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_hfs_fs() and exit_hfs_fs(). 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 15 #include <linux/module.h> 16 #include <linux/blkdev.h> 17 #include <linux/mount.h> 18 #include <linux/init.h> 19 #include <linux/nls.h> 20 #include <linux/parser.h> 21 #include <linux/seq_file.h> 22 #include <linux/slab.h> 23 #include <linux/vfs.h> 24 25 #include "hfs_fs.h" 26 #include "btree.h" 27 28 static struct kmem_cache *hfs_inode_cachep; 29 30 MODULE_LICENSE("GPL"); 31 32 /* 33 * hfs_write_super() 34 * 35 * Description: 36 * This function is called by the VFS only. When the filesystem 37 * is mounted r/w it updates the MDB on disk. 38 * Input Variable(s): 39 * struct super_block *sb: Pointer to the hfs superblock 40 * Output Variable(s): 41 * NONE 42 * Returns: 43 * void 44 * Preconditions: 45 * 'sb' points to a "valid" (struct super_block). 46 * Postconditions: 47 * The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb 48 * (hfs_put_super() must set this flag!). Some MDB fields are updated 49 * and the MDB buffer is written to disk by calling hfs_mdb_commit(). 50 */ 51 static void hfs_write_super(struct super_block *sb) 52 { 53 lock_super(sb); 54 sb->s_dirt = 0; 55 56 /* sync everything to the buffers */ 57 if (!(sb->s_flags & MS_RDONLY)) 58 hfs_mdb_commit(sb); 59 unlock_super(sb); 60 } 61 62 static int hfs_sync_fs(struct super_block *sb, int wait) 63 { 64 lock_super(sb); 65 hfs_mdb_commit(sb); 66 sb->s_dirt = 0; 67 unlock_super(sb); 68 69 return 0; 70 } 71 72 /* 73 * hfs_put_super() 74 * 75 * This is the put_super() entry in the super_operations structure for 76 * HFS filesystems. The purpose is to release the resources 77 * associated with the superblock sb. 78 */ 79 static void hfs_put_super(struct super_block *sb) 80 { 81 if (sb->s_dirt) 82 hfs_write_super(sb); 83 hfs_mdb_close(sb); 84 /* release the MDB's resources */ 85 hfs_mdb_put(sb); 86 } 87 88 /* 89 * hfs_statfs() 90 * 91 * This is the statfs() entry in the super_operations structure for 92 * HFS filesystems. The purpose is to return various data about the 93 * filesystem. 94 * 95 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks. 96 */ 97 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf) 98 { 99 struct super_block *sb = dentry->d_sb; 100 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 101 102 buf->f_type = HFS_SUPER_MAGIC; 103 buf->f_bsize = sb->s_blocksize; 104 buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div; 105 buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div; 106 buf->f_bavail = buf->f_bfree; 107 buf->f_files = HFS_SB(sb)->fs_ablocks; 108 buf->f_ffree = HFS_SB(sb)->free_ablocks; 109 buf->f_fsid.val[0] = (u32)id; 110 buf->f_fsid.val[1] = (u32)(id >> 32); 111 buf->f_namelen = HFS_NAMELEN; 112 113 return 0; 114 } 115 116 static int hfs_remount(struct super_block *sb, int *flags, char *data) 117 { 118 *flags |= MS_NODIRATIME; 119 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 120 return 0; 121 if (!(*flags & MS_RDONLY)) { 122 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) { 123 printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, " 124 "running fsck.hfs is recommended. leaving read-only.\n"); 125 sb->s_flags |= MS_RDONLY; 126 *flags |= MS_RDONLY; 127 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) { 128 printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n"); 129 sb->s_flags |= MS_RDONLY; 130 *flags |= MS_RDONLY; 131 } 132 } 133 return 0; 134 } 135 136 static int hfs_show_options(struct seq_file *seq, struct dentry *root) 137 { 138 struct hfs_sb_info *sbi = HFS_SB(root->d_sb); 139 140 if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f)) 141 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator); 142 if (sbi->s_type != cpu_to_be32(0x3f3f3f3f)) 143 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type); 144 seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid); 145 if (sbi->s_file_umask != 0133) 146 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask); 147 if (sbi->s_dir_umask != 0022) 148 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask); 149 if (sbi->part >= 0) 150 seq_printf(seq, ",part=%u", sbi->part); 151 if (sbi->session >= 0) 152 seq_printf(seq, ",session=%u", sbi->session); 153 if (sbi->nls_disk) 154 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset); 155 if (sbi->nls_io) 156 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset); 157 if (sbi->s_quiet) 158 seq_printf(seq, ",quiet"); 159 return 0; 160 } 161 162 static struct inode *hfs_alloc_inode(struct super_block *sb) 163 { 164 struct hfs_inode_info *i; 165 166 i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL); 167 return i ? &i->vfs_inode : NULL; 168 } 169 170 static void hfs_i_callback(struct rcu_head *head) 171 { 172 struct inode *inode = container_of(head, struct inode, i_rcu); 173 kmem_cache_free(hfs_inode_cachep, HFS_I(inode)); 174 } 175 176 static void hfs_destroy_inode(struct inode *inode) 177 { 178 call_rcu(&inode->i_rcu, hfs_i_callback); 179 } 180 181 static const struct super_operations hfs_super_operations = { 182 .alloc_inode = hfs_alloc_inode, 183 .destroy_inode = hfs_destroy_inode, 184 .write_inode = hfs_write_inode, 185 .evict_inode = hfs_evict_inode, 186 .put_super = hfs_put_super, 187 .write_super = hfs_write_super, 188 .sync_fs = hfs_sync_fs, 189 .statfs = hfs_statfs, 190 .remount_fs = hfs_remount, 191 .show_options = hfs_show_options, 192 }; 193 194 enum { 195 opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask, 196 opt_part, opt_session, opt_type, opt_creator, opt_quiet, 197 opt_codepage, opt_iocharset, 198 opt_err 199 }; 200 201 static const match_table_t tokens = { 202 { opt_uid, "uid=%u" }, 203 { opt_gid, "gid=%u" }, 204 { opt_umask, "umask=%o" }, 205 { opt_file_umask, "file_umask=%o" }, 206 { opt_dir_umask, "dir_umask=%o" }, 207 { opt_part, "part=%u" }, 208 { opt_session, "session=%u" }, 209 { opt_type, "type=%s" }, 210 { opt_creator, "creator=%s" }, 211 { opt_quiet, "quiet" }, 212 { opt_codepage, "codepage=%s" }, 213 { opt_iocharset, "iocharset=%s" }, 214 { opt_err, NULL } 215 }; 216 217 static inline int match_fourchar(substring_t *arg, u32 *result) 218 { 219 if (arg->to - arg->from != 4) 220 return -EINVAL; 221 memcpy(result, arg->from, 4); 222 return 0; 223 } 224 225 /* 226 * parse_options() 227 * 228 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger 229 * This function is called by hfs_read_super() to parse the mount options. 230 */ 231 static int parse_options(char *options, struct hfs_sb_info *hsb) 232 { 233 char *p; 234 substring_t args[MAX_OPT_ARGS]; 235 int tmp, token; 236 237 /* initialize the sb with defaults */ 238 hsb->s_uid = current_uid(); 239 hsb->s_gid = current_gid(); 240 hsb->s_file_umask = 0133; 241 hsb->s_dir_umask = 0022; 242 hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */ 243 hsb->s_quiet = 0; 244 hsb->part = -1; 245 hsb->session = -1; 246 247 if (!options) 248 return 1; 249 250 while ((p = strsep(&options, ",")) != NULL) { 251 if (!*p) 252 continue; 253 254 token = match_token(p, tokens, args); 255 switch (token) { 256 case opt_uid: 257 if (match_int(&args[0], &tmp)) { 258 printk(KERN_ERR "hfs: uid requires an argument\n"); 259 return 0; 260 } 261 hsb->s_uid = (uid_t)tmp; 262 break; 263 case opt_gid: 264 if (match_int(&args[0], &tmp)) { 265 printk(KERN_ERR "hfs: gid requires an argument\n"); 266 return 0; 267 } 268 hsb->s_gid = (gid_t)tmp; 269 break; 270 case opt_umask: 271 if (match_octal(&args[0], &tmp)) { 272 printk(KERN_ERR "hfs: umask requires a value\n"); 273 return 0; 274 } 275 hsb->s_file_umask = (umode_t)tmp; 276 hsb->s_dir_umask = (umode_t)tmp; 277 break; 278 case opt_file_umask: 279 if (match_octal(&args[0], &tmp)) { 280 printk(KERN_ERR "hfs: file_umask requires a value\n"); 281 return 0; 282 } 283 hsb->s_file_umask = (umode_t)tmp; 284 break; 285 case opt_dir_umask: 286 if (match_octal(&args[0], &tmp)) { 287 printk(KERN_ERR "hfs: dir_umask requires a value\n"); 288 return 0; 289 } 290 hsb->s_dir_umask = (umode_t)tmp; 291 break; 292 case opt_part: 293 if (match_int(&args[0], &hsb->part)) { 294 printk(KERN_ERR "hfs: part requires an argument\n"); 295 return 0; 296 } 297 break; 298 case opt_session: 299 if (match_int(&args[0], &hsb->session)) { 300 printk(KERN_ERR "hfs: session requires an argument\n"); 301 return 0; 302 } 303 break; 304 case opt_type: 305 if (match_fourchar(&args[0], &hsb->s_type)) { 306 printk(KERN_ERR "hfs: type requires a 4 character value\n"); 307 return 0; 308 } 309 break; 310 case opt_creator: 311 if (match_fourchar(&args[0], &hsb->s_creator)) { 312 printk(KERN_ERR "hfs: creator requires a 4 character value\n"); 313 return 0; 314 } 315 break; 316 case opt_quiet: 317 hsb->s_quiet = 1; 318 break; 319 case opt_codepage: 320 if (hsb->nls_disk) { 321 printk(KERN_ERR "hfs: unable to change codepage\n"); 322 return 0; 323 } 324 p = match_strdup(&args[0]); 325 if (p) 326 hsb->nls_disk = load_nls(p); 327 if (!hsb->nls_disk) { 328 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p); 329 kfree(p); 330 return 0; 331 } 332 kfree(p); 333 break; 334 case opt_iocharset: 335 if (hsb->nls_io) { 336 printk(KERN_ERR "hfs: unable to change iocharset\n"); 337 return 0; 338 } 339 p = match_strdup(&args[0]); 340 if (p) 341 hsb->nls_io = load_nls(p); 342 if (!hsb->nls_io) { 343 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p); 344 kfree(p); 345 return 0; 346 } 347 kfree(p); 348 break; 349 default: 350 return 0; 351 } 352 } 353 354 if (hsb->nls_disk && !hsb->nls_io) { 355 hsb->nls_io = load_nls_default(); 356 if (!hsb->nls_io) { 357 printk(KERN_ERR "hfs: unable to load default iocharset\n"); 358 return 0; 359 } 360 } 361 hsb->s_dir_umask &= 0777; 362 hsb->s_file_umask &= 0577; 363 364 return 1; 365 } 366 367 /* 368 * hfs_read_super() 369 * 370 * This is the function that is responsible for mounting an HFS 371 * filesystem. It performs all the tasks necessary to get enough data 372 * from the disk to read the root inode. This includes parsing the 373 * mount options, dealing with Macintosh partitions, reading the 374 * superblock and the allocation bitmap blocks, calling 375 * hfs_btree_init() to get the necessary data about the extents and 376 * catalog B-trees and, finally, reading the root inode into memory. 377 */ 378 static int hfs_fill_super(struct super_block *sb, void *data, int silent) 379 { 380 struct hfs_sb_info *sbi; 381 struct hfs_find_data fd; 382 hfs_cat_rec rec; 383 struct inode *root_inode; 384 int res; 385 386 sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); 387 if (!sbi) 388 return -ENOMEM; 389 390 sb->s_fs_info = sbi; 391 392 res = -EINVAL; 393 if (!parse_options((char *)data, sbi)) { 394 printk(KERN_ERR "hfs: unable to parse mount options.\n"); 395 goto bail; 396 } 397 398 sb->s_op = &hfs_super_operations; 399 sb->s_flags |= MS_NODIRATIME; 400 mutex_init(&sbi->bitmap_lock); 401 402 res = hfs_mdb_get(sb); 403 if (res) { 404 if (!silent) 405 printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n", 406 hfs_mdb_name(sb)); 407 res = -EINVAL; 408 goto bail; 409 } 410 411 /* try to get the root inode */ 412 hfs_find_init(HFS_SB(sb)->cat_tree, &fd); 413 res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd); 414 if (!res) { 415 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) { 416 res = -EIO; 417 goto bail; 418 } 419 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength); 420 } 421 if (res) { 422 hfs_find_exit(&fd); 423 goto bail_no_root; 424 } 425 res = -EINVAL; 426 root_inode = hfs_iget(sb, &fd.search_key->cat, &rec); 427 hfs_find_exit(&fd); 428 if (!root_inode) 429 goto bail_no_root; 430 431 sb->s_d_op = &hfs_dentry_operations; 432 res = -ENOMEM; 433 sb->s_root = d_make_root(root_inode); 434 if (!sb->s_root) 435 goto bail_no_root; 436 437 /* everything's okay */ 438 return 0; 439 440 bail_no_root: 441 printk(KERN_ERR "hfs: get root inode failed.\n"); 442 bail: 443 hfs_mdb_put(sb); 444 return res; 445 } 446 447 static struct dentry *hfs_mount(struct file_system_type *fs_type, 448 int flags, const char *dev_name, void *data) 449 { 450 return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super); 451 } 452 453 static struct file_system_type hfs_fs_type = { 454 .owner = THIS_MODULE, 455 .name = "hfs", 456 .mount = hfs_mount, 457 .kill_sb = kill_block_super, 458 .fs_flags = FS_REQUIRES_DEV, 459 }; 460 461 static void hfs_init_once(void *p) 462 { 463 struct hfs_inode_info *i = p; 464 465 inode_init_once(&i->vfs_inode); 466 } 467 468 static int __init init_hfs_fs(void) 469 { 470 int err; 471 472 hfs_inode_cachep = kmem_cache_create("hfs_inode_cache", 473 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN, 474 hfs_init_once); 475 if (!hfs_inode_cachep) 476 return -ENOMEM; 477 err = register_filesystem(&hfs_fs_type); 478 if (err) 479 kmem_cache_destroy(hfs_inode_cachep); 480 return err; 481 } 482 483 static void __exit exit_hfs_fs(void) 484 { 485 unregister_filesystem(&hfs_fs_type); 486 kmem_cache_destroy(hfs_inode_cachep); 487 } 488 489 module_init(init_hfs_fs) 490 module_exit(exit_hfs_fs) 491