blob: 96f3448b6eb40c0682ec915a71d5030d5bdf4283 [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
20 * Adrian Hunter
21 */
22
23/*
24 * This file implements UBIFS extended attributes support.
25 *
26 * Extended attributes are implemented as regular inodes with attached data,
27 * which limits extended attribute size to UBIFS block size (4KiB). Names of
28 * extended attributes are described by extended attribute entries (xentries),
29 * which are almost identical to directory entries, but have different key type.
30 *
31 * In other words, the situation with extended attributes is very similar to
32 * directories. Indeed, any inode (but of course not xattr inodes) may have a
33 * number of associated xentries, just like directory inodes have associated
34 * directory entries. Extended attribute entries store the name of the extended
35 * attribute, the host inode number, and the extended attribute inode number.
36 * Similarly, direntries store the name, the parent and the target inode
37 * numbers. Thus, most of the common UBIFS mechanisms may be re-used for
38 * extended attributes.
39 *
40 * The number of extended attributes is not limited, but there is Linux
41 * limitation on the maximum possible size of the list of all extended
42 * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
43 * the sum of all extended attribute names of the inode does not exceed that
44 * limit.
45 *
46 * Extended attributes are synchronous, which means they are written to the
47 * flash media synchronously and there is no write-back for extended attribute
48 * inodes. The extended attribute values are not stored in compressed form on
49 * the media.
50 *
51 * Since extended attributes are represented by regular inodes, they are cached
52 * in the VFS inode cache. The xentries are cached in the LNC cache (see
53 * tnc.c).
54 *
55 * ACL support is not implemented.
56 */
57
Al Viro073aaa12009-06-09 12:11:54 -040058#include "ubifs.h"
Jens Axboe7dcda1c2011-04-05 23:51:48 +020059#include <linux/fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090060#include <linux/slab.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030061#include <linux/xattr.h>
62#include <linux/posix_acl_xattr.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030063
64/*
65 * Limit the number of extended attributes per inode so that the total size
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +030066 * (@xattr_size) is guaranteeded to fit in an 'unsigned int'.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030067 */
68#define MAX_XATTRS_PER_INODE 65535
69
70/*
71 * Extended attribute type constants.
72 *
73 * USER_XATTR: user extended attribute ("user.*")
74 * TRUSTED_XATTR: trusted extended attribute ("trusted.*)
75 * SECURITY_XATTR: security extended attribute ("security.*")
76 */
77enum {
78 USER_XATTR,
79 TRUSTED_XATTR,
80 SECURITY_XATTR,
81};
82
Sedat Dilek14ffd5d2011-04-04 01:55:39 +020083static const struct inode_operations empty_iops;
84static const struct file_operations empty_fops;
Artem Bityutskiy1e517642008-07-14 19:08:37 +030085
86/**
87 * create_xattr - create an extended attribute.
88 * @c: UBIFS file-system description object
89 * @host: host inode
90 * @nm: extended attribute name
91 * @value: extended attribute value
92 * @size: size of extended attribute value
93 *
94 * This is a helper function which creates an extended attribute of name @nm
95 * and value @value for inode @host. The host inode is also updated on flash
96 * because the ctime and extended attribute accounting data changes. This
97 * function returns zero in case of success and a negative error code in case
98 * of failure.
99 */
100static int create_xattr(struct ubifs_info *c, struct inode *host,
101 const struct qstr *nm, const void *value, int size)
102{
Subodh Nijsurefee17562014-10-31 13:50:31 -0500103 int err, names_len;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300104 struct inode *inode;
105 struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
106 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Zoltan Sogor5acd6ff2008-08-12 13:54:54 +0300107 .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
108 .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300109
Subodh Nijsurefee17562014-10-31 13:50:31 -0500110 if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE) {
Sheng Yong235c3622015-03-20 10:39:42 +0000111 ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more",
Subodh Nijsurefee17562014-10-31 13:50:31 -0500112 host->i_ino, host_ui->xattr_cnt);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300113 return -ENOSPC;
Subodh Nijsurefee17562014-10-31 13:50:31 -0500114 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300115 /*
116 * Linux limits the maximum size of the extended attribute names list
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300117 * to %XATTR_LIST_MAX. This means we should not allow creating more
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300118 * extended attributes if the name list becomes larger. This limitation
119 * is artificial for UBIFS, though.
120 */
Subodh Nijsurefee17562014-10-31 13:50:31 -0500121 names_len = host_ui->xattr_names + host_ui->xattr_cnt + nm->len + 1;
122 if (names_len > XATTR_LIST_MAX) {
Sheng Yong235c3622015-03-20 10:39:42 +0000123 ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d",
Subodh Nijsurefee17562014-10-31 13:50:31 -0500124 host->i_ino, names_len, XATTR_LIST_MAX);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300125 return -ENOSPC;
Subodh Nijsurefee17562014-10-31 13:50:31 -0500126 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300127
128 err = ubifs_budget_space(c, &req);
129 if (err)
130 return err;
131
132 inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO);
133 if (IS_ERR(inode)) {
134 err = PTR_ERR(inode);
135 goto out_budg;
136 }
137
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300138 /* Re-define all operations to be "nothing" */
Jens Axboe7dcda1c2011-04-05 23:51:48 +0200139 inode->i_mapping->a_ops = &empty_aops;
Sedat Dilek14ffd5d2011-04-04 01:55:39 +0200140 inode->i_op = &empty_iops;
141 inode->i_fop = &empty_fops;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300142
143 inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME | S_NOQUOTA;
144 ui = ubifs_inode(inode);
145 ui->xattr = 1;
146 ui->flags |= UBIFS_XATTR_FL;
Thomas Meyereaecf432011-11-18 00:00:52 +0100147 ui->data = kmemdup(value, size, GFP_NOFS);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300148 if (!ui->data) {
149 err = -ENOMEM;
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300150 goto out_free;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300151 }
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300152 inode->i_size = ui->ui_size = size;
153 ui->data_len = size;
154
155 mutex_lock(&host_ui->ui_mutex);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300156 host->i_ctime = ubifs_current_time(host);
157 host_ui->xattr_cnt += 1;
158 host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
159 host_ui->xattr_size += CALC_XATTR_BYTES(size);
160 host_ui->xattr_names += nm->len;
161
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300162 err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
163 if (err)
164 goto out_cancel;
165 mutex_unlock(&host_ui->ui_mutex);
166
167 ubifs_release_budget(c, &req);
168 insert_inode_hash(inode);
169 iput(inode);
170 return 0;
171
172out_cancel:
173 host_ui->xattr_cnt -= 1;
174 host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
175 host_ui->xattr_size -= CALC_XATTR_BYTES(size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300176 mutex_unlock(&host_ui->ui_mutex);
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300177out_free:
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300178 make_bad_inode(inode);
179 iput(inode);
180out_budg:
181 ubifs_release_budget(c, &req);
182 return err;
183}
184
185/**
186 * change_xattr - change an extended attribute.
187 * @c: UBIFS file-system description object
188 * @host: host inode
189 * @inode: extended attribute inode
190 * @value: extended attribute value
191 * @size: size of extended attribute value
192 *
193 * This helper function changes the value of extended attribute @inode with new
194 * data from @value. Returns zero in case of success and a negative error code
195 * in case of failure.
196 */
197static int change_xattr(struct ubifs_info *c, struct inode *host,
198 struct inode *inode, const void *value, int size)
199{
200 int err;
201 struct ubifs_inode *host_ui = ubifs_inode(host);
202 struct ubifs_inode *ui = ubifs_inode(inode);
203 struct ubifs_budget_req req = { .dirtied_ino = 2,
Zoltan Sogor5acd6ff2008-08-12 13:54:54 +0300204 .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300205
206 ubifs_assert(ui->data_len == inode->i_size);
207 err = ubifs_budget_space(c, &req);
208 if (err)
209 return err;
210
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300211 kfree(ui->data);
Thomas Meyereaecf432011-11-18 00:00:52 +0100212 ui->data = kmemdup(value, size, GFP_NOFS);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300213 if (!ui->data) {
214 err = -ENOMEM;
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300215 goto out_free;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300216 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300217 inode->i_size = ui->ui_size = size;
218 ui->data_len = size;
219
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300220 mutex_lock(&host_ui->ui_mutex);
221 host->i_ctime = ubifs_current_time(host);
222 host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
223 host_ui->xattr_size += CALC_XATTR_BYTES(size);
224
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300225 /*
226 * It is important to write the host inode after the xattr inode
227 * because if the host inode gets synchronized (via 'fsync()'), then
228 * the extended attribute inode gets synchronized, because it goes
229 * before the host inode in the write-buffer.
230 */
231 err = ubifs_jnl_change_xattr(c, inode, host);
232 if (err)
233 goto out_cancel;
234 mutex_unlock(&host_ui->ui_mutex);
235
236 ubifs_release_budget(c, &req);
237 return 0;
238
239out_cancel:
240 host_ui->xattr_size -= CALC_XATTR_BYTES(size);
241 host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300242 mutex_unlock(&host_ui->ui_mutex);
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300243 make_bad_inode(inode);
244out_free:
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300245 ubifs_release_budget(c, &req);
246 return err;
247}
248
249/**
250 * check_namespace - check extended attribute name-space.
251 * @nm: extended attribute name
252 *
253 * This function makes sure the extended attribute name belongs to one of the
254 * supported extended attribute name-spaces. Returns name-space index in case
255 * of success and a negative error code in case of failure.
256 */
257static int check_namespace(const struct qstr *nm)
258{
259 int type;
260
261 if (nm->len > UBIFS_MAX_NLEN)
262 return -ENAMETOOLONG;
263
264 if (!strncmp(nm->name, XATTR_TRUSTED_PREFIX,
265 XATTR_TRUSTED_PREFIX_LEN)) {
266 if (nm->name[sizeof(XATTR_TRUSTED_PREFIX) - 1] == '\0')
267 return -EINVAL;
268 type = TRUSTED_XATTR;
269 } else if (!strncmp(nm->name, XATTR_USER_PREFIX,
270 XATTR_USER_PREFIX_LEN)) {
271 if (nm->name[XATTR_USER_PREFIX_LEN] == '\0')
272 return -EINVAL;
273 type = USER_XATTR;
274 } else if (!strncmp(nm->name, XATTR_SECURITY_PREFIX,
275 XATTR_SECURITY_PREFIX_LEN)) {
276 if (nm->name[sizeof(XATTR_SECURITY_PREFIX) - 1] == '\0')
277 return -EINVAL;
278 type = SECURITY_XATTR;
279 } else
280 return -EOPNOTSUPP;
281
282 return type;
283}
284
285static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
286{
287 struct inode *inode;
288
289 inode = ubifs_iget(c->vfs_sb, inum);
290 if (IS_ERR(inode)) {
Sheng Yong235c3622015-03-20 10:39:42 +0000291 ubifs_err(c, "dead extended attribute entry, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300292 (int)PTR_ERR(inode));
293 return inode;
294 }
295 if (ubifs_inode(inode)->xattr)
296 return inode;
Sheng Yong235c3622015-03-20 10:39:42 +0000297 ubifs_err(c, "corrupt extended attribute entry");
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300298 iput(inode);
299 return ERR_PTR(-EINVAL);
300}
301
Subodh Nijsure895d9db22014-10-31 13:50:29 -0500302static int setxattr(struct inode *host, const char *name, const void *value,
303 size_t size, int flags)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300304{
Subodh Nijsure895d9db22014-10-31 13:50:29 -0500305 struct inode *inode;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300306 struct ubifs_info *c = host->i_sb->s_fs_info;
Linus Torvalds26fe5752012-05-10 13:14:12 -0700307 struct qstr nm = QSTR_INIT(name, strlen(name));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300308 struct ubifs_dent_node *xent;
309 union ubifs_key key;
310 int err, type;
311
Artem Bityutskiyc78c7e32008-08-12 16:30:12 +0300312 ubifs_assert(mutex_is_locked(&host->i_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300313
314 if (size > UBIFS_MAX_INO_DATA)
315 return -ERANGE;
316
317 type = check_namespace(&nm);
318 if (type < 0)
319 return type;
320
321 xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
322 if (!xent)
323 return -ENOMEM;
324
325 /*
326 * The extended attribute entries are stored in LNC, so multiple
327 * look-ups do not involve reading the flash.
328 */
329 xent_key_init(c, &key, host->i_ino, &nm);
330 err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
331 if (err) {
332 if (err != -ENOENT)
333 goto out_free;
334
335 if (flags & XATTR_REPLACE)
336 /* We are asked not to create the xattr */
337 err = -ENODATA;
338 else
339 err = create_xattr(c, host, &nm, value, size);
340 goto out_free;
341 }
342
343 if (flags & XATTR_CREATE) {
344 /* We are asked not to replace the xattr */
345 err = -EEXIST;
346 goto out_free;
347 }
348
349 inode = iget_xattr(c, le64_to_cpu(xent->inum));
350 if (IS_ERR(inode)) {
351 err = PTR_ERR(inode);
352 goto out_free;
353 }
354
355 err = change_xattr(c, host, inode, value, size);
356 iput(inode);
357
358out_free:
359 kfree(xent);
360 return err;
361}
362
Subodh Nijsure895d9db22014-10-31 13:50:29 -0500363int ubifs_setxattr(struct dentry *dentry, const char *name,
364 const void *value, size_t size, int flags)
365{
366 dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
David Howells2b0143b2015-03-17 22:25:59 +0000367 name, d_inode(dentry)->i_ino, dentry, size);
Subodh Nijsure895d9db22014-10-31 13:50:29 -0500368
David Howells2b0143b2015-03-17 22:25:59 +0000369 return setxattr(d_inode(dentry), name, value, size, flags);
Subodh Nijsure895d9db22014-10-31 13:50:29 -0500370}
371
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300372ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
373 size_t size)
374{
David Howells2b0143b2015-03-17 22:25:59 +0000375 struct inode *inode, *host = d_inode(dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300376 struct ubifs_info *c = host->i_sb->s_fs_info;
Linus Torvalds26fe5752012-05-10 13:14:12 -0700377 struct qstr nm = QSTR_INIT(name, strlen(name));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300378 struct ubifs_inode *ui;
379 struct ubifs_dent_node *xent;
380 union ubifs_key key;
381 int err;
382
Al Viro4cb2a012013-09-16 10:58:53 -0400383 dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
384 host->i_ino, dentry, size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300385
386 err = check_namespace(&nm);
387 if (err < 0)
388 return err;
389
390 xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
391 if (!xent)
392 return -ENOMEM;
393
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300394 xent_key_init(c, &key, host->i_ino, &nm);
395 err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
396 if (err) {
397 if (err == -ENOENT)
398 err = -ENODATA;
399 goto out_unlock;
400 }
401
402 inode = iget_xattr(c, le64_to_cpu(xent->inum));
403 if (IS_ERR(inode)) {
404 err = PTR_ERR(inode);
405 goto out_unlock;
406 }
407
408 ui = ubifs_inode(inode);
409 ubifs_assert(inode->i_size == ui->data_len);
410 ubifs_assert(ubifs_inode(host)->xattr_size > ui->data_len);
411
412 if (buf) {
413 /* If @buf is %NULL we are supposed to return the length */
414 if (ui->data_len > size) {
Sheng Yong235c3622015-03-20 10:39:42 +0000415 ubifs_err(c, "buffer size %zd, xattr len %d",
Artem Bityutskiya6aae4d2012-05-16 20:11:23 +0300416 size, ui->data_len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300417 err = -ERANGE;
418 goto out_iput;
419 }
420
421 memcpy(buf, ui->data, ui->data_len);
422 }
423 err = ui->data_len;
424
425out_iput:
426 iput(inode);
427out_unlock:
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300428 kfree(xent);
429 return err;
430}
431
432ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
433{
434 union ubifs_key key;
David Howells2b0143b2015-03-17 22:25:59 +0000435 struct inode *host = d_inode(dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300436 struct ubifs_info *c = host->i_sb->s_fs_info;
437 struct ubifs_inode *host_ui = ubifs_inode(host);
438 struct ubifs_dent_node *xent, *pxent = NULL;
439 int err, len, written = 0;
440 struct qstr nm = { .name = NULL };
441
Al Viro4cb2a012013-09-16 10:58:53 -0400442 dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino,
443 dentry, size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300444
445 len = host_ui->xattr_names + host_ui->xattr_cnt;
446 if (!buffer)
447 /*
448 * We should return the minimum buffer size which will fit a
449 * null-terminated list of all the extended attribute names.
450 */
451 return len;
452
453 if (len > size)
454 return -ERANGE;
455
456 lowest_xent_key(c, &key, host->i_ino);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300457 while (1) {
458 int type;
459
460 xent = ubifs_tnc_next_ent(c, &key, &nm);
Hirofumi Nakagawa8d47aef2008-08-21 17:16:40 +0300461 if (IS_ERR(xent)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300462 err = PTR_ERR(xent);
463 break;
464 }
465
466 nm.name = xent->name;
467 nm.len = le16_to_cpu(xent->nlen);
468
469 type = check_namespace(&nm);
470 if (unlikely(type < 0)) {
471 err = type;
472 break;
473 }
474
475 /* Show trusted namespace only for "power" users */
476 if (type != TRUSTED_XATTR || capable(CAP_SYS_ADMIN)) {
477 memcpy(buffer + written, nm.name, nm.len + 1);
478 written += nm.len + 1;
479 }
480
481 kfree(pxent);
482 pxent = xent;
483 key_read(c, &xent->key, &key);
484 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300485
486 kfree(pxent);
487 if (err != -ENOENT) {
Sheng Yong235c3622015-03-20 10:39:42 +0000488 ubifs_err(c, "cannot find next direntry, error %d", err);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300489 return err;
490 }
491
492 ubifs_assert(written <= size);
493 return written;
494}
495
496static int remove_xattr(struct ubifs_info *c, struct inode *host,
497 struct inode *inode, const struct qstr *nm)
498{
499 int err;
500 struct ubifs_inode *host_ui = ubifs_inode(host);
501 struct ubifs_inode *ui = ubifs_inode(inode);
Zoltan Sogor5acd6ff2008-08-12 13:54:54 +0300502 struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
503 .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300504
505 ubifs_assert(ui->data_len == inode->i_size);
506
507 err = ubifs_budget_space(c, &req);
508 if (err)
509 return err;
510
511 mutex_lock(&host_ui->ui_mutex);
512 host->i_ctime = ubifs_current_time(host);
513 host_ui->xattr_cnt -= 1;
514 host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
515 host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
516 host_ui->xattr_names -= nm->len;
517
518 err = ubifs_jnl_delete_xattr(c, host, inode, nm);
519 if (err)
520 goto out_cancel;
521 mutex_unlock(&host_ui->ui_mutex);
522
523 ubifs_release_budget(c, &req);
524 return 0;
525
526out_cancel:
527 host_ui->xattr_cnt += 1;
528 host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
529 host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
530 mutex_unlock(&host_ui->ui_mutex);
531 ubifs_release_budget(c, &req);
532 make_bad_inode(inode);
533 return err;
534}
535
536int ubifs_removexattr(struct dentry *dentry, const char *name)
537{
David Howells2b0143b2015-03-17 22:25:59 +0000538 struct inode *inode, *host = d_inode(dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300539 struct ubifs_info *c = host->i_sb->s_fs_info;
Linus Torvalds26fe5752012-05-10 13:14:12 -0700540 struct qstr nm = QSTR_INIT(name, strlen(name));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300541 struct ubifs_dent_node *xent;
542 union ubifs_key key;
543 int err;
544
Al Viro4cb2a012013-09-16 10:58:53 -0400545 dbg_gen("xattr '%s', ino %lu ('%pd')", name,
546 host->i_ino, dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300547 ubifs_assert(mutex_is_locked(&host->i_mutex));
548
549 err = check_namespace(&nm);
550 if (err < 0)
551 return err;
552
553 xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
554 if (!xent)
555 return -ENOMEM;
556
557 xent_key_init(c, &key, host->i_ino, &nm);
558 err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
559 if (err) {
560 if (err == -ENOENT)
561 err = -ENODATA;
562 goto out_free;
563 }
564
565 inode = iget_xattr(c, le64_to_cpu(xent->inum));
566 if (IS_ERR(inode)) {
567 err = PTR_ERR(inode);
568 goto out_free;
569 }
570
571 ubifs_assert(inode->i_nlink == 1);
Miklos Szeredi6d6b77f2011-10-28 14:13:28 +0200572 clear_nlink(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300573 err = remove_xattr(c, host, inode, &nm);
574 if (err)
Miklos Szeredibfe86842011-10-28 14:13:29 +0200575 set_nlink(inode, 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300576
577 /* If @i_nlink is 0, 'iput()' will delete the inode */
578 iput(inode);
579
580out_free:
581 kfree(xent);
582 return err;
583}
Subodh Nijsured7f0b702014-10-31 13:50:30 -0500584
585static size_t security_listxattr(struct dentry *d, char *list, size_t list_size,
586 const char *name, size_t name_len, int flags)
587{
588 const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
589 const size_t total_len = prefix_len + name_len + 1;
590
591 if (list && total_len <= list_size) {
592 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
593 memcpy(list + prefix_len, name, name_len);
594 list[prefix_len + name_len] = '\0';
595 }
596
597 return total_len;
598}
599
600static int security_getxattr(struct dentry *d, const char *name, void *buffer,
601 size_t size, int flags)
602{
603 return ubifs_getxattr(d, name, buffer, size);
604}
605
606static int security_setxattr(struct dentry *d, const char *name,
607 const void *value, size_t size, int flags,
608 int handler_flags)
609{
610 return ubifs_setxattr(d, name, value, size, flags);
611}
612
613static const struct xattr_handler ubifs_xattr_security_handler = {
614 .prefix = XATTR_SECURITY_PREFIX,
615 .list = security_listxattr,
616 .get = security_getxattr,
617 .set = security_setxattr,
618};
619
620const struct xattr_handler *ubifs_xattr_handlers[] = {
621 &ubifs_xattr_security_handler,
622 NULL,
623};
624
625static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
626 void *fs_info)
627{
628 const struct xattr *xattr;
629 char *name;
630 int err = 0;
631
632 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
633 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
634 strlen(xattr->name) + 1, GFP_NOFS);
635 if (!name) {
636 err = -ENOMEM;
637 break;
638 }
639 strcpy(name, XATTR_SECURITY_PREFIX);
640 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
641 err = setxattr(inode, name, xattr->value, xattr->value_len, 0);
642 kfree(name);
643 if (err < 0)
644 break;
645 }
646
647 return err;
648}
649
650int ubifs_init_security(struct inode *dentry, struct inode *inode,
651 const struct qstr *qstr)
652{
653 int err;
654
655 mutex_lock(&inode->i_mutex);
656 err = security_inode_init_security(inode, dentry, qstr,
657 &init_xattrs, 0);
658 mutex_unlock(&inode->i_mutex);
659
Sheng Yong235c3622015-03-20 10:39:42 +0000660 if (err) {
661 struct ubifs_info *c = dentry->i_sb->s_fs_info;
662 ubifs_err(c, "cannot initialize security for inode %lu, error %d",
Subodh Nijsurefee17562014-10-31 13:50:31 -0500663 inode->i_ino, err);
Sheng Yong235c3622015-03-20 10:39:42 +0000664 }
Subodh Nijsured7f0b702014-10-31 13:50:30 -0500665 return err;
666}