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/buffer_head.h> 13 #include <linux/vmalloc.h> 14 #include <linux/writeback.h> 15 #include <linux/seq_file.h> 16 #include <linux/crc-itu-t.h> 17 #include <linux/fs_struct.h> 18 #include <linux/fs_context.h> 19 #include <linux/fs_parser.h> 20 #include "omfs.h" 21 22 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>"); 23 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux"); 24 MODULE_LICENSE("GPL"); 25 26 struct buffer_head *omfs_bread(struct super_block *sb, sector_t block) 27 { 28 struct omfs_sb_info *sbi = OMFS_SB(sb); 29 if (block >= sbi->s_num_blocks) 30 return NULL; 31 32 return sb_bread(sb, clus_to_blk(sbi, block)); 33 } 34 35 struct inode *omfs_new_inode(struct inode *dir, umode_t mode) 36 { 37 struct inode *inode; 38 u64 new_block; 39 int err; 40 int len; 41 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb); 42 43 inode = new_inode(dir->i_sb); 44 if (!inode) 45 return ERR_PTR(-ENOMEM); 46 47 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors, 48 &new_block, &len); 49 if (err) 50 goto fail; 51 52 inode->i_ino = new_block; 53 inode_init_owner(&nop_mnt_idmap, inode, NULL, mode); 54 inode->i_mapping->a_ops = &omfs_aops; 55 56 simple_inode_init_ts(inode); 57 switch (mode & S_IFMT) { 58 case S_IFDIR: 59 inode->i_op = &omfs_dir_inops; 60 inode->i_fop = &omfs_dir_operations; 61 inode->i_size = sbi->s_sys_blocksize; 62 inc_nlink(inode); 63 break; 64 case S_IFREG: 65 inode->i_op = &omfs_file_inops; 66 inode->i_fop = &omfs_file_operations; 67 inode->i_size = 0; 68 break; 69 } 70 71 insert_inode_hash(inode); 72 mark_inode_dirty(inode); 73 return inode; 74 fail: 75 make_bad_inode(inode); 76 iput(inode); 77 return ERR_PTR(err); 78 } 79 80 /* 81 * Update the header checksums for a dirty inode based on its contents. 82 * Caller is expected to hold the buffer head underlying oi and mark it 83 * dirty. 84 */ 85 static void omfs_update_checksums(struct omfs_inode *oi) 86 { 87 int xor, i, ofs = 0, count; 88 u16 crc = 0; 89 unsigned char *ptr = (unsigned char *) oi; 90 91 count = be32_to_cpu(oi->i_head.h_body_size); 92 ofs = sizeof(struct omfs_header); 93 94 crc = crc_itu_t(crc, ptr + ofs, count); 95 oi->i_head.h_crc = cpu_to_be16(crc); 96 97 xor = ptr[0]; 98 for (i = 1; i < OMFS_XOR_COUNT; i++) 99 xor ^= ptr[i]; 100 101 oi->i_head.h_check_xor = xor; 102 } 103 104 static int __omfs_write_inode(struct inode *inode, int wait) 105 { 106 struct omfs_inode *oi; 107 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); 108 struct buffer_head *bh, *bh2; 109 u64 ctime; 110 int i; 111 int ret = -EIO; 112 int sync_failed = 0; 113 114 /* get current inode since we may have written sibling ptrs etc. */ 115 bh = omfs_bread(inode->i_sb, inode->i_ino); 116 if (!bh) 117 goto out; 118 119 oi = (struct omfs_inode *) bh->b_data; 120 121 oi->i_head.h_self = cpu_to_be64(inode->i_ino); 122 if (S_ISDIR(inode->i_mode)) 123 oi->i_type = OMFS_DIR; 124 else if (S_ISREG(inode->i_mode)) 125 oi->i_type = OMFS_FILE; 126 else { 127 printk(KERN_WARNING "omfs: unknown file type: %d\n", 128 inode->i_mode); 129 goto out_brelse; 130 } 131 132 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize - 133 sizeof(struct omfs_header)); 134 oi->i_head.h_version = 1; 135 oi->i_head.h_type = OMFS_INODE_NORMAL; 136 oi->i_head.h_magic = OMFS_IMAGIC; 137 oi->i_size = cpu_to_be64(inode->i_size); 138 139 ctime = inode_get_ctime_sec(inode) * 1000LL + 140 ((inode_get_ctime_nsec(inode) + 999)/1000); 141 oi->i_ctime = cpu_to_be64(ctime); 142 143 omfs_update_checksums(oi); 144 145 mark_buffer_dirty(bh); 146 if (wait) { 147 sync_dirty_buffer(bh); 148 if (buffer_req(bh) && !buffer_uptodate(bh)) 149 sync_failed = 1; 150 } 151 152 /* if mirroring writes, copy to next fsblock */ 153 for (i = 1; i < sbi->s_mirrors; i++) { 154 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i); 155 if (!bh2) 156 goto out_brelse; 157 158 memcpy(bh2->b_data, bh->b_data, bh->b_size); 159 mark_buffer_dirty(bh2); 160 if (wait) { 161 sync_dirty_buffer(bh2); 162 if (buffer_req(bh2) && !buffer_uptodate(bh2)) 163 sync_failed = 1; 164 } 165 brelse(bh2); 166 } 167 ret = (sync_failed) ? -EIO : 0; 168 out_brelse: 169 brelse(bh); 170 out: 171 return ret; 172 } 173 174 static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc) 175 { 176 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 177 } 178 179 int omfs_sync_inode(struct inode *inode) 180 { 181 return __omfs_write_inode(inode, 1); 182 } 183 184 /* 185 * called when an entry is deleted, need to clear the bits in the 186 * bitmaps. 187 */ 188 static void omfs_evict_inode(struct inode *inode) 189 { 190 truncate_inode_pages_final(&inode->i_data); 191 clear_inode(inode); 192 193 if (inode->i_nlink) 194 return; 195 196 if (S_ISREG(inode->i_mode)) { 197 inode->i_size = 0; 198 omfs_shrink_inode(inode); 199 } 200 201 omfs_clear_range(inode->i_sb, inode->i_ino, 2); 202 } 203 204 struct inode *omfs_iget(struct super_block *sb, ino_t ino) 205 { 206 struct omfs_sb_info *sbi = OMFS_SB(sb); 207 struct omfs_inode *oi; 208 struct buffer_head *bh; 209 u64 ctime; 210 unsigned long nsecs; 211 struct inode *inode; 212 213 inode = iget_locked(sb, ino); 214 if (!inode) 215 return ERR_PTR(-ENOMEM); 216 if (!(inode_state_read_once(inode) & I_NEW)) 217 return inode; 218 219 bh = omfs_bread(inode->i_sb, ino); 220 if (!bh) 221 goto iget_failed; 222 223 oi = (struct omfs_inode *)bh->b_data; 224 225 /* check self */ 226 if (ino != be64_to_cpu(oi->i_head.h_self)) 227 goto fail_bh; 228 229 inode->i_uid = sbi->s_uid; 230 inode->i_gid = sbi->s_gid; 231 232 ctime = be64_to_cpu(oi->i_ctime); 233 nsecs = do_div(ctime, 1000) * 1000L; 234 235 inode_set_atime(inode, ctime, nsecs); 236 inode_set_mtime(inode, ctime, nsecs); 237 inode_set_ctime(inode, ctime, nsecs); 238 239 inode->i_mapping->a_ops = &omfs_aops; 240 241 switch (oi->i_type) { 242 case OMFS_DIR: 243 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask); 244 inode->i_op = &omfs_dir_inops; 245 inode->i_fop = &omfs_dir_operations; 246 inode->i_size = sbi->s_sys_blocksize; 247 inc_nlink(inode); 248 break; 249 case OMFS_FILE: 250 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask); 251 inode->i_fop = &omfs_file_operations; 252 inode->i_size = be64_to_cpu(oi->i_size); 253 break; 254 } 255 brelse(bh); 256 unlock_new_inode(inode); 257 return inode; 258 fail_bh: 259 brelse(bh); 260 iget_failed: 261 iget_failed(inode); 262 return ERR_PTR(-EIO); 263 } 264 265 static void omfs_put_super(struct super_block *sb) 266 { 267 struct omfs_sb_info *sbi = OMFS_SB(sb); 268 kfree(sbi->s_imap); 269 kfree(sbi); 270 sb->s_fs_info = NULL; 271 } 272 273 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf) 274 { 275 struct super_block *s = dentry->d_sb; 276 struct omfs_sb_info *sbi = OMFS_SB(s); 277 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 278 279 buf->f_type = OMFS_MAGIC; 280 buf->f_bsize = sbi->s_blocksize; 281 buf->f_blocks = sbi->s_num_blocks; 282 buf->f_files = sbi->s_num_blocks; 283 buf->f_namelen = OMFS_NAMELEN; 284 buf->f_fsid = u64_to_fsid(id); 285 286 buf->f_bfree = buf->f_bavail = buf->f_ffree = 287 omfs_count_free(s); 288 289 return 0; 290 } 291 292 /* 293 * Display the mount options in /proc/mounts. 294 */ 295 static int omfs_show_options(struct seq_file *m, struct dentry *root) 296 { 297 struct omfs_sb_info *sbi = OMFS_SB(root->d_sb); 298 umode_t cur_umask = current_umask(); 299 300 if (!uid_eq(sbi->s_uid, current_uid())) 301 seq_printf(m, ",uid=%u", 302 from_kuid_munged(&init_user_ns, sbi->s_uid)); 303 if (!gid_eq(sbi->s_gid, current_gid())) 304 seq_printf(m, ",gid=%u", 305 from_kgid_munged(&init_user_ns, sbi->s_gid)); 306 307 if (sbi->s_dmask == sbi->s_fmask) { 308 if (sbi->s_fmask != cur_umask) 309 seq_printf(m, ",umask=%o", sbi->s_fmask); 310 } else { 311 if (sbi->s_dmask != cur_umask) 312 seq_printf(m, ",dmask=%o", sbi->s_dmask); 313 if (sbi->s_fmask != cur_umask) 314 seq_printf(m, ",fmask=%o", sbi->s_fmask); 315 } 316 317 return 0; 318 } 319 320 static const struct super_operations omfs_sops = { 321 .write_inode = omfs_write_inode, 322 .evict_inode = omfs_evict_inode, 323 .put_super = omfs_put_super, 324 .statfs = omfs_statfs, 325 .show_options = omfs_show_options, 326 }; 327 328 /* 329 * For Rio Karma, there is an on-disk free bitmap whose location is 330 * stored in the root block. For ReplayTV, there is no such free bitmap 331 * so we have to walk the tree. Both inodes and file data are allocated 332 * from the same map. This array can be big (300k) so we allocate 333 * in units of the blocksize. 334 */ 335 static int omfs_get_imap(struct super_block *sb) 336 { 337 unsigned int bitmap_size, array_size; 338 int count; 339 struct omfs_sb_info *sbi = OMFS_SB(sb); 340 struct buffer_head *bh; 341 unsigned long **ptr; 342 sector_t block; 343 344 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8); 345 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize); 346 347 if (sbi->s_bitmap_ino == ~0ULL) 348 goto out; 349 350 sbi->s_imap_size = array_size; 351 sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL); 352 if (!sbi->s_imap) 353 goto nomem; 354 355 block = clus_to_blk(sbi, sbi->s_bitmap_ino); 356 if (block >= sbi->s_num_blocks) 357 goto nomem; 358 359 ptr = sbi->s_imap; 360 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { 361 bh = sb_bread(sb, block++); 362 if (!bh) 363 goto nomem_free; 364 *ptr = kmemdup(bh->b_data, sb->s_blocksize, GFP_KERNEL); 365 if (!*ptr) { 366 brelse(bh); 367 goto nomem_free; 368 } 369 if (count < sb->s_blocksize) 370 memset((void *)*ptr + count, 0xff, 371 sb->s_blocksize - count); 372 brelse(bh); 373 ptr++; 374 } 375 out: 376 return 0; 377 378 nomem_free: 379 for (count = 0; count < array_size; count++) 380 kfree(sbi->s_imap[count]); 381 382 kfree(sbi->s_imap); 383 nomem: 384 sbi->s_imap = NULL; 385 sbi->s_imap_size = 0; 386 return -ENOMEM; 387 } 388 389 struct omfs_mount_options { 390 kuid_t s_uid; 391 kgid_t s_gid; 392 int s_dmask; 393 int s_fmask; 394 }; 395 396 enum { 397 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, 398 }; 399 400 static const struct fs_parameter_spec omfs_param_spec[] = { 401 fsparam_uid ("uid", Opt_uid), 402 fsparam_gid ("gid", Opt_gid), 403 fsparam_u32oct ("umask", Opt_umask), 404 fsparam_u32oct ("dmask", Opt_dmask), 405 fsparam_u32oct ("fmask", Opt_fmask), 406 {} 407 }; 408 409 static int 410 omfs_parse_param(struct fs_context *fc, struct fs_parameter *param) 411 { 412 struct omfs_mount_options *opts = fc->fs_private; 413 int token; 414 struct fs_parse_result result; 415 416 /* All options are ignored on remount */ 417 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) 418 return 0; 419 420 token = fs_parse(fc, omfs_param_spec, param, &result); 421 if (token < 0) 422 return token; 423 424 switch (token) { 425 case Opt_uid: 426 opts->s_uid = result.uid; 427 break; 428 case Opt_gid: 429 opts->s_gid = result.gid; 430 break; 431 case Opt_umask: 432 opts->s_fmask = opts->s_dmask = result.uint_32; 433 break; 434 case Opt_dmask: 435 opts->s_dmask = result.uint_32; 436 break; 437 case Opt_fmask: 438 opts->s_fmask = result.uint_32; 439 break; 440 default: 441 return -EINVAL; 442 } 443 444 return 0; 445 } 446 447 static void 448 omfs_set_options(struct omfs_sb_info *sbi, struct omfs_mount_options *opts) 449 { 450 sbi->s_uid = opts->s_uid; 451 sbi->s_gid = opts->s_gid; 452 sbi->s_dmask = opts->s_dmask; 453 sbi->s_fmask = opts->s_fmask; 454 } 455 456 static int omfs_fill_super(struct super_block *sb, struct fs_context *fc) 457 { 458 struct buffer_head *bh, *bh2; 459 struct omfs_super_block *omfs_sb; 460 struct omfs_root_block *omfs_rb; 461 struct omfs_sb_info *sbi; 462 struct inode *root; 463 struct omfs_mount_options *parsed_opts = fc->fs_private; 464 int ret = -EINVAL; 465 int silent = fc->sb_flags & SB_SILENT; 466 467 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL); 468 if (!sbi) 469 return -ENOMEM; 470 471 sb->s_fs_info = sbi; 472 473 omfs_set_options(sbi, parsed_opts); 474 475 sb->s_maxbytes = 0xffffffff; 476 477 sb->s_time_gran = NSEC_PER_MSEC; 478 sb->s_time_min = 0; 479 sb->s_time_max = U64_MAX / MSEC_PER_SEC; 480 481 sb_set_blocksize(sb, 0x200); 482 483 bh = sb_bread(sb, 0); 484 if (!bh) 485 goto end; 486 487 omfs_sb = (struct omfs_super_block *)bh->b_data; 488 489 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) { 490 if (!silent) 491 printk(KERN_ERR "omfs: Invalid superblock (%x)\n", 492 omfs_sb->s_magic); 493 goto out_brelse_bh; 494 } 495 sb->s_magic = OMFS_MAGIC; 496 497 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks); 498 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize); 499 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors); 500 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block); 501 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize); 502 mutex_init(&sbi->s_bitmap_lock); 503 504 if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) { 505 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n", 506 (unsigned long long)sbi->s_num_blocks); 507 goto out_brelse_bh; 508 } 509 510 if (sbi->s_sys_blocksize > PAGE_SIZE) { 511 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n", 512 sbi->s_sys_blocksize); 513 goto out_brelse_bh; 514 } 515 516 if (sbi->s_blocksize < sbi->s_sys_blocksize || 517 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) { 518 printk(KERN_ERR "omfs: block size (%d) is out of range\n", 519 sbi->s_blocksize); 520 goto out_brelse_bh; 521 } 522 523 /* 524 * Use sys_blocksize as the fs block since it is smaller than a 525 * page while the fs blocksize can be larger. 526 */ 527 sb_set_blocksize(sb, sbi->s_sys_blocksize); 528 529 /* 530 * ...and the difference goes into a shift. sys_blocksize is always 531 * a power of two factor of blocksize. 532 */ 533 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - 534 get_bitmask_order(sbi->s_sys_blocksize); 535 536 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); 537 if (!bh2) 538 goto out_brelse_bh; 539 540 omfs_rb = (struct omfs_root_block *)bh2->b_data; 541 542 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap); 543 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize); 544 545 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) { 546 printk(KERN_ERR "omfs: block count discrepancy between " 547 "super and root blocks (%llx, %llx)\n", 548 (unsigned long long)sbi->s_num_blocks, 549 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks)); 550 goto out_brelse_bh2; 551 } 552 553 if (sbi->s_bitmap_ino != ~0ULL && 554 sbi->s_bitmap_ino > sbi->s_num_blocks) { 555 printk(KERN_ERR "omfs: free space bitmap location is corrupt " 556 "(%llx, total blocks %llx)\n", 557 (unsigned long long) sbi->s_bitmap_ino, 558 (unsigned long long) sbi->s_num_blocks); 559 goto out_brelse_bh2; 560 } 561 if (sbi->s_clustersize < 1 || 562 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) { 563 printk(KERN_ERR "omfs: cluster size out of range (%d)", 564 sbi->s_clustersize); 565 goto out_brelse_bh2; 566 } 567 568 ret = omfs_get_imap(sb); 569 if (ret) 570 goto out_brelse_bh2; 571 572 sb->s_op = &omfs_sops; 573 574 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir)); 575 if (IS_ERR(root)) { 576 ret = PTR_ERR(root); 577 goto out_brelse_bh2; 578 } 579 580 sb->s_root = d_make_root(root); 581 if (!sb->s_root) { 582 ret = -ENOMEM; 583 goto out_brelse_bh2; 584 } 585 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name); 586 587 ret = 0; 588 out_brelse_bh2: 589 brelse(bh2); 590 out_brelse_bh: 591 brelse(bh); 592 end: 593 if (ret) 594 kfree(sbi); 595 return ret; 596 } 597 598 static int omfs_get_tree(struct fs_context *fc) 599 { 600 return get_tree_bdev(fc, omfs_fill_super); 601 } 602 603 static void omfs_free_fc(struct fs_context *fc); 604 605 static const struct fs_context_operations omfs_context_ops = { 606 .parse_param = omfs_parse_param, 607 .get_tree = omfs_get_tree, 608 .free = omfs_free_fc, 609 }; 610 611 static int omfs_init_fs_context(struct fs_context *fc) 612 { 613 struct omfs_mount_options *opts; 614 615 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 616 if (!opts) 617 return -ENOMEM; 618 619 /* Set mount options defaults */ 620 opts->s_uid = current_uid(); 621 opts->s_gid = current_gid(); 622 opts->s_dmask = opts->s_fmask = current_umask(); 623 624 fc->fs_private = opts; 625 fc->ops = &omfs_context_ops; 626 627 return 0; 628 } 629 630 static void omfs_free_fc(struct fs_context *fc) 631 { 632 kfree(fc->fs_private); 633 } 634 635 static struct file_system_type omfs_fs_type = { 636 .owner = THIS_MODULE, 637 .name = "omfs", 638 .kill_sb = kill_block_super, 639 .fs_flags = FS_REQUIRES_DEV, 640 .init_fs_context = omfs_init_fs_context, 641 .parameters = omfs_param_spec, 642 }; 643 MODULE_ALIAS_FS("omfs"); 644 645 static int __init init_omfs_fs(void) 646 { 647 return register_filesystem(&omfs_fs_type); 648 } 649 650 static void __exit exit_omfs_fs(void) 651 { 652 unregister_filesystem(&omfs_fs_type); 653 } 654 655 module_init(init_omfs_fs); 656 module_exit(exit_omfs_fs); 657