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| author | Robbie Ko <robbieko@synology.com> | 2019-03-26 06:56:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 16:47:20 +0300 |
| commit | b971fb6b84e87cfb0c8fae74f303792cde4ed971 (patch) | |
| tree | 3c22bd11f480d217b9edfd35f88f0d8811c70119 /fs | |
| parent | c27f7f47e7cedb55bdcc01c1eb7730755fb75317 (diff) | |
| download | linux-b971fb6b84e87cfb0c8fae74f303792cde4ed971.tar.xz | |
Btrfs: fix data bytes_may_use underflow with fallocate due to failed quota reserve
[ Upstream commit 39ad317315887c2cb9a4347a93a8859326ddf136 ]
When doing fallocate, we first add the range to the reserve_list and
then reserve the quota. If quota reservation fails, we'll release all
reserved parts of reserve_list.
However, cur_offset is not updated to indicate that this range is
already been inserted into the list. Therefore, the same range is freed
twice. Once at list_for_each_entry loop, and once at the end of the
function. This will result in WARN_ON on bytes_may_use when we free the
remaining space.
At the end, under the 'out' label we have a call to:
btrfs_free_reserved_data_space(inode, data_reserved, alloc_start, alloc_end - cur_offset);
The start offset, third argument, should be cur_offset.
Everything from alloc_start to cur_offset was freed by the
list_for_each_entry_safe_loop.
Fixes: 18513091af94 ("btrfs: update btrfs_space_info's bytes_may_use timely")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/file.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 821001138c29..97958ecaeed9 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2976,6 +2976,7 @@ static long btrfs_fallocate(struct file *file, int mode, ret = btrfs_qgroup_reserve_data(inode, &data_reserved, cur_offset, last_byte - cur_offset); if (ret < 0) { + cur_offset = last_byte; free_extent_map(em); break; } @@ -3046,7 +3047,7 @@ out: /* Let go of our reservation. */ if (ret != 0) btrfs_free_reserved_data_space(inode, data_reserved, - alloc_start, alloc_end - cur_offset); + cur_offset, alloc_end - cur_offset); extent_changeset_free(data_reserved); return ret; } |