NFSv4: Fix an oops in nfs4_fill_super

The mount statistics patches introduced a call to nfs_free_iostats that is
not only redundant, but actually causes an oops.

Also fix a memory leak due to the lack of a call to nfs_free_iostats on
unmount.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 8 insertions, 8 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index b9f35ca266c2..17654bffc3c6 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -281,6 +281,10 @@ nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
 
         sb->s_magic      = NFS_SUPER_MAGIC;
 
+        server->io_stats = nfs_alloc_iostats();
+        if (server->io_stats == NULL)
+                return -ENOMEM;
+
         root_inode = nfs_get_root(sb, &server->fh, &fsinfo);
         /* Did getting the root inode fail? */
         if (IS_ERR(root_inode)) {
@@ -294,12 +298,6 @@ nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
         }
         sb->s_root->d_op = server->rpc_ops->dentry_ops;
 
-        server->io_stats = nfs_alloc_iostats();
-        if (!server->io_stats) {
-                no_root_error = -ENOMEM;
-                goto out_no_root;
-        }
-
         /* mount time stamp, in seconds */
         server->mount_time = jiffies;
 
@@ -1822,6 +1820,7 @@ static void nfs_kill_super(struct super_block *s)
 
         rpciod_down();          /* release rpciod */
 
+        nfs_free_iostats(server->io_stats);
         kfree(server->hostname);
         kfree(server);
 }
@@ -2122,7 +2121,6 @@ out_err:
 out_free:
         kfree(server->mnt_path);
         kfree(server->hostname);
-        nfs_free_iostats(server->io_stats);
         kfree(server);
         return s;
 }
@@ -2143,6 +2141,7 @@ static void nfs4_kill_super(struct super_block *sb)
 
         rpciod_down();
 
+        nfs_free_iostats(server->io_stats);
         kfree(server->hostname);
         kfree(server);
 }
diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
index 7a7495153317..6350ecbde589 100644
--- a/fs/nfs/iostat.h
+++ b/fs/nfs/iostat.h
@@ -156,7 +156,8 @@ static inline struct nfs_iostats *nfs_alloc_iostats(void)
 
 static inline void nfs_free_iostats(struct nfs_iostats *stats)
 {
-        free_percpu(stats);
+        if (stats != NULL)
+                free_percpu(stats);
 }
 
 #endif