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1/*
2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3 * Copyright (c) 2012-2013 Red Hat, Inc.
4 * All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19#include "xfs.h"
20#include "xfs_shared.h"
21#include "xfs_fs.h"
22#include "xfs_format.h"
23#include "xfs_log_format.h"
24#include "xfs_trans_resv.h"
25#include "xfs_bit.h"
26#include "xfs_sb.h"
27#include "xfs_ag.h"
28#include "xfs_mount.h"
29#include "xfs_da_format.h"
30#include "xfs_dir2.h"
31#include "xfs_inode.h"
32#include "xfs_ialloc.h"
33#include "xfs_alloc.h"
34#include "xfs_bmap.h"
35#include "xfs_bmap_btree.h"
36#include "xfs_bmap_util.h"
37#include "xfs_error.h"
38#include "xfs_quota.h"
39#include "xfs_trans_space.h"
40#include "xfs_trace.h"
41#include "xfs_symlink.h"
42#include "xfs_trans.h"
43#include "xfs_log.h"
44#include "xfs_dinode.h"
45
46/* ----- Kernel only functions below ----- */
47STATIC int
48xfs_readlink_bmap(
49 struct xfs_inode *ip,
50 char *link)
51{
52 struct xfs_mount *mp = ip->i_mount;
53 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
54 struct xfs_buf *bp;
55 xfs_daddr_t d;
56 char *cur_chunk;
57 int pathlen = ip->i_d.di_size;
58 int nmaps = XFS_SYMLINK_MAPS;
59 int byte_cnt;
60 int n;
61 int error = 0;
62 int fsblocks = 0;
63 int offset;
64
65 fsblocks = xfs_symlink_blocks(mp, pathlen);
66 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
67 if (error)
68 goto out;
69
70 offset = 0;
71 for (n = 0; n < nmaps; n++) {
72 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
73 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
74
75 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
76 &xfs_symlink_buf_ops);
77 if (!bp)
78 return XFS_ERROR(ENOMEM);
79 error = bp->b_error;
80 if (error) {
81 xfs_buf_ioerror_alert(bp, __func__);
82 xfs_buf_relse(bp);
83
84 /* bad CRC means corrupted metadata */
85 if (error == EFSBADCRC)
86 error = EFSCORRUPTED;
87 goto out;
88 }
89 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
90 if (pathlen < byte_cnt)
91 byte_cnt = pathlen;
92
93 cur_chunk = bp->b_addr;
94 if (xfs_sb_version_hascrc(&mp->m_sb)) {
95 if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
96 byte_cnt, bp)) {
97 error = EFSCORRUPTED;
98 xfs_alert(mp,
99"symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
100 offset, byte_cnt, ip->i_ino);
101 xfs_buf_relse(bp);
102 goto out;
103
104 }
105
106 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
107 }
108
109 memcpy(link + offset, bp->b_addr, byte_cnt);
110
111 pathlen -= byte_cnt;
112 offset += byte_cnt;
113
114 xfs_buf_relse(bp);
115 }
116 ASSERT(pathlen == 0);
117
118 link[ip->i_d.di_size] = '\0';
119 error = 0;
120
121 out:
122 return error;
123}
124
125int
126xfs_readlink(
127 struct xfs_inode *ip,
128 char *link)
129{
130 struct xfs_mount *mp = ip->i_mount;
131 xfs_fsize_t pathlen;
132 int error = 0;
133
134 trace_xfs_readlink(ip);
135
136 if (XFS_FORCED_SHUTDOWN(mp))
137 return XFS_ERROR(EIO);
138
139 xfs_ilock(ip, XFS_ILOCK_SHARED);
140
141 pathlen = ip->i_d.di_size;
142 if (!pathlen)
143 goto out;
144
145 if (pathlen < 0 || pathlen > MAXPATHLEN) {
146 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
147 __func__, (unsigned long long) ip->i_ino,
148 (long long) pathlen);
149 ASSERT(0);
150 error = XFS_ERROR(EFSCORRUPTED);
151 goto out;
152 }
153
154
155 if (ip->i_df.if_flags & XFS_IFINLINE) {
156 memcpy(link, ip->i_df.if_u1.if_data, pathlen);
157 link[pathlen] = '\0';
158 } else {
159 error = xfs_readlink_bmap(ip, link);
160 }
161
162 out:
163 xfs_iunlock(ip, XFS_ILOCK_SHARED);
164 return error;
165}
166
167int
168xfs_symlink(
169 struct xfs_inode *dp,
170 struct xfs_name *link_name,
171 const char *target_path,
172 umode_t mode,
173 struct xfs_inode **ipp)
174{
175 struct xfs_mount *mp = dp->i_mount;
176 struct xfs_trans *tp = NULL;
177 struct xfs_inode *ip = NULL;
178 int error = 0;
179 int pathlen;
180 struct xfs_bmap_free free_list;
181 xfs_fsblock_t first_block;
182 bool unlock_dp_on_error = false;
183 uint cancel_flags;
184 int committed;
185 xfs_fileoff_t first_fsb;
186 xfs_filblks_t fs_blocks;
187 int nmaps;
188 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
189 xfs_daddr_t d;
190 const char *cur_chunk;
191 int byte_cnt;
192 int n;
193 xfs_buf_t *bp;
194 prid_t prid;
195 struct xfs_dquot *udqp = NULL;
196 struct xfs_dquot *gdqp = NULL;
197 struct xfs_dquot *pdqp = NULL;
198 uint resblks;
199
200 *ipp = NULL;
201
202 trace_xfs_symlink(dp, link_name);
203
204 if (XFS_FORCED_SHUTDOWN(mp))
205 return XFS_ERROR(EIO);
206
207 /*
208 * Check component lengths of the target path name.
209 */
210 pathlen = strlen(target_path);
211 if (pathlen >= MAXPATHLEN) /* total string too long */
212 return XFS_ERROR(ENAMETOOLONG);
213
214 udqp = gdqp = NULL;
215 prid = xfs_get_initial_prid(dp);
216
217 /*
218 * Make sure that we have allocated dquot(s) on disk.
219 */
220 error = xfs_qm_vop_dqalloc(dp,
221 xfs_kuid_to_uid(current_fsuid()),
222 xfs_kgid_to_gid(current_fsgid()), prid,
223 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
224 &udqp, &gdqp, &pdqp);
225 if (error)
226 goto std_return;
227
228 tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
229 cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
230 /*
231 * The symlink will fit into the inode data fork?
232 * There can't be any attributes so we get the whole variable part.
233 */
234 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
235 fs_blocks = 0;
236 else
237 fs_blocks = xfs_symlink_blocks(mp, pathlen);
238 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
239 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, resblks, 0);
240 if (error == ENOSPC && fs_blocks == 0) {
241 resblks = 0;
242 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, 0, 0);
243 }
244 if (error) {
245 cancel_flags = 0;
246 goto error_return;
247 }
248
249 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
250 unlock_dp_on_error = true;
251
252 /*
253 * Check whether the directory allows new symlinks or not.
254 */
255 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
256 error = XFS_ERROR(EPERM);
257 goto error_return;
258 }
259
260 /*
261 * Reserve disk quota : blocks and inode.
262 */
263 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
264 pdqp, resblks, 1, 0);
265 if (error)
266 goto error_return;
267
268 /*
269 * Check for ability to enter directory entry, if no space reserved.
270 */
271 error = xfs_dir_canenter(tp, dp, link_name, resblks);
272 if (error)
273 goto error_return;
274 /*
275 * Initialize the bmap freelist prior to calling either
276 * bmapi or the directory create code.
277 */
278 xfs_bmap_init(&free_list, &first_block);
279
280 /*
281 * Allocate an inode for the symlink.
282 */
283 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
284 prid, resblks > 0, &ip, NULL);
285 if (error) {
286 if (error == ENOSPC)
287 goto error_return;
288 goto error1;
289 }
290
291 /*
292 * An error after we've joined dp to the transaction will result in the
293 * transaction cancel unlocking dp so don't do it explicitly in the
294 * error path.
295 */
296 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
297 unlock_dp_on_error = false;
298
299 /*
300 * Also attach the dquot(s) to it, if applicable.
301 */
302 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
303
304 if (resblks)
305 resblks -= XFS_IALLOC_SPACE_RES(mp);
306 /*
307 * If the symlink will fit into the inode, write it inline.
308 */
309 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
310 xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
311 memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
312 ip->i_d.di_size = pathlen;
313
314 /*
315 * The inode was initially created in extent format.
316 */
317 ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
318 ip->i_df.if_flags |= XFS_IFINLINE;
319
320 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
321 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
322
323 } else {
324 int offset;
325
326 first_fsb = 0;
327 nmaps = XFS_SYMLINK_MAPS;
328
329 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
330 XFS_BMAPI_METADATA, &first_block, resblks,
331 mval, &nmaps, &free_list);
332 if (error)
333 goto error2;
334
335 if (resblks)
336 resblks -= fs_blocks;
337 ip->i_d.di_size = pathlen;
338 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
339
340 cur_chunk = target_path;
341 offset = 0;
342 for (n = 0; n < nmaps; n++) {
343 char *buf;
344
345 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
346 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
347 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
348 BTOBB(byte_cnt), 0);
349 if (!bp) {
350 error = ENOMEM;
351 goto error2;
352 }
353 bp->b_ops = &xfs_symlink_buf_ops;
354
355 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
356 byte_cnt = min(byte_cnt, pathlen);
357
358 buf = bp->b_addr;
359 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
360 byte_cnt, bp);
361
362 memcpy(buf, cur_chunk, byte_cnt);
363
364 cur_chunk += byte_cnt;
365 pathlen -= byte_cnt;
366 offset += byte_cnt;
367
368 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
369 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
370 (char *)bp->b_addr);
371 }
372 ASSERT(pathlen == 0);
373 }
374
375 /*
376 * Create the directory entry for the symlink.
377 */
378 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
379 &first_block, &free_list, resblks);
380 if (error)
381 goto error2;
382 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
383 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
384
385 /*
386 * If this is a synchronous mount, make sure that the
387 * symlink transaction goes to disk before returning to
388 * the user.
389 */
390 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
391 xfs_trans_set_sync(tp);
392 }
393
394 error = xfs_bmap_finish(&tp, &free_list, &committed);
395 if (error) {
396 goto error2;
397 }
398 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
399 xfs_qm_dqrele(udqp);
400 xfs_qm_dqrele(gdqp);
401 xfs_qm_dqrele(pdqp);
402
403 *ipp = ip;
404 return 0;
405
406 error2:
407 IRELE(ip);
408 error1:
409 xfs_bmap_cancel(&free_list);
410 cancel_flags |= XFS_TRANS_ABORT;
411 error_return:
412 xfs_trans_cancel(tp, cancel_flags);
413 xfs_qm_dqrele(udqp);
414 xfs_qm_dqrele(gdqp);
415 xfs_qm_dqrele(pdqp);
416
417 if (unlock_dp_on_error)
418 xfs_iunlock(dp, XFS_ILOCK_EXCL);
419 std_return:
420 return error;
421}
422
423/*
424 * Free a symlink that has blocks associated with it.
425 */
426STATIC int
427xfs_inactive_symlink_rmt(
428 struct xfs_inode *ip)
429{
430 xfs_buf_t *bp;
431 int committed;
432 int done;
433 int error;
434 xfs_fsblock_t first_block;
435 xfs_bmap_free_t free_list;
436 int i;
437 xfs_mount_t *mp;
438 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
439 int nmaps;
440 int size;
441 xfs_trans_t *tp;
442
443 mp = ip->i_mount;
444 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
445 /*
446 * We're freeing a symlink that has some
447 * blocks allocated to it. Free the
448 * blocks here. We know that we've got
449 * either 1 or 2 extents and that we can
450 * free them all in one bunmapi call.
451 */
452 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
453
454 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
455 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
456 if (error) {
457 xfs_trans_cancel(tp, 0);
458 return error;
459 }
460
461 xfs_ilock(ip, XFS_ILOCK_EXCL);
462 xfs_trans_ijoin(tp, ip, 0);
463
464 /*
465 * Lock the inode, fix the size, and join it to the transaction.
466 * Hold it so in the normal path, we still have it locked for
467 * the second transaction. In the error paths we need it
468 * held so the cancel won't rele it, see below.
469 */
470 size = (int)ip->i_d.di_size;
471 ip->i_d.di_size = 0;
472 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
473 /*
474 * Find the block(s) so we can inval and unmap them.
475 */
476 done = 0;
477 xfs_bmap_init(&free_list, &first_block);
478 nmaps = ARRAY_SIZE(mval);
479 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
480 mval, &nmaps, 0);
481 if (error)
482 goto error_trans_cancel;
483 /*
484 * Invalidate the block(s). No validation is done.
485 */
486 for (i = 0; i < nmaps; i++) {
487 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
488 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
489 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
490 if (!bp) {
491 error = ENOMEM;
492 goto error_bmap_cancel;
493 }
494 xfs_trans_binval(tp, bp);
495 }
496 /*
497 * Unmap the dead block(s) to the free_list.
498 */
499 error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
500 &first_block, &free_list, &done);
501 if (error)
502 goto error_bmap_cancel;
503 ASSERT(done);
504 /*
505 * Commit the first transaction. This logs the EFI and the inode.
506 */
507 error = xfs_bmap_finish(&tp, &free_list, &committed);
508 if (error)
509 goto error_bmap_cancel;
510 /*
511 * The transaction must have been committed, since there were
512 * actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
513 * The new tp has the extent freeing and EFDs.
514 */
515 ASSERT(committed);
516 /*
517 * The first xact was committed, so add the inode to the new one.
518 * Mark it dirty so it will be logged and moved forward in the log as
519 * part of every commit.
520 */
521 xfs_trans_ijoin(tp, ip, 0);
522 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
523 /*
524 * Commit the transaction containing extent freeing and EFDs.
525 */
526 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
527 if (error) {
528 ASSERT(XFS_FORCED_SHUTDOWN(mp));
529 goto error_unlock;
530 }
531
532 /*
533 * Remove the memory for extent descriptions (just bookkeeping).
534 */
535 if (ip->i_df.if_bytes)
536 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
537 ASSERT(ip->i_df.if_bytes == 0);
538
539 xfs_iunlock(ip, XFS_ILOCK_EXCL);
540 return 0;
541
542error_bmap_cancel:
543 xfs_bmap_cancel(&free_list);
544error_trans_cancel:
545 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
546error_unlock:
547 xfs_iunlock(ip, XFS_ILOCK_EXCL);
548 return error;
549}
550
551/*
552 * xfs_inactive_symlink - free a symlink
553 */
554int
555xfs_inactive_symlink(
556 struct xfs_inode *ip)
557{
558 struct xfs_mount *mp = ip->i_mount;
559 int pathlen;
560
561 trace_xfs_inactive_symlink(ip);
562
563 if (XFS_FORCED_SHUTDOWN(mp))
564 return XFS_ERROR(EIO);
565
566 xfs_ilock(ip, XFS_ILOCK_EXCL);
567
568 /*
569 * Zero length symlinks _can_ exist.
570 */
571 pathlen = (int)ip->i_d.di_size;
572 if (!pathlen) {
573 xfs_iunlock(ip, XFS_ILOCK_EXCL);
574 return 0;
575 }
576
577 if (pathlen < 0 || pathlen > MAXPATHLEN) {
578 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
579 __func__, (unsigned long long)ip->i_ino, pathlen);
580 xfs_iunlock(ip, XFS_ILOCK_EXCL);
581 ASSERT(0);
582 return XFS_ERROR(EFSCORRUPTED);
583 }
584
585 if (ip->i_df.if_flags & XFS_IFINLINE) {
586 if (ip->i_df.if_bytes > 0)
587 xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
588 XFS_DATA_FORK);
589 xfs_iunlock(ip, XFS_ILOCK_EXCL);
590 ASSERT(ip->i_df.if_bytes == 0);
591 return 0;
592 }
593
594 xfs_iunlock(ip, XFS_ILOCK_EXCL);
595
596 /* remove the remote symlink */
597 return xfs_inactive_symlink_rmt(ip);
598}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4 * Copyright (c) 2012-2013 Red Hat, Inc.
5 * All rights reserved.
6 */
7#include "xfs.h"
8#include "xfs_shared.h"
9#include "xfs_fs.h"
10#include "xfs_format.h"
11#include "xfs_log_format.h"
12#include "xfs_trans_resv.h"
13#include "xfs_bit.h"
14#include "xfs_mount.h"
15#include "xfs_dir2.h"
16#include "xfs_inode.h"
17#include "xfs_bmap.h"
18#include "xfs_bmap_btree.h"
19#include "xfs_quota.h"
20#include "xfs_symlink.h"
21#include "xfs_trans_space.h"
22#include "xfs_trace.h"
23#include "xfs_trans.h"
24#include "xfs_ialloc.h"
25#include "xfs_error.h"
26#include "xfs_health.h"
27#include "xfs_symlink_remote.h"
28#include "xfs_parent.h"
29#include "xfs_defer.h"
30
31int
32xfs_readlink(
33 struct xfs_inode *ip,
34 char *link)
35{
36 struct xfs_mount *mp = ip->i_mount;
37 xfs_fsize_t pathlen;
38 int error;
39
40 trace_xfs_readlink(ip);
41
42 if (xfs_is_shutdown(mp))
43 return -EIO;
44 if (xfs_ifork_zapped(ip, XFS_DATA_FORK))
45 return -EIO;
46
47 xfs_ilock(ip, XFS_ILOCK_SHARED);
48
49 pathlen = ip->i_disk_size;
50 if (!pathlen)
51 goto out_corrupt;
52
53 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
54 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
55 __func__, (unsigned long long) ip->i_ino,
56 (long long) pathlen);
57 ASSERT(0);
58 goto out_corrupt;
59 }
60
61 if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
62 /*
63 * The VFS crashes on a NULL pointer, so return -EFSCORRUPTED
64 * if if_data is junk.
65 */
66 if (XFS_IS_CORRUPT(ip->i_mount, !ip->i_df.if_data))
67 goto out_corrupt;
68
69 memcpy(link, ip->i_df.if_data, pathlen + 1);
70 error = 0;
71 } else {
72 error = xfs_symlink_remote_read(ip, link);
73 }
74
75 xfs_iunlock(ip, XFS_ILOCK_SHARED);
76 return error;
77 out_corrupt:
78 xfs_iunlock(ip, XFS_ILOCK_SHARED);
79 xfs_inode_mark_sick(ip, XFS_SICK_INO_SYMLINK);
80 return -EFSCORRUPTED;
81}
82
83int
84xfs_symlink(
85 struct mnt_idmap *idmap,
86 struct xfs_inode *dp,
87 struct xfs_name *link_name,
88 const char *target_path,
89 umode_t mode,
90 struct xfs_inode **ipp)
91{
92 struct xfs_mount *mp = dp->i_mount;
93 struct xfs_icreate_args args = {
94 .idmap = idmap,
95 .pip = dp,
96 .mode = S_IFLNK | (mode & ~S_IFMT),
97 };
98 struct xfs_dir_update du = {
99 .dp = dp,
100 .name = link_name,
101 };
102 struct xfs_trans *tp = NULL;
103 int error = 0;
104 int pathlen;
105 bool unlock_dp_on_error = false;
106 xfs_filblks_t fs_blocks;
107 struct xfs_dquot *udqp;
108 struct xfs_dquot *gdqp;
109 struct xfs_dquot *pdqp;
110 uint resblks;
111 xfs_ino_t ino;
112
113 *ipp = NULL;
114
115 trace_xfs_symlink(dp, link_name);
116
117 if (xfs_is_shutdown(mp))
118 return -EIO;
119
120 /*
121 * Check component lengths of the target path name.
122 */
123 pathlen = strlen(target_path);
124 if (pathlen >= XFS_SYMLINK_MAXLEN) /* total string too long */
125 return -ENAMETOOLONG;
126 ASSERT(pathlen > 0);
127
128 /* Make sure that we have allocated dquot(s) on disk. */
129 error = xfs_icreate_dqalloc(&args, &udqp, &gdqp, &pdqp);
130 if (error)
131 return error;
132
133 /*
134 * The symlink will fit into the inode data fork?
135 * If there are no parent pointers, then there wont't be any attributes.
136 * So we get the whole variable part, and do not need to reserve extra
137 * blocks. Otherwise, we need to reserve the blocks.
138 */
139 if (pathlen <= XFS_LITINO(mp) && !xfs_has_parent(mp))
140 fs_blocks = 0;
141 else
142 fs_blocks = xfs_symlink_blocks(mp, pathlen);
143 resblks = xfs_symlink_space_res(mp, link_name->len, fs_blocks);
144
145 error = xfs_parent_start(mp, &du.ppargs);
146 if (error)
147 goto out_release_dquots;
148
149 error = xfs_trans_alloc_icreate(mp, &M_RES(mp)->tr_symlink, udqp, gdqp,
150 pdqp, resblks, &tp);
151 if (error)
152 goto out_parent;
153
154 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
155 unlock_dp_on_error = true;
156
157 /*
158 * Check whether the directory allows new symlinks or not.
159 */
160 if (dp->i_diflags & XFS_DIFLAG_NOSYMLINKS) {
161 error = -EPERM;
162 goto out_trans_cancel;
163 }
164
165 /*
166 * Allocate an inode for the symlink.
167 */
168 error = xfs_dialloc(&tp, &args, &ino);
169 if (!error)
170 error = xfs_icreate(tp, ino, &args, &du.ip);
171 if (error)
172 goto out_trans_cancel;
173
174 /*
175 * Now we join the directory inode to the transaction. We do not do it
176 * earlier because xfs_dir_ialloc might commit the previous transaction
177 * (and release all the locks). An error from here on will result in
178 * the transaction cancel unlocking dp so don't do it explicitly in the
179 * error path.
180 */
181 xfs_trans_ijoin(tp, dp, 0);
182
183 /*
184 * Also attach the dquot(s) to it, if applicable.
185 */
186 xfs_qm_vop_create_dqattach(tp, du.ip, udqp, gdqp, pdqp);
187
188 resblks -= XFS_IALLOC_SPACE_RES(mp);
189 error = xfs_symlink_write_target(tp, du.ip, du.ip->i_ino, target_path,
190 pathlen, fs_blocks, resblks);
191 if (error)
192 goto out_trans_cancel;
193 resblks -= fs_blocks;
194 i_size_write(VFS_I(du.ip), du.ip->i_disk_size);
195
196 /*
197 * Create the directory entry for the symlink.
198 */
199 error = xfs_dir_create_child(tp, resblks, &du);
200 if (error)
201 goto out_trans_cancel;
202
203 /*
204 * If this is a synchronous mount, make sure that the
205 * symlink transaction goes to disk before returning to
206 * the user.
207 */
208 if (xfs_has_wsync(mp) || xfs_has_dirsync(mp))
209 xfs_trans_set_sync(tp);
210
211 error = xfs_trans_commit(tp);
212 if (error)
213 goto out_release_inode;
214
215 xfs_qm_dqrele(udqp);
216 xfs_qm_dqrele(gdqp);
217 xfs_qm_dqrele(pdqp);
218
219 *ipp = du.ip;
220 xfs_iunlock(du.ip, XFS_ILOCK_EXCL);
221 xfs_iunlock(dp, XFS_ILOCK_EXCL);
222 xfs_parent_finish(mp, du.ppargs);
223 return 0;
224
225out_trans_cancel:
226 xfs_trans_cancel(tp);
227out_release_inode:
228 /*
229 * Wait until after the current transaction is aborted to finish the
230 * setup of the inode and release the inode. This prevents recursive
231 * transactions and deadlocks from xfs_inactive.
232 */
233 if (du.ip) {
234 xfs_iunlock(du.ip, XFS_ILOCK_EXCL);
235 xfs_finish_inode_setup(du.ip);
236 xfs_irele(du.ip);
237 }
238out_parent:
239 xfs_parent_finish(mp, du.ppargs);
240out_release_dquots:
241 xfs_qm_dqrele(udqp);
242 xfs_qm_dqrele(gdqp);
243 xfs_qm_dqrele(pdqp);
244
245 if (unlock_dp_on_error)
246 xfs_iunlock(dp, XFS_ILOCK_EXCL);
247 return error;
248}
249
250/*
251 * Free a symlink that has blocks associated with it.
252 *
253 * Note: zero length symlinks are not allowed to exist. When we set the size to
254 * zero, also change it to a regular file so that it does not get written to
255 * disk as a zero length symlink. The inode is on the unlinked list already, so
256 * userspace cannot find this inode anymore, so this change is not user visible
257 * but allows us to catch corrupt zero-length symlinks in the verifiers.
258 */
259STATIC int
260xfs_inactive_symlink_rmt(
261 struct xfs_inode *ip)
262{
263 struct xfs_mount *mp = ip->i_mount;
264 struct xfs_trans *tp;
265 int error;
266
267 ASSERT(!xfs_need_iread_extents(&ip->i_df));
268 /*
269 * We're freeing a symlink that has some
270 * blocks allocated to it. Free the
271 * blocks here. We know that we've got
272 * either 1 or 2 extents and that we can
273 * free them all in one bunmapi call.
274 */
275 ASSERT(ip->i_df.if_nextents > 0 && ip->i_df.if_nextents <= 2);
276
277 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
278 if (error)
279 return error;
280
281 xfs_ilock(ip, XFS_ILOCK_EXCL);
282 xfs_trans_ijoin(tp, ip, 0);
283
284 /*
285 * Lock the inode, fix the size, turn it into a regular file and join it
286 * to the transaction. Hold it so in the normal path, we still have it
287 * locked for the second transaction. In the error paths we need it
288 * held so the cancel won't rele it, see below.
289 */
290 ip->i_disk_size = 0;
291 VFS_I(ip)->i_mode = (VFS_I(ip)->i_mode & ~S_IFMT) | S_IFREG;
292 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
293
294 error = xfs_symlink_remote_truncate(tp, ip);
295 if (error)
296 goto error_trans_cancel;
297
298 error = xfs_trans_commit(tp);
299 if (error) {
300 ASSERT(xfs_is_shutdown(mp));
301 goto error_unlock;
302 }
303
304 /*
305 * Remove the memory for extent descriptions (just bookkeeping).
306 */
307 if (ip->i_df.if_bytes)
308 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
309 ASSERT(ip->i_df.if_bytes == 0);
310
311 xfs_iunlock(ip, XFS_ILOCK_EXCL);
312 return 0;
313
314error_trans_cancel:
315 xfs_trans_cancel(tp);
316error_unlock:
317 xfs_iunlock(ip, XFS_ILOCK_EXCL);
318 return error;
319}
320
321/*
322 * xfs_inactive_symlink - free a symlink
323 */
324int
325xfs_inactive_symlink(
326 struct xfs_inode *ip)
327{
328 struct xfs_mount *mp = ip->i_mount;
329 int pathlen;
330
331 trace_xfs_inactive_symlink(ip);
332
333 if (xfs_is_shutdown(mp))
334 return -EIO;
335
336 xfs_ilock(ip, XFS_ILOCK_EXCL);
337 pathlen = (int)ip->i_disk_size;
338 ASSERT(pathlen);
339
340 if (pathlen <= 0 || pathlen > XFS_SYMLINK_MAXLEN) {
341 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
342 __func__, (unsigned long long)ip->i_ino, pathlen);
343 xfs_iunlock(ip, XFS_ILOCK_EXCL);
344 ASSERT(0);
345 xfs_inode_mark_sick(ip, XFS_SICK_INO_SYMLINK);
346 return -EFSCORRUPTED;
347 }
348
349 /*
350 * Inline fork state gets removed by xfs_difree() so we have nothing to
351 * do here in that case.
352 */
353 if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
354 xfs_iunlock(ip, XFS_ILOCK_EXCL);
355 return 0;
356 }
357
358 xfs_iunlock(ip, XFS_ILOCK_EXCL);
359
360 /* remove the remote symlink */
361 return xfs_inactive_symlink_rmt(ip);
362}