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| author | Filipe Manana <fdmanana@suse.com> | 2014-12-04 15:31:01 +0000 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-12-10 12:22:28 -0800 |
| commit | a1e7e16ed36b9b059c5ee94e372287418e2dc7bc (patch) | |
| tree | f18b60f14d1601891aed8e978b66adb617b90d06 | |
| parent | 9627aeee3e203e30679549e4962633698a6bf87f (diff) | |
| download | blackbird-op-linux-a1e7e16ed36b9b059c5ee94e372287418e2dc7bc.tar.gz blackbird-op-linux-a1e7e16ed36b9b059c5ee94e372287418e2dc7bc.zip | |
Btrfs: ensure deletion from pinned_chunks list is protected
The call to remove_extent_mapping() actually deletes the extent map
from the list it's included in - fs_info->pinned_chunks - and that
list is protected by the chunk mutex. Therefore make that call
while holding the chunk mutex and remove the redundant list delete
call because it's a noop.
This fixes an overlook of the patch titled
"Btrfs: fix race between fs trimming and block group remove/allocation"
following the same obvervation from the patch titled
"Btrfs: fix unprotected deletion from pending_chunks list".
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
| -rw-r--r-- | fs/btrfs/free-space-cache.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 030847bf7cec..edf32c5bbef1 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -3185,16 +3185,18 @@ out: spin_unlock(&block_group->lock); + lock_chunks(block_group->fs_info->chunk_root); em_tree = &block_group->fs_info->mapping_tree.map_tree; write_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, block_group->key.objectid, 1); BUG_ON(!em); /* logic error, can't happen */ + /* + * remove_extent_mapping() will delete us from the pinned_chunks + * list, which is protected by the chunk mutex. + */ remove_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); - - lock_chunks(block_group->fs_info->chunk_root); - list_del_init(&em->list); unlock_chunks(block_group->fs_info->chunk_root); /* once for us and once for the tree */ |
