1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Optimized MPEG FS - inode and super operations. 4 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com> 5 */ 6 #include <linux/module.h> 7 #include <linux/sched.h> 8 #include <linux/slab.h> 9 #include <linux/fs.h> 10 #include <linux/vfs.h> 11 #include <linux/cred.h> 12 #include <linux/parser.h> 13 #include <linux/buffer_head.h> 14 #include <linux/vmalloc.h> 15 #include <linux/writeback.h> 16 #include <linux/seq_file.h> 17 #include <linux/crc-itu-t.h> 18 #include "omfs.h" 19 20 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>"); 21 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux"); 22 MODULE_LICENSE("GPL"); 23 24 struct buffer_head *omfs_bread(struct super_block *sb, sector_t block) 25 { 26 struct omfs_sb_info *sbi = OMFS_SB(sb); 27 if (block >= sbi->s_num_blocks) 28 return NULL; 29 30 return sb_bread(sb, clus_to_blk(sbi, block)); 31 } 32 33 struct inode *omfs_new_inode(struct inode *dir, umode_t mode) 34 { 35 struct inode *inode; 36 u64 new_block; 37 int err; 38 int len; 39 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb); 40 41 inode = new_inode(dir->i_sb); 42 if (!inode) 43 return ERR_PTR(-ENOMEM); 44 45 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors, 46 &new_block, &len); 47 if (err) 48 goto fail; 49 50 inode->i_ino = new_block; 51 inode_init_owner(&nop_mnt_idmap, inode, NULL, mode); 52 inode->i_mapping->a_ops = &omfs_aops; 53 54 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); 55 switch (mode & S_IFMT) { 56 case S_IFDIR: 57 inode->i_op = &omfs_dir_inops; 58 inode->i_fop = &omfs_dir_operations; 59 inode->i_size = sbi->s_sys_blocksize; 60 inc_nlink(inode); 61 break; 62 case S_IFREG: 63 inode->i_op = &omfs_file_inops; 64 inode->i_fop = &omfs_file_operations; 65 inode->i_size = 0; 66 break; 67 } 68 69 insert_inode_hash(inode); 70 mark_inode_dirty(inode); 71 return inode; 72 fail: 73 make_bad_inode(inode); 74 iput(inode); 75 return ERR_PTR(err); 76 } 77 78 /* 79 * Update the header checksums for a dirty inode based on its contents. 80 * Caller is expected to hold the buffer head underlying oi and mark it 81 * dirty. 82 */ 83 static void omfs_update_checksums(struct omfs_inode *oi) 84 { 85 int xor, i, ofs = 0, count; 86 u16 crc = 0; 87 unsigned char *ptr = (unsigned char *) oi; 88 89 count = be32_to_cpu(oi->i_head.h_body_size); 90 ofs = sizeof(struct omfs_header); 91 92 crc = crc_itu_t(crc, ptr + ofs, count); 93 oi->i_head.h_crc = cpu_to_be16(crc); 94 95 xor = ptr[0]; 96 for (i = 1; i < OMFS_XOR_COUNT; i++) 97 xor ^= ptr[i]; 98 99 oi->i_head.h_check_xor = xor; 100 } 101 102 static int __omfs_write_inode(struct inode *inode, int wait) 103 { 104 struct omfs_inode *oi; 105 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); 106 struct buffer_head *bh, *bh2; 107 u64 ctime; 108 int i; 109 int ret = -EIO; 110 int sync_failed = 0; 111 112 /* get current inode since we may have written sibling ptrs etc. */ 113 bh = omfs_bread(inode->i_sb, inode->i_ino); 114 if (!bh) 115 goto out; 116 117 oi = (struct omfs_inode *) bh->b_data; 118 119 oi->i_head.h_self = cpu_to_be64(inode->i_ino); 120 if (S_ISDIR(inode->i_mode)) 121 oi->i_type = OMFS_DIR; 122 else if (S_ISREG(inode->i_mode)) 123 oi->i_type = OMFS_FILE; 124 else { 125 printk(KERN_WARNING "omfs: unknown file type: %d\n", 126 inode->i_mode); 127 goto out_brelse; 128 } 129 130 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize - 131 sizeof(struct omfs_header)); 132 oi->i_head.h_version = 1; 133 oi->i_head.h_type = OMFS_INODE_NORMAL; 134 oi->i_head.h_magic = OMFS_IMAGIC; 135 oi->i_size = cpu_to_be64(inode->i_size); 136 137 ctime = inode->i_ctime.tv_sec * 1000LL + 138 ((inode->i_ctime.tv_nsec + 999)/1000); 139 oi->i_ctime = cpu_to_be64(ctime); 140 141 omfs_update_checksums(oi); 142 143 mark_buffer_dirty(bh); 144 if (wait) { 145 sync_dirty_buffer(bh); 146 if (buffer_req(bh) && !buffer_uptodate(bh)) 147 sync_failed = 1; 148 } 149 150 /* if mirroring writes, copy to next fsblock */ 151 for (i = 1; i < sbi->s_mirrors; i++) { 152 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i); 153 if (!bh2) 154 goto out_brelse; 155 156 memcpy(bh2->b_data, bh->b_data, bh->b_size); 157 mark_buffer_dirty(bh2); 158 if (wait) { 159 sync_dirty_buffer(bh2); 160 if (buffer_req(bh2) && !buffer_uptodate(bh2)) 161 sync_failed = 1; 162 } 163 brelse(bh2); 164 } 165 ret = (sync_failed) ? -EIO : 0; 166 out_brelse: 167 brelse(bh); 168 out: 169 return ret; 170 } 171 172 static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc) 173 { 174 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 175 } 176 177 int omfs_sync_inode(struct inode *inode) 178 { 179 return __omfs_write_inode(inode, 1); 180 } 181 182 /* 183 * called when an entry is deleted, need to clear the bits in the 184 * bitmaps. 185 */ 186 static void omfs_evict_inode(struct inode *inode) 187 { 188 truncate_inode_pages_final(&inode->i_data); 189 clear_inode(inode); 190 191 if (inode->i_nlink) 192 return; 193 194 if (S_ISREG(inode->i_mode)) { 195 inode->i_size = 0; 196 omfs_shrink_inode(inode); 197 } 198 199 omfs_clear_range(inode->i_sb, inode->i_ino, 2); 200 } 201 202 struct inode *omfs_iget(struct super_block *sb, ino_t ino) 203 { 204 struct omfs_sb_info *sbi = OMFS_SB(sb); 205 struct omfs_inode *oi; 206 struct buffer_head *bh; 207 u64 ctime; 208 unsigned long nsecs; 209 struct inode *inode; 210 211 inode = iget_locked(sb, ino); 212 if (!inode) 213 return ERR_PTR(-ENOMEM); 214 if (!(inode->i_state & I_NEW)) 215 return inode; 216 217 bh = omfs_bread(inode->i_sb, ino); 218 if (!bh) 219 goto iget_failed; 220 221 oi = (struct omfs_inode *)bh->b_data; 222 223 /* check self */ 224 if (ino != be64_to_cpu(oi->i_head.h_self)) 225 goto fail_bh; 226 227 inode->i_uid = sbi->s_uid; 228 inode->i_gid = sbi->s_gid; 229 230 ctime = be64_to_cpu(oi->i_ctime); 231 nsecs = do_div(ctime, 1000) * 1000L; 232 233 inode->i_atime.tv_sec = ctime; 234 inode->i_mtime.tv_sec = ctime; 235 inode->i_ctime.tv_sec = ctime; 236 inode->i_atime.tv_nsec = nsecs; 237 inode->i_mtime.tv_nsec = nsecs; 238 inode->i_ctime.tv_nsec = nsecs; 239 240 inode->i_mapping->a_ops = &omfs_aops; 241 242 switch (oi->i_type) { 243 case OMFS_DIR: 244 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask); 245 inode->i_op = &omfs_dir_inops; 246 inode->i_fop = &omfs_dir_operations; 247 inode->i_size = sbi->s_sys_blocksize; 248 inc_nlink(inode); 249 break; 250 case OMFS_FILE: 251 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask); 252 inode->i_fop = &omfs_file_operations; 253 inode->i_size = be64_to_cpu(oi->i_size); 254 break; 255 } 256 brelse(bh); 257 unlock_new_inode(inode); 258 return inode; 259 fail_bh: 260 brelse(bh); 261 iget_failed: 262 iget_failed(inode); 263 return ERR_PTR(-EIO); 264 } 265 266 static void omfs_put_super(struct super_block *sb) 267 { 268 struct omfs_sb_info *sbi = OMFS_SB(sb); 269 kfree(sbi->s_imap); 270 kfree(sbi); 271 sb->s_fs_info = NULL; 272 } 273 274 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf) 275 { 276 struct super_block *s = dentry->d_sb; 277 struct omfs_sb_info *sbi = OMFS_SB(s); 278 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 279 280 buf->f_type = OMFS_MAGIC; 281 buf->f_bsize = sbi->s_blocksize; 282 buf->f_blocks = sbi->s_num_blocks; 283 buf->f_files = sbi->s_num_blocks; 284 buf->f_namelen = OMFS_NAMELEN; 285 buf->f_fsid = u64_to_fsid(id); 286 287 buf->f_bfree = buf->f_bavail = buf->f_ffree = 288 omfs_count_free(s); 289 290 return 0; 291 } 292 293 /* 294 * Display the mount options in /proc/mounts. 295 */ 296 static int omfs_show_options(struct seq_file *m, struct dentry *root) 297 { 298 struct omfs_sb_info *sbi = OMFS_SB(root->d_sb); 299 umode_t cur_umask = current_umask(); 300 301 if (!uid_eq(sbi->s_uid, current_uid())) 302 seq_printf(m, ",uid=%u", 303 from_kuid_munged(&init_user_ns, sbi->s_uid)); 304 if (!gid_eq(sbi->s_gid, current_gid())) 305 seq_printf(m, ",gid=%u", 306 from_kgid_munged(&init_user_ns, sbi->s_gid)); 307 308 if (sbi->s_dmask == sbi->s_fmask) { 309 if (sbi->s_fmask != cur_umask) 310 seq_printf(m, ",umask=%o", sbi->s_fmask); 311 } else { 312 if (sbi->s_dmask != cur_umask) 313 seq_printf(m, ",dmask=%o", sbi->s_dmask); 314 if (sbi->s_fmask != cur_umask) 315 seq_printf(m, ",fmask=%o", sbi->s_fmask); 316 } 317 318 return 0; 319 } 320 321 static const struct super_operations omfs_sops = { 322 .write_inode = omfs_write_inode, 323 .evict_inode = omfs_evict_inode, 324 .put_super = omfs_put_super, 325 .statfs = omfs_statfs, 326 .show_options = omfs_show_options, 327 }; 328 329 /* 330 * For Rio Karma, there is an on-disk free bitmap whose location is 331 * stored in the root block. For ReplayTV, there is no such free bitmap 332 * so we have to walk the tree. Both inodes and file data are allocated 333 * from the same map. This array can be big (300k) so we allocate 334 * in units of the blocksize. 335 */ 336 static int omfs_get_imap(struct super_block *sb) 337 { 338 unsigned int bitmap_size, array_size; 339 int count; 340 struct omfs_sb_info *sbi = OMFS_SB(sb); 341 struct buffer_head *bh; 342 unsigned long **ptr; 343 sector_t block; 344 345 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8); 346 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize); 347 348 if (sbi->s_bitmap_ino == ~0ULL) 349 goto out; 350 351 sbi->s_imap_size = array_size; 352 sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL); 353 if (!sbi->s_imap) 354 goto nomem; 355 356 block = clus_to_blk(sbi, sbi->s_bitmap_ino); 357 if (block >= sbi->s_num_blocks) 358 goto nomem; 359 360 ptr = sbi->s_imap; 361 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { 362 bh = sb_bread(sb, block++); 363 if (!bh) 364 goto nomem_free; 365 *ptr = kmemdup(bh->b_data, sb->s_blocksize, GFP_KERNEL); 366 if (!*ptr) { 367 brelse(bh); 368 goto nomem_free; 369 } 370 if (count < sb->s_blocksize) 371 memset((void *)*ptr + count, 0xff, 372 sb->s_blocksize - count); 373 brelse(bh); 374 ptr++; 375 } 376 out: 377 return 0; 378 379 nomem_free: 380 for (count = 0; count < array_size; count++) 381 kfree(sbi->s_imap[count]); 382 383 kfree(sbi->s_imap); 384 nomem: 385 sbi->s_imap = NULL; 386 sbi->s_imap_size = 0; 387 return -ENOMEM; 388 } 389 390 enum { 391 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err 392 }; 393 394 static const match_table_t tokens = { 395 {Opt_uid, "uid=%u"}, 396 {Opt_gid, "gid=%u"}, 397 {Opt_umask, "umask=%o"}, 398 {Opt_dmask, "dmask=%o"}, 399 {Opt_fmask, "fmask=%o"}, 400 {Opt_err, NULL}, 401 }; 402 403 static int parse_options(char *options, struct omfs_sb_info *sbi) 404 { 405 char *p; 406 substring_t args[MAX_OPT_ARGS]; 407 int option; 408 409 if (!options) 410 return 1; 411 412 while ((p = strsep(&options, ",")) != NULL) { 413 int token; 414 if (!*p) 415 continue; 416 417 token = match_token(p, tokens, args); 418 switch (token) { 419 case Opt_uid: 420 if (match_int(&args[0], &option)) 421 return 0; 422 sbi->s_uid = make_kuid(current_user_ns(), option); 423 if (!uid_valid(sbi->s_uid)) 424 return 0; 425 break; 426 case Opt_gid: 427 if (match_int(&args[0], &option)) 428 return 0; 429 sbi->s_gid = make_kgid(current_user_ns(), option); 430 if (!gid_valid(sbi->s_gid)) 431 return 0; 432 break; 433 case Opt_umask: 434 if (match_octal(&args[0], &option)) 435 return 0; 436 sbi->s_fmask = sbi->s_dmask = option; 437 break; 438 case Opt_dmask: 439 if (match_octal(&args[0], &option)) 440 return 0; 441 sbi->s_dmask = option; 442 break; 443 case Opt_fmask: 444 if (match_octal(&args[0], &option)) 445 return 0; 446 sbi->s_fmask = option; 447 break; 448 default: 449 return 0; 450 } 451 } 452 return 1; 453 } 454 455 static int omfs_fill_super(struct super_block *sb, void *data, int silent) 456 { 457 struct buffer_head *bh, *bh2; 458 struct omfs_super_block *omfs_sb; 459 struct omfs_root_block *omfs_rb; 460 struct omfs_sb_info *sbi; 461 struct inode *root; 462 int ret = -EINVAL; 463 464 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL); 465 if (!sbi) 466 return -ENOMEM; 467 468 sb->s_fs_info = sbi; 469 470 sbi->s_uid = current_uid(); 471 sbi->s_gid = current_gid(); 472 sbi->s_dmask = sbi->s_fmask = current_umask(); 473 474 if (!parse_options((char *) data, sbi)) 475 goto end; 476 477 sb->s_maxbytes = 0xffffffff; 478 479 sb->s_time_gran = NSEC_PER_MSEC; 480 sb->s_time_min = 0; 481 sb->s_time_max = U64_MAX / MSEC_PER_SEC; 482 483 sb_set_blocksize(sb, 0x200); 484 485 bh = sb_bread(sb, 0); 486 if (!bh) 487 goto end; 488 489 omfs_sb = (struct omfs_super_block *)bh->b_data; 490 491 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) { 492 if (!silent) 493 printk(KERN_ERR "omfs: Invalid superblock (%x)\n", 494 omfs_sb->s_magic); 495 goto out_brelse_bh; 496 } 497 sb->s_magic = OMFS_MAGIC; 498 499 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks); 500 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize); 501 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors); 502 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block); 503 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize); 504 mutex_init(&sbi->s_bitmap_lock); 505 506 if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) { 507 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n", 508 (unsigned long long)sbi->s_num_blocks); 509 goto out_brelse_bh; 510 } 511 512 if (sbi->s_sys_blocksize > PAGE_SIZE) { 513 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n", 514 sbi->s_sys_blocksize); 515 goto out_brelse_bh; 516 } 517 518 if (sbi->s_blocksize < sbi->s_sys_blocksize || 519 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) { 520 printk(KERN_ERR "omfs: block size (%d) is out of range\n", 521 sbi->s_blocksize); 522 goto out_brelse_bh; 523 } 524 525 /* 526 * Use sys_blocksize as the fs block since it is smaller than a 527 * page while the fs blocksize can be larger. 528 */ 529 sb_set_blocksize(sb, sbi->s_sys_blocksize); 530 531 /* 532 * ...and the difference goes into a shift. sys_blocksize is always 533 * a power of two factor of blocksize. 534 */ 535 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - 536 get_bitmask_order(sbi->s_sys_blocksize); 537 538 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); 539 if (!bh2) 540 goto out_brelse_bh; 541 542 omfs_rb = (struct omfs_root_block *)bh2->b_data; 543 544 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap); 545 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize); 546 547 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) { 548 printk(KERN_ERR "omfs: block count discrepancy between " 549 "super and root blocks (%llx, %llx)\n", 550 (unsigned long long)sbi->s_num_blocks, 551 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks)); 552 goto out_brelse_bh2; 553 } 554 555 if (sbi->s_bitmap_ino != ~0ULL && 556 sbi->s_bitmap_ino > sbi->s_num_blocks) { 557 printk(KERN_ERR "omfs: free space bitmap location is corrupt " 558 "(%llx, total blocks %llx)\n", 559 (unsigned long long) sbi->s_bitmap_ino, 560 (unsigned long long) sbi->s_num_blocks); 561 goto out_brelse_bh2; 562 } 563 if (sbi->s_clustersize < 1 || 564 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) { 565 printk(KERN_ERR "omfs: cluster size out of range (%d)", 566 sbi->s_clustersize); 567 goto out_brelse_bh2; 568 } 569 570 ret = omfs_get_imap(sb); 571 if (ret) 572 goto out_brelse_bh2; 573 574 sb->s_op = &omfs_sops; 575 576 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir)); 577 if (IS_ERR(root)) { 578 ret = PTR_ERR(root); 579 goto out_brelse_bh2; 580 } 581 582 sb->s_root = d_make_root(root); 583 if (!sb->s_root) { 584 ret = -ENOMEM; 585 goto out_brelse_bh2; 586 } 587 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name); 588 589 ret = 0; 590 out_brelse_bh2: 591 brelse(bh2); 592 out_brelse_bh: 593 brelse(bh); 594 end: 595 if (ret) 596 kfree(sbi); 597 return ret; 598 } 599 600 static struct dentry *omfs_mount(struct file_system_type *fs_type, 601 int flags, const char *dev_name, void *data) 602 { 603 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super); 604 } 605 606 static struct file_system_type omfs_fs_type = { 607 .owner = THIS_MODULE, 608 .name = "omfs", 609 .mount = omfs_mount, 610 .kill_sb = kill_block_super, 611 .fs_flags = FS_REQUIRES_DEV, 612 }; 613 MODULE_ALIAS_FS("omfs"); 614 615 static int __init init_omfs_fs(void) 616 { 617 return register_filesystem(&omfs_fs_type); 618 } 619 620 static void __exit exit_omfs_fs(void) 621 { 622 unregister_filesystem(&omfs_fs_type); 623 } 624 625 module_init(init_omfs_fs); 626 module_exit(exit_omfs_fs); 627