kernel-ark/include/linux/posix_acl_xattr.h
Christoph Hellwig 2aeccbe957 fs: add generic xattr_acl handlers
With the ->set_acl inode operation we can implement the Posix ACL
xattr handlers in generic code instead of duplicating them all
over the tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25 23:58:17 -05:00

76 lines
1.9 KiB
C

/*
File: linux/posix_acl_xattr.h
Extended attribute system call representation of Access Control Lists.
Copyright (C) 2000 by Andreas Gruenbacher <a.gruenbacher@computer.org>
Copyright (C) 2002 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
*/
#ifndef _POSIX_ACL_XATTR_H
#define _POSIX_ACL_XATTR_H
#include <linux/posix_acl.h>
/* Extended attribute names */
#define POSIX_ACL_XATTR_ACCESS "system.posix_acl_access"
#define POSIX_ACL_XATTR_DEFAULT "system.posix_acl_default"
/* Supported ACL a_version fields */
#define POSIX_ACL_XATTR_VERSION 0x0002
/* An undefined entry e_id value */
#define ACL_UNDEFINED_ID (-1)
typedef struct {
__le16 e_tag;
__le16 e_perm;
__le32 e_id;
} posix_acl_xattr_entry;
typedef struct {
__le32 a_version;
posix_acl_xattr_entry a_entries[0];
} posix_acl_xattr_header;
static inline size_t
posix_acl_xattr_size(int count)
{
return (sizeof(posix_acl_xattr_header) +
(count * sizeof(posix_acl_xattr_entry)));
}
static inline int
posix_acl_xattr_count(size_t size)
{
if (size < sizeof(posix_acl_xattr_header))
return -1;
size -= sizeof(posix_acl_xattr_header);
if (size % sizeof(posix_acl_xattr_entry))
return -1;
return size / sizeof(posix_acl_xattr_entry);
}
#ifdef CONFIG_FS_POSIX_ACL
void posix_acl_fix_xattr_from_user(void *value, size_t size);
void posix_acl_fix_xattr_to_user(void *value, size_t size);
#else
static inline void posix_acl_fix_xattr_from_user(void *value, size_t size)
{
}
static inline void posix_acl_fix_xattr_to_user(void *value, size_t size)
{
}
#endif
struct posix_acl *posix_acl_from_xattr(struct user_namespace *user_ns,
const void *value, size_t size);
int posix_acl_to_xattr(struct user_namespace *user_ns,
const struct posix_acl *acl, void *buffer, size_t size);
extern const struct xattr_handler posix_acl_access_xattr_handler;
extern const struct xattr_handler posix_acl_default_xattr_handler;
#endif /* _POSIX_ACL_XATTR_H */