Re: [PATCH] btrfs: Fix quota reservation leak on preallocated files
From: Qu Wenruo <hidden>
Date: 2017-10-30 23:40:10
On 2017年10月31日 06:29, Justin Maggard wrote:
Commit c6887cd11149 (Btrfs: don't do nocow check unless we have to) changed the behavior of __btrfs_buffered_write() so that it first tries to get a data space reservation, and then skips the relatively expensive nocow check if the reservation succeeded. If we have quotas enabled, the data space reservation also includes a quota reservation. But in the rewrite case, the space has already been accounted for in qgroups. So btrfs_check_data_free_space() increases the quota reservation, but it never gets decreased when the data actually gets written and overwrites the pre-existing data. So we're left with both the qgroup and qgroup reservation accounting for the same space. This commit adds the missing btrfs_qgroup_free_data() call in the case of BTRFS_ORDERED_PREALLOC extents. Signed-off-by: Justin Maggard <redacted>
Reviewed-by: Qu Wenruo <redacted> Thanks, Qu
quoted hunk ↗ jump to hunk
--- fs/btrfs/inode.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index d94e3f68b9b1..d7881ccf5310 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c@@ -3006,6 +3006,8 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) compress_type = ordered_extent->compress_type; if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { BUG_ON(compress_type); + btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset, + ordered_extent->len); ret = btrfs_mark_extent_written(trans, BTRFS_I(inode), ordered_extent->file_offset, ordered_extent->file_offset +
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