1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * directory.c
4 *
5 * PURPOSE
6 * Directory related functions
7 *
8 */
9
10#include "udfdecl.h"
11#include "udf_i.h"
12
13#include <linux/fs.h>
14#include <linux/string.h>
15#include <linux/bio.h>
16#include <linux/crc-itu-t.h>
17#include <linux/iversion.h>
18
19static int udf_verify_fi(struct udf_fileident_iter *iter)
20{
21 unsigned int len;
22
23 if (iter->fi.descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
24 udf_err(iter->dir->i_sb,
25 "directory (ino %lu) has entry at pos %llu with incorrect tag %x\n",
26 iter->dir->i_ino, (unsigned long long)iter->pos,
27 le16_to_cpu(iter->fi.descTag.tagIdent));
28 return -EFSCORRUPTED;
29 }
30 len = udf_dir_entry_len(cfi: &iter->fi);
31 if (le16_to_cpu(iter->fi.lengthOfImpUse) & 3) {
32 udf_err(iter->dir->i_sb,
33 "directory (ino %lu) has entry at pos %llu with unaligned length of impUse field\n",
34 iter->dir->i_ino, (unsigned long long)iter->pos);
35 return -EFSCORRUPTED;
36 }
37 /*
38 * This is in fact allowed by the spec due to long impUse field but
39 * we don't support it. If there is real media with this large impUse
40 * field, support can be added.
41 */
42 if (len > 1 << iter->dir->i_blkbits) {
43 udf_err(iter->dir->i_sb,
44 "directory (ino %lu) has too big (%u) entry at pos %llu\n",
45 iter->dir->i_ino, len, (unsigned long long)iter->pos);
46 return -EFSCORRUPTED;
47 }
48 if (iter->pos + len > iter->dir->i_size) {
49 udf_err(iter->dir->i_sb,
50 "directory (ino %lu) has entry past directory size at pos %llu\n",
51 iter->dir->i_ino, (unsigned long long)iter->pos);
52 return -EFSCORRUPTED;
53 }
54 if (udf_dir_entry_len(cfi: &iter->fi) !=
55 sizeof(struct tag) + le16_to_cpu(iter->fi.descTag.descCRCLength)) {
56 udf_err(iter->dir->i_sb,
57 "directory (ino %lu) has entry where CRC length (%u) does not match entry length (%u)\n",
58 iter->dir->i_ino,
59 (unsigned)le16_to_cpu(iter->fi.descTag.descCRCLength),
60 (unsigned)(udf_dir_entry_len(&iter->fi) -
61 sizeof(struct tag)));
62 return -EFSCORRUPTED;
63 }
64 return 0;
65}
66
67static int udf_copy_fi(struct udf_fileident_iter *iter)
68{
69 struct udf_inode_info *iinfo = UDF_I(inode: iter->dir);
70 u32 blksize = 1 << iter->dir->i_blkbits;
71 u32 off, len, nameoff;
72 int err;
73
74 /* Skip copying when we are at EOF */
75 if (iter->pos >= iter->dir->i_size) {
76 iter->name = NULL;
77 return 0;
78 }
79 if (iter->dir->i_size < iter->pos + sizeof(struct fileIdentDesc)) {
80 udf_err(iter->dir->i_sb,
81 "directory (ino %lu) has entry straddling EOF\n",
82 iter->dir->i_ino);
83 return -EFSCORRUPTED;
84 }
85 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
86 memcpy(&iter->fi, iinfo->i_data + iinfo->i_lenEAttr + iter->pos,
87 sizeof(struct fileIdentDesc));
88 err = udf_verify_fi(iter);
89 if (err < 0)
90 return err;
91 iter->name = iinfo->i_data + iinfo->i_lenEAttr + iter->pos +
92 sizeof(struct fileIdentDesc) +
93 le16_to_cpu(iter->fi.lengthOfImpUse);
94 return 0;
95 }
96
97 off = iter->pos & (blksize - 1);
98 len = min_t(u32, sizeof(struct fileIdentDesc), blksize - off);
99 memcpy(&iter->fi, iter->bh[0]->b_data + off, len);
100 if (len < sizeof(struct fileIdentDesc))
101 memcpy((char *)(&iter->fi) + len, iter->bh[1]->b_data,
102 sizeof(struct fileIdentDesc) - len);
103 err = udf_verify_fi(iter);
104 if (err < 0)
105 return err;
106
107 /* Handle directory entry name */
108 nameoff = off + sizeof(struct fileIdentDesc) +
109 le16_to_cpu(iter->fi.lengthOfImpUse);
110 if (off + udf_dir_entry_len(cfi: &iter->fi) <= blksize) {
111 iter->name = iter->bh[0]->b_data + nameoff;
112 } else if (nameoff >= blksize) {
113 iter->name = iter->bh[1]->b_data + (nameoff - blksize);
114 } else {
115 iter->name = iter->namebuf;
116 len = blksize - nameoff;
117 memcpy(iter->name, iter->bh[0]->b_data + nameoff, len);
118 memcpy(iter->name + len, iter->bh[1]->b_data,
119 iter->fi.lengthFileIdent - len);
120 }
121 return 0;
122}
123
124/* Readahead 8k once we are at 8k boundary */
125static void udf_readahead_dir(struct udf_fileident_iter *iter)
126{
127 unsigned int ralen = 16 >> (iter->dir->i_blkbits - 9);
128 struct buffer_head *tmp, *bha[16];
129 int i, num;
130 udf_pblk_t blk;
131
132 if (iter->loffset & (ralen - 1))
133 return;
134
135 if (iter->loffset + ralen > (iter->elen >> iter->dir->i_blkbits))
136 ralen = (iter->elen >> iter->dir->i_blkbits) - iter->loffset;
137 num = 0;
138 for (i = 0; i < ralen; i++) {
139 blk = udf_get_lb_pblock(sb: iter->dir->i_sb, loc: &iter->eloc,
140 offset: iter->loffset + i);
141 tmp = sb_getblk(sb: iter->dir->i_sb, block: blk);
142 if (tmp && !buffer_uptodate(bh: tmp) && !buffer_locked(bh: tmp))
143 bha[num++] = tmp;
144 else
145 brelse(bh: tmp);
146 }
147 if (num) {
148 bh_readahead_batch(nr: num, bhs: bha, REQ_RAHEAD);
149 for (i = 0; i < num; i++)
150 brelse(bh: bha[i]);
151 }
152}
153
154static struct buffer_head *udf_fiiter_bread_blk(struct udf_fileident_iter *iter)
155{
156 udf_pblk_t blk;
157
158 udf_readahead_dir(iter);
159 blk = udf_get_lb_pblock(sb: iter->dir->i_sb, loc: &iter->eloc, offset: iter->loffset);
160 return sb_bread(sb: iter->dir->i_sb, block: blk);
161}
162
163/*
164 * Updates loffset to point to next directory block; eloc, elen & epos are
165 * updated if we need to traverse to the next extent as well.
166 */
167static int udf_fiiter_advance_blk(struct udf_fileident_iter *iter)
168{
169 int8_t etype = -1;
170 int err = 0;
171
172 iter->loffset++;
173 if (iter->loffset < DIV_ROUND_UP(iter->elen, 1<<iter->dir->i_blkbits))
174 return 0;
175
176 iter->loffset = 0;
177 err = udf_next_aext(inode: iter->dir, epos: &iter->epos, eloc: &iter->eloc,
178 elen: &iter->elen, etype: &etype, inc: 1);
179 if (err < 0)
180 return err;
181 else if (err == 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
182 if (iter->pos == iter->dir->i_size) {
183 iter->elen = 0;
184 return 0;
185 }
186 udf_err(iter->dir->i_sb,
187 "extent after position %llu not allocated in directory (ino %lu)\n",
188 (unsigned long long)iter->pos, iter->dir->i_ino);
189 return -EFSCORRUPTED;
190 }
191 return 0;
192}
193
194static int udf_fiiter_load_bhs(struct udf_fileident_iter *iter)
195{
196 int blksize = 1 << iter->dir->i_blkbits;
197 int off = iter->pos & (blksize - 1);
198 int err;
199 struct fileIdentDesc *fi;
200
201 /* Is there any further extent we can map from? */
202 if (!iter->bh[0] && iter->elen) {
203 iter->bh[0] = udf_fiiter_bread_blk(iter);
204 if (!iter->bh[0]) {
205 err = -ENOMEM;
206 goto out_brelse;
207 }
208 if (!buffer_uptodate(bh: iter->bh[0])) {
209 err = -EIO;
210 goto out_brelse;
211 }
212 }
213 /* There's no next block so we are done */
214 if (iter->pos >= iter->dir->i_size)
215 return 0;
216 /* Need to fetch next block as well? */
217 if (off + sizeof(struct fileIdentDesc) > blksize)
218 goto fetch_next;
219 fi = (struct fileIdentDesc *)(iter->bh[0]->b_data + off);
220 /* Need to fetch next block to get name? */
221 if (off + udf_dir_entry_len(cfi: fi) > blksize) {
222fetch_next:
223 err = udf_fiiter_advance_blk(iter);
224 if (err)
225 goto out_brelse;
226 iter->bh[1] = udf_fiiter_bread_blk(iter);
227 if (!iter->bh[1]) {
228 err = -ENOMEM;
229 goto out_brelse;
230 }
231 if (!buffer_uptodate(bh: iter->bh[1])) {
232 err = -EIO;
233 goto out_brelse;
234 }
235 }
236 return 0;
237out_brelse:
238 brelse(bh: iter->bh[0]);
239 brelse(bh: iter->bh[1]);
240 iter->bh[0] = iter->bh[1] = NULL;
241 return err;
242}
243
244int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir,
245 loff_t pos)
246{
247 struct udf_inode_info *iinfo = UDF_I(inode: dir);
248 int err = 0;
249 int8_t etype;
250
251 iter->dir = dir;
252 iter->bh[0] = iter->bh[1] = NULL;
253 iter->pos = pos;
254 iter->elen = 0;
255 iter->epos.bh = NULL;
256 iter->name = NULL;
257 /*
258 * When directory is verified, we don't expect directory iteration to
259 * fail and it can be difficult to undo without corrupting filesystem.
260 * So just do not allow memory allocation failures here.
261 */
262 iter->namebuf = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL | __GFP_NOFAIL);
263
264 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
265 err = udf_copy_fi(iter);
266 goto out;
267 }
268
269 err = inode_bmap(inode: dir, block: iter->pos >> dir->i_blkbits, pos: &iter->epos,
270 eloc: &iter->eloc, elen: &iter->elen, offset: &iter->loffset, etype: &etype);
271 if (err <= 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
272 if (pos == dir->i_size)
273 return 0;
274 udf_err(dir->i_sb,
275 "position %llu not allocated in directory (ino %lu)\n",
276 (unsigned long long)pos, dir->i_ino);
277 err = -EFSCORRUPTED;
278 goto out;
279 }
280 err = udf_fiiter_load_bhs(iter);
281 if (err < 0)
282 goto out;
283 err = udf_copy_fi(iter);
284out:
285 if (err < 0)
286 udf_fiiter_release(iter);
287 return err;
288}
289
290int udf_fiiter_advance(struct udf_fileident_iter *iter)
291{
292 unsigned int oldoff, len;
293 int blksize = 1 << iter->dir->i_blkbits;
294 int err;
295
296 oldoff = iter->pos & (blksize - 1);
297 len = udf_dir_entry_len(cfi: &iter->fi);
298 iter->pos += len;
299 if (UDF_I(inode: iter->dir)->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
300 if (oldoff + len >= blksize) {
301 brelse(bh: iter->bh[0]);
302 iter->bh[0] = NULL;
303 /* Next block already loaded? */
304 if (iter->bh[1]) {
305 iter->bh[0] = iter->bh[1];
306 iter->bh[1] = NULL;
307 } else {
308 err = udf_fiiter_advance_blk(iter);
309 if (err < 0)
310 return err;
311 }
312 }
313 err = udf_fiiter_load_bhs(iter);
314 if (err < 0)
315 return err;
316 }
317 return udf_copy_fi(iter);
318}
319
320void udf_fiiter_release(struct udf_fileident_iter *iter)
321{
322 iter->dir = NULL;
323 brelse(bh: iter->bh[0]);
324 brelse(bh: iter->bh[1]);
325 iter->bh[0] = iter->bh[1] = NULL;
326 kfree(objp: iter->namebuf);
327 iter->namebuf = NULL;
328}
329
330static void udf_copy_to_bufs(void *buf1, int len1, void *buf2, int len2,
331 int off, void *src, int len)
332{
333 int copy;
334
335 if (off >= len1) {
336 off -= len1;
337 } else {
338 copy = min(off + len, len1) - off;
339 memcpy(buf1 + off, src, copy);
340 src += copy;
341 len -= copy;
342 off = 0;
343 }
344 if (len > 0) {
345 if (WARN_ON_ONCE(off + len > len2 || !buf2))
346 return;
347 memcpy(buf2 + off, src, len);
348 }
349}
350
351static uint16_t udf_crc_fi_bufs(void *buf1, int len1, void *buf2, int len2,
352 int off, int len)
353{
354 int copy;
355 uint16_t crc = 0;
356
357 if (off >= len1) {
358 off -= len1;
359 } else {
360 copy = min(off + len, len1) - off;
361 crc = crc_itu_t(crc, buffer: buf1 + off, len: copy);
362 len -= copy;
363 off = 0;
364 }
365 if (len > 0) {
366 if (WARN_ON_ONCE(off + len > len2 || !buf2))
367 return 0;
368 crc = crc_itu_t(crc, buffer: buf2 + off, len);
369 }
370 return crc;
371}
372
373static void udf_copy_fi_to_bufs(char *buf1, int len1, char *buf2, int len2,
374 int off, struct fileIdentDesc *fi,
375 uint8_t *impuse, uint8_t *name)
376{
377 uint16_t crc;
378 int fioff = off;
379 int crcoff = off + sizeof(struct tag);
380 unsigned int crclen = udf_dir_entry_len(cfi: fi) - sizeof(struct tag);
381 char zeros[UDF_NAME_PAD] = {};
382 int endoff = off + udf_dir_entry_len(cfi: fi);
383
384 udf_copy_to_bufs(buf1, len1, buf2, len2, off, src: fi,
385 len: sizeof(struct fileIdentDesc));
386 off += sizeof(struct fileIdentDesc);
387 if (impuse)
388 udf_copy_to_bufs(buf1, len1, buf2, len2, off, src: impuse,
389 le16_to_cpu(fi->lengthOfImpUse));
390 off += le16_to_cpu(fi->lengthOfImpUse);
391 if (name) {
392 udf_copy_to_bufs(buf1, len1, buf2, len2, off, src: name,
393 len: fi->lengthFileIdent);
394 off += fi->lengthFileIdent;
395 udf_copy_to_bufs(buf1, len1, buf2, len2, off, src: zeros,
396 len: endoff - off);
397 }
398
399 crc = udf_crc_fi_bufs(buf1, len1, buf2, len2, off: crcoff, len: crclen);
400 fi->descTag.descCRC = cpu_to_le16(crc);
401 fi->descTag.descCRCLength = cpu_to_le16(crclen);
402 fi->descTag.tagChecksum = udf_tag_checksum(t: &fi->descTag);
403
404 udf_copy_to_bufs(buf1, len1, buf2, len2, off: fioff, src: fi, len: sizeof(struct tag));
405}
406
407void udf_fiiter_write_fi(struct udf_fileident_iter *iter, uint8_t *impuse)
408{
409 struct udf_inode_info *iinfo = UDF_I(inode: iter->dir);
410 void *buf1, *buf2 = NULL;
411 int len1, len2 = 0, off;
412 int blksize = 1 << iter->dir->i_blkbits;
413
414 off = iter->pos & (blksize - 1);
415 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
416 buf1 = iinfo->i_data + iinfo->i_lenEAttr;
417 len1 = iter->dir->i_size;
418 } else {
419 buf1 = iter->bh[0]->b_data;
420 len1 = blksize;
421 if (iter->bh[1]) {
422 buf2 = iter->bh[1]->b_data;
423 len2 = blksize;
424 }
425 }
426
427 udf_copy_fi_to_bufs(buf1, len1, buf2, len2, off, fi: &iter->fi, impuse,
428 name: iter->name == iter->namebuf ? iter->name : NULL);
429
430 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
431 mark_inode_dirty(inode: iter->dir);
432 } else {
433 mark_buffer_dirty_inode(bh: iter->bh[0], inode: iter->dir);
434 if (iter->bh[1])
435 mark_buffer_dirty_inode(bh: iter->bh[1], inode: iter->dir);
436 }
437 inode_inc_iversion(inode: iter->dir);
438}
439
440void udf_fiiter_update_elen(struct udf_fileident_iter *iter, uint32_t new_elen)
441{
442 struct udf_inode_info *iinfo = UDF_I(inode: iter->dir);
443 int diff = new_elen - iter->elen;
444
445 /* Skip update when we already went past the last extent */
446 if (!iter->elen)
447 return;
448 iter->elen = new_elen;
449 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
450 iter->epos.offset -= sizeof(struct short_ad);
451 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
452 iter->epos.offset -= sizeof(struct long_ad);
453 udf_write_aext(iter->dir, &iter->epos, &iter->eloc, iter->elen, 1);
454 iinfo->i_lenExtents += diff;
455 mark_inode_dirty(inode: iter->dir);
456}
457
458/* Append new block to directory. @iter is expected to point at EOF */
459int udf_fiiter_append_blk(struct udf_fileident_iter *iter)
460{
461 struct udf_inode_info *iinfo = UDF_I(inode: iter->dir);
462 int blksize = 1 << iter->dir->i_blkbits;
463 struct buffer_head *bh;
464 sector_t block;
465 uint32_t old_elen = iter->elen;
466 int err;
467 int8_t etype;
468
469 if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
470 return -EINVAL;
471
472 /* Round up last extent in the file */
473 udf_fiiter_update_elen(iter, ALIGN(iter->elen, blksize));
474
475 /* Allocate new block and refresh mapping information */
476 block = iinfo->i_lenExtents >> iter->dir->i_blkbits;
477 bh = udf_bread(inode: iter->dir, block, create: 1, err: &err);
478 if (!bh) {
479 udf_fiiter_update_elen(iter, new_elen: old_elen);
480 return err;
481 }
482 err = inode_bmap(inode: iter->dir, block, pos: &iter->epos, eloc: &iter->eloc, elen: &iter->elen,
483 offset: &iter->loffset, etype: &etype);
484 if (err <= 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
485 udf_err(iter->dir->i_sb,
486 "block %llu not allocated in directory (ino %lu)\n",
487 (unsigned long long)block, iter->dir->i_ino);
488 return -EFSCORRUPTED;
489 }
490 if (!(iter->pos & (blksize - 1))) {
491 brelse(bh: iter->bh[0]);
492 iter->bh[0] = bh;
493 } else {
494 iter->bh[1] = bh;
495 }
496 return 0;
497}
498
499struct short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
500 int inc)
501{
502 struct short_ad *sa;
503
504 if ((!ptr) || (!offset)) {
505 pr_err("%s: invalidparms\n", __func__);
506 return NULL;
507 }
508
509 if ((*offset + sizeof(struct short_ad)) > maxoffset)
510 return NULL;
511 else {
512 sa = (struct short_ad *)ptr;
513 if (sa->extLength == 0)
514 return NULL;
515 }
516
517 if (inc)
518 *offset += sizeof(struct short_ad);
519 return sa;
520}
521
522struct long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
523{
524 struct long_ad *la;
525
526 if ((!ptr) || (!offset)) {
527 pr_err("%s: invalidparms\n", __func__);
528 return NULL;
529 }
530
531 if ((*offset + sizeof(struct long_ad)) > maxoffset)
532 return NULL;
533 else {
534 la = (struct long_ad *)ptr;
535 if (la->extLength == 0)
536 return NULL;
537 }
538
539 if (inc)
540 *offset += sizeof(struct long_ad);
541 return la;
542}
543

source code of linux/fs/udf/directory.c