diff options
| author | Dongsheng Yang <yangds.fnst@cn.fujitsu.com> | 2014-12-12 16:44:35 +0800 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2015-04-13 07:52:47 -0700 |
| commit | 31193213f1f9c13f6485007ef1e233b119e46910 (patch) | |
| tree | 755184ecff35a6387944eeefa4d2448917a43bbb /fs/btrfs/qgroup.h | |
| parent | 804ca127fb93988c6a9d5f2bf4a8f1a780c9a2d0 (diff) | |
Btrfs: qgroup: Introduce a may_use to account space_info->bytes_may_use.
Currently, for pre_alloc or delay_alloc, the bytes will be accounted
in space_info by the three guys.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
But on the other hand, in qgroup, there are only two counters to account the
bytes, qgroup->reserved and qgroup->excl. And qg->reserved accounts
bytes in space_info->bytes_may_use and qg->excl accounts bytes in
space_info->used. So the bytes in space_info->reserved is not accounted
in qgroup. If so, there is a window we can exceed the quota limit when
bytes is in space_info->reserved.
Example:
# btrfs quota enable /mnt
# btrfs qgroup limit -e 10M /mnt
# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
# sync
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 20987904 20987904 0 10485760 --- ---
qg->excl is 20987904 larger than max_excl 10485760.
This patch introduce a new counter named may_use to qgroup, then
there are three counters in qgroup to account bytes in space_info
as below.
space_info->bytes_may_use --- space_info->reserved --- space_info->used.
qgroup->may_use --- qgroup->reserved --- qgroup->excl
With this patch applied:
# btrfs quota enable /mnt
# btrfs qgroup limit -e 10M /mnt
# for((i=0;i<20;i++));do fallocate -l 1M /mnt/data$i; done
fallocate: /mnt/data9: fallocate failed: Disk quota exceeded
fallocate: /mnt/data10: fallocate failed: Disk quota exceeded
fallocate: /mnt/data11: fallocate failed: Disk quota exceeded
fallocate: /mnt/data12: fallocate failed: Disk quota exceeded
fallocate: /mnt/data13: fallocate failed: Disk quota exceeded
fallocate: /mnt/data14: fallocate failed: Disk quota exceeded
fallocate: /mnt/data15: fallocate failed: Disk quota exceeded
fallocate: /mnt/data16: fallocate failed: Disk quota exceeded
fallocate: /mnt/data17: fallocate failed: Disk quota exceeded
fallocate: /mnt/data18: fallocate failed: Disk quota exceeded
fallocate: /mnt/data19: fallocate failed: Disk quota exceeded
# sync
# btrfs qgroup show -pcre /mnt
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 9453568 9453568 0 10485760 --- ---
Reported-by: Cyril SCETBON <cyril.scetbon@free.fr>
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/qgroup.h')
| -rw-r--r-- | fs/btrfs/qgroup.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h index c5242aa9a4b2..64d49b8482b3 100644 --- a/fs/btrfs/qgroup.h +++ b/fs/btrfs/qgroup.h @@ -94,6 +94,10 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans, int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid, struct btrfs_qgroup_inherit *inherit); +int btrfs_qgroup_update_reserved_bytes(struct btrfs_fs_info *fs_info, + u64 ref_root, + u64 num_bytes, + int sign); int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes); void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes); |