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/smp_lock.h> 24 #include <linux/vfs.h> 25 26 #include "hfs_fs.h" 27 #include "btree.h" 28 29 static struct kmem_cache *hfs_inode_cachep; 30 31 MODULE_LICENSE("GPL"); 32 33 /* 34 * hfs_write_super() 35 * 36 * Description: 37 * This function is called by the VFS only. When the filesystem 38 * is mounted r/w it updates the MDB on disk. 39 * Input Variable(s): 40 * struct super_block *sb: Pointer to the hfs superblock 41 * Output Variable(s): 42 * NONE 43 * Returns: 44 * void 45 * Preconditions: 46 * 'sb' points to a "valid" (struct super_block). 47 * Postconditions: 48 * The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb 49 * (hfs_put_super() must set this flag!). Some MDB fields are updated 50 * and the MDB buffer is written to disk by calling hfs_mdb_commit(). 51 */ 52 static void hfs_write_super(struct super_block *sb) 53 { 54 lock_super(sb); 55 sb->s_dirt = 0; 56 57 /* sync everything to the buffers */ 58 if (!(sb->s_flags & MS_RDONLY)) 59 hfs_mdb_commit(sb); 60 unlock_super(sb); 61 } 62 63 static int hfs_sync_fs(struct super_block *sb, int wait) 64 { 65 lock_super(sb); 66 hfs_mdb_commit(sb); 67 sb->s_dirt = 0; 68 unlock_super(sb); 69 70 return 0; 71 } 72 73 /* 74 * hfs_put_super() 75 * 76 * This is the put_super() entry in the super_operations structure for 77 * HFS filesystems. The purpose is to release the resources 78 * associated with the superblock sb. 79 */ 80 static void hfs_put_super(struct super_block *sb) 81 { 82 lock_kernel(); 83 84 if (sb->s_dirt) 85 hfs_write_super(sb); 86 hfs_mdb_close(sb); 87 /* release the MDB's resources */ 88 hfs_mdb_put(sb); 89 90 unlock_kernel(); 91 } 92 93 /* 94 * hfs_statfs() 95 * 96 * This is the statfs() entry in the super_operations structure for 97 * HFS filesystems. The purpose is to return various data about the 98 * filesystem. 99 * 100 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks. 101 */ 102 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf) 103 { 104 struct super_block *sb = dentry->d_sb; 105 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 106 107 buf->f_type = HFS_SUPER_MAGIC; 108 buf->f_bsize = sb->s_blocksize; 109 buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div; 110 buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div; 111 buf->f_bavail = buf->f_bfree; 112 buf->f_files = HFS_SB(sb)->fs_ablocks; 113 buf->f_ffree = HFS_SB(sb)->free_ablocks; 114 buf->f_fsid.val[0] = (u32)id; 115 buf->f_fsid.val[1] = (u32)(id >> 32); 116 buf->f_namelen = HFS_NAMELEN; 117 118 return 0; 119 } 120 121 static int hfs_remount(struct super_block *sb, int *flags, char *data) 122 { 123 *flags |= MS_NODIRATIME; 124 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 125 return 0; 126 if (!(*flags & MS_RDONLY)) { 127 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) { 128 printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, " 129 "running fsck.hfs is recommended. leaving read-only.\n"); 130 sb->s_flags |= MS_RDONLY; 131 *flags |= MS_RDONLY; 132 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) { 133 printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n"); 134 sb->s_flags |= MS_RDONLY; 135 *flags |= MS_RDONLY; 136 } 137 } 138 return 0; 139 } 140 141 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt) 142 { 143 struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb); 144 145 if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f)) 146 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator); 147 if (sbi->s_type != cpu_to_be32(0x3f3f3f3f)) 148 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type); 149 seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid); 150 if (sbi->s_file_umask != 0133) 151 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask); 152 if (sbi->s_dir_umask != 0022) 153 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask); 154 if (sbi->part >= 0) 155 seq_printf(seq, ",part=%u", sbi->part); 156 if (sbi->session >= 0) 157 seq_printf(seq, ",session=%u", sbi->session); 158 if (sbi->nls_disk) 159 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset); 160 if (sbi->nls_io) 161 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset); 162 if (sbi->s_quiet) 163 seq_printf(seq, ",quiet"); 164 return 0; 165 } 166 167 static struct inode *hfs_alloc_inode(struct super_block *sb) 168 { 169 struct hfs_inode_info *i; 170 171 i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL); 172 return i ? &i->vfs_inode : NULL; 173 } 174 175 static void hfs_destroy_inode(struct inode *inode) 176 { 177 kmem_cache_free(hfs_inode_cachep, HFS_I(inode)); 178 } 179 180 static const struct super_operations hfs_super_operations = { 181 .alloc_inode = hfs_alloc_inode, 182 .destroy_inode = hfs_destroy_inode, 183 .write_inode = hfs_write_inode, 184 .evict_inode = hfs_evict_inode, 185 .put_super = hfs_put_super, 186 .write_super = hfs_write_super, 187 .sync_fs = hfs_sync_fs, 188 .statfs = hfs_statfs, 189 .remount_fs = hfs_remount, 190 .show_options = hfs_show_options, 191 }; 192 193 enum { 194 opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask, 195 opt_part, opt_session, opt_type, opt_creator, opt_quiet, 196 opt_codepage, opt_iocharset, 197 opt_err 198 }; 199 200 static const match_table_t tokens = { 201 { opt_uid, "uid=%u" }, 202 { opt_gid, "gid=%u" }, 203 { opt_umask, "umask=%o" }, 204 { opt_file_umask, "file_umask=%o" }, 205 { opt_dir_umask, "dir_umask=%o" }, 206 { opt_part, "part=%u" }, 207 { opt_session, "session=%u" }, 208 { opt_type, "type=%s" }, 209 { opt_creator, "creator=%s" }, 210 { opt_quiet, "quiet" }, 211 { opt_codepage, "codepage=%s" }, 212 { opt_iocharset, "iocharset=%s" }, 213 { opt_err, NULL } 214 }; 215 216 static inline int match_fourchar(substring_t *arg, u32 *result) 217 { 218 if (arg->to - arg->from != 4) 219 return -EINVAL; 220 memcpy(result, arg->from, 4); 221 return 0; 222 } 223 224 /* 225 * parse_options() 226 * 227 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger 228 * This function is called by hfs_read_super() to parse the mount options. 229 */ 230 static int parse_options(char *options, struct hfs_sb_info *hsb) 231 { 232 char *p; 233 substring_t args[MAX_OPT_ARGS]; 234 int tmp, token; 235 236 /* initialize the sb with defaults */ 237 hsb->s_uid = current_uid(); 238 hsb->s_gid = current_gid(); 239 hsb->s_file_umask = 0133; 240 hsb->s_dir_umask = 0022; 241 hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */ 242 hsb->s_quiet = 0; 243 hsb->part = -1; 244 hsb->session = -1; 245 246 if (!options) 247 return 1; 248 249 while ((p = strsep(&options, ",")) != NULL) { 250 if (!*p) 251 continue; 252 253 token = match_token(p, tokens, args); 254 switch (token) { 255 case opt_uid: 256 if (match_int(&args[0], &tmp)) { 257 printk(KERN_ERR "hfs: uid requires an argument\n"); 258 return 0; 259 } 260 hsb->s_uid = (uid_t)tmp; 261 break; 262 case opt_gid: 263 if (match_int(&args[0], &tmp)) { 264 printk(KERN_ERR "hfs: gid requires an argument\n"); 265 return 0; 266 } 267 hsb->s_gid = (gid_t)tmp; 268 break; 269 case opt_umask: 270 if (match_octal(&args[0], &tmp)) { 271 printk(KERN_ERR "hfs: umask requires a value\n"); 272 return 0; 273 } 274 hsb->s_file_umask = (umode_t)tmp; 275 hsb->s_dir_umask = (umode_t)tmp; 276 break; 277 case opt_file_umask: 278 if (match_octal(&args[0], &tmp)) { 279 printk(KERN_ERR "hfs: file_umask requires a value\n"); 280 return 0; 281 } 282 hsb->s_file_umask = (umode_t)tmp; 283 break; 284 case opt_dir_umask: 285 if (match_octal(&args[0], &tmp)) { 286 printk(KERN_ERR "hfs: dir_umask requires a value\n"); 287 return 0; 288 } 289 hsb->s_dir_umask = (umode_t)tmp; 290 break; 291 case opt_part: 292 if (match_int(&args[0], &hsb->part)) { 293 printk(KERN_ERR "hfs: part requires an argument\n"); 294 return 0; 295 } 296 break; 297 case opt_session: 298 if (match_int(&args[0], &hsb->session)) { 299 printk(KERN_ERR "hfs: session requires an argument\n"); 300 return 0; 301 } 302 break; 303 case opt_type: 304 if (match_fourchar(&args[0], &hsb->s_type)) { 305 printk(KERN_ERR "hfs: type requires a 4 character value\n"); 306 return 0; 307 } 308 break; 309 case opt_creator: 310 if (match_fourchar(&args[0], &hsb->s_creator)) { 311 printk(KERN_ERR "hfs: creator requires a 4 character value\n"); 312 return 0; 313 } 314 break; 315 case opt_quiet: 316 hsb->s_quiet = 1; 317 break; 318 case opt_codepage: 319 if (hsb->nls_disk) { 320 printk(KERN_ERR "hfs: unable to change codepage\n"); 321 return 0; 322 } 323 p = match_strdup(&args[0]); 324 if (p) 325 hsb->nls_disk = load_nls(p); 326 if (!hsb->nls_disk) { 327 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p); 328 kfree(p); 329 return 0; 330 } 331 kfree(p); 332 break; 333 case opt_iocharset: 334 if (hsb->nls_io) { 335 printk(KERN_ERR "hfs: unable to change iocharset\n"); 336 return 0; 337 } 338 p = match_strdup(&args[0]); 339 if (p) 340 hsb->nls_io = load_nls(p); 341 if (!hsb->nls_io) { 342 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p); 343 kfree(p); 344 return 0; 345 } 346 kfree(p); 347 break; 348 default: 349 return 0; 350 } 351 } 352 353 if (hsb->nls_disk && !hsb->nls_io) { 354 hsb->nls_io = load_nls_default(); 355 if (!hsb->nls_io) { 356 printk(KERN_ERR "hfs: unable to load default iocharset\n"); 357 return 0; 358 } 359 } 360 hsb->s_dir_umask &= 0777; 361 hsb->s_file_umask &= 0577; 362 363 return 1; 364 } 365 366 /* 367 * hfs_read_super() 368 * 369 * This is the function that is responsible for mounting an HFS 370 * filesystem. It performs all the tasks necessary to get enough data 371 * from the disk to read the root inode. This includes parsing the 372 * mount options, dealing with Macintosh partitions, reading the 373 * superblock and the allocation bitmap blocks, calling 374 * hfs_btree_init() to get the necessary data about the extents and 375 * catalog B-trees and, finally, reading the root inode into memory. 376 */ 377 static int hfs_fill_super(struct super_block *sb, void *data, int silent) 378 { 379 struct hfs_sb_info *sbi; 380 struct hfs_find_data fd; 381 hfs_cat_rec rec; 382 struct inode *root_inode; 383 int res; 384 385 sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); 386 if (!sbi) 387 return -ENOMEM; 388 sb->s_fs_info = sbi; 389 INIT_HLIST_HEAD(&sbi->rsrc_inodes); 390 391 res = -EINVAL; 392 if (!parse_options((char *)data, sbi)) { 393 printk(KERN_ERR "hfs: unable to parse mount options.\n"); 394 goto bail; 395 } 396 397 sb->s_op = &hfs_super_operations; 398 sb->s_flags |= MS_NODIRATIME; 399 mutex_init(&sbi->bitmap_lock); 400 401 res = hfs_mdb_get(sb); 402 if (res) { 403 if (!silent) 404 printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n", 405 hfs_mdb_name(sb)); 406 res = -EINVAL; 407 goto bail; 408 } 409 410 /* try to get the root inode */ 411 hfs_find_init(HFS_SB(sb)->cat_tree, &fd); 412 res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd); 413 if (!res) { 414 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) { 415 res = -EIO; 416 goto bail; 417 } 418 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength); 419 } 420 if (res) { 421 hfs_find_exit(&fd); 422 goto bail_no_root; 423 } 424 res = -EINVAL; 425 root_inode = hfs_iget(sb, &fd.search_key->cat, &rec); 426 hfs_find_exit(&fd); 427 if (!root_inode) 428 goto bail_no_root; 429 430 res = -ENOMEM; 431 sb->s_root = d_alloc_root(root_inode); 432 if (!sb->s_root) 433 goto bail_iput; 434 435 sb->s_root->d_op = &hfs_dentry_operations; 436 437 /* everything's okay */ 438 return 0; 439 440 bail_iput: 441 iput(root_inode); 442 bail_no_root: 443 printk(KERN_ERR "hfs: get root inode failed.\n"); 444 bail: 445 hfs_mdb_put(sb); 446 return res; 447 } 448 449 static int hfs_get_sb(struct file_system_type *fs_type, 450 int flags, const char *dev_name, void *data, 451 struct vfsmount *mnt) 452 { 453 return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt); 454 } 455 456 static struct file_system_type hfs_fs_type = { 457 .owner = THIS_MODULE, 458 .name = "hfs", 459 .get_sb = hfs_get_sb, 460 .kill_sb = kill_block_super, 461 .fs_flags = FS_REQUIRES_DEV, 462 }; 463 464 static void hfs_init_once(void *p) 465 { 466 struct hfs_inode_info *i = p; 467 468 inode_init_once(&i->vfs_inode); 469 } 470 471 static int __init init_hfs_fs(void) 472 { 473 int err; 474 475 hfs_inode_cachep = kmem_cache_create("hfs_inode_cache", 476 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN, 477 hfs_init_once); 478 if (!hfs_inode_cachep) 479 return -ENOMEM; 480 err = register_filesystem(&hfs_fs_type); 481 if (err) 482 kmem_cache_destroy(hfs_inode_cachep); 483 return err; 484 } 485 486 static void __exit exit_hfs_fs(void) 487 { 488 unregister_filesystem(&hfs_fs_type); 489 kmem_cache_destroy(hfs_inode_cachep); 490 } 491 492 module_init(init_hfs_fs) 493 module_exit(exit_hfs_fs) 494