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         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(iter->dir, &iter->epos, &iter->eloc,
 178                             &iter->elen, &etype, 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
 194 static 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(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(fi) > blksize) {
 222 fetch_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(iter->bh[1])) {
 232                         err = -EIO;
 233                         goto out_brelse;
 234                 }
 235         }
 236         return 0;
 237 out_brelse:
 238         brelse(iter->bh[0]);
 239         brelse(iter->bh[1]);
 240         iter->bh[0] = iter->bh[1] = NULL;
 241         return err;
 242 }
 243
 244 int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir,
 245                     loff_t pos)
 246 {
 247         struct udf_inode_info *iinfo = UDF_I(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(dir, iter->pos >> dir->i_blkbits, &iter->epos,
 270                          &iter->eloc, &iter->elen, &iter->loffset, &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);
 284 out:
 285         if (err < 0)
 286                 udf_fiiter_release(iter);
 287         return err;
 288 }
 289
 290 int 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(&iter->fi);
 298         iter->pos += len;
 299         if (UDF_I(iter->dir)->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
 300                 if (oldoff + len >= blksize) {
 301                         brelse(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
 320 void udf_fiiter_release(struct udf_fileident_iter *iter)
 321 {
 322         iter->dir = NULL;
 323         brelse(iter->bh[0]);
 324         brelse(iter->bh[1]);
 325         iter->bh[0] = iter->bh[1] = NULL;
 326         kfree(iter->namebuf);
 327         iter->namebuf = NULL;
 328 }
 329
 330 static 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
 351 static 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, buf1 + off, 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, buf2 + off, len);
 369         }
 370         return crc;
 371 }
 372
 373 static 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(fi) - sizeof(struct tag);
 381         char zeros[UDF_NAME_PAD] = {};
 382         int endoff = off + udf_dir_entry_len(fi);
 383
 384         udf_copy_to_bufs(buf1, len1, buf2, len2, off, fi,
 385                          sizeof(struct fileIdentDesc));
 386         off += sizeof(struct fileIdentDesc);
 387         if (impuse)
 388                 udf_copy_to_bufs(buf1, len1, buf2, len2, off, 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, name,
 393                                  fi->lengthFileIdent);
 394                 off += fi->lengthFileIdent;
 395                 udf_copy_to_bufs(buf1, len1, buf2, len2, off, zeros,
 396                                  endoff - off);
 397         }
 398
 399         crc = udf_crc_fi_bufs(buf1, len1, buf2, len2, crcoff, crclen);
 400         fi->descTag.descCRC = cpu_to_le16(crc);
 401         fi->descTag.descCRCLength = cpu_to_le16(crclen);
 402         fi->descTag.tagChecksum = udf_tag_checksum(&fi->descTag);
 403
 404         udf_copy_to_bufs(buf1, len1, buf2, len2, fioff, fi, sizeof(struct tag));
 405 }
 406
 407 void udf_fiiter_write_fi(struct udf_fileident_iter *iter, uint8_t *impuse)
 408 {
 409         struct udf_inode_info *iinfo = UDF_I(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, &iter->fi, impuse,
 428                             iter->name == iter->namebuf ? iter->name : NULL);
 429
 430         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 431                 mark_inode_dirty(iter->dir);
 432         } else {
 433                 mark_buffer_dirty_inode(iter->bh[0], iter->dir);
 434                 if (iter->bh[1])
 435                         mark_buffer_dirty_inode(iter->bh[1], iter->dir);
 436         }
 437         inode_inc_iversion(iter->dir);
 438 }
 439
 440 void udf_fiiter_update_elen(struct udf_fileident_iter *iter, uint32_t new_elen)
 441 {
 442         struct udf_inode_info *iinfo = UDF_I(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(iter->dir);
 456 }
 457
 458 /* Append new block to directory. @iter is expected to point at EOF */
 459 int udf_fiiter_append_blk(struct udf_fileident_iter *iter)
 460 {
 461         struct udf_inode_info *iinfo = UDF_I(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(iter->dir, block, 1, &err);
 478         if (!bh) {
 479                 udf_fiiter_update_elen(iter, old_elen);
 480                 return err;
 481         }
 482         err = inode_bmap(iter->dir, block, &iter->epos, &iter->eloc, &iter->elen,
 483                    &iter->loffset, &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(iter->bh[0]);
 492                 iter->bh[0] = bh;
 493         } else {
 494                 iter->bh[1] = bh;
 495         }
 496         return 0;
 497 }
 498
 499 struct 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
 522 struct 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 }