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