1 /* 2 * Optimized MPEG FS - inode and super operations. 3 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com> 4 * Released under GPL v2. 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/parser.h> 12 #include <linux/buffer_head.h> 13 #include <linux/vmalloc.h> 14 #include <linux/writeback.h> 15 #include <linux/crc-itu-t.h> 16 #include "omfs.h" 17 18 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>"); 19 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux"); 20 MODULE_LICENSE("GPL"); 21 22 struct buffer_head *omfs_bread(struct super_block *sb, sector_t block) 23 { 24 struct omfs_sb_info *sbi = OMFS_SB(sb); 25 if (block >= sbi->s_num_blocks) 26 return NULL; 27 28 return sb_bread(sb, clus_to_blk(sbi, block)); 29 } 30 31 struct inode *omfs_new_inode(struct inode *dir, umode_t mode) 32 { 33 struct inode *inode; 34 u64 new_block; 35 int err; 36 int len; 37 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb); 38 39 inode = new_inode(dir->i_sb); 40 if (!inode) 41 return ERR_PTR(-ENOMEM); 42 43 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors, 44 &new_block, &len); 45 if (err) 46 goto fail; 47 48 inode->i_ino = new_block; 49 inode_init_owner(inode, NULL, mode); 50 inode->i_mapping->a_ops = &omfs_aops; 51 52 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 53 switch (mode & S_IFMT) { 54 case S_IFDIR: 55 inode->i_op = &omfs_dir_inops; 56 inode->i_fop = &omfs_dir_operations; 57 inode->i_size = sbi->s_sys_blocksize; 58 inc_nlink(inode); 59 break; 60 case S_IFREG: 61 inode->i_op = &omfs_file_inops; 62 inode->i_fop = &omfs_file_operations; 63 inode->i_size = 0; 64 break; 65 } 66 67 insert_inode_hash(inode); 68 mark_inode_dirty(inode); 69 return inode; 70 fail: 71 make_bad_inode(inode); 72 iput(inode); 73 return ERR_PTR(err); 74 } 75 76 /* 77 * Update the header checksums for a dirty inode based on its contents. 78 * Caller is expected to hold the buffer head underlying oi and mark it 79 * dirty. 80 */ 81 static void omfs_update_checksums(struct omfs_inode *oi) 82 { 83 int xor, i, ofs = 0, count; 84 u16 crc = 0; 85 unsigned char *ptr = (unsigned char *) oi; 86 87 count = be32_to_cpu(oi->i_head.h_body_size); 88 ofs = sizeof(struct omfs_header); 89 90 crc = crc_itu_t(crc, ptr + ofs, count); 91 oi->i_head.h_crc = cpu_to_be16(crc); 92 93 xor = ptr[0]; 94 for (i = 1; i < OMFS_XOR_COUNT; i++) 95 xor ^= ptr[i]; 96 97 oi->i_head.h_check_xor = xor; 98 } 99 100 static int __omfs_write_inode(struct inode *inode, int wait) 101 { 102 struct omfs_inode *oi; 103 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb); 104 struct buffer_head *bh, *bh2; 105 u64 ctime; 106 int i; 107 int ret = -EIO; 108 int sync_failed = 0; 109 110 /* get current inode since we may have written sibling ptrs etc. */ 111 bh = omfs_bread(inode->i_sb, inode->i_ino); 112 if (!bh) 113 goto out; 114 115 oi = (struct omfs_inode *) bh->b_data; 116 117 oi->i_head.h_self = cpu_to_be64(inode->i_ino); 118 if (S_ISDIR(inode->i_mode)) 119 oi->i_type = OMFS_DIR; 120 else if (S_ISREG(inode->i_mode)) 121 oi->i_type = OMFS_FILE; 122 else { 123 printk(KERN_WARNING "omfs: unknown file type: %d\n", 124 inode->i_mode); 125 goto out_brelse; 126 } 127 128 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize - 129 sizeof(struct omfs_header)); 130 oi->i_head.h_version = 1; 131 oi->i_head.h_type = OMFS_INODE_NORMAL; 132 oi->i_head.h_magic = OMFS_IMAGIC; 133 oi->i_size = cpu_to_be64(inode->i_size); 134 135 ctime = inode->i_ctime.tv_sec * 1000LL + 136 ((inode->i_ctime.tv_nsec + 999)/1000); 137 oi->i_ctime = cpu_to_be64(ctime); 138 139 omfs_update_checksums(oi); 140 141 mark_buffer_dirty(bh); 142 if (wait) { 143 sync_dirty_buffer(bh); 144 if (buffer_req(bh) && !buffer_uptodate(bh)) 145 sync_failed = 1; 146 } 147 148 /* if mirroring writes, copy to next fsblock */ 149 for (i = 1; i < sbi->s_mirrors; i++) { 150 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i); 151 if (!bh2) 152 goto out_brelse; 153 154 memcpy(bh2->b_data, bh->b_data, bh->b_size); 155 mark_buffer_dirty(bh2); 156 if (wait) { 157 sync_dirty_buffer(bh2); 158 if (buffer_req(bh2) && !buffer_uptodate(bh2)) 159 sync_failed = 1; 160 } 161 brelse(bh2); 162 } 163 ret = (sync_failed) ? -EIO : 0; 164 out_brelse: 165 brelse(bh); 166 out: 167 return ret; 168 } 169 170 static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc) 171 { 172 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); 173 } 174 175 int omfs_sync_inode(struct inode *inode) 176 { 177 return __omfs_write_inode(inode, 1); 178 } 179 180 /* 181 * called when an entry is deleted, need to clear the bits in the 182 * bitmaps. 183 */ 184 static void omfs_evict_inode(struct inode *inode) 185 { 186 truncate_inode_pages(&inode->i_data, 0); 187 clear_inode(inode); 188 189 if (inode->i_nlink) 190 return; 191 192 if (S_ISREG(inode->i_mode)) { 193 inode->i_size = 0; 194 omfs_shrink_inode(inode); 195 } 196 197 omfs_clear_range(inode->i_sb, inode->i_ino, 2); 198 } 199 200 struct inode *omfs_iget(struct super_block *sb, ino_t ino) 201 { 202 struct omfs_sb_info *sbi = OMFS_SB(sb); 203 struct omfs_inode *oi; 204 struct buffer_head *bh; 205 u64 ctime; 206 unsigned long nsecs; 207 struct inode *inode; 208 209 inode = iget_locked(sb, ino); 210 if (!inode) 211 return ERR_PTR(-ENOMEM); 212 if (!(inode->i_state & I_NEW)) 213 return inode; 214 215 bh = omfs_bread(inode->i_sb, ino); 216 if (!bh) 217 goto iget_failed; 218 219 oi = (struct omfs_inode *)bh->b_data; 220 221 /* check self */ 222 if (ino != be64_to_cpu(oi->i_head.h_self)) 223 goto fail_bh; 224 225 inode->i_uid = sbi->s_uid; 226 inode->i_gid = sbi->s_gid; 227 228 ctime = be64_to_cpu(oi->i_ctime); 229 nsecs = do_div(ctime, 1000) * 1000L; 230 231 inode->i_atime.tv_sec = ctime; 232 inode->i_mtime.tv_sec = ctime; 233 inode->i_ctime.tv_sec = ctime; 234 inode->i_atime.tv_nsec = nsecs; 235 inode->i_mtime.tv_nsec = nsecs; 236 inode->i_ctime.tv_nsec = nsecs; 237 238 inode->i_mapping->a_ops = &omfs_aops; 239 240 switch (oi->i_type) { 241 case OMFS_DIR: 242 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask); 243 inode->i_op = &omfs_dir_inops; 244 inode->i_fop = &omfs_dir_operations; 245 inode->i_size = sbi->s_sys_blocksize; 246 inc_nlink(inode); 247 break; 248 case OMFS_FILE: 249 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask); 250 inode->i_fop = &omfs_file_operations; 251 inode->i_size = be64_to_cpu(oi->i_size); 252 break; 253 } 254 brelse(bh); 255 unlock_new_inode(inode); 256 return inode; 257 fail_bh: 258 brelse(bh); 259 iget_failed: 260 iget_failed(inode); 261 return ERR_PTR(-EIO); 262 } 263 264 static void omfs_put_super(struct super_block *sb) 265 { 266 struct omfs_sb_info *sbi = OMFS_SB(sb); 267 kfree(sbi->s_imap); 268 kfree(sbi); 269 sb->s_fs_info = NULL; 270 } 271 272 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf) 273 { 274 struct super_block *s = dentry->d_sb; 275 struct omfs_sb_info *sbi = OMFS_SB(s); 276 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 277 278 buf->f_type = OMFS_MAGIC; 279 buf->f_bsize = sbi->s_blocksize; 280 buf->f_blocks = sbi->s_num_blocks; 281 buf->f_files = sbi->s_num_blocks; 282 buf->f_namelen = OMFS_NAMELEN; 283 buf->f_fsid.val[0] = (u32)id; 284 buf->f_fsid.val[1] = (u32)(id >> 32); 285 286 buf->f_bfree = buf->f_bavail = buf->f_ffree = 287 omfs_count_free(s); 288 289 return 0; 290 } 291 292 static const struct super_operations omfs_sops = { 293 .write_inode = omfs_write_inode, 294 .evict_inode = omfs_evict_inode, 295 .put_super = omfs_put_super, 296 .statfs = omfs_statfs, 297 .show_options = generic_show_options, 298 }; 299 300 /* 301 * For Rio Karma, there is an on-disk free bitmap whose location is 302 * stored in the root block. For ReplayTV, there is no such free bitmap 303 * so we have to walk the tree. Both inodes and file data are allocated 304 * from the same map. This array can be big (300k) so we allocate 305 * in units of the blocksize. 306 */ 307 static int omfs_get_imap(struct super_block *sb) 308 { 309 int bitmap_size; 310 int array_size; 311 int count; 312 struct omfs_sb_info *sbi = OMFS_SB(sb); 313 struct buffer_head *bh; 314 unsigned long **ptr; 315 sector_t block; 316 317 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8); 318 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize); 319 320 if (sbi->s_bitmap_ino == ~0ULL) 321 goto out; 322 323 sbi->s_imap_size = array_size; 324 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL); 325 if (!sbi->s_imap) 326 goto nomem; 327 328 block = clus_to_blk(sbi, sbi->s_bitmap_ino); 329 if (block >= sbi->s_num_blocks) 330 goto nomem; 331 332 ptr = sbi->s_imap; 333 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { 334 bh = sb_bread(sb, block++); 335 if (!bh) 336 goto nomem_free; 337 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL); 338 if (!*ptr) { 339 brelse(bh); 340 goto nomem_free; 341 } 342 memcpy(*ptr, bh->b_data, sb->s_blocksize); 343 if (count < sb->s_blocksize) 344 memset((void *)*ptr + count, 0xff, 345 sb->s_blocksize - count); 346 brelse(bh); 347 ptr++; 348 } 349 out: 350 return 0; 351 352 nomem_free: 353 for (count = 0; count < array_size; count++) 354 kfree(sbi->s_imap[count]); 355 356 kfree(sbi->s_imap); 357 nomem: 358 sbi->s_imap = NULL; 359 sbi->s_imap_size = 0; 360 return -ENOMEM; 361 } 362 363 enum { 364 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask 365 }; 366 367 static const match_table_t tokens = { 368 {Opt_uid, "uid=%u"}, 369 {Opt_gid, "gid=%u"}, 370 {Opt_umask, "umask=%o"}, 371 {Opt_dmask, "dmask=%o"}, 372 {Opt_fmask, "fmask=%o"}, 373 }; 374 375 static int parse_options(char *options, struct omfs_sb_info *sbi) 376 { 377 char *p; 378 substring_t args[MAX_OPT_ARGS]; 379 int option; 380 381 if (!options) 382 return 1; 383 384 while ((p = strsep(&options, ",")) != NULL) { 385 int token; 386 if (!*p) 387 continue; 388 389 token = match_token(p, tokens, args); 390 switch (token) { 391 case Opt_uid: 392 if (match_int(&args[0], &option)) 393 return 0; 394 sbi->s_uid = make_kuid(current_user_ns(), option); 395 if (!uid_valid(sbi->s_uid)) 396 return 0; 397 break; 398 case Opt_gid: 399 if (match_int(&args[0], &option)) 400 return 0; 401 sbi->s_gid = make_kgid(current_user_ns(), option); 402 if (!gid_valid(sbi->s_gid)) 403 return 0; 404 break; 405 case Opt_umask: 406 if (match_octal(&args[0], &option)) 407 return 0; 408 sbi->s_fmask = sbi->s_dmask = option; 409 break; 410 case Opt_dmask: 411 if (match_octal(&args[0], &option)) 412 return 0; 413 sbi->s_dmask = option; 414 break; 415 case Opt_fmask: 416 if (match_octal(&args[0], &option)) 417 return 0; 418 sbi->s_fmask = option; 419 break; 420 default: 421 return 0; 422 } 423 } 424 return 1; 425 } 426 427 static int omfs_fill_super(struct super_block *sb, void *data, int silent) 428 { 429 struct buffer_head *bh, *bh2; 430 struct omfs_super_block *omfs_sb; 431 struct omfs_root_block *omfs_rb; 432 struct omfs_sb_info *sbi; 433 struct inode *root; 434 int ret = -EINVAL; 435 436 save_mount_options(sb, (char *) data); 437 438 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL); 439 if (!sbi) 440 return -ENOMEM; 441 442 sb->s_fs_info = sbi; 443 444 sbi->s_uid = current_uid(); 445 sbi->s_gid = current_gid(); 446 sbi->s_dmask = sbi->s_fmask = current_umask(); 447 448 if (!parse_options((char *) data, sbi)) 449 goto end; 450 451 sb->s_maxbytes = 0xffffffff; 452 453 sb_set_blocksize(sb, 0x200); 454 455 bh = sb_bread(sb, 0); 456 if (!bh) 457 goto end; 458 459 omfs_sb = (struct omfs_super_block *)bh->b_data; 460 461 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) { 462 if (!silent) 463 printk(KERN_ERR "omfs: Invalid superblock (%x)\n", 464 omfs_sb->s_magic); 465 goto out_brelse_bh; 466 } 467 sb->s_magic = OMFS_MAGIC; 468 469 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks); 470 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize); 471 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors); 472 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block); 473 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize); 474 mutex_init(&sbi->s_bitmap_lock); 475 476 if (sbi->s_sys_blocksize > PAGE_SIZE) { 477 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n", 478 sbi->s_sys_blocksize); 479 goto out_brelse_bh; 480 } 481 482 if (sbi->s_blocksize < sbi->s_sys_blocksize || 483 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) { 484 printk(KERN_ERR "omfs: block size (%d) is out of range\n", 485 sbi->s_blocksize); 486 goto out_brelse_bh; 487 } 488 489 /* 490 * Use sys_blocksize as the fs block since it is smaller than a 491 * page while the fs blocksize can be larger. 492 */ 493 sb_set_blocksize(sb, sbi->s_sys_blocksize); 494 495 /* 496 * ...and the difference goes into a shift. sys_blocksize is always 497 * a power of two factor of blocksize. 498 */ 499 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - 500 get_bitmask_order(sbi->s_sys_blocksize); 501 502 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); 503 if (!bh2) 504 goto out_brelse_bh; 505 506 omfs_rb = (struct omfs_root_block *)bh2->b_data; 507 508 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap); 509 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize); 510 511 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) { 512 printk(KERN_ERR "omfs: block count discrepancy between " 513 "super and root blocks (%llx, %llx)\n", 514 (unsigned long long)sbi->s_num_blocks, 515 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks)); 516 goto out_brelse_bh2; 517 } 518 519 if (sbi->s_bitmap_ino != ~0ULL && 520 sbi->s_bitmap_ino > sbi->s_num_blocks) { 521 printk(KERN_ERR "omfs: free space bitmap location is corrupt " 522 "(%llx, total blocks %llx)\n", 523 (unsigned long long) sbi->s_bitmap_ino, 524 (unsigned long long) sbi->s_num_blocks); 525 goto out_brelse_bh2; 526 } 527 if (sbi->s_clustersize < 1 || 528 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) { 529 printk(KERN_ERR "omfs: cluster size out of range (%d)", 530 sbi->s_clustersize); 531 goto out_brelse_bh2; 532 } 533 534 ret = omfs_get_imap(sb); 535 if (ret) 536 goto out_brelse_bh2; 537 538 sb->s_op = &omfs_sops; 539 540 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir)); 541 if (IS_ERR(root)) { 542 ret = PTR_ERR(root); 543 goto out_brelse_bh2; 544 } 545 546 sb->s_root = d_make_root(root); 547 if (!sb->s_root) 548 goto out_brelse_bh2; 549 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name); 550 551 ret = 0; 552 out_brelse_bh2: 553 brelse(bh2); 554 out_brelse_bh: 555 brelse(bh); 556 end: 557 if (ret) 558 kfree(sbi); 559 return ret; 560 } 561 562 static struct dentry *omfs_mount(struct file_system_type *fs_type, 563 int flags, const char *dev_name, void *data) 564 { 565 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super); 566 } 567 568 static struct file_system_type omfs_fs_type = { 569 .owner = THIS_MODULE, 570 .name = "omfs", 571 .mount = omfs_mount, 572 .kill_sb = kill_block_super, 573 .fs_flags = FS_REQUIRES_DEV, 574 }; 575 MODULE_ALIAS_FS("omfs"); 576 577 static int __init init_omfs_fs(void) 578 { 579 return register_filesystem(&omfs_fs_type); 580 } 581 582 static void __exit exit_omfs_fs(void) 583 { 584 unregister_filesystem(&omfs_fs_type); 585 } 586 587 module_init(init_omfs_fs); 588 module_exit(exit_omfs_fs); 589