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