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->s_flags & MS_RDONLY)
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.val[0] = (u32)id;
108 buf->f_fsid.val[1] = (u32)(id >> 32);
109 buf->f_namelen = HFS_NAMELEN;
110
111 return 0;
112 }
113
hfs_remount(struct super_block * sb,int * flags,char * data)114 static int hfs_remount(struct super_block *sb, int *flags, char *data)
115 {
116 sync_filesystem(sb);
117 *flags |= MS_NODIRATIME;
118 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
119 return 0;
120 if (!(*flags & MS_RDONLY)) {
121 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
122 pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended. leaving read-only.\n");
123 sb->s_flags |= MS_RDONLY;
124 *flags |= MS_RDONLY;
125 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
126 pr_warn("filesystem is marked locked, leaving read-only.\n");
127 sb->s_flags |= MS_RDONLY;
128 *flags |= MS_RDONLY;
129 }
130 }
131 return 0;
132 }
133
hfs_show_options(struct seq_file * seq,struct dentry * root)134 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
135 {
136 struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
137
138 if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
139 seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
140 if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
141 seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
142 seq_printf(seq, ",uid=%u,gid=%u",
143 from_kuid_munged(&init_user_ns, sbi->s_uid),
144 from_kgid_munged(&init_user_ns, 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
hfs_alloc_inode(struct super_block * sb)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
hfs_i_callback(struct rcu_head * head)170 static void hfs_i_callback(struct rcu_head *head)
171 {
172 struct inode *inode = container_of(head, struct inode, i_rcu);
173 kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
174 }
175
hfs_destroy_inode(struct inode * inode)176 static void hfs_destroy_inode(struct inode *inode)
177 {
178 call_rcu(&inode->i_rcu, hfs_i_callback);
179 }
180
181 static const struct super_operations hfs_super_operations = {
182 .alloc_inode = hfs_alloc_inode,
183 .destroy_inode = hfs_destroy_inode,
184 .write_inode = hfs_write_inode,
185 .evict_inode = hfs_evict_inode,
186 .put_super = hfs_put_super,
187 .sync_fs = hfs_sync_fs,
188 .statfs = hfs_statfs,
189 .remount_fs = hfs_remount,
190 .show_options = hfs_show_options,
191 };
192
193 enum {
194 opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
195 opt_part, opt_session, opt_type, opt_creator, opt_quiet,
196 opt_codepage, opt_iocharset,
197 opt_err
198 };
199
200 static const match_table_t tokens = {
201 { opt_uid, "uid=%u" },
202 { opt_gid, "gid=%u" },
203 { opt_umask, "umask=%o" },
204 { opt_file_umask, "file_umask=%o" },
205 { opt_dir_umask, "dir_umask=%o" },
206 { opt_part, "part=%u" },
207 { opt_session, "session=%u" },
208 { opt_type, "type=%s" },
209 { opt_creator, "creator=%s" },
210 { opt_quiet, "quiet" },
211 { opt_codepage, "codepage=%s" },
212 { opt_iocharset, "iocharset=%s" },
213 { opt_err, NULL }
214 };
215
match_fourchar(substring_t * arg,u32 * result)216 static inline int match_fourchar(substring_t *arg, u32 *result)
217 {
218 if (arg->to - arg->from != 4)
219 return -EINVAL;
220 memcpy(result, arg->from, 4);
221 return 0;
222 }
223
224 /*
225 * parse_options()
226 *
227 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
228 * This function is called by hfs_read_super() to parse the mount options.
229 */
parse_options(char * options,struct hfs_sb_info * hsb)230 static int parse_options(char *options, struct hfs_sb_info *hsb)
231 {
232 char *p;
233 substring_t args[MAX_OPT_ARGS];
234 int tmp, token;
235
236 /* initialize the sb with defaults */
237 hsb->s_uid = current_uid();
238 hsb->s_gid = current_gid();
239 hsb->s_file_umask = 0133;
240 hsb->s_dir_umask = 0022;
241 hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
242 hsb->s_quiet = 0;
243 hsb->part = -1;
244 hsb->session = -1;
245
246 if (!options)
247 return 1;
248
249 while ((p = strsep(&options, ",")) != NULL) {
250 if (!*p)
251 continue;
252
253 token = match_token(p, tokens, args);
254 switch (token) {
255 case opt_uid:
256 if (match_int(&args[0], &tmp)) {
257 pr_err("uid requires an argument\n");
258 return 0;
259 }
260 hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
261 if (!uid_valid(hsb->s_uid)) {
262 pr_err("invalid uid %d\n", tmp);
263 return 0;
264 }
265 break;
266 case opt_gid:
267 if (match_int(&args[0], &tmp)) {
268 pr_err("gid requires an argument\n");
269 return 0;
270 }
271 hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
272 if (!gid_valid(hsb->s_gid)) {
273 pr_err("invalid gid %d\n", tmp);
274 return 0;
275 }
276 break;
277 case opt_umask:
278 if (match_octal(&args[0], &tmp)) {
279 pr_err("umask requires a value\n");
280 return 0;
281 }
282 hsb->s_file_umask = (umode_t)tmp;
283 hsb->s_dir_umask = (umode_t)tmp;
284 break;
285 case opt_file_umask:
286 if (match_octal(&args[0], &tmp)) {
287 pr_err("file_umask requires a value\n");
288 return 0;
289 }
290 hsb->s_file_umask = (umode_t)tmp;
291 break;
292 case opt_dir_umask:
293 if (match_octal(&args[0], &tmp)) {
294 pr_err("dir_umask requires a value\n");
295 return 0;
296 }
297 hsb->s_dir_umask = (umode_t)tmp;
298 break;
299 case opt_part:
300 if (match_int(&args[0], &hsb->part)) {
301 pr_err("part requires an argument\n");
302 return 0;
303 }
304 break;
305 case opt_session:
306 if (match_int(&args[0], &hsb->session)) {
307 pr_err("session requires an argument\n");
308 return 0;
309 }
310 break;
311 case opt_type:
312 if (match_fourchar(&args[0], &hsb->s_type)) {
313 pr_err("type requires a 4 character value\n");
314 return 0;
315 }
316 break;
317 case opt_creator:
318 if (match_fourchar(&args[0], &hsb->s_creator)) {
319 pr_err("creator requires a 4 character value\n");
320 return 0;
321 }
322 break;
323 case opt_quiet:
324 hsb->s_quiet = 1;
325 break;
326 case opt_codepage:
327 if (hsb->nls_disk) {
328 pr_err("unable to change codepage\n");
329 return 0;
330 }
331 p = match_strdup(&args[0]);
332 if (p)
333 hsb->nls_disk = load_nls(p);
334 if (!hsb->nls_disk) {
335 pr_err("unable to load codepage \"%s\"\n", p);
336 kfree(p);
337 return 0;
338 }
339 kfree(p);
340 break;
341 case opt_iocharset:
342 if (hsb->nls_io) {
343 pr_err("unable to change iocharset\n");
344 return 0;
345 }
346 p = match_strdup(&args[0]);
347 if (p)
348 hsb->nls_io = load_nls(p);
349 if (!hsb->nls_io) {
350 pr_err("unable to load iocharset \"%s\"\n", p);
351 kfree(p);
352 return 0;
353 }
354 kfree(p);
355 break;
356 default:
357 return 0;
358 }
359 }
360
361 if (hsb->nls_disk && !hsb->nls_io) {
362 hsb->nls_io = load_nls_default();
363 if (!hsb->nls_io) {
364 pr_err("unable to load default iocharset\n");
365 return 0;
366 }
367 }
368 hsb->s_dir_umask &= 0777;
369 hsb->s_file_umask &= 0577;
370
371 return 1;
372 }
373
374 /*
375 * hfs_read_super()
376 *
377 * This is the function that is responsible for mounting an HFS
378 * filesystem. It performs all the tasks necessary to get enough data
379 * from the disk to read the root inode. This includes parsing the
380 * mount options, dealing with Macintosh partitions, reading the
381 * superblock and the allocation bitmap blocks, calling
382 * hfs_btree_init() to get the necessary data about the extents and
383 * catalog B-trees and, finally, reading the root inode into memory.
384 */
hfs_fill_super(struct super_block * sb,void * data,int silent)385 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
386 {
387 struct hfs_sb_info *sbi;
388 struct hfs_find_data fd;
389 hfs_cat_rec rec;
390 struct inode *root_inode;
391 int res;
392
393 sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
394 if (!sbi)
395 return -ENOMEM;
396
397 sbi->sb = sb;
398 sb->s_fs_info = sbi;
399 spin_lock_init(&sbi->work_lock);
400 INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
401
402 res = -EINVAL;
403 if (!parse_options((char *)data, sbi)) {
404 pr_err("unable to parse mount options\n");
405 goto bail;
406 }
407
408 sb->s_op = &hfs_super_operations;
409 sb->s_flags |= MS_NODIRATIME;
410 mutex_init(&sbi->bitmap_lock);
411
412 res = hfs_mdb_get(sb);
413 if (res) {
414 if (!silent)
415 pr_warn("can't find a HFS filesystem on dev %s\n",
416 hfs_mdb_name(sb));
417 res = -EINVAL;
418 goto bail;
419 }
420
421 /* try to get the root inode */
422 res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
423 if (res)
424 goto bail_no_root;
425 res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
426 if (!res) {
427 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
428 res = -EIO;
429 goto bail_hfs_find;
430 }
431 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
432 }
433 if (res)
434 goto bail_hfs_find;
435 res = -EINVAL;
436 root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
437 hfs_find_exit(&fd);
438 if (!root_inode)
439 goto bail_no_root;
440
441 sb->s_d_op = &hfs_dentry_operations;
442 res = -ENOMEM;
443 sb->s_root = d_make_root(root_inode);
444 if (!sb->s_root)
445 goto bail_no_root;
446
447 /* everything's okay */
448 return 0;
449
450 bail_hfs_find:
451 hfs_find_exit(&fd);
452 bail_no_root:
453 pr_err("get root inode failed\n");
454 bail:
455 hfs_mdb_put(sb);
456 return res;
457 }
458
hfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)459 static struct dentry *hfs_mount(struct file_system_type *fs_type,
460 int flags, const char *dev_name, void *data)
461 {
462 return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
463 }
464
465 static struct file_system_type hfs_fs_type = {
466 .owner = THIS_MODULE,
467 .name = "hfs",
468 .mount = hfs_mount,
469 .kill_sb = kill_block_super,
470 .fs_flags = FS_REQUIRES_DEV,
471 };
472 MODULE_ALIAS_FS("hfs");
473
hfs_init_once(void * p)474 static void hfs_init_once(void *p)
475 {
476 struct hfs_inode_info *i = p;
477
478 inode_init_once(&i->vfs_inode);
479 }
480
init_hfs_fs(void)481 static int __init init_hfs_fs(void)
482 {
483 int err;
484
485 hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
486 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
487 hfs_init_once);
488 if (!hfs_inode_cachep)
489 return -ENOMEM;
490 err = register_filesystem(&hfs_fs_type);
491 if (err)
492 kmem_cache_destroy(hfs_inode_cachep);
493 return err;
494 }
495
exit_hfs_fs(void)496 static void __exit exit_hfs_fs(void)
497 {
498 unregister_filesystem(&hfs_fs_type);
499
500 /*
501 * Make sure all delayed rcu free inodes are flushed before we
502 * destroy cache.
503 */
504 rcu_barrier();
505 kmem_cache_destroy(hfs_inode_cachep);
506 }
507
508 module_init(init_hfs_fs)
509 module_exit(exit_hfs_fs)
510