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