Revert "mtd: switch ubi_open_volume_path() to vfs_stat()"

This reverts commit 322ea0bbf3003df17b6253f76e572c37d79a6810.

vfs_stat() can only be used on user supplied buffers.
UBI's kapi.c is the API to the kernel and therefore vfs_stat()
is inappropriate.

This solves the problem that mounting any UBIFS will immediately
fail with -EINVAL.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 348dbbcbedc8fc3e3c93f9257cf1c4ccb7abddf8..cc6fa0115c9ad86995fb0bc577df9dd474493099 100644 (file)
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -301,24 +301,27 @@ EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
  */
 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
 {
-       int error, ubi_num, vol_id;
-       struct kstat stat;
+       int error, ubi_num, vol_id, mod;
+       struct inode *inode;
+       struct path path;
 
        dbg_gen("open volume %s, mode %d", pathname, mode);
 
        if (!pathname || !*pathname)
                return ERR_PTR(-EINVAL);
 
-       error = vfs_stat(pathname, &stat);
+       error = kern_path(pathname, LOOKUP_FOLLOW, &path);
        if (error)
                return ERR_PTR(error);
 
-       if (!S_ISCHR(stat.mode))
-               return ERR_PTR(-EINVAL);
-
-       ubi_num = ubi_major2num(MAJOR(stat.rdev));
-       vol_id = MINOR(stat.rdev) - 1;
+       inode = d_backing_inode(path.dentry);
+       mod = inode->i_mode;
+       ubi_num = ubi_major2num(imajor(inode));
+       vol_id = iminor(inode) - 1;
+       path_put(&path);
 
+       if (!S_ISCHR(mod))
+               return ERR_PTR(-EINVAL);
        if (vol_id >= 0 && ubi_num >= 0)
                return ubi_open_volume(ubi_num, vol_id, mode);
        return ERR_PTR(-ENODEV);