1 files changed, 35 insertions, 6 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index ce907efc5508..e01637240eeb 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -48,6 +48,7 @@
 #include <linux/vfs.h>
 #include <linux/inet.h>
 #include <linux/in6.h>
+#include <linux/slab.h>
 #include <net/ipv6.h>
 #include <linux/netdevice.h>
 #include <linux/nfs_xdr.h>
@@ -243,6 +244,7 @@ static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
+static void nfs_put_super(struct super_block *);
 static void nfs_kill_super(struct super_block *);
 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
 
@@ -266,6 +268,7 @@ static const struct super_operations nfs_sops = {
         .alloc_inode    = nfs_alloc_inode,
         .destroy_inode  = nfs_destroy_inode,
         .write_inode    = nfs_write_inode,
+        .put_super      = nfs_put_super,
         .statfs         = nfs_statfs,
         .clear_inode    = nfs_clear_inode,
         .umount_begin   = nfs_umount_begin,
@@ -335,6 +338,7 @@ static const struct super_operations nfs4_sops = {
         .alloc_inode    = nfs_alloc_inode,
         .destroy_inode  = nfs_destroy_inode,
         .write_inode    = nfs_write_inode,
+        .put_super      = nfs_put_super,
         .statfs         = nfs_statfs,
         .clear_inode    = nfs4_clear_inode,
         .umount_begin   = nfs_umount_begin,
@@ -2211,7 +2215,7 @@ static int nfs_get_sb(struct file_system_type *fs_type,
         } else {
                 error = nfs_bdi_register(server);
                 if (error)
-                        goto error_splat_super;
+                        goto error_splat_bdi;
         }
 
         if (!s->s_root) {
@@ -2253,11 +2257,25 @@ out_err_nosb:
 error_splat_root:
         dput(mntroot);
 error_splat_super:
+        if (server && !s->s_root)
+                bdi_unregister(&server->backing_dev_info);
+error_splat_bdi:
         deactivate_locked_super(s);
         goto out;
 }
 
 /*
+ * Ensure that we unregister the bdi before kill_anon_super
+ * releases the device name
+ */
+static void nfs_put_super(struct super_block *s)
+{
+        struct nfs_server *server = NFS_SB(s);
+
+        bdi_unregister(&server->backing_dev_info);
+}
+
+/*
  * Destroy an NFS2/3 superblock
  */
 static void nfs_kill_super(struct super_block *s)
@@ -2265,7 +2283,6 @@ static void nfs_kill_super(struct super_block *s)
         struct nfs_server *server = NFS_SB(s);
 
         kill_anon_super(s);
-        bdi_unregister(&server->backing_dev_info);
         nfs_fscache_release_super_cookie(s);
         nfs_free_server(server);
 }
@@ -2313,7 +2330,7 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
         } else {
                 error = nfs_bdi_register(server);
                 if (error)
-                        goto error_splat_super;
+                        goto error_splat_bdi;
         }
 
         if (!s->s_root) {
@@ -2350,6 +2367,9 @@ out_err_noserver:
         return error;
 
 error_splat_super:
+        if (server && !s->s_root)
+                bdi_unregister(&server->backing_dev_info);
+error_splat_bdi:
         deactivate_locked_super(s);
         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
         return error;
@@ -2565,7 +2585,7 @@ static int nfs4_remote_get_sb(struct file_system_type *fs_type,
         } else {
                 error = nfs_bdi_register(server);
                 if (error)
-                        goto error_splat_super;
+                        goto error_splat_bdi;
         }
 
         if (!s->s_root) {
@@ -2603,6 +2623,9 @@ out_free:
 error_splat_root:
         dput(mntroot);
 error_splat_super:
+        if (server && !s->s_root)
+                bdi_unregister(&server->backing_dev_info);
+error_splat_bdi:
         deactivate_locked_super(s);
         goto out;
 }
@@ -2798,7 +2821,7 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
         } else {
                 error = nfs_bdi_register(server);
                 if (error)
-                        goto error_splat_super;
+                        goto error_splat_bdi;
         }
 
         if (!s->s_root) {
@@ -2834,6 +2857,9 @@ out_err_noserver:
         return error;
 
 error_splat_super:
+        if (server && !s->s_root)
+                bdi_unregister(&server->backing_dev_info);
+error_splat_bdi:
         deactivate_locked_super(s);
         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
         return error;
@@ -2880,7 +2906,7 @@ static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
         } else {
                 error = nfs_bdi_register(server);
                 if (error)
-                        goto error_splat_super;
+                        goto error_splat_bdi;
         }
 
         if (!s->s_root) {
@@ -2916,6 +2942,9 @@ out_err_noserver:
         return error;
 
 error_splat_super:
+        if (server && !s->s_root)
+                bdi_unregister(&server->backing_dev_info);
+error_splat_bdi:
         deactivate_locked_super(s);
         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
         return error;