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