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 vfsmount *mnt) 137 { 138 struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_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 INIT_LIST_HEAD(&inode->i_dentry); 174 kmem_cache_free(hfs_inode_cachep, HFS_I(inode)); 175 } 176 177 static void hfs_destroy_inode(struct inode *inode) 178 { 179 call_rcu(&inode->i_rcu, hfs_i_callback); 180 } 181 182 static const struct super_operations hfs_super_operations = { 183 .alloc_inode = hfs_alloc_inode, 184 .destroy_inode = hfs_destroy_inode, 185 .write_inode = hfs_write_inode, 186 .evict_inode = hfs_evict_inode, 187 .put_super = hfs_put_super, 188 .write_super = hfs_write_super, 189 .sync_fs = hfs_sync_fs, 190 .statfs = hfs_statfs, 191 .remount_fs = hfs_remount, 192 .show_options = hfs_show_options, 193 }; 194 195 enum { 196 opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask, 197 opt_part, opt_session, opt_type, opt_creator, opt_quiet, 198 opt_codepage, opt_iocharset, 199 opt_err 200 }; 201 202 static const match_table_t tokens = { 203 { opt_uid, "uid=%u" }, 204 { opt_gid, "gid=%u" }, 205 { opt_umask, "umask=%o" }, 206 { opt_file_umask, "file_umask=%o" }, 207 { opt_dir_umask, "dir_umask=%o" }, 208 { opt_part, "part=%u" }, 209 { opt_session, "session=%u" }, 210 { opt_type, "type=%s" }, 211 { opt_creator, "creator=%s" }, 212 { opt_quiet, "quiet" }, 213 { opt_codepage, "codepage=%s" }, 214 { opt_iocharset, "iocharset=%s" }, 215 { opt_err, NULL } 216 }; 217 218 static inline int match_fourchar(substring_t *arg, u32 *result) 219 { 220 if (arg->to - arg->from != 4) 221 return -EINVAL; 222 memcpy(result, arg->from, 4); 223 return 0; 224 } 225 226 /* 227 * parse_options() 228 * 229 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger 230 * This function is called by hfs_read_super() to parse the mount options. 231 */ 232 static int parse_options(char *options, struct hfs_sb_info *hsb) 233 { 234 char *p; 235 substring_t args[MAX_OPT_ARGS]; 236 int tmp, token; 237 238 /* initialize the sb with defaults */ 239 hsb->s_uid = current_uid(); 240 hsb->s_gid = current_gid(); 241 hsb->s_file_umask = 0133; 242 hsb->s_dir_umask = 0022; 243 hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */ 244 hsb->s_quiet = 0; 245 hsb->part = -1; 246 hsb->session = -1; 247 248 if (!options) 249 return 1; 250 251 while ((p = strsep(&options, ",")) != NULL) { 252 if (!*p) 253 continue; 254 255 token = match_token(p, tokens, args); 256 switch (token) { 257 case opt_uid: 258 if (match_int(&args[0], &tmp)) { 259 printk(KERN_ERR "hfs: uid requires an argument\n"); 260 return 0; 261 } 262 hsb->s_uid = (uid_t)tmp; 263 break; 264 case opt_gid: 265 if (match_int(&args[0], &tmp)) { 266 printk(KERN_ERR "hfs: gid requires an argument\n"); 267 return 0; 268 } 269 hsb->s_gid = (gid_t)tmp; 270 break; 271 case opt_umask: 272 if (match_octal(&args[0], &tmp)) { 273 printk(KERN_ERR "hfs: umask requires a value\n"); 274 return 0; 275 } 276 hsb->s_file_umask = (umode_t)tmp; 277 hsb->s_dir_umask = (umode_t)tmp; 278 break; 279 case opt_file_umask: 280 if (match_octal(&args[0], &tmp)) { 281 printk(KERN_ERR "hfs: file_umask requires a value\n"); 282 return 0; 283 } 284 hsb->s_file_umask = (umode_t)tmp; 285 break; 286 case opt_dir_umask: 287 if (match_octal(&args[0], &tmp)) { 288 printk(KERN_ERR "hfs: dir_umask requires a value\n"); 289 return 0; 290 } 291 hsb->s_dir_umask = (umode_t)tmp; 292 break; 293 case opt_part: 294 if (match_int(&args[0], &hsb->part)) { 295 printk(KERN_ERR "hfs: part requires an argument\n"); 296 return 0; 297 } 298 break; 299 case opt_session: 300 if (match_int(&args[0], &hsb->session)) { 301 printk(KERN_ERR "hfs: session requires an argument\n"); 302 return 0; 303 } 304 break; 305 case opt_type: 306 if (match_fourchar(&args[0], &hsb->s_type)) { 307 printk(KERN_ERR "hfs: type requires a 4 character value\n"); 308 return 0; 309 } 310 break; 311 case opt_creator: 312 if (match_fourchar(&args[0], &hsb->s_creator)) { 313 printk(KERN_ERR "hfs: creator requires a 4 character value\n"); 314 return 0; 315 } 316 break; 317 case opt_quiet: 318 hsb->s_quiet = 1; 319 break; 320 case opt_codepage: 321 if (hsb->nls_disk) { 322 printk(KERN_ERR "hfs: unable to change codepage\n"); 323 return 0; 324 } 325 p = match_strdup(&args[0]); 326 if (p) 327 hsb->nls_disk = load_nls(p); 328 if (!hsb->nls_disk) { 329 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p); 330 kfree(p); 331 return 0; 332 } 333 kfree(p); 334 break; 335 case opt_iocharset: 336 if (hsb->nls_io) { 337 printk(KERN_ERR "hfs: unable to change iocharset\n"); 338 return 0; 339 } 340 p = match_strdup(&args[0]); 341 if (p) 342 hsb->nls_io = load_nls(p); 343 if (!hsb->nls_io) { 344 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p); 345 kfree(p); 346 return 0; 347 } 348 kfree(p); 349 break; 350 default: 351 return 0; 352 } 353 } 354 355 if (hsb->nls_disk && !hsb->nls_io) { 356 hsb->nls_io = load_nls_default(); 357 if (!hsb->nls_io) { 358 printk(KERN_ERR "hfs: unable to load default iocharset\n"); 359 return 0; 360 } 361 } 362 hsb->s_dir_umask &= 0777; 363 hsb->s_file_umask &= 0577; 364 365 return 1; 366 } 367 368 /* 369 * hfs_read_super() 370 * 371 * This is the function that is responsible for mounting an HFS 372 * filesystem. It performs all the tasks necessary to get enough data 373 * from the disk to read the root inode. This includes parsing the 374 * mount options, dealing with Macintosh partitions, reading the 375 * superblock and the allocation bitmap blocks, calling 376 * hfs_btree_init() to get the necessary data about the extents and 377 * catalog B-trees and, finally, reading the root inode into memory. 378 */ 379 static int hfs_fill_super(struct super_block *sb, void *data, int silent) 380 { 381 struct hfs_sb_info *sbi; 382 struct hfs_find_data fd; 383 hfs_cat_rec rec; 384 struct inode *root_inode; 385 int res; 386 387 sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); 388 if (!sbi) 389 return -ENOMEM; 390 391 sb->s_fs_info = sbi; 392 393 res = -EINVAL; 394 if (!parse_options((char *)data, sbi)) { 395 printk(KERN_ERR "hfs: unable to parse mount options.\n"); 396 goto bail; 397 } 398 399 sb->s_op = &hfs_super_operations; 400 sb->s_flags |= MS_NODIRATIME; 401 mutex_init(&sbi->bitmap_lock); 402 403 res = hfs_mdb_get(sb); 404 if (res) { 405 if (!silent) 406 printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n", 407 hfs_mdb_name(sb)); 408 res = -EINVAL; 409 goto bail; 410 } 411 412 /* try to get the root inode */ 413 hfs_find_init(HFS_SB(sb)->cat_tree, &fd); 414 res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd); 415 if (!res) { 416 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) { 417 res = -EIO; 418 goto bail; 419 } 420 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength); 421 } 422 if (res) { 423 hfs_find_exit(&fd); 424 goto bail_no_root; 425 } 426 res = -EINVAL; 427 root_inode = hfs_iget(sb, &fd.search_key->cat, &rec); 428 hfs_find_exit(&fd); 429 if (!root_inode) 430 goto bail_no_root; 431 432 sb->s_d_op = &hfs_dentry_operations; 433 res = -ENOMEM; 434 sb->s_root = d_alloc_root(root_inode); 435 if (!sb->s_root) 436 goto bail_iput; 437 438 /* everything's okay */ 439 return 0; 440 441 bail_iput: 442 iput(root_inode); 443 bail_no_root: 444 printk(KERN_ERR "hfs: get root inode failed.\n"); 445 bail: 446 hfs_mdb_put(sb); 447 return res; 448 } 449 450 static struct dentry *hfs_mount(struct file_system_type *fs_type, 451 int flags, const char *dev_name, void *data) 452 { 453 return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super); 454 } 455 456 static struct file_system_type hfs_fs_type = { 457 .owner = THIS_MODULE, 458 .name = "hfs", 459 .mount = hfs_mount, 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