[PATCH] switch mtd and dm-table to lookup_bdev()

No need to open-code it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 18 insertions, 45 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 798e468103b8..61f441409234 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -316,29 +316,12 @@ static inline int check_space(struct dm_table *t)
  */
 static int lookup_device(const char *path, dev_t *dev)
 {
-        int r;
-        struct nameidata nd;
-        struct inode *inode;
-
-        if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd)))
-                return r;
-
-        inode = nd.path.dentry->d_inode;
-        if (!inode) {
-                r = -ENOENT;
-                goto out;
-        }
-
-        if (!S_ISBLK(inode->i_mode)) {
-                r = -ENOTBLK;
-                goto out;
-        }
-
-        *dev = inode->i_rdev;
-
- out:
-        path_put(&nd.path);
-        return r;
+        struct block_device *bdev = lookup_bdev(path);
+        if (IS_ERR(bdev))
+                return PTR_ERR(bdev);
+        *dev = bdev->bd_dev;
+        bdput(bdev);
+        return 0;
 }
 
 /*
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index 28cc6787a800..9b6af7e74a65 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -125,7 +125,7 @@ int get_sb_mtd(struct file_system_type *fs_type, int flags,
                int (*fill_super)(struct super_block *, void *, int),
                struct vfsmount *mnt)
 {
-        struct nameidata nd;
+        struct block_device *bdev;
         int mtdnr, ret;
 
         if (!dev_name)
@@ -181,29 +181,20 @@ int get_sb_mtd(struct file_system_type *fs_type, int flags,
         /* try the old way - the hack where we allowed users to mount
          * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
          */
-        ret = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
-
-        DEBUG(1, "MTDSB: path_lookup() returned %d, inode %p\n",
-              ret, nd.path.dentry ? nd.path.dentry->d_inode : NULL);
-
-        if (ret)
+        bdev = lookup_bdev(dev_name);
+        if (IS_ERR(bdev)) {
+                ret = PTR_ERR(bdev);
+                DEBUG(1, "MTDSB: lookup_bdev() returned %d\n", ret);
                 return ret;
-
-        ret = -EINVAL;
-
-        if (!S_ISBLK(nd.path.dentry->d_inode->i_mode))
-                goto out;
-
-        if (nd.path.mnt->mnt_flags & MNT_NODEV) {
-                ret = -EACCES;
-                goto out;
         }
+        DEBUG(1, "MTDSB: lookup_bdev() returned 0\n");
 
-        if (imajor(nd.path.dentry->d_inode) != MTD_BLOCK_MAJOR)
+        ret = -EINVAL;
+        if (MAJOR(bdev->bd_dev) != MTD_BLOCK_MAJOR)
                 goto not_an_MTD_device;
 
-        mtdnr = iminor(nd.path.dentry->d_inode);
-        path_put(&nd.path);
+        mtdnr = MINOR(bdev->bd_dev);
+        bdput(bdev);
 
         return get_sb_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super,
                              mnt);
@@ -213,10 +204,8 @@ not_an_MTD_device:
                 printk(KERN_NOTICE
                        "MTD: Attempt to mount non-MTD device \"%s\"\n",
                        dev_name);
-out:
-        path_put(&nd.path);
+        bdput(bdev);
         return ret;
-
 }
 
 EXPORT_SYMBOL_GPL(get_sb_mtd);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index e664b0b70489..aff54219e049 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1236,6 +1236,7 @@ fail:
         bdev = ERR_PTR(error);
         goto out;
 }
+EXPORT_SYMBOL(lookup_bdev);
 
 /**
  * open_bdev_excl  -  open a block device by name and set it up for use