FS-Cache: Don't override netfs's primary_index if registering failed

Only override netfs->primary_index when registering success.

Cc: stable@vger.kernel.org # v2.6.30+
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 17 insertions, 18 deletions

diff --git a/fs/fscache/netfs.c b/fs/fscache/netfs.c
index 458cc968d9a0..9b28649df3a1 100644
--- a/fs/fscache/netfs.c
+++ b/fs/fscache/netfs.c
@@ -22,6 +22,7 @@ static LIST_HEAD(fscache_netfs_list);
 int __fscache_register_netfs(struct fscache_netfs *netfs)
 {
         struct fscache_netfs *ptr;
+        struct fscache_cookie *cookie;
         int ret;
 
         _enter("{%s}", netfs->name);
@@ -29,26 +30,25 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
         INIT_LIST_HEAD(&netfs->link);
 
         /* allocate a cookie for the primary index */
-        netfs->primary_index =
-                kmem_cache_zalloc(fscache_cookie_jar, GFP_KERNEL);
+        cookie = kmem_cache_zalloc(fscache_cookie_jar, GFP_KERNEL);
 
-        if (!netfs->primary_index) {
+        if (!cookie) {
                 _leave(" = -ENOMEM");
                 return -ENOMEM;
         }
 
         /* initialise the primary index cookie */
-        atomic_set(&netfs->primary_index->usage, 1);
-        atomic_set(&netfs->primary_index->n_children, 0);
-        atomic_set(&netfs->primary_index->n_active, 1);
+        atomic_set(&cookie->usage, 1);
+        atomic_set(&cookie->n_children, 0);
+        atomic_set(&cookie->n_active, 1);
 
-        netfs->primary_index->def               = &fscache_fsdef_netfs_def;
-        netfs->primary_index->parent            = &fscache_fsdef_index;
-        netfs->primary_index->netfs_data        = netfs;
-        netfs->primary_index->flags             = 1 << FSCACHE_COOKIE_ENABLED;
+        cookie->def             = &fscache_fsdef_netfs_def;
+        cookie->parent          = &fscache_fsdef_index;
+        cookie->netfs_data      = netfs;
+        cookie->flags           = 1 << FSCACHE_COOKIE_ENABLED;
 
-        spin_lock_init(&netfs->primary_index->lock);
-        INIT_HLIST_HEAD(&netfs->primary_index->backing_objects);
+        spin_lock_init(&cookie->lock);
+        INIT_HLIST_HEAD(&cookie->backing_objects);
 
         /* check the netfs type is not already present */
         down_write(&fscache_addremove_sem);
@@ -59,9 +59,10 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
                         goto already_registered;
         }
 
-        atomic_inc(&netfs->primary_index->parent->usage);
-        atomic_inc(&netfs->primary_index->parent->n_children);
+        atomic_inc(&cookie->parent->usage);
+        atomic_inc(&cookie->parent->n_children);
 
+        netfs->primary_index = cookie;
         list_add(&netfs->link, &fscache_netfs_list);
         ret = 0;
 
@@ -70,10 +71,8 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
 already_registered:
         up_write(&fscache_addremove_sem);
 
-        if (ret < 0) {
-                kmem_cache_free(fscache_cookie_jar, netfs->primary_index);
-                netfs->primary_index = NULL;
-        }
+        if (ret < 0)
+                kmem_cache_free(fscache_cookie_jar, cookie);
 
         _leave(" = %d", ret);
         return ret;