xattr.h

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/*
  File: linux/xattr.h

  Extended attributes handling.

  Copyright (C) 2001 by Andreas Gruenbacher <[email protected]>
  Copyright (c) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
  Copyright (c) 2004 Red Hat, Inc., James Morris <[email protected]>
*/
#ifndef _LINUX_XATTR_H
#define _LINUX_XATTR_H


#include <linux/slab.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <uapi/linux/xattr.h>

struct inode;
struct dentry;

struct xattr_handler {
    const char *prefix;
    int flags;  /* fs private flags passed back to the handlers */
    size_t (*list)(struct dentry *dentry, char *list, size_t list_size,
               const char *name, size_t name_len, int handler_flags);
    int (*get)(struct dentry *dentry, const char *name, void *buffer,
           size_t size, int handler_flags);
    int (*set)(struct dentry *dentry, const char *name, const void *buffer,
           size_t size, int flags, int handler_flags);
};

struct xattr {
    char *name;
    void *value;
    size_t value_len;
};

ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
int vfs_removexattr(struct dentry *, const char *);

ssize_t generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size);
ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
int generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
int generic_removexattr(struct dentry *dentry, const char *name);
ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
               char **xattr_value, size_t size, gfp_t flags);
int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
          const char *value, size_t size, gfp_t flags);

struct simple_xattrs {
    struct list_head head;
    spinlock_t lock;
};

struct simple_xattr {
    struct list_head list;
    char *name;
    size_t size;
    char value[0];
};

/*
 * initialize the simple_xattrs structure
 */
static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
{
    INIT_LIST_HEAD(&xattrs->head);
    spin_lock_init(&xattrs->lock);
}

/*
 * free all the xattrs
 */
static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
{
    struct simple_xattr *xattr, *node;

    list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
        kfree(xattr->name);
        kfree(xattr);
    }
}

struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
             void *buffer, size_t size);
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
             const void *value, size_t size, int flags);
int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name);
ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
              size_t size);
void simple_xattr_list_add(struct simple_xattrs *xattrs,
               struct simple_xattr *new_xattr);

#endif  /* _LINUX_XATTR_H */