From: Wang Shilong <wangsl-f...@cn.fujitsu.com>

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-f...@cn.fujitsu.com>
Reviewed-by: Arne Jansen <sensi...@gmx.net>
---
Changelog v1->v2:
-use s64 instead of signed long long
---
 fs/btrfs/qgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index b44124d..ab364a2 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1523,14 +1523,14 @@ 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;
-- 
1.7.11.7

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to