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, int 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_delete_inode(struct inode *inode) 185 { 186 truncate_inode_pages(&inode->i_data, 0); 187 188 if (S_ISREG(inode->i_mode)) { 189 inode->i_size = 0; 190 omfs_shrink_inode(inode); 191 } 192 193 omfs_clear_range(inode->i_sb, inode->i_ino, 2); 194 clear_inode(inode); 195 } 196 197 struct inode *omfs_iget(struct super_block *sb, ino_t ino) 198 { 199 struct omfs_sb_info *sbi = OMFS_SB(sb); 200 struct omfs_inode *oi; 201 struct buffer_head *bh; 202 u64 ctime; 203 unsigned long nsecs; 204 struct inode *inode; 205 206 inode = iget_locked(sb, ino); 207 if (!inode) 208 return ERR_PTR(-ENOMEM); 209 if (!(inode->i_state & I_NEW)) 210 return inode; 211 212 bh = omfs_bread(inode->i_sb, ino); 213 if (!bh) 214 goto iget_failed; 215 216 oi = (struct omfs_inode *)bh->b_data; 217 218 /* check self */ 219 if (ino != be64_to_cpu(oi->i_head.h_self)) 220 goto fail_bh; 221 222 inode->i_uid = sbi->s_uid; 223 inode->i_gid = sbi->s_gid; 224 225 ctime = be64_to_cpu(oi->i_ctime); 226 nsecs = do_div(ctime, 1000) * 1000L; 227 228 inode->i_atime.tv_sec = ctime; 229 inode->i_mtime.tv_sec = ctime; 230 inode->i_ctime.tv_sec = ctime; 231 inode->i_atime.tv_nsec = nsecs; 232 inode->i_mtime.tv_nsec = nsecs; 233 inode->i_ctime.tv_nsec = nsecs; 234 235 inode->i_mapping->a_ops = &omfs_aops; 236 237 switch (oi->i_type) { 238 case OMFS_DIR: 239 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask); 240 inode->i_op = &omfs_dir_inops; 241 inode->i_fop = &omfs_dir_operations; 242 inode->i_size = sbi->s_sys_blocksize; 243 inc_nlink(inode); 244 break; 245 case OMFS_FILE: 246 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask); 247 inode->i_fop = &omfs_file_operations; 248 inode->i_size = be64_to_cpu(oi->i_size); 249 break; 250 } 251 brelse(bh); 252 unlock_new_inode(inode); 253 return inode; 254 fail_bh: 255 brelse(bh); 256 iget_failed: 257 iget_failed(inode); 258 return ERR_PTR(-EIO); 259 } 260 261 static void omfs_put_super(struct super_block *sb) 262 { 263 struct omfs_sb_info *sbi = OMFS_SB(sb); 264 kfree(sbi->s_imap); 265 kfree(sbi); 266 sb->s_fs_info = NULL; 267 } 268 269 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf) 270 { 271 struct super_block *s = dentry->d_sb; 272 struct omfs_sb_info *sbi = OMFS_SB(s); 273 u64 id = huge_encode_dev(s->s_bdev->bd_dev); 274 275 buf->f_type = OMFS_MAGIC; 276 buf->f_bsize = sbi->s_blocksize; 277 buf->f_blocks = sbi->s_num_blocks; 278 buf->f_files = sbi->s_num_blocks; 279 buf->f_namelen = OMFS_NAMELEN; 280 buf->f_fsid.val[0] = (u32)id; 281 buf->f_fsid.val[1] = (u32)(id >> 32); 282 283 buf->f_bfree = buf->f_bavail = buf->f_ffree = 284 omfs_count_free(s); 285 286 return 0; 287 } 288 289 static const struct super_operations omfs_sops = { 290 .write_inode = omfs_write_inode, 291 .delete_inode = omfs_delete_inode, 292 .put_super = omfs_put_super, 293 .statfs = omfs_statfs, 294 .show_options = generic_show_options, 295 }; 296 297 /* 298 * For Rio Karma, there is an on-disk free bitmap whose location is 299 * stored in the root block. For ReplayTV, there is no such free bitmap 300 * so we have to walk the tree. Both inodes and file data are allocated 301 * from the same map. This array can be big (300k) so we allocate 302 * in units of the blocksize. 303 */ 304 static int omfs_get_imap(struct super_block *sb) 305 { 306 int bitmap_size; 307 int array_size; 308 int count; 309 struct omfs_sb_info *sbi = OMFS_SB(sb); 310 struct buffer_head *bh; 311 unsigned long **ptr; 312 sector_t block; 313 314 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8); 315 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize); 316 317 if (sbi->s_bitmap_ino == ~0ULL) 318 goto out; 319 320 sbi->s_imap_size = array_size; 321 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL); 322 if (!sbi->s_imap) 323 goto nomem; 324 325 block = clus_to_blk(sbi, sbi->s_bitmap_ino); 326 if (block >= sbi->s_num_blocks) 327 goto nomem; 328 329 ptr = sbi->s_imap; 330 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) { 331 bh = sb_bread(sb, block++); 332 if (!bh) 333 goto nomem_free; 334 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL); 335 if (!*ptr) { 336 brelse(bh); 337 goto nomem_free; 338 } 339 memcpy(*ptr, bh->b_data, sb->s_blocksize); 340 if (count < sb->s_blocksize) 341 memset((void *)*ptr + count, 0xff, 342 sb->s_blocksize - count); 343 brelse(bh); 344 ptr++; 345 } 346 out: 347 return 0; 348 349 nomem_free: 350 for (count = 0; count < array_size; count++) 351 kfree(sbi->s_imap[count]); 352 353 kfree(sbi->s_imap); 354 nomem: 355 sbi->s_imap = NULL; 356 sbi->s_imap_size = 0; 357 return -ENOMEM; 358 } 359 360 enum { 361 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask 362 }; 363 364 static const match_table_t tokens = { 365 {Opt_uid, "uid=%u"}, 366 {Opt_gid, "gid=%u"}, 367 {Opt_umask, "umask=%o"}, 368 {Opt_dmask, "dmask=%o"}, 369 {Opt_fmask, "fmask=%o"}, 370 }; 371 372 static int parse_options(char *options, struct omfs_sb_info *sbi) 373 { 374 char *p; 375 substring_t args[MAX_OPT_ARGS]; 376 int option; 377 378 if (!options) 379 return 1; 380 381 while ((p = strsep(&options, ",")) != NULL) { 382 int token; 383 if (!*p) 384 continue; 385 386 token = match_token(p, tokens, args); 387 switch (token) { 388 case Opt_uid: 389 if (match_int(&args[0], &option)) 390 return 0; 391 sbi->s_uid = option; 392 break; 393 case Opt_gid: 394 if (match_int(&args[0], &option)) 395 return 0; 396 sbi->s_gid = option; 397 break; 398 case Opt_umask: 399 if (match_octal(&args[0], &option)) 400 return 0; 401 sbi->s_fmask = sbi->s_dmask = option; 402 break; 403 case Opt_dmask: 404 if (match_octal(&args[0], &option)) 405 return 0; 406 sbi->s_dmask = option; 407 break; 408 case Opt_fmask: 409 if (match_octal(&args[0], &option)) 410 return 0; 411 sbi->s_fmask = option; 412 break; 413 default: 414 return 0; 415 } 416 } 417 return 1; 418 } 419 420 static int omfs_fill_super(struct super_block *sb, void *data, int silent) 421 { 422 struct buffer_head *bh, *bh2; 423 struct omfs_super_block *omfs_sb; 424 struct omfs_root_block *omfs_rb; 425 struct omfs_sb_info *sbi; 426 struct inode *root; 427 int ret = -EINVAL; 428 429 save_mount_options(sb, (char *) data); 430 431 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL); 432 if (!sbi) 433 return -ENOMEM; 434 435 sb->s_fs_info = sbi; 436 437 sbi->s_uid = current_uid(); 438 sbi->s_gid = current_gid(); 439 sbi->s_dmask = sbi->s_fmask = current_umask(); 440 441 if (!parse_options((char *) data, sbi)) 442 goto end; 443 444 sb->s_maxbytes = 0xffffffff; 445 446 sb_set_blocksize(sb, 0x200); 447 448 bh = sb_bread(sb, 0); 449 if (!bh) 450 goto end; 451 452 omfs_sb = (struct omfs_super_block *)bh->b_data; 453 454 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) { 455 if (!silent) 456 printk(KERN_ERR "omfs: Invalid superblock (%x)\n", 457 omfs_sb->s_magic); 458 goto out_brelse_bh; 459 } 460 sb->s_magic = OMFS_MAGIC; 461 462 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks); 463 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize); 464 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors); 465 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block); 466 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize); 467 mutex_init(&sbi->s_bitmap_lock); 468 469 if (sbi->s_sys_blocksize > PAGE_SIZE) { 470 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n", 471 sbi->s_sys_blocksize); 472 goto out_brelse_bh; 473 } 474 475 if (sbi->s_blocksize < sbi->s_sys_blocksize || 476 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) { 477 printk(KERN_ERR "omfs: block size (%d) is out of range\n", 478 sbi->s_blocksize); 479 goto out_brelse_bh; 480 } 481 482 /* 483 * Use sys_blocksize as the fs block since it is smaller than a 484 * page while the fs blocksize can be larger. 485 */ 486 sb_set_blocksize(sb, sbi->s_sys_blocksize); 487 488 /* 489 * ...and the difference goes into a shift. sys_blocksize is always 490 * a power of two factor of blocksize. 491 */ 492 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) - 493 get_bitmask_order(sbi->s_sys_blocksize); 494 495 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block)); 496 if (!bh2) 497 goto out_brelse_bh; 498 499 omfs_rb = (struct omfs_root_block *)bh2->b_data; 500 501 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap); 502 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize); 503 504 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) { 505 printk(KERN_ERR "omfs: block count discrepancy between " 506 "super and root blocks (%llx, %llx)\n", 507 (unsigned long long)sbi->s_num_blocks, 508 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks)); 509 goto out_brelse_bh2; 510 } 511 512 if (sbi->s_bitmap_ino != ~0ULL && 513 sbi->s_bitmap_ino > sbi->s_num_blocks) { 514 printk(KERN_ERR "omfs: free space bitmap location is corrupt " 515 "(%llx, total blocks %llx)\n", 516 (unsigned long long) sbi->s_bitmap_ino, 517 (unsigned long long) sbi->s_num_blocks); 518 goto out_brelse_bh2; 519 } 520 if (sbi->s_clustersize < 1 || 521 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) { 522 printk(KERN_ERR "omfs: cluster size out of range (%d)", 523 sbi->s_clustersize); 524 goto out_brelse_bh2; 525 } 526 527 ret = omfs_get_imap(sb); 528 if (ret) 529 goto out_brelse_bh2; 530 531 sb->s_op = &omfs_sops; 532 533 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir)); 534 if (IS_ERR(root)) { 535 ret = PTR_ERR(root); 536 goto out_brelse_bh2; 537 } 538 539 sb->s_root = d_alloc_root(root); 540 if (!sb->s_root) { 541 iput(root); 542 goto out_brelse_bh2; 543 } 544 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name); 545 546 ret = 0; 547 out_brelse_bh2: 548 brelse(bh2); 549 out_brelse_bh: 550 brelse(bh); 551 end: 552 if (ret) 553 kfree(sbi); 554 return ret; 555 } 556 557 static int omfs_get_sb(struct file_system_type *fs_type, 558 int flags, const char *dev_name, 559 void *data, struct vfsmount *m) 560 { 561 return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m); 562 } 563 564 static struct file_system_type omfs_fs_type = { 565 .owner = THIS_MODULE, 566 .name = "omfs", 567 .get_sb = omfs_get_sb, 568 .kill_sb = kill_block_super, 569 .fs_flags = FS_REQUIRES_DEV, 570 }; 571 572 static int __init init_omfs_fs(void) 573 { 574 return register_filesystem(&omfs_fs_type); 575 } 576 577 static void __exit exit_omfs_fs(void) 578 { 579 unregister_filesystem(&omfs_fs_type); 580 } 581 582 module_init(init_omfs_fs); 583 module_exit(exit_omfs_fs); 584