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 20MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>"); 21MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux"); 22MODULE_LICENSE("GPL"); 23 24struct 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 33struct 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 simple_inode_init_ts(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; 72fail: 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 */ 83static 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 102static 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_get_ctime_sec(inode) * 1000LL + 138 ((inode_get_ctime_nsec(inode) + 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; 166out_brelse: 167 brelse(bh); 168out: 169 return ret; 170} 171 172static 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 177int 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 */ 186static 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 202struct 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_set_atime(inode, ctime, nsecs); 234 inode_set_mtime(inode, ctime, nsecs); 235 inode_set_ctime(inode, ctime, nsecs); 236 237 inode->i_mapping->a_ops = &omfs_aops; 238 239 switch (oi->i_type) { 240 case OMFS_DIR: 241 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask); 242 inode->i_op = &omfs_dir_inops; 243 inode->i_fop = &omfs_dir_operations; 244 inode->i_size = sbi->s_sys_blocksize; 245 inc_nlink(inode); 246 break; 247 case OMFS_FILE: 248 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask); 249 inode->i_fop = &omfs_file_operations; 250 inode->i_size = be64_to_cpu(oi->i_size); 251 break; 252 } 253 brelse(bh); 254 unlock_new_inode(inode); 255 return inode; 256fail_bh: 257 brelse(bh); 258iget_failed: 259 iget_failed(inode); 260 return ERR_PTR(-EIO); 261} 262 263static void omfs_put_super(struct super_block *sb) 264{ 265 struct omfs_sb_info *sbi = OMFS_SB(sb); 266 kfree(sbi->s_imap); 267 kfree(sbi); 268 sb->s_fs_info = NULL; 269} 270 271static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf) 272{ 273 struct super_block *s = dentry->d_sb; 274 struct omfs_sb_info *sbi = OMFS_SB(s); 275 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 276 277 buf->f_type = OMFS_MAGIC; 278 buf->f_bsize = sbi->s_blocksize; 279 buf->f_blocks = sbi->s_num_blocks; 280 buf->f_files = sbi->s_num_blocks; 281 buf->f_namelen = OMFS_NAMELEN; 282 buf->f_fsid = u64_to_fsid(id); 283 284 buf->f_bfree = buf->f_bavail = buf->f_ffree = 285 omfs_count_free(s); 286 287 return 0; 288} 289 290/* 291 * Display the mount options in /proc/mounts. 292 */ 293static int omfs_show_options(struct seq_file *m, struct dentry *root) 294{ 295 struct omfs_sb_info *sbi = OMFS_SB(root->d_sb); 296 umode_t cur_umask = current_umask(); 297 298 if (!uid_eq(sbi->s_uid, current_uid())) 299 seq_printf(m, ",uid=%u", 300 from_kuid_munged(&init_user_ns, sbi->s_uid)); 301 if (!gid_eq(sbi->s_gid, current_gid())) 302 seq_printf(m, ",gid=%u", 303 from_kgid_munged(&init_user_ns, sbi->s_gid)); 304 305 if (sbi->s_dmask == sbi->s_fmask) { 306 if (sbi->s_fmask != cur_umask) 307 seq_printf(m, ",umask=%o", sbi->s_fmask); 308 } else { 309 if (sbi->s_dmask != cur_umask) 310 seq_printf(m, ",dmask=%o", sbi->s_dmask); 311 if (sbi->s_fmask != cur_umask) 312 seq_printf(m, ",fmask=%o", sbi->s_fmask); 313 } 314 315 return 0; 316} 317 318static const struct super_operations omfs_sops = { 319 .write_inode = omfs_write_inode, 320 .evict_inode = omfs_evict_inode, 321 .put_super = omfs_put_super, 322 .statfs = omfs_statfs, 323 .show_options = omfs_show_options, 324}; 325 326/* 327 * For Rio Karma, there is an on-disk free bitmap whose location is 328 * stored in the root block. For ReplayTV, there is no such free bitmap 329 * so we have to walk the tree. Both inodes and file data are allocated 330 * from the same map. This array can be big (300k) so we allocate 331 * in units of the blocksize. 332 */ 333static int omfs_get_imap(struct super_block *sb) 334{ 335 unsigned int bitmap_size, array_size; 336 int count; 337 struct omfs_sb_info *sbi = OMFS_SB(sb); 338 struct buffer_head *bh; 339 unsigned long **ptr; 340 sector_t block; 341 342 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8); 343 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize); 344 345 if (sbi->s_bitmap_ino == ~0ULL) 346 goto out; 347 348 sbi->s_imap_size = array_size; 349 sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL); 350 if (!sbi->s_imap) 351 goto nomem; 352 353 block = clus_to_blk(sbi, sbi->s_bitmap_ino); 354 if (block >= sbi->s_num_blocks) 355 goto nomem; 356 357 ptr = sbi->s_imap; 358 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { 359 bh = sb_bread(sb, block++); 360 if (!bh) 361 goto nomem_free; 362 *ptr = kmemdup(bh->b_data, sb->s_blocksize, GFP_KERNEL); 363 if (!*ptr) { 364 brelse(bh); 365 goto nomem_free; 366 } 367 if (count < sb->s_blocksize) 368 memset((void *)*ptr + count, 0xff, 369 sb->s_blocksize - count); 370 brelse(bh); 371 ptr++; 372 } 373out: 374 return 0; 375 376nomem_free: 377 for (count = 0; count < array_size; count++) 378 kfree(sbi->s_imap[count]); 379 380 kfree(sbi->s_imap); 381nomem: 382 sbi->s_imap = NULL; 383 sbi->s_imap_size = 0; 384 return -ENOMEM; 385} 386 387enum { 388 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err 389}; 390 391static const match_table_t tokens = { 392 {Opt_uid, "uid=%u"}, 393 {Opt_gid, "gid=%u"}, 394 {Opt_umask, "umask=%o"}, 395 {Opt_dmask, "dmask=%o"}, 396 {Opt_fmask, "fmask=%o"}, 397 {Opt_err, NULL}, 398}; 399 400static int parse_options(char *options, struct omfs_sb_info *sbi) 401{ 402 char *p; 403 substring_t args[MAX_OPT_ARGS]; 404 int option; 405 406 if (!options) 407 return 1; 408 409 while ((p = strsep(&options, ",")) != NULL) { 410 int token; 411 if (!*p) 412 continue; 413 414 token = match_token(p, tokens, args); 415 switch (token) { 416 case Opt_uid: 417 if (match_int(&args[0], &option)) 418 return 0; 419 sbi->s_uid = make_kuid(current_user_ns(), option); 420 if (!uid_valid(sbi->s_uid)) 421 return 0; 422 break; 423 case Opt_gid: 424 if (match_int(&args[0], &option)) 425 return 0; 426 sbi->s_gid = make_kgid(current_user_ns(), option); 427 if (!gid_valid(sbi->s_gid)) 428 return 0; 429 break; 430 case Opt_umask: 431 if (match_octal(&args[0], &option)) 432 return 0; 433 sbi->s_fmask = sbi->s_dmask = option; 434 break; 435 case Opt_dmask: 436 if (match_octal(&args[0], &option)) 437 return 0; 438 sbi->s_dmask = option; 439 break; 440 case Opt_fmask: 441 if (match_octal(&args[0], &option)) 442 return 0; 443 sbi->s_fmask = option; 444 break; 445 default: 446 return 0; 447 } 448 } 449 return 1; 450} 451 452static int omfs_fill_super(struct super_block *sb, void *data, int silent) 453{ 454 struct buffer_head *bh, *bh2; 455 struct omfs_super_block *omfs_sb; 456 struct omfs_root_block *omfs_rb; 457 struct omfs_sb_info *sbi; 458 struct inode *root; 459 int ret = -EINVAL; 460 461 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL); 462 if (!sbi) 463 return -ENOMEM; 464 465 sb->s_fs_info = sbi; 466 467 sbi->s_uid = current_uid(); 468 sbi->s_gid = current_gid(); 469 sbi->s_dmask = sbi->s_fmask = current_umask(); 470 471 if (!parse_options((char *) data, sbi)) 472 goto end; 473 474 sb->s_maxbytes = 0xffffffff; 475 476 sb->s_time_gran = NSEC_PER_MSEC; 477 sb->s_time_min = 0; 478 sb->s_time_max = U64_MAX / MSEC_PER_SEC; 479 480 sb_set_blocksize(sb, 0x200); 481 482 bh = sb_bread(sb, 0); 483 if (!bh) 484 goto end; 485 486 omfs_sb = (struct omfs_super_block *)bh->b_data; 487 488 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) { 489 if (!silent) 490 printk(KERN_ERR "omfs: Invalid superblock (%x)\n", 491 omfs_sb->s_magic); 492 goto out_brelse_bh; 493 } 494 sb->s_magic = OMFS_MAGIC; 495 496 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks); 497 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize); 498 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors); 499 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block); 500 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize); 501 mutex_init(&sbi->s_bitmap_lock); 502 503 if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) { 504 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n", 505 (unsigned long long)sbi->s_num_blocks); 506 goto out_brelse_bh; 507 } 508 509 if (sbi->s_sys_blocksize > PAGE_SIZE) { 510 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n", 511 sbi->s_sys_blocksize); 512 goto out_brelse_bh; 513 } 514 515 if (sbi->s_blocksize < sbi->s_sys_blocksize || 516 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) { 517 printk(KERN_ERR "omfs: block size (%d) is out of range\n", 518 sbi->s_blocksize); 519 goto out_brelse_bh; 520 } 521 522 /* 523 * Use sys_blocksize as the fs block since it is smaller than a 524 * page while the fs blocksize can be larger. 525 */ 526 sb_set_blocksize(sb, sbi->s_sys_blocksize); 527 528 /* 529 * ...and the difference goes into a shift. sys_blocksize is always 530 * a power of two factor of blocksize. 531 */ 532 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - 533 get_bitmask_order(sbi->s_sys_blocksize); 534 535 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); 536 if (!bh2) 537 goto out_brelse_bh; 538 539 omfs_rb = (struct omfs_root_block *)bh2->b_data; 540 541 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap); 542 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize); 543 544 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) { 545 printk(KERN_ERR "omfs: block count discrepancy between " 546 "super and root blocks (%llx, %llx)\n", 547 (unsigned long long)sbi->s_num_blocks, 548 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks)); 549 goto out_brelse_bh2; 550 } 551 552 if (sbi->s_bitmap_ino != ~0ULL && 553 sbi->s_bitmap_ino > sbi->s_num_blocks) { 554 printk(KERN_ERR "omfs: free space bitmap location is corrupt " 555 "(%llx, total blocks %llx)\n", 556 (unsigned long long) sbi->s_bitmap_ino, 557 (unsigned long long) sbi->s_num_blocks); 558 goto out_brelse_bh2; 559 } 560 if (sbi->s_clustersize < 1 || 561 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) { 562 printk(KERN_ERR "omfs: cluster size out of range (%d)", 563 sbi->s_clustersize); 564 goto out_brelse_bh2; 565 } 566 567 ret = omfs_get_imap(sb); 568 if (ret) 569 goto out_brelse_bh2; 570 571 sb->s_op = &omfs_sops; 572 573 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir)); 574 if (IS_ERR(root)) { 575 ret = PTR_ERR(root); 576 goto out_brelse_bh2; 577 } 578 579 sb->s_root = d_make_root(root); 580 if (!sb->s_root) { 581 ret = -ENOMEM; 582 goto out_brelse_bh2; 583 } 584 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name); 585 586 ret = 0; 587out_brelse_bh2: 588 brelse(bh2); 589out_brelse_bh: 590 brelse(bh); 591end: 592 if (ret) 593 kfree(sbi); 594 return ret; 595} 596 597static struct dentry *omfs_mount(struct file_system_type *fs_type, 598 int flags, const char *dev_name, void *data) 599{ 600 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super); 601} 602 603static struct file_system_type omfs_fs_type = { 604 .owner = THIS_MODULE, 605 .name = "omfs", 606 .mount = omfs_mount, 607 .kill_sb = kill_block_super, 608 .fs_flags = FS_REQUIRES_DEV, 609}; 610MODULE_ALIAS_FS("omfs"); 611 612static int __init init_omfs_fs(void) 613{ 614 return register_filesystem(&omfs_fs_type); 615} 616 617static void __exit exit_omfs_fs(void) 618{ 619 unregister_filesystem(&omfs_fs_type); 620} 621 622module_init(init_omfs_fs); 623module_exit(exit_omfs_fs); 624