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