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| author |   Forrest Liu <forrestl@synology.com> | 2015-02-09 17:30:47 +0800 |
|---|---|---|
| committer |   Chris Mason <clm@fb.com> | 2015-04-26 06:26:59 -0700 |
| commit | 1b9845081633072c18f30d8cfd09c267adf0b109 (patch) | |
| tree | 7f323994cb18808d9f557ac4e932d21b8052a5f9 /fs | |
| parent | Btrfs: don't check for delalloc_bytes in cache_save_setup (diff) | |
| download | linux-dev-1b9845081633072c18f30d8cfd09c267adf0b109.tar.xz linux-dev-1b9845081633072c18f30d8cfd09c267adf0b109.zip | |
Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
If device tree has hole, find_free_dev_extent() cannot find available
address properly.
The problem can be reproduce by following script.
mntpath=/btrfs
loopdev=/dev/loop0
filepath=/home/forrest/image
umount $mntpath
losetup -d $loopdev
truncate --size 100g $filepath
losetup $loopdev $filepath
mkfs.btrfs -f $loopdev
mount $loopdev $mntpath
# make device tree with one big hole
for i in `seq 1 1 100`; do
fallocate -l 1g $mntpath/$i
done
sync
for i in `seq 1 1 95`; do
rm $mntpath/$i
done
sync
# wait cleaner thread remove unused block group
sleep 300
fallocate -l 1g $mntpath/aaa
# failed to allocate new chunk
fallocate -l 1g $mntpath/bbb
Above script will make device tree with one big hole, and can only allocate
just one chunk in a transaction, so failed to allocate new chunk for $mntpath/bbb
item 8 key (1 DEV_EXTENT 2185232384) itemoff 15859 itemsize 48
dev extent chunk_tree 3
chunk objectid 256 chunk offset 106292051968 length 1073741824
item 9 key (1 DEV_EXTENT 104190705664) itemoff 15811 itemsize 48
dev extent chunk_tree 3
chunk objectid 256 chunk offset 103108575232 length 1073741824
Signed-off-by: Forrest Liu <forrestl@synology.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/volumes.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 8bcd2a007517..96aebf3bcd5b 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1058,6 +1058,7 @@ static int contains_pending_extent(struct btrfs_trans_handle *trans, struct extent_map *em; struct list_head *search_list = &trans->transaction->pending_chunks; int ret = 0; + u64 physical_start = *start; again: list_for_each_entry(em, search_list, list) { @@ -1068,9 +1069,9 @@ again: for (i = 0; i < map->num_stripes; i++) { if (map->stripes[i].dev != device) continue; - if (map->stripes[i].physical >= *start + len || + if (map->stripes[i].physical >= physical_start + len || map->stripes[i].physical + em->orig_block_len <= - *start) + physical_start) continue; *start = map->stripes[i].physical + em->orig_block_len; @@ -1193,8 +1194,14 @@ again: */ if (contains_pending_extent(trans, device, &search_start, - hole_size)) - hole_size = 0; + hole_size)) { + if (key.offset >= search_start) { + hole_size = key.offset - search_start; + } else { + WARN_ON_ONCE(1); + hole_size = 0; + } + } if (hole_size > max_hole_size) { max_hole_start = search_start; |