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