xattr.h (3977B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 File: linux/xattr.h 4 5 Extended attributes handling. 6 7 Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org> 8 Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved. 9 Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> 10*/ 11#ifndef _LINUX_XATTR_H 12#define _LINUX_XATTR_H 13 14 15#include <linux/slab.h> 16#include <linux/types.h> 17#include <linux/spinlock.h> 18#include <linux/mm.h> 19#include <linux/user_namespace.h> 20#include <uapi/linux/xattr.h> 21 22struct inode; 23struct dentry; 24 25/* 26 * struct xattr_handler: When @name is set, match attributes with exactly that 27 * name. When @prefix is set instead, match attributes with that prefix and 28 * with a non-empty suffix. 29 */ 30struct xattr_handler { 31 const char *name; 32 const char *prefix; 33 int flags; /* fs private flags */ 34 bool (*list)(struct dentry *dentry); 35 int (*get)(const struct xattr_handler *, struct dentry *dentry, 36 struct inode *inode, const char *name, void *buffer, 37 size_t size); 38 int (*set)(const struct xattr_handler *, 39 struct user_namespace *mnt_userns, struct dentry *dentry, 40 struct inode *inode, const char *name, const void *buffer, 41 size_t size, int flags); 42}; 43 44const char *xattr_full_name(const struct xattr_handler *, const char *); 45 46struct xattr { 47 const char *name; 48 void *value; 49 size_t value_len; 50}; 51 52ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); 53ssize_t vfs_getxattr(struct user_namespace *, struct dentry *, const char *, 54 void *, size_t); 55ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); 56int __vfs_setxattr(struct user_namespace *, struct dentry *, struct inode *, 57 const char *, const void *, size_t, int); 58int __vfs_setxattr_noperm(struct user_namespace *, struct dentry *, 59 const char *, const void *, size_t, int); 60int __vfs_setxattr_locked(struct user_namespace *, struct dentry *, 61 const char *, const void *, size_t, int, 62 struct inode **); 63int vfs_setxattr(struct user_namespace *, struct dentry *, const char *, 64 const void *, size_t, int); 65int __vfs_removexattr(struct user_namespace *, struct dentry *, const char *); 66int __vfs_removexattr_locked(struct user_namespace *, struct dentry *, 67 const char *, struct inode **); 68int vfs_removexattr(struct user_namespace *, struct dentry *, const char *); 69 70ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size); 71ssize_t vfs_getxattr_alloc(struct user_namespace *mnt_userns, 72 struct dentry *dentry, const char *name, 73 char **xattr_value, size_t size, gfp_t flags); 74 75int xattr_supported_namespace(struct inode *inode, const char *prefix); 76 77static inline const char *xattr_prefix(const struct xattr_handler *handler) 78{ 79 return handler->prefix ?: handler->name; 80} 81 82struct simple_xattrs { 83 struct list_head head; 84 spinlock_t lock; 85}; 86 87struct simple_xattr { 88 struct list_head list; 89 char *name; 90 size_t size; 91 char value[]; 92}; 93 94/* 95 * initialize the simple_xattrs structure 96 */ 97static inline void simple_xattrs_init(struct simple_xattrs *xattrs) 98{ 99 INIT_LIST_HEAD(&xattrs->head); 100 spin_lock_init(&xattrs->lock); 101} 102 103/* 104 * free all the xattrs 105 */ 106static inline void simple_xattrs_free(struct simple_xattrs *xattrs) 107{ 108 struct simple_xattr *xattr, *node; 109 110 list_for_each_entry_safe(xattr, node, &xattrs->head, list) { 111 kfree(xattr->name); 112 kvfree(xattr); 113 } 114} 115 116struct simple_xattr *simple_xattr_alloc(const void *value, size_t size); 117int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, 118 void *buffer, size_t size); 119int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, 120 const void *value, size_t size, int flags, 121 ssize_t *removed_size); 122ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer, 123 size_t size); 124void simple_xattr_list_add(struct simple_xattrs *xattrs, 125 struct simple_xattr *new_xattr); 126 127#endif /* _LINUX_XATTR_H */