Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b6ba1177 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Al Viro
Browse files

vfs: Move xattr_resolve_name to the front of fs/xattr.c 



Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent bf02f5d2

fs/xattr.c

+50 −51
Original line number Diff line number Diff line
@@ -24,6 +24,56 @@ 


#include <asm/uaccess.h>



static const char *

strcmp_prefix(const char *a, const char *a_prefix)

{

	while (*a_prefix && *a == *a_prefix) {

		a++;

		a_prefix++;

	}

	return *a_prefix ? NULL : a;

}



/*

 * In order to implement different sets of xattr operations for each xattr

 * prefix with the generic xattr API, a filesystem should create a

 * null-terminated array of struct xattr_handler (one for each prefix) and

 * hang a pointer to it off of the s_xattr field of the superblock.

 *

 * The generic_fooxattr() functions will use this list to dispatch xattr

 * operations to the correct xattr_handler.

 */

#define for_each_xattr_handler(handlers, handler)		\

	if (handlers)						\

		for ((handler) = *(handlers)++;			\

			(handler) != NULL;			\

			(handler) = *(handlers)++)



/*

 * Find the xattr_handler with the matching prefix.

 */

static const struct xattr_handler *

xattr_resolve_name(const struct xattr_handler **handlers, const char **name)

{

	const struct xattr_handler *handler;



	for_each_xattr_handler(handlers, handler) {

		const char *n;



		n = strcmp_prefix(*name, xattr_prefix(handler));

		if (n) {

			if (!handler->prefix ^ !*n) {

				if (*n)

					continue;

				return ERR_PTR(-EINVAL);

			}

			*name = n;

			return handler;

		}

	}

	return ERR_PTR(-EOPNOTSUPP);

}



/*

 * Check permissions for extended attribute access.  This is a bit complicated

 * because different namespaces have very different rules.
@@ -641,57 +691,6 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) 
	return error;

}





static const char *

strcmp_prefix(const char *a, const char *a_prefix)

{

	while (*a_prefix && *a == *a_prefix) {

		a++;

		a_prefix++;

	}

	return *a_prefix ? NULL : a;

}



/*

 * In order to implement different sets of xattr operations for each xattr

 * prefix with the generic xattr API, a filesystem should create a

 * null-terminated array of struct xattr_handler (one for each prefix) and

 * hang a pointer to it off of the s_xattr field of the superblock.

 *

 * The generic_fooxattr() functions will use this list to dispatch xattr

 * operations to the correct xattr_handler.

 */

#define for_each_xattr_handler(handlers, handler)		\

	if (handlers)						\

		for ((handler) = *(handlers)++;			\

			(handler) != NULL;			\

			(handler) = *(handlers)++)



/*

 * Find the xattr_handler with the matching prefix.

 */

static const struct xattr_handler *

xattr_resolve_name(const struct xattr_handler **handlers, const char **name)

{

	const struct xattr_handler *handler;



	for_each_xattr_handler(handlers, handler) {

		const char *n;



		n = strcmp_prefix(*name, xattr_prefix(handler));

		if (n) {

			if (!handler->prefix ^ !*n) {

				if (*n)

					continue;

				return ERR_PTR(-EINVAL);

			}

			*name = n;

			return handler;

		}

	}

	return ERR_PTR(-EOPNOTSUPP);

}



/*

 * Find the handler for the prefix and dispatch its get() operation.

 */