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/backing-dev.h>
18 #include <linux/mount.h>
19 #include <linux/init.h>
20 #include <linux/nls.h>
21 #include <linux/parser.h>
22 #include <linux/seq_file.h>
23 #include <linux/slab.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
hfs_sync_fs(struct super_block * sb,int wait)33 static int hfs_sync_fs(struct super_block *sb, int wait)
34 {
35 hfs_mdb_commit(sb);
36 return 0;
37 }
38
39 /*
40 * hfs_put_super()
41 *
42 * This is the put_super() entry in the super_operations structure for
43 * HFS filesystems. The purpose is to release the resources
44 * associated with the superblock sb.
45 */
hfs_put_super(struct super_block * sb)46 static void hfs_put_super(struct super_block *sb)
47 {
48 cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
49 hfs_mdb_close(sb);
50 /* release the MDB's resources */
51 hfs_mdb_put(sb);
52 }
53
flush_mdb(struct work_struct * work)54 static void flush_mdb(struct work_struct *work)
55 {
56 struct hfs_sb_info *sbi;
57 struct super_block *sb;
58
59 sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
60 sb = sbi->sb;
61
62 spin_lock(&sbi->work_lock);
63 sbi->work_queued = 0;
64 spin_unlock(&sbi->work_lock);
65
66 hfs_mdb_commit(sb);
67 }
68
hfs_mark_mdb_dirty(struct super_block * sb)69 void hfs_mark_mdb_dirty(struct super_block *sb)
70 {
71 struct hfs_sb_info *sbi = HFS_SB(sb);
72 unsigned long delay;
73
74 if (sb_rdonly(sb))
75 return;
76
77 spin_lock(&sbi->work_lock);
78 if (!sbi->work_queued) {
79 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
80 queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
81 sbi->work_queued = 1;
82 }
83 spin_unlock(&sbi->work_lock);
84 }
85
86 /*
87 * hfs_statfs()
88 *
89 * This is the statfs() entry in the super_operations structure for
90 * HFS filesystems. The purpose is to return various data about the
91 * filesystem.
92 *
93 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
94 */
hfs_statfs(struct dentry * dentry,struct kstatfs * buf)95 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
96 {
97 struct super_block *sb = dentry->d_sb;
98 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
99
100 buf->f_type = HFS_SUPER_MAGIC;
101 buf->f_bsize = sb->s_blocksize;
102 buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
103 buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
104 buf->f_bavail = buf->f_bfree;
105 buf->f_files = HFS_SB(sb)->fs_ablocks;
106 buf->f_ffree = HFS_SB(sb)->free_ablocks;
107 buf->f_fsid = u64_to_fsid(id);
108 buf->f_namelen = HFS_NAMELEN;
109
110 return 0;
111 }
112
hfs_remount(struct super_block * sb,int * flags,char * data)113 static int hfs_remount(struct super_block *sb, int *flags, char *data)
114 {
115 sync_filesystem(sb);
116 *flags |= SB_NODIRATIME;
117 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
118 return 0;
119 if (!(*flags & SB_RDONLY)) {
120 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
121 pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended. leaving read-only.\n");
122 sb->s_flags |= SB_RDONLY;
123 *flags |= SB_RDONLY;
124 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
125 pr_warn("filesystem is marked locked, leaving read-only.\n");
126 sb->s_flags |= SB_RDONLY;
127 *flags |= SB_RDONLY;
128 }
129 }
130 return 0;
131 }
132
hfs_show_options(struct seq_file * seq,struct dentry * root)133 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
134 {
135 struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
136
137 if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
138 seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
139 if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
140 seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
141 seq_printf(seq, ",uid=%u,gid=%u",
142 from_kuid_munged(&init_user_ns, sbi->s_uid),
143 from_kgid_munged(&init_user_ns, sbi->s_gid));
144 if (sbi->s_file_umask != 0133)
145 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
146 if (sbi->s_dir_umask != 0022)
147 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
148 if (sbi->part >= 0)
149 seq_printf(seq, ",part=%u", sbi->part);
150 if (sbi->session >= 0)
151 seq_printf(seq, ",session=%u", sbi->session);
152 if (sbi->nls_disk)
153 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
154 if (sbi->nls_io)
155 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
156 if (sbi->s_quiet)
157 seq_printf(seq, ",quiet");
158 return 0;
159 }
160
hfs_alloc_inode(struct super_block * sb)161 static struct inode *hfs_alloc_inode(struct super_block *sb)
162 {
163 struct hfs_inode_info *i;
164
165 i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
166 return i ? &i->vfs_inode : NULL;
167 }
168
hfs_free_inode(struct inode * inode)169 static void hfs_free_inode(struct inode *inode)
170 {
171 kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
172 }
173
174 static const struct super_operations hfs_super_operations = {
175 .alloc_inode = hfs_alloc_inode,
176 .free_inode = hfs_free_inode,
177 .write_inode = hfs_write_inode,
178 .evict_inode = hfs_evict_inode,
179 .put_super = hfs_put_super,
180 .sync_fs = hfs_sync_fs,
181 .statfs = hfs_statfs,
182 .remount_fs = hfs_remount,
183 .show_options = hfs_show_options,
184 };
185
186 enum {
187 opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
188 opt_part, opt_session, opt_type, opt_creator, opt_quiet,
189 opt_codepage, opt_iocharset,
190 opt_err
191 };
192
193 static const match_table_t tokens = {
194 { opt_uid, "uid=%u" },
195 { opt_gid, "gid=%u" },
196 { opt_umask, "umask=%o" },
197 { opt_file_umask, "file_umask=%o" },
198 { opt_dir_umask, "dir_umask=%o" },
199 { opt_part, "part=%u" },
200 { opt_session, "session=%u" },
201 { opt_type, "type=%s" },
202 { opt_creator, "creator=%s" },
203 { opt_quiet, "quiet" },
204 { opt_codepage, "codepage=%s" },
205 { opt_iocharset, "iocharset=%s" },
206 { opt_err, NULL }
207 };
208
match_fourchar(substring_t * arg,u32 * result)209 static inline int match_fourchar(substring_t *arg, u32 *result)
210 {
211 if (arg->to - arg->from != 4)
212 return -EINVAL;
213 memcpy(result, arg->from, 4);
214 return 0;
215 }
216
217 /*
218 * parse_options()
219 *
220 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
221 * This function is called by hfs_read_super() to parse the mount options.
222 */
parse_options(char * options,struct hfs_sb_info * hsb)223 static int parse_options(char *options, struct hfs_sb_info *hsb)
224 {
225 char *p;
226 substring_t args[MAX_OPT_ARGS];
227 int tmp, token;
228
229 /* initialize the sb with defaults */
230 hsb->s_uid = current_uid();
231 hsb->s_gid = current_gid();
232 hsb->s_file_umask = 0133;
233 hsb->s_dir_umask = 0022;
234 hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
235 hsb->s_quiet = 0;
236 hsb->part = -1;
237 hsb->session = -1;
238
239 if (!options)
240 return 1;
241
242 while ((p = strsep(&options, ",")) != NULL) {
243 if (!*p)
244 continue;
245
246 token = match_token(p, tokens, args);
247 switch (token) {
248 case opt_uid:
249 if (match_int(&args[0], &tmp)) {
250 pr_err("uid requires an argument\n");
251 return 0;
252 }
253 hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
254 if (!uid_valid(hsb->s_uid)) {
255 pr_err("invalid uid %d\n", tmp);
256 return 0;
257 }
258 break;
259 case opt_gid:
260 if (match_int(&args[0], &tmp)) {
261 pr_err("gid requires an argument\n");
262 return 0;
263 }
264 hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
265 if (!gid_valid(hsb->s_gid)) {
266 pr_err("invalid gid %d\n", tmp);
267 return 0;
268 }
269 break;
270 case opt_umask:
271 if (match_octal(&args[0], &tmp)) {
272 pr_err("umask requires a value\n");
273 return 0;
274 }
275 hsb->s_file_umask = (umode_t)tmp;
276 hsb->s_dir_umask = (umode_t)tmp;
277 break;
278 case opt_file_umask:
279 if (match_octal(&args[0], &tmp)) {
280 pr_err("file_umask requires a value\n");
281 return 0;
282 }
283 hsb->s_file_umask = (umode_t)tmp;
284 break;
285 case opt_dir_umask:
286 if (match_octal(&args[0], &tmp)) {
287 pr_err("dir_umask requires a value\n");
288 return 0;
289 }
290 hsb->s_dir_umask = (umode_t)tmp;
291 break;
292 case opt_part:
293 if (match_int(&args[0], &hsb->part)) {
294 pr_err("part requires an argument\n");
295 return 0;
296 }
297 break;
298 case opt_session:
299 if (match_int(&args[0], &hsb->session)) {
300 pr_err("session requires an argument\n");
301 return 0;
302 }
303 break;
304 case opt_type:
305 if (match_fourchar(&args[0], &hsb->s_type)) {
306 pr_err("type requires a 4 character value\n");
307 return 0;
308 }
309 break;
310 case opt_creator:
311 if (match_fourchar(&args[0], &hsb->s_creator)) {
312 pr_err("creator requires a 4 character value\n");
313 return 0;
314 }
315 break;
316 case opt_quiet:
317 hsb->s_quiet = 1;
318 break;
319 case opt_codepage:
320 if (hsb->nls_disk) {
321 pr_err("unable to change codepage\n");
322 return 0;
323 }
324 p = match_strdup(&args[0]);
325 if (p)
326 hsb->nls_disk = load_nls(p);
327 if (!hsb->nls_disk) {
328 pr_err("unable to load codepage \"%s\"\n", p);
329 kfree(p);
330 return 0;
331 }
332 kfree(p);
333 break;
334 case opt_iocharset:
335 if (hsb->nls_io) {
336 pr_err("unable to change iocharset\n");
337 return 0;
338 }
339 p = match_strdup(&args[0]);
340 if (p)
341 hsb->nls_io = load_nls(p);
342 if (!hsb->nls_io) {
343 pr_err("unable to load iocharset \"%s\"\n", p);
344 kfree(p);
345 return 0;
346 }
347 kfree(p);
348 break;
349 default:
350 return 0;
351 }
352 }
353
354 if (hsb->nls_disk && !hsb->nls_io) {
355 hsb->nls_io = load_nls_default();
356 if (!hsb->nls_io) {
357 pr_err("unable to load default iocharset\n");
358 return 0;
359 }
360 }
361 hsb->s_dir_umask &= 0777;
362 hsb->s_file_umask &= 0577;
363
364 return 1;
365 }
366
367 /*
368 * hfs_read_super()
369 *
370 * This is the function that is responsible for mounting an HFS
371 * filesystem. It performs all the tasks necessary to get enough data
372 * from the disk to read the root inode. This includes parsing the
373 * mount options, dealing with Macintosh partitions, reading the
374 * superblock and the allocation bitmap blocks, calling
375 * hfs_btree_init() to get the necessary data about the extents and
376 * catalog B-trees and, finally, reading the root inode into memory.
377 */
hfs_fill_super(struct super_block * sb,void * data,int silent)378 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
379 {
380 struct hfs_sb_info *sbi;
381 struct hfs_find_data fd;
382 hfs_cat_rec rec;
383 struct inode *root_inode;
384 int res;
385
386 sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
387 if (!sbi)
388 return -ENOMEM;
389
390 sbi->sb = sb;
391 sb->s_fs_info = sbi;
392 spin_lock_init(&sbi->work_lock);
393 INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
394
395 res = -EINVAL;
396 if (!parse_options((char *)data, sbi)) {
397 pr_err("unable to parse mount options\n");
398 goto bail;
399 }
400
401 sb->s_op = &hfs_super_operations;
402 sb->s_xattr = hfs_xattr_handlers;
403 sb->s_flags |= SB_NODIRATIME;
404 mutex_init(&sbi->bitmap_lock);
405
406 res = hfs_mdb_get(sb);
407 if (res) {
408 if (!silent)
409 pr_warn("can't find a HFS filesystem on dev %s\n",
410 hfs_mdb_name(sb));
411 res = -EINVAL;
412 goto bail;
413 }
414
415 /* try to get the root inode */
416 res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
417 if (res)
418 goto bail_no_root;
419 res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
420 if (!res) {
421 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
422 res = -EIO;
423 goto bail;
424 }
425 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
426 }
427 if (res) {
428 hfs_find_exit(&fd);
429 goto bail_no_root;
430 }
431 res = -EINVAL;
432 root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
433 hfs_find_exit(&fd);
434 if (!root_inode)
435 goto bail_no_root;
436
437 sb->s_d_op = &hfs_dentry_operations;
438 res = -ENOMEM;
439 sb->s_root = d_make_root(root_inode);
440 if (!sb->s_root)
441 goto bail_no_root;
442
443 /* everything's okay */
444 return 0;
445
446 bail_no_root:
447 pr_err("get root inode failed\n");
448 bail:
449 hfs_mdb_put(sb);
450 return res;
451 }
452
hfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)453 static struct dentry *hfs_mount(struct file_system_type *fs_type,
454 int flags, const char *dev_name, void *data)
455 {
456 return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
457 }
458
459 static struct file_system_type hfs_fs_type = {
460 .owner = THIS_MODULE,
461 .name = "hfs",
462 .mount = hfs_mount,
463 .kill_sb = kill_block_super,
464 .fs_flags = FS_REQUIRES_DEV,
465 };
466 MODULE_ALIAS_FS("hfs");
467
hfs_init_once(void * p)468 static void hfs_init_once(void *p)
469 {
470 struct hfs_inode_info *i = p;
471
472 inode_init_once(&i->vfs_inode);
473 }
474
init_hfs_fs(void)475 static int __init init_hfs_fs(void)
476 {
477 int err;
478
479 hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
480 sizeof(struct hfs_inode_info), 0,
481 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
482 if (!hfs_inode_cachep)
483 return -ENOMEM;
484 err = register_filesystem(&hfs_fs_type);
485 if (err)
486 kmem_cache_destroy(hfs_inode_cachep);
487 return err;
488 }
489
exit_hfs_fs(void)490 static void __exit exit_hfs_fs(void)
491 {
492 unregister_filesystem(&hfs_fs_type);
493
494 /*
495 * Make sure all delayed rcu free inodes are flushed before we
496 * destroy cache.
497 */
498 rcu_barrier();
499 kmem_cache_destroy(hfs_inode_cachep);
500 }
501
502 module_init(init_hfs_fs)
503 module_exit(exit_hfs_fs)
504