1 files changed, 31 insertions, 13 deletions

diff --git a/fs/quota.c b/fs/quota.c
index d6a2be826e29..b9dae76a0b6e 100644
--- a/fs/quota.c
+++ b/fs/quota.c
@@ -338,6 +338,34 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id, void
 }
 
 /*
+ * look up a superblock on which quota ops will be performed
+ * - use the name of a block device to find the superblock thereon
+ */
+static inline struct super_block *quotactl_block(const char __user *special)
+{
+#ifdef CONFIG_BLOCK
+        struct block_device *bdev;
+        struct super_block *sb;
+        char *tmp = getname(special);
+
+        if (IS_ERR(tmp))
+                return ERR_PTR(PTR_ERR(tmp));
+        bdev = lookup_bdev(tmp);
+        putname(tmp);
+        if (IS_ERR(bdev))
+                return ERR_PTR(PTR_ERR(bdev));
+        sb = get_super(bdev);
+        bdput(bdev);
+        if (!sb)
+                return ERR_PTR(-ENODEV);
+
+        return sb;
+#else
+        return ERR_PTR(-ENODEV);
+#endif
+}
+
+/*
  * This is the system call interface. This communicates with
  * the user-level programs. Currently this only supports diskquota
  * calls. Maybe we need to add the process quotas etc. in the future,
@@ -347,25 +375,15 @@ asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special, qid_t
 {
         uint cmds, type;
         struct super_block *sb = NULL;
-        struct block_device *bdev;
-        char *tmp;
         int ret;
 
         cmds = cmd >> SUBCMDSHIFT;
         type = cmd & SUBCMDMASK;
 
         if (cmds != Q_SYNC || special) {
-                tmp = getname(special);
-                if (IS_ERR(tmp))
-                        return PTR_ERR(tmp);
-                bdev = lookup_bdev(tmp);
-                putname(tmp);
-                if (IS_ERR(bdev))
-                        return PTR_ERR(bdev);
-                sb = get_super(bdev);
-                bdput(bdev);
-                if (!sb)
-                        return -ENODEV;
+                sb = quotactl_block(special);
+                if (IS_ERR(sb))
+                        return PTR_ERR(sb);
         }
 
         ret = check_quotactl_valid(sb, type, cmds, id);