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 xfs_attr_want_log_assist(
76 /* Logged xattrs require a V5 super for log_incompat */
77 return xfs_has_crc(mp) && xfs_globals.larp;
84 * Set or remove an xattr, having grabbed the appropriate logging resources
85 * prior to calling libxfs.
89 struct xfs_da_args *args)
91 struct xfs_mount *mp = args->dp->i_mount;
92 bool use_logging = false;
95 ASSERT(!(args->op_flags & XFS_DA_OP_LOGGED));
97 if (xfs_attr_want_log_assist(mp)) {
98 error = xfs_attr_grab_log_assist(mp);
102 args->op_flags |= XFS_DA_OP_LOGGED;
106 error = xfs_attr_set(args);
109 xfs_attr_rele_log_assist(mp);
115 xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
116 struct inode *inode, const char *name, void *value, size_t size)
118 struct xfs_da_args args = {
120 .attr_filter = handler->flags,
122 .namelen = strlen(name),
128 error = xfs_attr_get(&args);
131 return args.valuelen;
135 xfs_xattr_set(const struct xattr_handler *handler,
136 struct mnt_idmap *idmap, struct dentry *unused,
137 struct inode *inode, const char *name, const void *value,
138 size_t size, int flags)
140 struct xfs_da_args args = {
142 .attr_filter = handler->flags,
145 .namelen = strlen(name),
146 .value = (void *)value,
151 error = xfs_attr_change(&args);
152 if (!error && (handler->flags & XFS_ATTR_ROOT))
153 xfs_forget_acl(inode, name);
157 static const struct xattr_handler xfs_xattr_user_handler = {
158 .prefix = XATTR_USER_PREFIX,
159 .flags = 0, /* no flags implies user namespace */
160 .get = xfs_xattr_get,
161 .set = xfs_xattr_set,
164 static const struct xattr_handler xfs_xattr_trusted_handler = {
165 .prefix = XATTR_TRUSTED_PREFIX,
166 .flags = XFS_ATTR_ROOT,
167 .get = xfs_xattr_get,
168 .set = xfs_xattr_set,
171 static const struct xattr_handler xfs_xattr_security_handler = {
172 .prefix = XATTR_SECURITY_PREFIX,
173 .flags = XFS_ATTR_SECURE,
174 .get = xfs_xattr_get,
175 .set = xfs_xattr_set,
178 const struct xattr_handler *xfs_xattr_handlers[] = {
179 &xfs_xattr_user_handler,
180 &xfs_xattr_trusted_handler,
181 &xfs_xattr_security_handler,
186 __xfs_xattr_put_listent(
187 struct xfs_attr_list_context *context,
196 if (context->count < 0 || context->seen_enough)
199 if (!context->buffer)
202 arraytop = context->count + prefix_len + namelen + 1;
203 if (arraytop > context->firstu) {
204 context->count = -1; /* insufficient space */
205 context->seen_enough = 1;
208 offset = context->buffer + context->count;
209 memcpy(offset, prefix, prefix_len);
210 offset += prefix_len;
211 strncpy(offset, (char *)name, namelen); /* real name */
216 context->count += prefix_len + namelen + 1;
221 xfs_xattr_put_listent(
222 struct xfs_attr_list_context *context,
231 ASSERT(context->count >= 0);
233 if (flags & XFS_ATTR_ROOT) {
234 #ifdef CONFIG_XFS_POSIX_ACL
235 if (namelen == SGI_ACL_FILE_SIZE &&
236 strncmp(name, SGI_ACL_FILE,
237 SGI_ACL_FILE_SIZE) == 0) {
238 __xfs_xattr_put_listent(
239 context, XATTR_SYSTEM_PREFIX,
240 XATTR_SYSTEM_PREFIX_LEN,
241 XATTR_POSIX_ACL_ACCESS,
242 strlen(XATTR_POSIX_ACL_ACCESS));
243 } else if (namelen == SGI_ACL_DEFAULT_SIZE &&
244 strncmp(name, SGI_ACL_DEFAULT,
245 SGI_ACL_DEFAULT_SIZE) == 0) {
246 __xfs_xattr_put_listent(
247 context, XATTR_SYSTEM_PREFIX,
248 XATTR_SYSTEM_PREFIX_LEN,
249 XATTR_POSIX_ACL_DEFAULT,
250 strlen(XATTR_POSIX_ACL_DEFAULT));
255 * Only show root namespace entries if we are actually allowed to
258 if (!capable(CAP_SYS_ADMIN))
261 prefix = XATTR_TRUSTED_PREFIX;
262 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
263 } else if (flags & XFS_ATTR_SECURE) {
264 prefix = XATTR_SECURITY_PREFIX;
265 prefix_len = XATTR_SECURITY_PREFIX_LEN;
267 prefix = XATTR_USER_PREFIX;
268 prefix_len = XATTR_USER_PREFIX_LEN;
271 __xfs_xattr_put_listent(context, prefix, prefix_len, name,
278 struct dentry *dentry,
282 struct xfs_attr_list_context context;
283 struct inode *inode = d_inode(dentry);
287 * First read the regular on-disk attributes.
289 memset(&context, 0, sizeof(context));
290 context.dp = XFS_I(inode);
292 context.buffer = size ? data : NULL;
293 context.bufsize = size;
294 context.firstu = context.bufsize;
295 context.put_listent = xfs_xattr_put_listent;
297 error = xfs_attr_list(&context);
300 if (context.count < 0)
303 return context.count;