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Commit 61edc3f3 authored by Richard Weinberger's avatar Richard Weinberger
Browse files

ubi: Don't bypass ->getattr() 



Directly accessing inode fields bypasses ->getattr()
and can cause problems when the underlying filesystem
does not have the default ->getattr() implementation.

So instead of obtaining the backing inode via d_backing_inode()
use vfs_getattr() and obtain what we need from the kstat struct.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 1a498ec4

drivers/mtd/ubi/build.c

+10 −6
Original line number Diff line number Diff line
@@ -1147,22 +1147,26 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway) 
 */

static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)

{

	int err, major, minor, mode;

	int err, minor;

	struct path path;

	struct kstat stat;



	/* Probably this is an MTD character device node path */

	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);

	if (err)

		return ERR_PTR(err);



	/* MTD device number is defined by the major / minor numbers */

	major = imajor(d_backing_inode(path.dentry));

	minor = iminor(d_backing_inode(path.dentry));

	mode = d_backing_inode(path.dentry)->i_mode;

	err = vfs_getattr(&path, &stat);

	path_put(&path);

	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))

	if (err)

		return ERR_PTR(err);



	/* MTD device number is defined by the major / minor numbers */

	if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))

		return ERR_PTR(-EINVAL);



	minor = MINOR(stat.rdev);



	if (minor & 1)

		/*

		 * Just do not think the "/dev/mtdrX" devices support is need,

drivers/mtd/ubi/kapi.c

+10 −7
Original line number Diff line number Diff line
@@ -301,9 +301,9 @@ 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, mod;

	struct inode *inode;

	int error, ubi_num, vol_id;

	struct path path;

	struct kstat stat;



	dbg_gen("open volume %s, mode %d", pathname, mode);
@@ -314,14 +314,17 @@ struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode) 
	if (error)

		return ERR_PTR(error);



	inode = d_backing_inode(path.dentry);

	mod = inode->i_mode;

	ubi_num = ubi_major2num(imajor(inode));

	vol_id = iminor(inode) - 1;

	error = vfs_getattr(&path, &stat);

	path_put(&path);

	if (error)

		return ERR_PTR(error);



	if (!S_ISCHR(mod))

	if (!S_ISCHR(stat.mode))

		return ERR_PTR(-EINVAL);



	ubi_num = ubi_major2num(MAJOR(stat.rdev));

	vol_id = MINOR(stat.rdev) - 1;



	if (vol_id >= 0 && ubi_num >= 0)

		return ubi_open_volume(ubi_num, vol_id, mode);

	return ERR_PTR(-ENODEV);