From: Richard Weinberger <richard@nod.at>
Date: Sun, 12 Jun 2016 21:37:53 +0000 (+0200)
Subject: Revert "mtd: switch ubi_open_volume_path() to vfs_stat()"
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ad022c87187b50f50937bd9bcd1ef312442a89af;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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 348dbbcbedc8..cc6fa0115c9a 100644
--- 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);