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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_trans_space.h"
21#include "xfs_trace.h"
22#include "xfs_trans.h"
23
24/* ----- Kernel only functions below ----- */
25int
26xfs_readlink_bmap_ilocked(
27 struct xfs_inode *ip,
28 char *link)
29{
30 struct xfs_mount *mp = ip->i_mount;
31 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
32 struct xfs_buf *bp;
33 xfs_daddr_t d;
34 char *cur_chunk;
35 int pathlen = ip->i_d.di_size;
36 int nmaps = XFS_SYMLINK_MAPS;
37 int byte_cnt;
38 int n;
39 int error = 0;
40 int fsblocks = 0;
41 int offset;
42
43 ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
44
45 fsblocks = xfs_symlink_blocks(mp, pathlen);
46 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
47 if (error)
48 goto out;
49
50 offset = 0;
51 for (n = 0; n < nmaps; n++) {
52 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
53 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
54
55 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
56 &xfs_symlink_buf_ops);
57 if (!bp)
58 return -ENOMEM;
59 error = bp->b_error;
60 if (error) {
61 xfs_buf_ioerror_alert(bp, __func__);
62 xfs_buf_relse(bp);
63
64 /* bad CRC means corrupted metadata */
65 if (error == -EFSBADCRC)
66 error = -EFSCORRUPTED;
67 goto out;
68 }
69 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
70 if (pathlen < byte_cnt)
71 byte_cnt = pathlen;
72
73 cur_chunk = bp->b_addr;
74 if (xfs_sb_version_hascrc(&mp->m_sb)) {
75 if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
76 byte_cnt, bp)) {
77 error = -EFSCORRUPTED;
78 xfs_alert(mp,
79"symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
80 offset, byte_cnt, ip->i_ino);
81 xfs_buf_relse(bp);
82 goto out;
83
84 }
85
86 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
87 }
88
89 memcpy(link + offset, cur_chunk, byte_cnt);
90
91 pathlen -= byte_cnt;
92 offset += byte_cnt;
93
94 xfs_buf_relse(bp);
95 }
96 ASSERT(pathlen == 0);
97
98 link[ip->i_d.di_size] = '\0';
99 error = 0;
100
101 out:
102 return error;
103}
104
105int
106xfs_readlink(
107 struct xfs_inode *ip,
108 char *link)
109{
110 struct xfs_mount *mp = ip->i_mount;
111 xfs_fsize_t pathlen;
112 int error = 0;
113
114 trace_xfs_readlink(ip);
115
116 ASSERT(!(ip->i_df.if_flags & XFS_IFINLINE));
117
118 if (XFS_FORCED_SHUTDOWN(mp))
119 return -EIO;
120
121 xfs_ilock(ip, XFS_ILOCK_SHARED);
122
123 pathlen = ip->i_d.di_size;
124 if (!pathlen)
125 goto out;
126
127 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
128 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
129 __func__, (unsigned long long) ip->i_ino,
130 (long long) pathlen);
131 ASSERT(0);
132 error = -EFSCORRUPTED;
133 goto out;
134 }
135
136
137 error = xfs_readlink_bmap_ilocked(ip, link);
138
139 out:
140 xfs_iunlock(ip, XFS_ILOCK_SHARED);
141 return error;
142}
143
144int
145xfs_symlink(
146 struct xfs_inode *dp,
147 struct xfs_name *link_name,
148 const char *target_path,
149 umode_t mode,
150 struct xfs_inode **ipp)
151{
152 struct xfs_mount *mp = dp->i_mount;
153 struct xfs_trans *tp = NULL;
154 struct xfs_inode *ip = NULL;
155 int error = 0;
156 int pathlen;
157 bool unlock_dp_on_error = false;
158 xfs_fileoff_t first_fsb;
159 xfs_filblks_t fs_blocks;
160 int nmaps;
161 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
162 xfs_daddr_t d;
163 const char *cur_chunk;
164 int byte_cnt;
165 int n;
166 xfs_buf_t *bp;
167 prid_t prid;
168 struct xfs_dquot *udqp = NULL;
169 struct xfs_dquot *gdqp = NULL;
170 struct xfs_dquot *pdqp = NULL;
171 uint resblks;
172
173 *ipp = NULL;
174
175 trace_xfs_symlink(dp, link_name);
176
177 if (XFS_FORCED_SHUTDOWN(mp))
178 return -EIO;
179
180 /*
181 * Check component lengths of the target path name.
182 */
183 pathlen = strlen(target_path);
184 if (pathlen >= XFS_SYMLINK_MAXLEN) /* total string too long */
185 return -ENAMETOOLONG;
186 ASSERT(pathlen > 0);
187
188 udqp = gdqp = NULL;
189 prid = xfs_get_initial_prid(dp);
190
191 /*
192 * Make sure that we have allocated dquot(s) on disk.
193 */
194 error = xfs_qm_vop_dqalloc(dp,
195 xfs_kuid_to_uid(current_fsuid()),
196 xfs_kgid_to_gid(current_fsgid()), prid,
197 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
198 &udqp, &gdqp, &pdqp);
199 if (error)
200 return error;
201
202 /*
203 * The symlink will fit into the inode data fork?
204 * There can't be any attributes so we get the whole variable part.
205 */
206 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
207 fs_blocks = 0;
208 else
209 fs_blocks = xfs_symlink_blocks(mp, pathlen);
210 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
211
212 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
213 if (error)
214 goto out_release_inode;
215
216 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
217 unlock_dp_on_error = true;
218
219 /*
220 * Check whether the directory allows new symlinks or not.
221 */
222 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
223 error = -EPERM;
224 goto out_trans_cancel;
225 }
226
227 /*
228 * Reserve disk quota : blocks and inode.
229 */
230 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
231 pdqp, resblks, 1, 0);
232 if (error)
233 goto out_trans_cancel;
234
235 /*
236 * Allocate an inode for the symlink.
237 */
238 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
239 prid, &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 if (resblks)
259 resblks -= XFS_IALLOC_SPACE_RES(mp);
260 /*
261 * If the symlink will fit into the inode, write it inline.
262 */
263 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
264 xfs_init_local_fork(ip, XFS_DATA_FORK, target_path, pathlen);
265
266 ip->i_d.di_size = pathlen;
267 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
268 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
269 } else {
270 int offset;
271
272 first_fsb = 0;
273 nmaps = XFS_SYMLINK_MAPS;
274
275 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
276 XFS_BMAPI_METADATA, resblks, mval, &nmaps);
277 if (error)
278 goto out_trans_cancel;
279
280 if (resblks)
281 resblks -= fs_blocks;
282 ip->i_d.di_size = pathlen;
283 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
284
285 cur_chunk = target_path;
286 offset = 0;
287 for (n = 0; n < nmaps; n++) {
288 char *buf;
289
290 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
291 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
292 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
293 BTOBB(byte_cnt), 0);
294 if (!bp) {
295 error = -ENOMEM;
296 goto out_trans_cancel;
297 }
298 bp->b_ops = &xfs_symlink_buf_ops;
299
300 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
301 byte_cnt = min(byte_cnt, pathlen);
302
303 buf = bp->b_addr;
304 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
305 byte_cnt, bp);
306
307 memcpy(buf, cur_chunk, byte_cnt);
308
309 cur_chunk += byte_cnt;
310 pathlen -= byte_cnt;
311 offset += byte_cnt;
312
313 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
314 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
315 (char *)bp->b_addr);
316 }
317 ASSERT(pathlen == 0);
318 }
319
320 /*
321 * Create the directory entry for the symlink.
322 */
323 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino, resblks);
324 if (error)
325 goto out_trans_cancel;
326 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
327 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
328
329 /*
330 * If this is a synchronous mount, make sure that the
331 * symlink transaction goes to disk before returning to
332 * the user.
333 */
334 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
335 xfs_trans_set_sync(tp);
336 }
337
338 error = xfs_trans_commit(tp);
339 if (error)
340 goto out_release_inode;
341
342 xfs_qm_dqrele(udqp);
343 xfs_qm_dqrele(gdqp);
344 xfs_qm_dqrele(pdqp);
345
346 *ipp = ip;
347 return 0;
348
349out_trans_cancel:
350 xfs_trans_cancel(tp);
351out_release_inode:
352 /*
353 * Wait until after the current transaction is aborted to finish the
354 * setup of the inode and release the inode. This prevents recursive
355 * transactions and deadlocks from xfs_inactive.
356 */
357 if (ip) {
358 xfs_finish_inode_setup(ip);
359 xfs_irele(ip);
360 }
361
362 xfs_qm_dqrele(udqp);
363 xfs_qm_dqrele(gdqp);
364 xfs_qm_dqrele(pdqp);
365
366 if (unlock_dp_on_error)
367 xfs_iunlock(dp, XFS_ILOCK_EXCL);
368 return error;
369}
370
371/*
372 * Free a symlink that has blocks associated with it.
373 *
374 * Note: zero length symlinks are not allowed to exist. When we set the size to
375 * zero, also change it to a regular file so that it does not get written to
376 * disk as a zero length symlink. The inode is on the unlinked list already, so
377 * userspace cannot find this inode anymore, so this change is not user visible
378 * but allows us to catch corrupt zero-length symlinks in the verifiers.
379 */
380STATIC int
381xfs_inactive_symlink_rmt(
382 struct xfs_inode *ip)
383{
384 xfs_buf_t *bp;
385 int done;
386 int error;
387 int i;
388 xfs_mount_t *mp;
389 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
390 int nmaps;
391 int size;
392 xfs_trans_t *tp;
393
394 mp = ip->i_mount;
395 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
396 /*
397 * We're freeing a symlink that has some
398 * blocks allocated to it. Free the
399 * blocks here. We know that we've got
400 * either 1 or 2 extents and that we can
401 * free them all in one bunmapi call.
402 */
403 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
404
405 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
406 if (error)
407 return error;
408
409 xfs_ilock(ip, XFS_ILOCK_EXCL);
410 xfs_trans_ijoin(tp, ip, 0);
411
412 /*
413 * Lock the inode, fix the size, turn it into a regular file and join it
414 * to the transaction. Hold it so in the normal path, we still have it
415 * locked for the second transaction. In the error paths we need it
416 * held so the cancel won't rele it, see below.
417 */
418 size = (int)ip->i_d.di_size;
419 ip->i_d.di_size = 0;
420 VFS_I(ip)->i_mode = (VFS_I(ip)->i_mode & ~S_IFMT) | S_IFREG;
421 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
422 /*
423 * Find the block(s) so we can inval and unmap them.
424 */
425 done = 0;
426 nmaps = ARRAY_SIZE(mval);
427 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
428 mval, &nmaps, 0);
429 if (error)
430 goto error_trans_cancel;
431 /*
432 * Invalidate the block(s). No validation is done.
433 */
434 for (i = 0; i < nmaps; i++) {
435 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
436 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
437 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
438 if (!bp) {
439 error = -ENOMEM;
440 goto error_trans_cancel;
441 }
442 xfs_trans_binval(tp, bp);
443 }
444 /*
445 * Unmap the dead block(s) to the dfops.
446 */
447 error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps, &done);
448 if (error)
449 goto error_trans_cancel;
450 ASSERT(done);
451
452 /*
453 * Commit the transaction. This first logs the EFI and the inode, then
454 * rolls and commits the transaction that frees the extents.
455 */
456 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
457 error = xfs_trans_commit(tp);
458 if (error) {
459 ASSERT(XFS_FORCED_SHUTDOWN(mp));
460 goto error_unlock;
461 }
462
463 /*
464 * Remove the memory for extent descriptions (just bookkeeping).
465 */
466 if (ip->i_df.if_bytes)
467 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
468 ASSERT(ip->i_df.if_bytes == 0);
469
470 xfs_iunlock(ip, XFS_ILOCK_EXCL);
471 return 0;
472
473error_trans_cancel:
474 xfs_trans_cancel(tp);
475error_unlock:
476 xfs_iunlock(ip, XFS_ILOCK_EXCL);
477 return error;
478}
479
480/*
481 * xfs_inactive_symlink - free a symlink
482 */
483int
484xfs_inactive_symlink(
485 struct xfs_inode *ip)
486{
487 struct xfs_mount *mp = ip->i_mount;
488 int pathlen;
489
490 trace_xfs_inactive_symlink(ip);
491
492 if (XFS_FORCED_SHUTDOWN(mp))
493 return -EIO;
494
495 xfs_ilock(ip, XFS_ILOCK_EXCL);
496 pathlen = (int)ip->i_d.di_size;
497 ASSERT(pathlen);
498
499 if (pathlen <= 0 || pathlen > XFS_SYMLINK_MAXLEN) {
500 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
501 __func__, (unsigned long long)ip->i_ino, pathlen);
502 xfs_iunlock(ip, XFS_ILOCK_EXCL);
503 ASSERT(0);
504 return -EFSCORRUPTED;
505 }
506
507 /*
508 * Inline fork state gets removed by xfs_difree() so we have nothing to
509 * do here in that case.
510 */
511 if (ip->i_df.if_flags & XFS_IFINLINE) {
512 xfs_iunlock(ip, XFS_ILOCK_EXCL);
513 return 0;
514 }
515
516 xfs_iunlock(ip, XFS_ILOCK_EXCL);
517
518 /* remove the remote symlink */
519 return xfs_inactive_symlink_rmt(ip);
520}