Fix zmo leak when zfs_sb_create fails

zfs_sb_create would normally takes ownership of zmo, and it will be freed in
zfs_sb_free. However, when zfs_sb_create fails we need to explicit free it.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Chunwei Chen <[email protected]>
Closes #5490 
Closes #5496 

1 files changed, 9 insertions, 10 deletions

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index 1c3dccdca..3c76cfe6f 100644
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -744,19 +744,17 @@ zfs_sb_create(const char *osname, zfs_mntopts_t *zmo, zfs_sb_t **zsbp)
 	zsb = kmem_zalloc(sizeof (zfs_sb_t), KM_SLEEP);
 
 	/*
-	 * We claim to always be readonly so we can open snapshots;
-	 * other ZPL code will prevent us from writing to snapshots.
+	 * Optional temporary mount options, free'd in zfs_sb_free().
 	 */
-	error = dmu_objset_own(osname, DMU_OST_ZFS, B_TRUE, zsb, &os);
-	if (error) {
-		kmem_free(zsb, sizeof (zfs_sb_t));
-		return (error);
-	}
+	zsb->z_mntopts = (zmo ? zmo : zfs_mntopts_alloc());
 
 	/*
-	 * Optional temporary mount options, free'd in zfs_sb_free().
+	 * We claim to always be readonly so we can open snapshots;
+	 * other ZPL code will prevent us from writing to snapshots.
 	 */
-	zsb->z_mntopts = (zmo ? zmo : zfs_mntopts_alloc());
+	error = dmu_objset_own(osname, DMU_OST_ZFS, B_TRUE, zsb, &os);
+	if (error)
+		goto out_zmo;
 
 	/*
 	 * Initialize the zfs-specific filesystem structure.
@@ -896,8 +894,9 @@ zfs_sb_create(const char *osname, zfs_mntopts_t *zmo, zfs_sb_t **zsbp)
 
 out:
 	dmu_objset_disown(os, zsb);
+out_zmo:
 	*zsbp = NULL;
-
+	zfs_mntopts_free(zsb->z_mntopts);
 	kmem_free(zsb, sizeof (zfs_sb_t));
 	return (error);
 }