blob: 446a6848c5548f2f8f03f2b532eac9a174bd56c7 [file] [log] [blame]
Josef Bacik5103e942007-11-16 11:45:54 -05001/*
2 * Copyright (C) 2007 Red Hat. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/init.h>
20#include <linux/fs.h>
21#include <linux/slab.h>
22#include <linux/rwsem.h>
23#include <linux/xattr.h>
Jim Owens0279b4c2009-02-04 09:29:13 -050024#include <linux/security.h>
Josef Bacik5103e942007-11-16 11:45:54 -050025#include "ctree.h"
26#include "btrfs_inode.h"
27#include "transaction.h"
28#include "xattr.h"
29#include "disk-io.h"
Josef Bacik33268ea2008-07-24 12:16:36 -040030
Josef Bacik33268ea2008-07-24 12:16:36 -040031
Christoph Hellwig95819c02008-08-28 06:21:17 -040032ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
33 void *buffer, size_t size)
Josef Bacik5103e942007-11-16 11:45:54 -050034{
35 struct btrfs_dir_item *di;
36 struct btrfs_root *root = BTRFS_I(inode)->root;
37 struct btrfs_path *path;
38 struct extent_buffer *leaf;
Josef Bacik5103e942007-11-16 11:45:54 -050039 int ret = 0;
40 unsigned long data_ptr;
Josef Bacik5103e942007-11-16 11:45:54 -050041
42 path = btrfs_alloc_path();
Christoph Hellwig95819c02008-08-28 06:21:17 -040043 if (!path)
Josef Bacik5103e942007-11-16 11:45:54 -050044 return -ENOMEM;
Josef Bacik5103e942007-11-16 11:45:54 -050045
Josef Bacik5103e942007-11-16 11:45:54 -050046 /* lookup the xattr by name */
Li Zefan33345d012011-04-20 10:31:50 +080047 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
Josef Bacik5103e942007-11-16 11:45:54 -050048 strlen(name), 0);
Josef Bacik07060402009-01-21 10:49:16 -050049 if (!di) {
Josef Bacik5103e942007-11-16 11:45:54 -050050 ret = -ENODATA;
51 goto out;
Josef Bacik07060402009-01-21 10:49:16 -050052 } else if (IS_ERR(di)) {
53 ret = PTR_ERR(di);
54 goto out;
Josef Bacik5103e942007-11-16 11:45:54 -050055 }
56
57 leaf = path->nodes[0];
58 /* if size is 0, that means we want the size of the attr */
59 if (!size) {
60 ret = btrfs_dir_data_len(leaf, di);
61 goto out;
62 }
63
64 /* now get the data out of our dir_item */
65 if (btrfs_dir_data_len(leaf, di) > size) {
66 ret = -ERANGE;
67 goto out;
68 }
Josef Bacik07060402009-01-21 10:49:16 -050069
70 /*
71 * The way things are packed into the leaf is like this
72 * |struct btrfs_dir_item|name|data|
73 * where name is the xattr name, so security.foo, and data is the
74 * content of the xattr. data_ptr points to the location in memory
75 * where the data starts in the in memory leaf
76 */
Josef Bacik5103e942007-11-16 11:45:54 -050077 data_ptr = (unsigned long)((char *)(di + 1) +
78 btrfs_dir_name_len(leaf, di));
79 read_extent_buffer(leaf, buffer, data_ptr,
Josef Bacik3acd7ee2007-11-19 10:18:19 -050080 btrfs_dir_data_len(leaf, di));
Josef Bacik5103e942007-11-16 11:45:54 -050081 ret = btrfs_dir_data_len(leaf, di);
82
83out:
Josef Bacik5103e942007-11-16 11:45:54 -050084 btrfs_free_path(path);
85 return ret;
86}
87
Yan, Zhengf34f57a2009-11-12 09:35:27 +000088static int do_setxattr(struct btrfs_trans_handle *trans,
89 struct inode *inode, const char *name,
90 const void *value, size_t size, int flags)
Josef Bacik5103e942007-11-16 11:45:54 -050091{
92 struct btrfs_dir_item *di;
93 struct btrfs_root *root = BTRFS_I(inode)->root;
Josef Bacik5103e942007-11-16 11:45:54 -050094 struct btrfs_path *path;
Yan, Zhengf34f57a2009-11-12 09:35:27 +000095 size_t name_len = strlen(name);
96 int ret = 0;
97
98 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
99 return -ENOSPC;
Josef Bacik5103e942007-11-16 11:45:54 -0500100
101 path = btrfs_alloc_path();
Christoph Hellwig95819c02008-08-28 06:21:17 -0400102 if (!path)
Josef Bacik5103e942007-11-16 11:45:54 -0500103 return -ENOMEM;
Josef Bacik5103e942007-11-16 11:45:54 -0500104
Josef Bacikfa092002011-05-27 12:06:11 -0400105 if (flags & XATTR_REPLACE) {
106 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
107 name_len, -1);
108 if (IS_ERR(di)) {
109 ret = PTR_ERR(di);
Josef Bacik5103e942007-11-16 11:45:54 -0500110 goto out;
Josef Bacikfa092002011-05-27 12:06:11 -0400111 } else if (!di) {
Josef Bacik33268ea2008-07-24 12:16:36 -0400112 ret = -ENODATA;
113 goto out;
114 }
Josef Bacikfa092002011-05-27 12:06:11 -0400115 ret = btrfs_delete_one_dir_name(trans, root, path, di);
116 if (ret)
117 goto out;
118 btrfs_release_path(path);
David Sterba48150532011-09-11 10:52:25 -0400119
120 /*
121 * remove the attribute
122 */
123 if (!value)
124 goto out;
Liu Bo01e6deb2012-11-28 10:43:12 +0000125 } else {
126 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode),
127 name, name_len, 0);
128 if (IS_ERR(di)) {
129 ret = PTR_ERR(di);
130 goto out;
131 }
132 if (!di && !value)
133 goto out;
134 btrfs_release_path(path);
Josef Bacik5103e942007-11-16 11:45:54 -0500135 }
136
Josef Bacikfa092002011-05-27 12:06:11 -0400137again:
Li Zefan33345d012011-04-20 10:31:50 +0800138 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000139 name, name_len, value, size);
Josef Baciked3ee9f2011-10-13 13:09:22 -0400140 /*
141 * If we're setting an xattr to a new value but the new value is say
142 * exactly BTRFS_MAX_XATTR_SIZE, we could end up with EOVERFLOW getting
143 * back from split_leaf. This is because it thinks we'll be extending
144 * the existing item size, but we're asking for enough space to add the
145 * item itself. So if we get EOVERFLOW just set ret to EEXIST and let
146 * the rest of the function figure it out.
147 */
148 if (ret == -EOVERFLOW)
149 ret = -EEXIST;
150
Josef Bacikfa092002011-05-27 12:06:11 -0400151 if (ret == -EEXIST) {
152 if (flags & XATTR_CREATE)
153 goto out;
154 /*
155 * We can't use the path we already have since we won't have the
156 * proper locking for a delete, so release the path and
157 * re-lookup to delete the thing.
158 */
159 btrfs_release_path(path);
160 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
161 name, name_len, -1);
162 if (IS_ERR(di)) {
163 ret = PTR_ERR(di);
164 goto out;
165 } else if (!di) {
166 /* Shouldn't happen but just in case... */
167 btrfs_release_path(path);
168 goto again;
169 }
170
171 ret = btrfs_delete_one_dir_name(trans, root, path, di);
172 if (ret)
173 goto out;
174
175 /*
176 * We have a value to set, so go back and try to insert it now.
177 */
178 if (value) {
179 btrfs_release_path(path);
180 goto again;
181 }
182 }
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000183out:
184 btrfs_free_path(path);
185 return ret;
186}
187
David Sterba48150532011-09-11 10:52:25 -0400188/*
189 * @value: "" makes the attribute to empty, NULL removes it
190 */
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000191int __btrfs_setxattr(struct btrfs_trans_handle *trans,
192 struct inode *inode, const char *name,
193 const void *value, size_t size, int flags)
194{
195 struct btrfs_root *root = BTRFS_I(inode)->root;
196 int ret;
197
198 if (trans)
199 return do_setxattr(trans, inode, name, value, size, flags);
200
Yan, Zhenga22285a2010-05-16 10:48:46 -0400201 trans = btrfs_start_transaction(root, 2);
202 if (IS_ERR(trans))
203 return PTR_ERR(trans);
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000204
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000205 ret = do_setxattr(trans, inode, name, value, size, flags);
Josef Bacik5103e942007-11-16 11:45:54 -0500206 if (ret)
207 goto out;
Josef Bacik5103e942007-11-16 11:45:54 -0500208
Josef Bacik0c4d2d92012-04-05 15:03:02 -0400209 inode_inc_iversion(inode);
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000210 inode->i_ctime = CURRENT_TIME;
Josef Bacike9976152012-10-11 15:53:56 -0400211 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000212 ret = btrfs_update_inode(trans, root, inode);
213 BUG_ON(ret);
Josef Bacik5103e942007-11-16 11:45:54 -0500214out:
Josef Bacik7ad85bb2012-01-12 19:10:12 -0500215 btrfs_end_transaction(trans, root);
Josef Bacik5103e942007-11-16 11:45:54 -0500216 return ret;
217}
218
219ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
220{
221 struct btrfs_key key, found_key;
222 struct inode *inode = dentry->d_inode;
223 struct btrfs_root *root = BTRFS_I(inode)->root;
224 struct btrfs_path *path;
Josef Bacik5103e942007-11-16 11:45:54 -0500225 struct extent_buffer *leaf;
226 struct btrfs_dir_item *di;
Li Zefan2e6a0032011-03-17 15:17:59 +0800227 int ret = 0, slot;
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400228 size_t total_size = 0, size_left = size;
Josef Bacik5103e942007-11-16 11:45:54 -0500229 unsigned long name_ptr;
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400230 size_t name_len;
Josef Bacik5103e942007-11-16 11:45:54 -0500231
232 /*
233 * ok we want all objects associated with this id.
234 * NOTE: we set key.offset = 0; because we want to start with the
235 * first xattr that we find and walk forward
236 */
Li Zefan33345d012011-04-20 10:31:50 +0800237 key.objectid = btrfs_ino(inode);
Josef Bacik5103e942007-11-16 11:45:54 -0500238 btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
239 key.offset = 0;
240
241 path = btrfs_alloc_path();
Josef Bacik5103e942007-11-16 11:45:54 -0500242 if (!path)
243 return -ENOMEM;
Josef Bacik1caf9342007-11-19 10:18:17 -0500244 path->reada = 2;
Josef Bacik5103e942007-11-16 11:45:54 -0500245
Josef Bacik5103e942007-11-16 11:45:54 -0500246 /* search for our xattrs */
247 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
248 if (ret < 0)
249 goto err;
Li Zefan2e6a0032011-03-17 15:17:59 +0800250
Josef Bacik5103e942007-11-16 11:45:54 -0500251 while (1) {
252 leaf = path->nodes[0];
Josef Bacik5103e942007-11-16 11:45:54 -0500253 slot = path->slots[0];
254
255 /* this is where we start walking through the path */
Li Zefan2e6a0032011-03-17 15:17:59 +0800256 if (slot >= btrfs_header_nritems(leaf)) {
Josef Bacik5103e942007-11-16 11:45:54 -0500257 /*
258 * if we've reached the last slot in this leaf we need
259 * to go to the next leaf and reset everything
260 */
Li Zefan2e6a0032011-03-17 15:17:59 +0800261 ret = btrfs_next_leaf(root, path);
262 if (ret < 0)
263 goto err;
264 else if (ret > 0)
265 break;
266 continue;
Josef Bacik5103e942007-11-16 11:45:54 -0500267 }
Josef Bacik5103e942007-11-16 11:45:54 -0500268
Josef Bacik5103e942007-11-16 11:45:54 -0500269 btrfs_item_key_to_cpu(leaf, &found_key, slot);
270
271 /* check to make sure this item is what we want */
272 if (found_key.objectid != key.objectid)
273 break;
274 if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
275 break;
276
277 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
Josef Bacik22a94d42011-03-16 16:47:17 -0400278 if (verify_dir_item(root, leaf, di))
Liu Bodb2254b2012-11-26 02:58:36 +0000279 goto next;
Josef Bacik5103e942007-11-16 11:45:54 -0500280
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400281 name_len = btrfs_dir_name_len(leaf, di);
282 total_size += name_len + 1;
Josef Bacik5103e942007-11-16 11:45:54 -0500283
284 /* we are just looking for how big our buffer needs to be */
285 if (!size)
Li Zefan2e6a0032011-03-17 15:17:59 +0800286 goto next;
Josef Bacik5103e942007-11-16 11:45:54 -0500287
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400288 if (!buffer || (name_len + 1) > size_left) {
Josef Bacik5103e942007-11-16 11:45:54 -0500289 ret = -ERANGE;
Yehuda Sadeh Weinraubb16281c2008-12-17 10:21:26 -0500290 goto err;
Josef Bacik5103e942007-11-16 11:45:54 -0500291 }
292
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400293 name_ptr = (unsigned long)(di + 1);
294 read_extent_buffer(leaf, buffer, name_ptr, name_len);
295 buffer[name_len] = '\0';
296
297 size_left -= name_len + 1;
298 buffer += name_len + 1;
Li Zefan2e6a0032011-03-17 15:17:59 +0800299next:
300 path->slots[0]++;
Josef Bacik5103e942007-11-16 11:45:54 -0500301 }
302 ret = total_size;
303
304err:
Josef Bacik5103e942007-11-16 11:45:54 -0500305 btrfs_free_path(path);
306
307 return ret;
308}
309
310/*
Christoph Hellwig95819c02008-08-28 06:21:17 -0400311 * List of handlers for synthetic system.* attributes. All real ondisk
312 * attributes are handled directly.
Josef Bacik5103e942007-11-16 11:45:54 -0500313 */
Stephen Hemmingerf01cbd32010-05-13 17:53:15 -0700314const struct xattr_handler *btrfs_xattr_handlers[] = {
Chris Mason0eda2942009-10-13 13:50:18 -0400315#ifdef CONFIG_BTRFS_FS_POSIX_ACL
Christoph Hellwig95819c02008-08-28 06:21:17 -0400316 &btrfs_xattr_acl_access_handler,
317 &btrfs_xattr_acl_default_handler,
318#endif
319 NULL,
320};
321
322/*
323 * Check if the attribute is in a supported namespace.
324 *
325 * This applied after the check for the synthetic attributes in the system
326 * namespace.
327 */
328static bool btrfs_is_valid_xattr(const char *name)
329{
Chris Masond3977122009-01-05 21:25:51 -0500330 return !strncmp(name, XATTR_SECURITY_PREFIX,
331 XATTR_SECURITY_PREFIX_LEN) ||
Christoph Hellwig95819c02008-08-28 06:21:17 -0400332 !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) ||
333 !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
334 !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
Chris Mason69a32ac2008-01-14 14:33:35 -0500335}
336
Christoph Hellwig95819c02008-08-28 06:21:17 -0400337ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
338 void *buffer, size_t size)
339{
340 /*
341 * If this is a request for a synthetic attribute in the system.*
342 * namespace use the generic infrastructure to resolve a handler
343 * for it via sb->s_xattr.
344 */
345 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
346 return generic_getxattr(dentry, name, buffer, size);
Josef Bacik5103e942007-11-16 11:45:54 -0500347
Christoph Hellwig95819c02008-08-28 06:21:17 -0400348 if (!btrfs_is_valid_xattr(name))
349 return -EOPNOTSUPP;
350 return __btrfs_getxattr(dentry->d_inode, name, buffer, size);
351}
Josef Bacik5103e942007-11-16 11:45:54 -0500352
Christoph Hellwig95819c02008-08-28 06:21:17 -0400353int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
354 size_t size, int flags)
355{
Li Zefanb83cc962010-12-20 16:04:08 +0800356 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
357
358 /*
359 * The permission on security.* and system.* is not checked
360 * in permission().
361 */
362 if (btrfs_root_readonly(root))
363 return -EROFS;
364
Christoph Hellwig95819c02008-08-28 06:21:17 -0400365 /*
366 * If this is a request for a synthetic attribute in the system.*
367 * namespace use the generic infrastructure to resolve a handler
368 * for it via sb->s_xattr.
369 */
370 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
371 return generic_setxattr(dentry, name, value, size, flags);
Josef Bacik5103e942007-11-16 11:45:54 -0500372
Christoph Hellwig95819c02008-08-28 06:21:17 -0400373 if (!btrfs_is_valid_xattr(name))
374 return -EOPNOTSUPP;
Josef Bacik5103e942007-11-16 11:45:54 -0500375
Christoph Hellwig95819c02008-08-28 06:21:17 -0400376 if (size == 0)
377 value = ""; /* empty EA, do not remove */
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000378
379 return __btrfs_setxattr(NULL, dentry->d_inode, name, value, size,
380 flags);
Christoph Hellwig95819c02008-08-28 06:21:17 -0400381}
382
383int btrfs_removexattr(struct dentry *dentry, const char *name)
384{
Li Zefanb83cc962010-12-20 16:04:08 +0800385 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
386
387 /*
388 * The permission on security.* and system.* is not checked
389 * in permission().
390 */
391 if (btrfs_root_readonly(root))
392 return -EROFS;
393
Christoph Hellwig95819c02008-08-28 06:21:17 -0400394 /*
395 * If this is a request for a synthetic attribute in the system.*
396 * namespace use the generic infrastructure to resolve a handler
397 * for it via sb->s_xattr.
398 */
399 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
400 return generic_removexattr(dentry, name);
401
402 if (!btrfs_is_valid_xattr(name))
403 return -EOPNOTSUPP;
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000404
405 return __btrfs_setxattr(NULL, dentry->d_inode, name, NULL, 0,
406 XATTR_REPLACE);
Christoph Hellwig95819c02008-08-28 06:21:17 -0400407}
Jim Owens0279b4c2009-02-04 09:29:13 -0500408
Mimi Zohar9d8f13b2011-06-06 15:29:25 -0400409int btrfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
410 void *fs_info)
411{
412 const struct xattr *xattr;
413 struct btrfs_trans_handle *trans = fs_info;
414 char *name;
415 int err = 0;
416
417 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
418 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
419 strlen(xattr->name) + 1, GFP_NOFS);
420 if (!name) {
421 err = -ENOMEM;
422 break;
423 }
424 strcpy(name, XATTR_SECURITY_PREFIX);
425 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
426 err = __btrfs_setxattr(trans, inode, name,
427 xattr->value, xattr->value_len, 0);
428 kfree(name);
429 if (err < 0)
430 break;
431 }
432 return err;
433}
434
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000435int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
Eric Paris2a7dba32011-02-01 11:05:39 -0500436 struct inode *inode, struct inode *dir,
437 const struct qstr *qstr)
Jim Owens0279b4c2009-02-04 09:29:13 -0500438{
Mimi Zohar9d8f13b2011-06-06 15:29:25 -0400439 return security_inode_init_security(inode, dir, qstr,
440 &btrfs_initxattrs, trans);
Jim Owens0279b4c2009-02-04 09:29:13 -0500441}