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