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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 <uapi/linux/xattr.h> 19 20struct inode; 21struct dentry; 22 23/* 24 * struct xattr_handler: When @name is set, match attributes with exactly that 25 * name. When @prefix is set instead, match attributes with that prefix and 26 * with a non-empty suffix. 27 */ 28struct xattr_handler { 29 const char *name; 30 const char *prefix; 31 int flags; /* fs private flags */ 32 bool (*list)(struct dentry *dentry); 33 int (*get)(const struct xattr_handler *, struct dentry *dentry, 34 struct inode *inode, const char *name, void *buffer, 35 size_t size); 36 int (*set)(const struct xattr_handler *, struct dentry *dentry, 37 struct inode *inode, const char *name, const void *buffer, 38 size_t size, int flags); 39}; 40 41const char *xattr_full_name(const struct xattr_handler *, const char *); 42 43struct xattr { 44 const char *name; 45 void *value; 46 size_t value_len; 47}; 48 49ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); 50ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t); 51ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); 52int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int); 53int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int); 54int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int); 55int __vfs_removexattr(struct dentry *, const char *); 56int vfs_removexattr(struct dentry *, const char *); 57 58ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size); 59ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name, 60 char **xattr_value, size_t size, gfp_t flags); 61 62static inline const char *xattr_prefix(const struct xattr_handler *handler) 63{ 64 return handler->prefix ?: handler->name; 65} 66 67struct simple_xattrs { 68 struct list_head head; 69 spinlock_t lock; 70}; 71 72struct simple_xattr { 73 struct list_head list; 74 char *name; 75 size_t size; 76 char value[0]; 77}; 78 79/* 80 * initialize the simple_xattrs structure 81 */ 82static inline void simple_xattrs_init(struct simple_xattrs *xattrs) 83{ 84 INIT_LIST_HEAD(&xattrs->head); 85 spin_lock_init(&xattrs->lock); 86} 87 88/* 89 * free all the xattrs 90 */ 91static inline void simple_xattrs_free(struct simple_xattrs *xattrs) 92{ 93 struct simple_xattr *xattr, *node; 94 95 list_for_each_entry_safe(xattr, node, &xattrs->head, list) { 96 kfree(xattr->name); 97 kfree(xattr); 98 } 99} 100 101struct simple_xattr *simple_xattr_alloc(const void *value, size_t size); 102int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, 103 void *buffer, size_t size); 104int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, 105 const void *value, size_t size, int flags); 106ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer, 107 size_t size); 108void simple_xattr_list_add(struct simple_xattrs *xattrs, 109 struct simple_xattr *new_xattr); 110 111#endif /* _LINUX_XATTR_H */