Btrfs: fix confusing edquot happening case
authorWang Shilong <wangsl-fnst@cn.fujitsu.com>
Mon, 15 Apr 2013 12:56:49 +0000 (12:56 +0000)
committerJosef Bacik <jbacik@fusionio.com>
Mon, 6 May 2013 19:54:51 +0000 (15:54 -0400)
Step to reproduce:
mkfs.btrfs <disk>
mount <disk> <mnt>
dd if=/dev/zero of=/<mnt>/data bs=1M count=10
sync
btrfs quota enable <mnt>
btrfs qgroup create 0/5 <mnt>
btrfs qgroup limit 5M 0/5 <mnt>
rm -f /<mnt>/data
sync
btrfs qgroup show <mnt>
dd if=/dev/zero of=data bs=1M count=1

>From the perspective of users, qgroup's referenced or exclusive
is negative,but user can not continue to write data! a workaround
way is to cast u64 to s64 when doing qgroup reservation.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
fs/btrfs/qgroup.c

index e089fc108483f3a65685df1c52aa2d3f1a7a51aa..4beea047f4edfafdf77cd05217f5bf91eaeee318 100644 (file)
@@ -1616,14 +1616,14 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes)
                qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
 
                if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
-                   qg->reserved + qg->rfer + num_bytes >
+                   qg->reserved + (s64)qg->rfer + num_bytes >
                    qg->max_rfer) {
                        ret = -EDQUOT;
                        goto out;
                }
 
                if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) &&
-                   qg->reserved + qg->excl + num_bytes >
+                   qg->reserved + (s64)qg->excl + num_bytes >
                    qg->max_excl) {
                        ret = -EDQUOT;
                        goto out;