super.c 12 KB

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  1. /*
  2. * linux/fs/hfs/super.c
  3. *
  4. * Copyright (C) 1995-1997 Paul H. Hargrove
  5. * (C) 2003 Ardis Technologies <roman@ardistech.com>
  6. * This file may be distributed under the terms of the GNU General Public License.
  7. *
  8. * This file contains hfs_read_super(), some of the super_ops and
  9. * init_module() and cleanup_module(). The remaining super_ops are in
  10. * inode.c since they deal with inodes.
  11. *
  12. * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
  13. */
  14. #include <linux/module.h>
  15. #include <linux/blkdev.h>
  16. #include <linux/mount.h>
  17. #include <linux/init.h>
  18. #include <linux/nls.h>
  19. #include <linux/parser.h>
  20. #include <linux/seq_file.h>
  21. #include <linux/vfs.h>
  22. #include "hfs_fs.h"
  23. #include "btree.h"
  24. static struct kmem_cache *hfs_inode_cachep;
  25. MODULE_LICENSE("GPL");
  26. /*
  27. * hfs_write_super()
  28. *
  29. * Description:
  30. * This function is called by the VFS only. When the filesystem
  31. * is mounted r/w it updates the MDB on disk.
  32. * Input Variable(s):
  33. * struct super_block *sb: Pointer to the hfs superblock
  34. * Output Variable(s):
  35. * NONE
  36. * Returns:
  37. * void
  38. * Preconditions:
  39. * 'sb' points to a "valid" (struct super_block).
  40. * Postconditions:
  41. * The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
  42. * (hfs_put_super() must set this flag!). Some MDB fields are updated
  43. * and the MDB buffer is written to disk by calling hfs_mdb_commit().
  44. */
  45. static void hfs_write_super(struct super_block *sb)
  46. {
  47. sb->s_dirt = 0;
  48. if (sb->s_flags & MS_RDONLY)
  49. return;
  50. /* sync everything to the buffers */
  51. hfs_mdb_commit(sb);
  52. }
  53. /*
  54. * hfs_put_super()
  55. *
  56. * This is the put_super() entry in the super_operations structure for
  57. * HFS filesystems. The purpose is to release the resources
  58. * associated with the superblock sb.
  59. */
  60. static void hfs_put_super(struct super_block *sb)
  61. {
  62. hfs_mdb_close(sb);
  63. /* release the MDB's resources */
  64. hfs_mdb_put(sb);
  65. }
  66. /*
  67. * hfs_statfs()
  68. *
  69. * This is the statfs() entry in the super_operations structure for
  70. * HFS filesystems. The purpose is to return various data about the
  71. * filesystem.
  72. *
  73. * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
  74. */
  75. static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
  76. {
  77. struct super_block *sb = dentry->d_sb;
  78. buf->f_type = HFS_SUPER_MAGIC;
  79. buf->f_bsize = sb->s_blocksize;
  80. buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
  81. buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
  82. buf->f_bavail = buf->f_bfree;
  83. buf->f_files = HFS_SB(sb)->fs_ablocks;
  84. buf->f_ffree = HFS_SB(sb)->free_ablocks;
  85. buf->f_namelen = HFS_NAMELEN;
  86. return 0;
  87. }
  88. static int hfs_remount(struct super_block *sb, int *flags, char *data)
  89. {
  90. *flags |= MS_NODIRATIME;
  91. if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
  92. return 0;
  93. if (!(*flags & MS_RDONLY)) {
  94. if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
  95. printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
  96. "running fsck.hfs is recommended. leaving read-only.\n");
  97. sb->s_flags |= MS_RDONLY;
  98. *flags |= MS_RDONLY;
  99. } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
  100. printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
  101. sb->s_flags |= MS_RDONLY;
  102. *flags |= MS_RDONLY;
  103. }
  104. }
  105. return 0;
  106. }
  107. static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
  108. {
  109. struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
  110. if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
  111. seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
  112. if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
  113. seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
  114. seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
  115. if (sbi->s_file_umask != 0133)
  116. seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
  117. if (sbi->s_dir_umask != 0022)
  118. seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
  119. if (sbi->part >= 0)
  120. seq_printf(seq, ",part=%u", sbi->part);
  121. if (sbi->session >= 0)
  122. seq_printf(seq, ",session=%u", sbi->session);
  123. if (sbi->nls_disk)
  124. seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
  125. if (sbi->nls_io)
  126. seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
  127. if (sbi->s_quiet)
  128. seq_printf(seq, ",quiet");
  129. return 0;
  130. }
  131. static struct inode *hfs_alloc_inode(struct super_block *sb)
  132. {
  133. struct hfs_inode_info *i;
  134. i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
  135. return i ? &i->vfs_inode : NULL;
  136. }
  137. static void hfs_destroy_inode(struct inode *inode)
  138. {
  139. kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
  140. }
  141. static const struct super_operations hfs_super_operations = {
  142. .alloc_inode = hfs_alloc_inode,
  143. .destroy_inode = hfs_destroy_inode,
  144. .write_inode = hfs_write_inode,
  145. .clear_inode = hfs_clear_inode,
  146. .put_super = hfs_put_super,
  147. .write_super = hfs_write_super,
  148. .statfs = hfs_statfs,
  149. .remount_fs = hfs_remount,
  150. .show_options = hfs_show_options,
  151. };
  152. enum {
  153. opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
  154. opt_part, opt_session, opt_type, opt_creator, opt_quiet,
  155. opt_codepage, opt_iocharset,
  156. opt_err
  157. };
  158. static match_table_t tokens = {
  159. { opt_uid, "uid=%u" },
  160. { opt_gid, "gid=%u" },
  161. { opt_umask, "umask=%o" },
  162. { opt_file_umask, "file_umask=%o" },
  163. { opt_dir_umask, "dir_umask=%o" },
  164. { opt_part, "part=%u" },
  165. { opt_session, "session=%u" },
  166. { opt_type, "type=%s" },
  167. { opt_creator, "creator=%s" },
  168. { opt_quiet, "quiet" },
  169. { opt_codepage, "codepage=%s" },
  170. { opt_iocharset, "iocharset=%s" },
  171. { opt_err, NULL }
  172. };
  173. static inline int match_fourchar(substring_t *arg, u32 *result)
  174. {
  175. if (arg->to - arg->from != 4)
  176. return -EINVAL;
  177. memcpy(result, arg->from, 4);
  178. return 0;
  179. }
  180. /*
  181. * parse_options()
  182. *
  183. * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
  184. * This function is called by hfs_read_super() to parse the mount options.
  185. */
  186. static int parse_options(char *options, struct hfs_sb_info *hsb)
  187. {
  188. char *p;
  189. substring_t args[MAX_OPT_ARGS];
  190. int tmp, token;
  191. /* initialize the sb with defaults */
  192. hsb->s_uid = current->uid;
  193. hsb->s_gid = current->gid;
  194. hsb->s_file_umask = 0133;
  195. hsb->s_dir_umask = 0022;
  196. hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
  197. hsb->s_quiet = 0;
  198. hsb->part = -1;
  199. hsb->session = -1;
  200. if (!options)
  201. return 1;
  202. while ((p = strsep(&options, ",")) != NULL) {
  203. if (!*p)
  204. continue;
  205. token = match_token(p, tokens, args);
  206. switch (token) {
  207. case opt_uid:
  208. if (match_int(&args[0], &tmp)) {
  209. printk(KERN_ERR "hfs: uid requires an argument\n");
  210. return 0;
  211. }
  212. hsb->s_uid = (uid_t)tmp;
  213. break;
  214. case opt_gid:
  215. if (match_int(&args[0], &tmp)) {
  216. printk(KERN_ERR "hfs: gid requires an argument\n");
  217. return 0;
  218. }
  219. hsb->s_gid = (gid_t)tmp;
  220. break;
  221. case opt_umask:
  222. if (match_octal(&args[0], &tmp)) {
  223. printk(KERN_ERR "hfs: umask requires a value\n");
  224. return 0;
  225. }
  226. hsb->s_file_umask = (umode_t)tmp;
  227. hsb->s_dir_umask = (umode_t)tmp;
  228. break;
  229. case opt_file_umask:
  230. if (match_octal(&args[0], &tmp)) {
  231. printk(KERN_ERR "hfs: file_umask requires a value\n");
  232. return 0;
  233. }
  234. hsb->s_file_umask = (umode_t)tmp;
  235. break;
  236. case opt_dir_umask:
  237. if (match_octal(&args[0], &tmp)) {
  238. printk(KERN_ERR "hfs: dir_umask requires a value\n");
  239. return 0;
  240. }
  241. hsb->s_dir_umask = (umode_t)tmp;
  242. break;
  243. case opt_part:
  244. if (match_int(&args[0], &hsb->part)) {
  245. printk(KERN_ERR "hfs: part requires an argument\n");
  246. return 0;
  247. }
  248. break;
  249. case opt_session:
  250. if (match_int(&args[0], &hsb->session)) {
  251. printk(KERN_ERR "hfs: session requires an argument\n");
  252. return 0;
  253. }
  254. break;
  255. case opt_type:
  256. if (match_fourchar(&args[0], &hsb->s_type)) {
  257. printk(KERN_ERR "hfs: type requires a 4 character value\n");
  258. return 0;
  259. }
  260. break;
  261. case opt_creator:
  262. if (match_fourchar(&args[0], &hsb->s_creator)) {
  263. printk(KERN_ERR "hfs: creator requires a 4 character value\n");
  264. return 0;
  265. }
  266. break;
  267. case opt_quiet:
  268. hsb->s_quiet = 1;
  269. break;
  270. case opt_codepage:
  271. if (hsb->nls_disk) {
  272. printk(KERN_ERR "hfs: unable to change codepage\n");
  273. return 0;
  274. }
  275. p = match_strdup(&args[0]);
  276. hsb->nls_disk = load_nls(p);
  277. if (!hsb->nls_disk) {
  278. printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
  279. kfree(p);
  280. return 0;
  281. }
  282. kfree(p);
  283. break;
  284. case opt_iocharset:
  285. if (hsb->nls_io) {
  286. printk(KERN_ERR "hfs: unable to change iocharset\n");
  287. return 0;
  288. }
  289. p = match_strdup(&args[0]);
  290. hsb->nls_io = load_nls(p);
  291. if (!hsb->nls_io) {
  292. printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
  293. kfree(p);
  294. return 0;
  295. }
  296. kfree(p);
  297. break;
  298. default:
  299. return 0;
  300. }
  301. }
  302. if (hsb->nls_disk && !hsb->nls_io) {
  303. hsb->nls_io = load_nls_default();
  304. if (!hsb->nls_io) {
  305. printk(KERN_ERR "hfs: unable to load default iocharset\n");
  306. return 0;
  307. }
  308. }
  309. hsb->s_dir_umask &= 0777;
  310. hsb->s_file_umask &= 0577;
  311. return 1;
  312. }
  313. /*
  314. * hfs_read_super()
  315. *
  316. * This is the function that is responsible for mounting an HFS
  317. * filesystem. It performs all the tasks necessary to get enough data
  318. * from the disk to read the root inode. This includes parsing the
  319. * mount options, dealing with Macintosh partitions, reading the
  320. * superblock and the allocation bitmap blocks, calling
  321. * hfs_btree_init() to get the necessary data about the extents and
  322. * catalog B-trees and, finally, reading the root inode into memory.
  323. */
  324. static int hfs_fill_super(struct super_block *sb, void *data, int silent)
  325. {
  326. struct hfs_sb_info *sbi;
  327. struct hfs_find_data fd;
  328. hfs_cat_rec rec;
  329. struct inode *root_inode;
  330. int res;
  331. sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
  332. if (!sbi)
  333. return -ENOMEM;
  334. sb->s_fs_info = sbi;
  335. INIT_HLIST_HEAD(&sbi->rsrc_inodes);
  336. res = -EINVAL;
  337. if (!parse_options((char *)data, sbi)) {
  338. printk(KERN_ERR "hfs: unable to parse mount options.\n");
  339. goto bail;
  340. }
  341. sb->s_op = &hfs_super_operations;
  342. sb->s_flags |= MS_NODIRATIME;
  343. init_MUTEX(&sbi->bitmap_lock);
  344. res = hfs_mdb_get(sb);
  345. if (res) {
  346. if (!silent)
  347. printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
  348. hfs_mdb_name(sb));
  349. res = -EINVAL;
  350. goto bail;
  351. }
  352. /* try to get the root inode */
  353. hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
  354. res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
  355. if (!res)
  356. hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
  357. if (res) {
  358. hfs_find_exit(&fd);
  359. goto bail_no_root;
  360. }
  361. res = -EINVAL;
  362. root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
  363. hfs_find_exit(&fd);
  364. if (!root_inode)
  365. goto bail_no_root;
  366. res = -ENOMEM;
  367. sb->s_root = d_alloc_root(root_inode);
  368. if (!sb->s_root)
  369. goto bail_iput;
  370. sb->s_root->d_op = &hfs_dentry_operations;
  371. /* everything's okay */
  372. return 0;
  373. bail_iput:
  374. iput(root_inode);
  375. bail_no_root:
  376. printk(KERN_ERR "hfs: get root inode failed.\n");
  377. bail:
  378. hfs_mdb_put(sb);
  379. return res;
  380. }
  381. static int hfs_get_sb(struct file_system_type *fs_type,
  382. int flags, const char *dev_name, void *data,
  383. struct vfsmount *mnt)
  384. {
  385. return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
  386. }
  387. static struct file_system_type hfs_fs_type = {
  388. .owner = THIS_MODULE,
  389. .name = "hfs",
  390. .get_sb = hfs_get_sb,
  391. .kill_sb = kill_block_super,
  392. .fs_flags = FS_REQUIRES_DEV,
  393. };
  394. static void hfs_init_once(void *p, struct kmem_cache *cachep, unsigned long flags)
  395. {
  396. struct hfs_inode_info *i = p;
  397. if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
  398. inode_init_once(&i->vfs_inode);
  399. }
  400. static int __init init_hfs_fs(void)
  401. {
  402. int err;
  403. hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
  404. sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
  405. hfs_init_once, NULL);
  406. if (!hfs_inode_cachep)
  407. return -ENOMEM;
  408. err = register_filesystem(&hfs_fs_type);
  409. if (err)
  410. kmem_cache_destroy(hfs_inode_cachep);
  411. return err;
  412. }
  413. static void __exit exit_hfs_fs(void)
  414. {
  415. unregister_filesystem(&hfs_fs_type);
  416. kmem_cache_destroy(hfs_inode_cachep);
  417. }
  418. module_init(init_hfs_fs)
  419. module_exit(exit_hfs_fs)