summaryrefslogtreecommitdiffstats
path: root/fs/btrfs/qgroup.h
diff options
context:
space:
mode:
authorDongsheng Yang <yangds.fnst@cn.fujitsu.com>2014-12-12 16:44:35 +0800
committerChris Mason <clm@fb.com>2015-04-13 07:52:47 -0700
commit31193213f1f9c13f6485007ef1e233b119e46910 (patch)
tree755184ecff35a6387944eeefa4d2448917a43bbb /fs/btrfs/qgroup.h
parent804ca127fb93988c6a9d5f2bf4a8f1a780c9a2d0 (diff)
downloadlinux-stable-31193213f1f9c13f6485007ef1e233b119e46910.tar.gz
linux-stable-31193213f1f9c13f6485007ef1e233b119e46910.tar.bz2
linux-stable-31193213f1f9c13f6485007ef1e233b119e46910.zip
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.h4
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);