root/fs/ext4/acl.h

INCLUDED FROM

DEFINITIONS

1. ext4_acl_size
2. ext4_acl_count
3. ext4_acl_chmod
4. ext4_init_acl

/*
  File: fs/ext4/acl.h

  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/

#include <linux/posix_acl_xattr.h>

#define EXT4_ACL_VERSION        0x0001

typedef struct {
        __le16          e_tag;
        __le16          e_perm;
        __le32          e_id;
} ext4_acl_entry;

typedef struct {
        __le16          e_tag;
        __le16          e_perm;
} ext4_acl_entry_short;

typedef struct {
        __le32          a_version;
} ext4_acl_header;

static inline size_t ext4_acl_size(int count)
{
        if (count <= 4) {
                return sizeof(ext4_acl_header) +
                       count * sizeof(ext4_acl_entry_short);
        } else {
                return sizeof(ext4_acl_header) +
                       4 * sizeof(ext4_acl_entry_short) +
                       (count - 4) * sizeof(ext4_acl_entry);
        }
}

static inline int ext4_acl_count(size_t size)
{
        ssize_t s;
        size -= sizeof(ext4_acl_header);
        s = size - 4 * sizeof(ext4_acl_entry_short);
        if (s < 0) {
                if (size % sizeof(ext4_acl_entry_short))
                        return -1;
                return size / sizeof(ext4_acl_entry_short);
        } else {
                if (s % sizeof(ext4_acl_entry))
                        return -1;
                return s / sizeof(ext4_acl_entry) + 4;
        }
}

#ifdef CONFIG_EXT4_FS_POSIX_ACL

/* Value for inode->u.ext4_i.i_acl and inode->u.ext4_i.i_default_acl
   if the ACL has not been cached */
#define EXT4_ACL_NOT_CACHED ((void *)-1)

/* acl.c */
extern int ext4_permission(struct inode *, int);
extern int ext4_acl_chmod(struct inode *);
extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);

#else  /* CONFIG_EXT4_FS_POSIX_ACL */
#include <linux/sched.h>
#define ext4_permission NULL

static inline int
ext4_acl_chmod(struct inode *inode)
{
        return 0;
}

static inline int
ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
{
        return 0;
}
#endif  /* CONFIG_EXT4_FS_POSIX_ACL */