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