[PATCH 4.9 37/56] xfs: quota: check result of register_shrinker()

Greg Kroah-Hartman
2018-03-02T08:51:23Z

From: Aliaksei Karaliou <akaraliou.dev@gmail.com>

[ Upstream commit 3a3882ff26fbdbaf5f7e13f6a0bccfbf7121041d ]

xfs_qm_init_quotainfo() does not check result of register_shrinker()
which was tagged as __must_check recently, reported by sparse.

Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
[darrick: move xfs_qm_destroy_quotainos nearer xfs_qm_init_quotainos]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/xfs/xfs_qm.c | 45 +++++++++++++++++++++++++++++----------------
1 file changed, 29 insertions(+), 16 deletions(-)

--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -47,7 +47,7 @@
STATIC int xfs_qm_init_quotainos(xfs_mount_t *);
STATIC int xfs_qm_init_quotainfo(xfs_mount_t *);

-
+STATIC void xfs_qm_destroy_quotainos(xfs_quotainfo_t *qi);
STATIC void xfs_qm_dqfree_one(struct xfs_dquot *dqp);
/*
* We use the batch lookup interface to iterate over the dquots as it
@@ -694,9 +694,17 @@ xfs_qm_init_quotainfo(
qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
qinf->qi_shrinker.flags = SHRINKER_NUMA_AWARE;
- register_shrinker(&qinf->qi_shrinker);
+
+ error = register_shrinker(&qinf->qi_shrinker);
+ if (error)
+ goto out_free_inos;
+
return 0;

+out_free_inos:
+ mutex_destroy(&qinf->qi_quotaofflock);
+ mutex_destroy(&qinf->qi_tree_lock);
+ xfs_qm_destroy_quotainos(qinf);
out_free_lru:
list_lru_destroy(&qinf->qi_lru);
out_free_qinf:
@@ -705,7 +713,6 @@ out_free_qinf:
return error;
}

-
/*
* Gets called when unmounting a filesystem or when all quotas get
* turned off.
@@ -722,19 +729,7 @@ xfs_qm_destroy_quotainfo(

unregister_shrinker(&qi->qi_shrinker);
list_lru_destroy(&qi->qi_lru);
-
- if (qi->qi_uquotaip) {
- IRELE(qi->qi_uquotaip);
- qi->qi_uquotaip = NULL; /* paranoia */
- }
- if (qi->qi_gquotaip) {
- IRELE(qi->qi_gquotaip);
- qi->qi_gquotaip = NULL;
- }
- if (qi->qi_pquotaip) {
- IRELE(qi->qi_pquotaip);
- qi->qi_pquotaip = NULL;
- }
+ xfs_qm_destroy_quotainos(qi);
mutex_destroy(&qi->qi_tree_lock);
mutex_destroy(&qi->qi_quotaofflock);
kmem_free(qi);
@@ -1621,6 +1616,24 @@ error_rele:
}

STATIC void
+xfs_qm_destroy_quotainos(
+ xfs_quotainfo_t *qi)
+{
+ if (qi->qi_uquotaip) {
+ IRELE(qi->qi_uquotaip);
+ qi->qi_uquotaip = NULL; /* paranoia */
+ }
+ if (qi->qi_gquotaip) {
+ IRELE(qi->qi_gquotaip);
+ qi->qi_gquotaip = NULL;
+ }
+ if (qi->qi_pquotaip) {
+ IRELE(qi->qi_pquotaip);
+ qi->qi_pquotaip = NULL;
+ }
+}
+
+STATIC void
xfs_qm_dqfree_one(
struct xfs_dquot *dqp)
{