fs/udf/directory.c

   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
  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
  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 */
 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
 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  */
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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 */
 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
 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
 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 }