1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2008 Christoph Hellwig.
4 * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_da_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_mount.h"
14 #include "xfs_inode.h"
15 #include "xfs_da_btree.h"
19 #include "xfs_xattr.h"
21 #include <linux/posix_acl_xattr.h>
24 * Get permission to use log-assisted atomic exchange of file extents.
26 * Callers must not be running any transactions or hold any inode locks, and
27 * they must release the permission by calling xlog_drop_incompat_feat
31 xfs_attr_grab_log_assist(
37 * Protect ourselves from an idle log clearing the logged xattrs log
38 * incompat feature bit.
40 xlog_use_incompat_feat(mp->m_log);
43 * If log-assisted xattrs are already enabled, the caller can use the
44 * log assisted swap functions with the log-incompat reference we got.
46 if (xfs_sb_version_haslogxattrs(&mp->m_sb))
49 /* Enable log-assisted xattrs. */
50 error = xfs_add_incompat_log_feature(mp,
51 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
55 xfs_warn_mount(mp, XFS_OPSTATE_WARNED_LARP,
56 "EXPERIMENTAL logged extended attributes feature in use. Use at your own risk!");
60 xlog_drop_incompat_feat(mp->m_log);
65 xfs_attr_rele_log_assist(
68 xlog_drop_incompat_feat(mp->m_log);
72 * Set or remove an xattr, having grabbed the appropriate logging resources
73 * prior to calling libxfs.
77 struct xfs_da_args *args)
79 struct xfs_mount *mp = args->dp->i_mount;
80 bool use_logging = false;
83 if (xfs_has_larp(mp)) {
84 error = xfs_attr_grab_log_assist(mp);
91 error = xfs_attr_set(args);
94 xfs_attr_rele_log_assist(mp);
100 xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
101 struct inode *inode, const char *name, void *value, size_t size)
103 struct xfs_da_args args = {
105 .attr_filter = handler->flags,
107 .namelen = strlen(name),
113 error = xfs_attr_get(&args);
116 return args.valuelen;
120 xfs_xattr_set(const struct xattr_handler *handler,
121 struct user_namespace *mnt_userns, struct dentry *unused,
122 struct inode *inode, const char *name, const void *value,
123 size_t size, int flags)
125 struct xfs_da_args args = {
127 .attr_filter = handler->flags,
130 .namelen = strlen(name),
131 .value = (void *)value,
136 error = xfs_attr_change(&args);
137 if (!error && (handler->flags & XFS_ATTR_ROOT))
138 xfs_forget_acl(inode, name);
142 static const struct xattr_handler xfs_xattr_user_handler = {
143 .prefix = XATTR_USER_PREFIX,
144 .flags = 0, /* no flags implies user namespace */
145 .get = xfs_xattr_get,
146 .set = xfs_xattr_set,
149 static const struct xattr_handler xfs_xattr_trusted_handler = {
150 .prefix = XATTR_TRUSTED_PREFIX,
151 .flags = XFS_ATTR_ROOT,
152 .get = xfs_xattr_get,
153 .set = xfs_xattr_set,
156 static const struct xattr_handler xfs_xattr_security_handler = {
157 .prefix = XATTR_SECURITY_PREFIX,
158 .flags = XFS_ATTR_SECURE,
159 .get = xfs_xattr_get,
160 .set = xfs_xattr_set,
163 const struct xattr_handler *xfs_xattr_handlers[] = {
164 &xfs_xattr_user_handler,
165 &xfs_xattr_trusted_handler,
166 &xfs_xattr_security_handler,
167 #ifdef CONFIG_XFS_POSIX_ACL
168 &posix_acl_access_xattr_handler,
169 &posix_acl_default_xattr_handler,
175 __xfs_xattr_put_listent(
176 struct xfs_attr_list_context *context,
185 if (context->count < 0 || context->seen_enough)
188 if (!context->buffer)
191 arraytop = context->count + prefix_len + namelen + 1;
192 if (arraytop > context->firstu) {
193 context->count = -1; /* insufficient space */
194 context->seen_enough = 1;
197 offset = context->buffer + context->count;
198 strncpy(offset, prefix, prefix_len);
199 offset += prefix_len;
200 strncpy(offset, (char *)name, namelen); /* real name */
205 context->count += prefix_len + namelen + 1;
210 xfs_xattr_put_listent(
211 struct xfs_attr_list_context *context,
220 ASSERT(context->count >= 0);
222 if (flags & XFS_ATTR_ROOT) {
223 #ifdef CONFIG_XFS_POSIX_ACL
224 if (namelen == SGI_ACL_FILE_SIZE &&
225 strncmp(name, SGI_ACL_FILE,
226 SGI_ACL_FILE_SIZE) == 0) {
227 __xfs_xattr_put_listent(
228 context, XATTR_SYSTEM_PREFIX,
229 XATTR_SYSTEM_PREFIX_LEN,
230 XATTR_POSIX_ACL_ACCESS,
231 strlen(XATTR_POSIX_ACL_ACCESS));
232 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
233 strncmp(name, SGI_ACL_DEFAULT,
234 SGI_ACL_DEFAULT_SIZE) == 0) {
235 __xfs_xattr_put_listent(
236 context, XATTR_SYSTEM_PREFIX,
237 XATTR_SYSTEM_PREFIX_LEN,
238 XATTR_POSIX_ACL_DEFAULT,
239 strlen(XATTR_POSIX_ACL_DEFAULT));
244 * Only show root namespace entries if we are actually allowed to
247 if (!capable(CAP_SYS_ADMIN))
250 prefix = XATTR_TRUSTED_PREFIX;
251 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
252 } else if (flags & XFS_ATTR_SECURE) {
253 prefix = XATTR_SECURITY_PREFIX;
254 prefix_len = XATTR_SECURITY_PREFIX_LEN;
256 prefix = XATTR_USER_PREFIX;
257 prefix_len = XATTR_USER_PREFIX_LEN;
260 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
267 struct dentry *dentry,
271 struct xfs_attr_list_context context;
272 struct inode *inode = d_inode(dentry);
276 * First read the regular on-disk attributes.
278 memset(&context, 0, sizeof(context));
279 context.dp = XFS_I(inode);
281 context.buffer = size ? data : NULL;
282 context.bufsize = size;
283 context.firstu = context.bufsize;
284 context.put_listent = xfs_xattr_put_listent;
286 error = xfs_attr_list(&context);
289 if (context.count < 0)
292 return context.count;