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