inode.c 13 KB

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