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
udf_verify_fi(struct udf_fileident_iter * iter)19 static 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(&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(&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
udf_copy_fi(struct udf_fileident_iter * iter)67 static int udf_copy_fi(struct udf_fileident_iter *iter)
68 {
69 struct udf_inode_info *iinfo = UDF_I(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(&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 */
udf_readahead_dir(struct udf_fileident_iter * iter)125 static 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(iter->dir->i_sb, &iter->eloc,
140 iter->loffset + i);
141 tmp = sb_getblk(iter->dir->i_sb, blk);
142 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
143 bha[num++] = tmp;
144 else
145 brelse(tmp);
146 }
147 if (num) {
148 bh_readahead_batch(num, bha, REQ_RAHEAD);
149 for (i = 0; i < num; i++)
150 brelse(bha[i]);
151 }
152 }
153
udf_fiiter_bread_blk(struct udf_fileident_iter * iter)154 static 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(iter->dir->i_sb, &iter->eloc, iter->loffset);
160 return sb_bread(iter->dir->i_sb, 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 */
udf_fiiter_advance_blk(struct udf_fileident_iter * iter)167 static int udf_fiiter_advance_blk(struct udf_fileident_iter *iter)
168 {
169 iter->loffset++;
170 if (iter->loffset < DIV_ROUND_UP(iter->elen, 1<<iter->dir->i_blkbits))
171 return 0;
172
173 iter->loffset = 0;
174 if (udf_next_aext(iter->dir, &iter->epos, &iter->eloc, &iter->elen, 1)
175 != (EXT_RECORDED_ALLOCATED >> 30)) {
176 if (iter->pos == iter->dir->i_size) {
177 iter->elen = 0;
178 return 0;
179 }
180 udf_err(iter->dir->i_sb,
181 "extent after position %llu not allocated in directory (ino %lu)\n",
182 (unsigned long long)iter->pos, iter->dir->i_ino);
183 return -EFSCORRUPTED;
184 }
185 return 0;
186 }
187
udf_fiiter_load_bhs(struct udf_fileident_iter * iter)188 static int udf_fiiter_load_bhs(struct udf_fileident_iter *iter)
189 {
190 int blksize = 1 << iter->dir->i_blkbits;
191 int off = iter->pos & (blksize - 1);
192 int err;
193 struct fileIdentDesc *fi;
194
195 /* Is there any further extent we can map from? */
196 if (!iter->bh[0] && iter->elen) {
197 iter->bh[0] = udf_fiiter_bread_blk(iter);
198 if (!iter->bh[0]) {
199 err = -ENOMEM;
200 goto out_brelse;
201 }
202 if (!buffer_uptodate(iter->bh[0])) {
203 err = -EIO;
204 goto out_brelse;
205 }
206 }
207 /* There's no next block so we are done */
208 if (iter->pos >= iter->dir->i_size)
209 return 0;
210 /* Need to fetch next block as well? */
211 if (off + sizeof(struct fileIdentDesc) > blksize)
212 goto fetch_next;
213 fi = (struct fileIdentDesc *)(iter->bh[0]->b_data + off);
214 /* Need to fetch next block to get name? */
215 if (off + udf_dir_entry_len(fi) > blksize) {
216 fetch_next:
217 err = udf_fiiter_advance_blk(iter);
218 if (err)
219 goto out_brelse;
220 iter->bh[1] = udf_fiiter_bread_blk(iter);
221 if (!iter->bh[1]) {
222 err = -ENOMEM;
223 goto out_brelse;
224 }
225 if (!buffer_uptodate(iter->bh[1])) {
226 err = -EIO;
227 goto out_brelse;
228 }
229 }
230 return 0;
231 out_brelse:
232 brelse(iter->bh[0]);
233 brelse(iter->bh[1]);
234 iter->bh[0] = iter->bh[1] = NULL;
235 return err;
236 }
237
udf_fiiter_init(struct udf_fileident_iter * iter,struct inode * dir,loff_t pos)238 int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir,
239 loff_t pos)
240 {
241 struct udf_inode_info *iinfo = UDF_I(dir);
242 int err = 0;
243
244 iter->dir = dir;
245 iter->bh[0] = iter->bh[1] = NULL;
246 iter->pos = pos;
247 iter->elen = 0;
248 iter->epos.bh = NULL;
249 iter->name = NULL;
250 /*
251 * When directory is verified, we don't expect directory iteration to
252 * fail and it can be difficult to undo without corrupting filesystem.
253 * So just do not allow memory allocation failures here.
254 */
255 iter->namebuf = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL | __GFP_NOFAIL);
256
257 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
258 err = udf_copy_fi(iter);
259 goto out;
260 }
261
262 if (inode_bmap(dir, iter->pos >> dir->i_blkbits, &iter->epos,
263 &iter->eloc, &iter->elen, &iter->loffset) !=
264 (EXT_RECORDED_ALLOCATED >> 30)) {
265 if (pos == dir->i_size)
266 return 0;
267 udf_err(dir->i_sb,
268 "position %llu not allocated in directory (ino %lu)\n",
269 (unsigned long long)pos, dir->i_ino);
270 err = -EFSCORRUPTED;
271 goto out;
272 }
273 err = udf_fiiter_load_bhs(iter);
274 if (err < 0)
275 goto out;
276 err = udf_copy_fi(iter);
277 out:
278 if (err < 0)
279 udf_fiiter_release(iter);
280 return err;
281 }
282
udf_fiiter_advance(struct udf_fileident_iter * iter)283 int udf_fiiter_advance(struct udf_fileident_iter *iter)
284 {
285 unsigned int oldoff, len;
286 int blksize = 1 << iter->dir->i_blkbits;
287 int err;
288
289 oldoff = iter->pos & (blksize - 1);
290 len = udf_dir_entry_len(&iter->fi);
291 iter->pos += len;
292 if (UDF_I(iter->dir)->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
293 if (oldoff + len >= blksize) {
294 brelse(iter->bh[0]);
295 iter->bh[0] = NULL;
296 /* Next block already loaded? */
297 if (iter->bh[1]) {
298 iter->bh[0] = iter->bh[1];
299 iter->bh[1] = NULL;
300 } else {
301 err = udf_fiiter_advance_blk(iter);
302 if (err < 0)
303 return err;
304 }
305 }
306 err = udf_fiiter_load_bhs(iter);
307 if (err < 0)
308 return err;
309 }
310 return udf_copy_fi(iter);
311 }
312
udf_fiiter_release(struct udf_fileident_iter * iter)313 void udf_fiiter_release(struct udf_fileident_iter *iter)
314 {
315 iter->dir = NULL;
316 brelse(iter->bh[0]);
317 brelse(iter->bh[1]);
318 iter->bh[0] = iter->bh[1] = NULL;
319 kfree(iter->namebuf);
320 iter->namebuf = NULL;
321 }
322
udf_copy_to_bufs(void * buf1,int len1,void * buf2,int len2,int off,void * src,int len)323 static void udf_copy_to_bufs(void *buf1, int len1, void *buf2, int len2,
324 int off, void *src, int len)
325 {
326 int copy;
327
328 if (off >= len1) {
329 off -= len1;
330 } else {
331 copy = min(off + len, len1) - off;
332 memcpy(buf1 + off, src, copy);
333 src += copy;
334 len -= copy;
335 off = 0;
336 }
337 if (len > 0) {
338 if (WARN_ON_ONCE(off + len > len2 || !buf2))
339 return;
340 memcpy(buf2 + off, src, len);
341 }
342 }
343
udf_crc_fi_bufs(void * buf1,int len1,void * buf2,int len2,int off,int len)344 static uint16_t udf_crc_fi_bufs(void *buf1, int len1, void *buf2, int len2,
345 int off, int len)
346 {
347 int copy;
348 uint16_t crc = 0;
349
350 if (off >= len1) {
351 off -= len1;
352 } else {
353 copy = min(off + len, len1) - off;
354 crc = crc_itu_t(crc, buf1 + off, copy);
355 len -= copy;
356 off = 0;
357 }
358 if (len > 0) {
359 if (WARN_ON_ONCE(off + len > len2 || !buf2))
360 return 0;
361 crc = crc_itu_t(crc, buf2 + off, len);
362 }
363 return crc;
364 }
365
udf_copy_fi_to_bufs(char * buf1,int len1,char * buf2,int len2,int off,struct fileIdentDesc * fi,uint8_t * impuse,uint8_t * name)366 static void udf_copy_fi_to_bufs(char *buf1, int len1, char *buf2, int len2,
367 int off, struct fileIdentDesc *fi,
368 uint8_t *impuse, uint8_t *name)
369 {
370 uint16_t crc;
371 int fioff = off;
372 int crcoff = off + sizeof(struct tag);
373 unsigned int crclen = udf_dir_entry_len(fi) - sizeof(struct tag);
374 char zeros[UDF_NAME_PAD] = {};
375 int endoff = off + udf_dir_entry_len(fi);
376
377 udf_copy_to_bufs(buf1, len1, buf2, len2, off, fi,
378 sizeof(struct fileIdentDesc));
379 off += sizeof(struct fileIdentDesc);
380 if (impuse)
381 udf_copy_to_bufs(buf1, len1, buf2, len2, off, impuse,
382 le16_to_cpu(fi->lengthOfImpUse));
383 off += le16_to_cpu(fi->lengthOfImpUse);
384 if (name) {
385 udf_copy_to_bufs(buf1, len1, buf2, len2, off, name,
386 fi->lengthFileIdent);
387 off += fi->lengthFileIdent;
388 udf_copy_to_bufs(buf1, len1, buf2, len2, off, zeros,
389 endoff - off);
390 }
391
392 crc = udf_crc_fi_bufs(buf1, len1, buf2, len2, crcoff, crclen);
393 fi->descTag.descCRC = cpu_to_le16(crc);
394 fi->descTag.descCRCLength = cpu_to_le16(crclen);
395 fi->descTag.tagChecksum = udf_tag_checksum(&fi->descTag);
396
397 udf_copy_to_bufs(buf1, len1, buf2, len2, fioff, fi, sizeof(struct tag));
398 }
399
udf_fiiter_write_fi(struct udf_fileident_iter * iter,uint8_t * impuse)400 void udf_fiiter_write_fi(struct udf_fileident_iter *iter, uint8_t *impuse)
401 {
402 struct udf_inode_info *iinfo = UDF_I(iter->dir);
403 void *buf1, *buf2 = NULL;
404 int len1, len2 = 0, off;
405 int blksize = 1 << iter->dir->i_blkbits;
406
407 off = iter->pos & (blksize - 1);
408 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
409 buf1 = iinfo->i_data + iinfo->i_lenEAttr;
410 len1 = iter->dir->i_size;
411 } else {
412 buf1 = iter->bh[0]->b_data;
413 len1 = blksize;
414 if (iter->bh[1]) {
415 buf2 = iter->bh[1]->b_data;
416 len2 = blksize;
417 }
418 }
419
420 udf_copy_fi_to_bufs(buf1, len1, buf2, len2, off, &iter->fi, impuse,
421 iter->name == iter->namebuf ? iter->name : NULL);
422
423 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
424 mark_inode_dirty(iter->dir);
425 } else {
426 mark_buffer_dirty_inode(iter->bh[0], iter->dir);
427 if (iter->bh[1])
428 mark_buffer_dirty_inode(iter->bh[1], iter->dir);
429 }
430 inode_inc_iversion(iter->dir);
431 }
432
udf_fiiter_update_elen(struct udf_fileident_iter * iter,uint32_t new_elen)433 void udf_fiiter_update_elen(struct udf_fileident_iter *iter, uint32_t new_elen)
434 {
435 struct udf_inode_info *iinfo = UDF_I(iter->dir);
436 int diff = new_elen - iter->elen;
437
438 /* Skip update when we already went past the last extent */
439 if (!iter->elen)
440 return;
441 iter->elen = new_elen;
442 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
443 iter->epos.offset -= sizeof(struct short_ad);
444 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
445 iter->epos.offset -= sizeof(struct long_ad);
446 udf_write_aext(iter->dir, &iter->epos, &iter->eloc, iter->elen, 1);
447 iinfo->i_lenExtents += diff;
448 mark_inode_dirty(iter->dir);
449 }
450
451 /* Append new block to directory. @iter is expected to point at EOF */
udf_fiiter_append_blk(struct udf_fileident_iter * iter)452 int udf_fiiter_append_blk(struct udf_fileident_iter *iter)
453 {
454 struct udf_inode_info *iinfo = UDF_I(iter->dir);
455 int blksize = 1 << iter->dir->i_blkbits;
456 struct buffer_head *bh;
457 sector_t block;
458 uint32_t old_elen = iter->elen;
459 int err;
460
461 if (WARN_ON_ONCE(iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB))
462 return -EINVAL;
463
464 /* Round up last extent in the file */
465 udf_fiiter_update_elen(iter, ALIGN(iter->elen, blksize));
466
467 /* Allocate new block and refresh mapping information */
468 block = iinfo->i_lenExtents >> iter->dir->i_blkbits;
469 bh = udf_bread(iter->dir, block, 1, &err);
470 if (!bh) {
471 udf_fiiter_update_elen(iter, old_elen);
472 return err;
473 }
474 if (inode_bmap(iter->dir, block, &iter->epos, &iter->eloc, &iter->elen,
475 &iter->loffset) != (EXT_RECORDED_ALLOCATED >> 30)) {
476 udf_err(iter->dir->i_sb,
477 "block %llu not allocated in directory (ino %lu)\n",
478 (unsigned long long)block, iter->dir->i_ino);
479 return -EFSCORRUPTED;
480 }
481 if (!(iter->pos & (blksize - 1))) {
482 brelse(iter->bh[0]);
483 iter->bh[0] = bh;
484 } else {
485 iter->bh[1] = bh;
486 }
487 return 0;
488 }
489
udf_get_fileshortad(uint8_t * ptr,int maxoffset,uint32_t * offset,int inc)490 struct short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
491 int inc)
492 {
493 struct short_ad *sa;
494
495 if ((!ptr) || (!offset)) {
496 pr_err("%s: invalidparms\n", __func__);
497 return NULL;
498 }
499
500 if ((*offset + sizeof(struct short_ad)) > maxoffset)
501 return NULL;
502 else {
503 sa = (struct short_ad *)ptr;
504 if (sa->extLength == 0)
505 return NULL;
506 }
507
508 if (inc)
509 *offset += sizeof(struct short_ad);
510 return sa;
511 }
512
udf_get_filelongad(uint8_t * ptr,int maxoffset,uint32_t * offset,int inc)513 struct long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
514 {
515 struct long_ad *la;
516
517 if ((!ptr) || (!offset)) {
518 pr_err("%s: invalidparms\n", __func__);
519 return NULL;
520 }
521
522 if ((*offset + sizeof(struct long_ad)) > maxoffset)
523 return NULL;
524 else {
525 la = (struct long_ad *)ptr;
526 if (la->extLength == 0)
527 return NULL;
528 }
529
530 if (inc)
531 *offset += sizeof(struct long_ad);
532 return la;
533 }
534