->start + em->len < chunk_offset);
+	if (!em || em->start > chunk_offset ||
+	    em->start + em->len < chunk_offset) {
+		/*
+		 * This is a logic error, but we don't want to just rely on the
+		 * user having built with ASSERT enabled, so if ASSERT doens't
+		 * do anything we still error out.
+		 */
+		ASSERT(0);
+		if (em)
+			free_extent_map(em);
+		return -EINVAL;
+	}
 	map = (struct map_lookup *)em->bdev;
 
 	for (i = 0; i < map->num_stripes; i++) {
-		ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
-					    map->stripes[i].physical);
-		BUG_ON(ret);
+		struct btrfs_device *device = map->stripes[i].dev;
+		ret = btrfs_free_dev_extent(trans, device,
+					    map->stripes[i].physical,
+					    &dev_extent_len);
+		if (ret) {
+			btrfs_abort_transaction(trans, root, ret);
+			goto out;
+		}
+
+		if (device->bytes_used > 0) {
+			lock_chunks(root);
+			btrfs_device_set_bytes_used(device,
+					device->bytes_used - dev_extent_len);
+			spin_lock(&root->fs_info->free_chunk_lock);
+			root->fs_info->free_chunk_space += dev_extent_len;
+			spin_unlock(&root->fs_info->free_chunk_lock);
+			btrfs_clear_space_info_full(root->fs_info);
+			unlock_chunks(root);
+		}
 
 		if (map->stripes[i].dev) {
 			ret = btrfs_update_device(trans, map->stripes[i].dev);
-			BUG_ON(ret);
+			if (ret) {
+				btrfs_abort_transaction(trans, root, ret);
+				goto out;
+			}
 		}
 	}
 	ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
 			       chunk_offset);
-
-	BUG_ON(ret);
+	if (ret) {
+		btrfs_abort_transaction(trans, root, ret);
+		goto out;
+	}
 
 	trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
 
 	if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
 		ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, root, ret);
+			goto out;
+		}
 	}
 
 	ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
-	BUG_ON(ret);
+	if (ret) {
+		btrfs_abort_transaction(trans, extent_root, ret);
+		goto out;
+	}
 
 	write_lock(&em_tree->lock);
 	remove_extent_mapping(em_tree, em);
@@ -2618,12 +2659,46 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 
 	/* once for the tree */
 	free_extent_map(em);
+out:
 	/* once for us */
 	free_extent_map(em);
+	return ret;
+}
 
-	unlock_chunks(root);
+static int btrfs_relocate_chunk(struct btrfs_root *root,
+			 u64 chunk_tree, u64 chunk_objectid,
+			 u64 chunk_offset)
+{
+	struct btrfs_root *extent_root;
+	struct btrfs_trans_handle *trans;
+	int ret;
+
+	root = root->fs_info->chunk_root;
+	extent_root = root->fs_info->extent_root;
+
+	ret = btrfs_can_relocate(extent_root, chunk_offset);
+	if (ret)
+		return -ENOSPC;
+
+	/* step one, relocate all the extents inside this chunk */
+	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
+	if (ret)
+		return ret;
+
+	trans = btrfs_start_transaction(root, 0);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		btrfs_std_error(root->fs_info, ret);
+		return ret;
+	}
+
+	/*
+	 * step two, delete the device extents and the
+	 * chunk tree entries
+	 */
+	ret = btrfs_remove_chunk(trans, root, chunk_offset);
 	btrfs_end_transaction(trans, root);
-	return 0;
+	return ret;
 }
 
 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
@@ -2676,8 +2751,8 @@ again:
 						   found_key.offset);
 			if (ret == -ENOSPC)
 				failed++;
-			else if (ret)
-				BUG();
+			else
+				BUG_ON(ret);
 		}
 
 		if (found_key.offset == 0)
@@ -3084,11 +3159,12 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
 	/* step one make some room on all the devices */
 	devices = &fs_info->fs_devices->devices;
 	list_for_each_entry(device, devices, dev_list) {
-		old_size = device->total_bytes;
+		old_size = btrfs_device_get_total_bytes(device);
 		size_to_free = div_factor(old_size, 1);
 		size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
 		if (!device->writeable ||
-		    device->total_bytes - device->bytes_used > size_to_free ||
+		    btrfs_device_get_total_bytes(device) -
+		    btrfs_device_get_bytes_used(device) > size_to_free ||
 		    device->is_tgtdev_for_dev_replace)
 			continue;
 
@@ -3643,8 +3719,6 @@ static int btrfs_uuid_scan_kthread(void *data)
 	max_key.type = BTRFS_ROOT_ITEM_KEY;
 	max_key.offset = (u64)-1;
 
-	path->keep_locks = 1;
-
 	while (1) {
 		ret = btrfs_search_forward(root, &key, path, 0);
 		if (ret) {
@@ -3896,8 +3970,8 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	struct btrfs_key key;
 	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
 	u64 old_total = btrfs_super_total_bytes(super_copy);
-	u64 old_size = device->total_bytes;
-	u64 diff = device->total_bytes - new_size;
+	u64 old_size = btrfs_device_get_total_bytes(device);
+	u64 diff = old_size - new_size;
 
 	if (device->is_tgtdev_for_dev_replace)
 		return -EINVAL;
@@ -3910,7 +3984,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 
 	lock_chunks(root);
 
-	device->total_bytes = new_size;
+	btrfs_device_set_total_bytes(device, new_size);
 	if (device->writeable) {
 		device->fs_devices->total_rw_bytes -= diff;
 		spin_lock(&root->fs_info->free_chunk_lock);
@@ -3976,7 +4050,7 @@ again:
 		ret = -ENOSPC;
 		lock_chunks(root);
 
-		device->total_bytes = old_size;
+		btrfs_device_set_total_bytes(device, old_size);
 		if (device->writeable)
 			device->fs_devices->total_rw_bytes += diff;
 		spin_lock(&root->fs_info->free_chunk_lock);
@@ -3994,18 +4068,17 @@ again:
 	}
 
 	lock_chunks(root);
+	btrfs_device_set_disk_total_bytes(device, new_size);
+	if (list_empty(&device->resized_list))
+		list_add_tail(&device->resized_list,
+			      &root->fs_info->fs_devices->resized_devices);
 
-	device->disk_total_bytes = new_size;
-	/* Now btrfs_update_device() will change the on-disk size. */
-	ret = btrfs_update_device(trans, device);
-	if (ret) {
-		unlock_chunks(root);
-		btrfs_end_transaction(trans, root);
-		goto done;
-	}
 	WARN_ON(diff > old_total);
 	btrfs_set_super_total_bytes(super_copy, old_total - diff);
 	unlock_chunks(root);
+
+	/* Now btrfs_update_device() will change the on-disk size. */
+	ret = btrfs_update_device(trans, device);
 	btrfs_end_transaction(trans, root);
 done:
 	btrfs_free_path(path);
@@ -4021,10 +4094,13 @@ static int btrfs_add_system_chunk(struct btrfs_root *root,
 	u32 array_size;
 	u8 *ptr;
 
+	lock_chunks(root);
 	array_size = btrfs_super_sys_array_size(super_copy);
 	if (array_size + item_size + sizeof(disk_key)
-			> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
+			> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
+		unlock_chunks(root);
 		return -EFBIG;
+	}
 
 	ptr = super_copy->sys_chunk_array + array_size;
 	btrfs_cpu_key_to_disk(&disk_key, key);
@@ -4033,6 +4109,8 @@ static int btrfs_add_system_chunk(struct btrfs_root *root,
 	memcpy(ptr, chunk, item_size);
 	item_size += sizeof(disk_key);
 	btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
+	unlock_chunks(root);
+
 	return 0;
 }
 
@@ -4402,6 +4480,16 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	if (ret)
 		goto error_del_extent;
 
+	for (i = 0; i < map->num_stripes; i++) {
+		num_bytes = map->stripes[i].dev->bytes_used + stripe_size;
+		btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
+	}
+
+	spin_lock(&extent_root->fs_info->free_chunk_lock);
+	extent_root->fs_info->free_chunk_space -= (stripe_size *
+						   map->num_stripes);
+	spin_unlock(&extent_root->fs_info->free_chunk_lock);
+
 	free_extent_map(em);
 	check_raid56_incompat_flag(extent_root->fs_info, type);
 
@@ -4473,7 +4561,6 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
 		device = map->stripes[i].dev;
 		dev_offset = map->stripes[i].physical;
 
-		device->bytes_used += stripe_size;
 		ret = btrfs_update_device(trans, device);
 		if (ret)
 			goto out;
@@ -4486,11 +4573,6 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
 			goto out;
 	}
 
-	spin_lock(&extent_root->fs_info->free_chunk_lock);
-	extent_root->fs_info->free_chunk_space -= (stripe_size *
-						   map->num_stripes);
-	spin_unlock(&extent_root->fs_info->free_chunk_lock);
-
 	stripe = &chunk->stripe;
 	for (i = 0; i < map->num_stripes; i++) {
 		device = map->stripes[i].dev;
@@ -4570,16 +4652,25 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
 	alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
 	ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
 				  alloc_profile);
-	if (ret) {
-		btrfs_abort_transaction(trans, root, ret);
-		goto out;
+	return ret;
+}
+
+static inline int btrfs_chunk_max_errors(struct map_lookup *map)
+{
+	int max_errors;
+
+	if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+			 BTRFS_BLOCK_GROUP_RAID10 |
+			 BTRFS_BLOCK_GROUP_RAID5 |
+			 BTRFS_BLOCK_GROUP_DUP)) {
+		max_errors = 1;
+	} else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
+		max_errors = 2;
+	} else {
+		max_errors = 0;
 	}
 
-	ret = btrfs_add_device(trans, fs_info->chunk_root, device);
-	if (ret)
-		btrfs_abort_transaction(trans, root, ret);
-out:
-	return ret;
+	return max_errors;
 }
 
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
@@ -4588,6 +4679,7 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
 	struct map_lookup *map;
 	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
 	int readonly = 0;
+	int miss_ndevs = 0;
 	int i;
 
 	read_lock(&map_tree->map_tree.lock);
@@ -4596,18 +4688,27 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
 	if (!em)
 		return 1;
 
-	if (btrfs_test_opt(root, DEGRADED)) {
-		free_extent_map(em);
-		return 0;
-	}
-
 	map = (struct map_lookup *)em->bdev;
 	for (i = 0; i < map->num_stripes; i++) {
+		if (map->stripes[i].dev->missing) {
+			miss_ndevs++;
+			continue;
+		}
+
 		if (!map->stripes[i].dev->writeable) {
 			readonly = 1;
-			break;
+			goto end;
 		}
 	}
+
+	/*
+	 * If the number of missing devices is larger than max errors,
+	 * we can not write the data into that chunk successfully, so
+	 * set it readonly.
+	 */
+	if (miss_ndevs > btrfs_chunk_max_errors(map))
+		readonly = 1;
+end:
 	free_extent_map(em);
 	return readonly;
 }
@@ -5008,6 +5109,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 			num_stripes = min_t(u64, map->num_stripes,
 					    stripe_nr_end - stripe_nr_orig);
 		stripe_index = do_div(stripe_nr, map->num_stripes);
+		if (!(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)))
+			mirror_num = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
 		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
 			num_stripes = map->num_stripes;
@@ -5111,6 +5214,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 			/* We distribute the parity blocks across stripes */
 			tmp = stripe_nr + stripe_index;
 			stripe_index = do_div(tmp, map->num_stripes);
+			if (!(rw & (REQ_WRITE | REQ_DISCARD |
+				    REQ_GET_READ_MIRRORS)) && mirror_num <= 1)
+				mirror_num = 1;
 		}
 	} else {
 		/*
@@ -5218,16 +5324,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 		}
 	}
 
-	if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
-		if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
-				 BTRFS_BLOCK_GROUP_RAID10 |
-				 BTRFS_BLOCK_GROUP_RAID5 |
-				 BTRFS_BLOCK_GROUP_DUP)) {
-			max_errors = 1;
-		} else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
-			max_errors = 2;
-		}
-	}
+	if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
+		max_errors = btrfs_chunk_max_errors(map);
 
 	if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
 	    dev_replace->tgtdev != NULL) {
@@ -5610,8 +5708,8 @@ static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
 		name = rcu_dereference(dev->name);
 		pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
 			 "(%s id %llu), size=%u\n", rw,
-			 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
-			 name->str, dev->devid, bio->bi_size);
+			 (u64)bio->bi_iter.bi_sector, (u_long)dev->bdev->bd_dev,
+			 name->str, dev->devid, bio->bi_iter.bi_size);
 		rcu_read_unlock();
 	}
 #endif
@@ -5789,10 +5887,10 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
 }
 
 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
+					    struct btrfs_fs_devices *fs_devices,
 					    u64 devid, u8 *dev_uuid)
 {
 	struct btrfs_device *device;
-	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 
 	device = btrfs_alloc_device(NULL, &devid, dev_uuid);
 	if (IS_ERR(device))
@@ -5929,7 +6027,8 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 		}
 		if (!map->stripes[i].dev) {
 			map->stripes[i].dev =
-				add_missing_dev(root, devid, uuid);
+				add_missing_dev(root, root->fs_info->fs_devices,
+						devid, uuid);
 			if (!map->stripes[i].dev) {
 				free_extent_map(em);
 				return -EIO;
@@ -5956,7 +6055,9 @@ static void fill_device_from_item(struct extent_buffer *leaf,
 	device->devid = btrfs_device_id(leaf, dev_item);
 	device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
 	device->total_bytes = device->disk_total_bytes;
+	device->commit_total_bytes = device->disk_total_bytes;
 	device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
+	device->commit_bytes_used = device->bytes_used;
 	device->type = btrfs_device_type(leaf, dev_item);
 	device->io_align = btrfs_device_io_align(leaf, dev_item);
 	device->io_width = btrfs_device_io_width(leaf, dev_item);
@@ -5968,7 +6069,8 @@ static void fill_device_from_item(struct extent_buffer *leaf,
 	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
 }
 
-static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
+static struct btrfs_fs_devices *open_seed_devices(struct btrfs_root *root,
+						  u8 *fsid)
 {
 	struct btrfs_fs_devices *fs_devices;
 	int ret;
@@ -5977,49 +6079,56 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
 
 	fs_devices = root->fs_info->fs_devices->seed;
 	while (fs_devices) {
-		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
-			ret = 0;
-			goto out;
-		}
+		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE))
+			return fs_devices;
+
 		fs_devices = fs_devices->seed;
 	}
 
 	fs_devices = find_fsid(fsid);
 	if (!fs_devices) {
-		ret = -ENOENT;
-		goto out;
+		if (!btrfs_test_opt(root, DEGRADED))
+			return ERR_PTR(-ENOENT);
+
+		fs_devices = alloc_fs_devices(fsid);
+		if (IS_ERR(fs_devices))
+			return fs_devices;
+
+		fs_devices->seeding = 1;
+		fs_devices->opened = 1;
+		return fs_devices;
 	}
 
 	fs_devices = clone_fs_devices(fs_devices);
-	if (IS_ERR(fs_devices)) {
-		ret = PTR_ERR(fs_devices);
-		goto out;
-	}
+	if (IS_ERR(fs_devices))
+		return fs_devices;
 
 	ret = __btrfs_open_devices(fs_devices, FMODE_READ,
 				   root->fs_info->bdev_holder);
 	if (ret) {
 		free_fs_devices(fs_devices);
+		fs_devices = ERR_PTR(ret);
 		goto out;
 	}
 
 	if (!fs_devices->seeding) {
 		__btrfs_close_devices(fs_devices);
 		free_fs_devices(fs_devices);
-		ret = -EINVAL;
+		fs_devices = ERR_PTR(-EINVAL);
 		goto out;
 	}
 
 	fs_devices->seed = root->fs_info->fs_devices->seed;
 	root->fs_info->fs_devices->seed = fs_devices;
 out:
-	return ret;
+	return fs_devices;
 }
 
 static int read_one_dev(struct btrfs_root *root,
 			struct extent_buffer *leaf,
 			struct btrfs_dev_item *dev_item)
 {
+	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 	struct btrfs_device *device;
 	u64 devid;
 	int ret;
@@ -6033,31 +6142,48 @@ static int read_one_dev(struct btrfs_root *root,
 			   BTRFS_UUID_SIZE);
 
 	if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
-		ret = open_seed_devices(root, fs_uuid);
-		if (ret && !btrfs_test_opt(root, DEGRADED))
-			return ret;
+		fs_devices = open_seed_devices(root, fs_uuid);
+		if (IS_ERR(fs_devices))
+			return PTR_ERR(fs_devices);
 	}
 
 	device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
-	if (!device || !device->bdev) {
+	if (!device) {
 		if (!btrfs_test_opt(root, DEGRADED))
 			return -EIO;
 
-		if (!device) {
-			btrfs_warn(root->fs_info, "devid %llu missing", devid);
-			device = add_missing_dev(root, devid, dev_uuid);
-			if (!device)
-				return -ENOMEM;
-		} else if (!device->missing) {
+		btrfs_warn(root->fs_info, "devid %llu missing", devid);
+		device = add_missing_dev(root, fs_devices, devid, dev_uuid);
+		if (!device)
+			return -ENOMEM;
+	} else {
+		if (!device->bdev && !btrfs_test_opt(root, DEGRADED))
+			return -EIO;
+
+		if(!device->bdev && !device->missing) {
 			/*
 			 * this happens when a device that was properly setup
 			 * in the device info lists suddenly goes bad.
 			 * device->bdev is NULL, and so we have to set
 			 * device->missing to one here
 			 */
-			root->fs_info->fs_devices->missing_devices++;
+			device->fs_devices->missing_devices++;
 			device->missing = 1;
 		}
+
+		/* Move the device to its own fs_devices */
+		if (device->fs_devices != fs_devices) {
+			ASSERT(device->missing);
+
+			list_move(&device->dev_list, &fs_devices->devices);
+			device->fs_devices->num_devices--;
+			fs_devices->num_devices++;
+
+			device->fs_devices->missing_devices--;
+			fs_devices->missing_devices++;
+
+			device->fs_devices = fs_devices;
+		}
 	}
 
 	if (device->fs_devices != root->fs_info->fs_devices) {
@@ -6373,16 +6499,18 @@ int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
 	struct btrfs_root *dev_root = fs_info->dev_root;
 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
 	struct btrfs_device *device;
+	int stats_cnt;
 	int ret = 0;
 
 	mutex_lock(&fs_devices->device_list_mutex);
 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
-		if (!device->dev_stats_valid || !device->dev_stats_dirty)
+		if (!device->dev_stats_valid || !btrfs_dev_stats_dirty(device))
 			continue;
 
+		stats_cnt = atomic_read(&device->dev_stats_ccnt);
 		ret = update_dev_stat_item(trans, dev_root, device);
 		if (!ret)
-			device->dev_stats_dirty = 0;
+			atomic_sub(stats_cnt, &device->dev_stats_ccnt);
 	}
 	mutex_unlock(&fs_devices->device_list_mutex);
 
@@ -6481,3 +6609,51 @@ int btrfs_scratch_superblock(struct btrfs_device *device)
 
 	return 0;
 }
+
+/*
+ * Update the size of all devices, which is used for writing out the
+ * super blocks.
+ */
+void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+	struct btrfs_device *curr, *next;
+
+	if (list_empty(&fs_devices->resized_devices))
+		return;
+
+	mutex_lock(&fs_devices->device_list_mutex);
+	lock_chunks(fs_info->dev_root);
+	list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
+				 resized_list) {
+		list_del_init(&curr->resized_list);
+		curr->commit_total_bytes = curr->disk_total_bytes;
+	}
+	unlock_chunks(fs_info->dev_root);
+	mutex_unlock(&fs_devices->device_list_mutex);
+}
+
+/* Must be invoked during the transaction commit */
+void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
+					struct btrfs_transaction *transaction)
+{
+	struct extent_map *em;
+	struct map_lookup *map;
+	struct btrfs_device *dev;
+	int i;
+
+	if (list_empty(&transaction->pending_chunks))
+		return;
+
+	/* In order to kick the device replace finish process */
+	lock_chunks(root);
+	list_for_each_entry(em, &transaction->pending_chunks, list) {
+		map = (struct map_lookup *)em->bdev;
+
+		for (i = 0; i < map->num_stripes; i++) {
+			dev = map->stripes[i].dev;
+			dev->commit_bytes_used = dev->bytes_used;
+		}
+	}
+	unlock_chunks(root);
+}