173876782f73fd33838bec0e5508cbe79fa5c868
[muen/linux.git] / fs / hfs / super.c
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
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  */
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
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
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  */
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
114 static int hfs_remount(struct super_block *sb, int *flags, char *data)
115 {
116         sync_filesystem(sb);
117         *flags |= SB_NODIRATIME;
118         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
119                 return 0;
120         if (!(*flags & SB_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 |= SB_RDONLY;
124                         *flags |= SB_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 |= SB_RDONLY;
128                         *flags |= SB_RDONLY;
129                 }
130         }
131         return 0;
132 }
133
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
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
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
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
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  */
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  */
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_xattr = hfs_xattr_handlers;
410         sb->s_flags |= SB_NODIRATIME;
411         mutex_init(&sbi->bitmap_lock);
412
413         res = hfs_mdb_get(sb);
414         if (res) {
415                 if (!silent)
416                         pr_warn("can't find a HFS filesystem on dev %s\n",
417                                 hfs_mdb_name(sb));
418                 res = -EINVAL;
419                 goto bail;
420         }
421
422         /* try to get the root inode */
423         res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
424         if (res)
425                 goto bail_no_root;
426         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
427         if (!res) {
428                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
429                         res =  -EIO;
430                         goto bail;
431                 }
432                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
433         }
434         if (res) {
435                 hfs_find_exit(&fd);
436                 goto bail_no_root;
437         }
438         res = -EINVAL;
439         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
440         hfs_find_exit(&fd);
441         if (!root_inode)
442                 goto bail_no_root;
443
444         sb->s_d_op = &hfs_dentry_operations;
445         res = -ENOMEM;
446         sb->s_root = d_make_root(root_inode);
447         if (!sb->s_root)
448                 goto bail_no_root;
449
450         /* everything's okay */
451         return 0;
452
453 bail_no_root:
454         pr_err("get root inode failed\n");
455 bail:
456         hfs_mdb_put(sb);
457         return res;
458 }
459
460 static struct dentry *hfs_mount(struct file_system_type *fs_type,
461                       int flags, const char *dev_name, void *data)
462 {
463         return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
464 }
465
466 static struct file_system_type hfs_fs_type = {
467         .owner          = THIS_MODULE,
468         .name           = "hfs",
469         .mount          = hfs_mount,
470         .kill_sb        = kill_block_super,
471         .fs_flags       = FS_REQUIRES_DEV,
472 };
473 MODULE_ALIAS_FS("hfs");
474
475 static void hfs_init_once(void *p)
476 {
477         struct hfs_inode_info *i = p;
478
479         inode_init_once(&i->vfs_inode);
480 }
481
482 static int __init init_hfs_fs(void)
483 {
484         int err;
485
486         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
487                 sizeof(struct hfs_inode_info), 0,
488                 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
489         if (!hfs_inode_cachep)
490                 return -ENOMEM;
491         err = register_filesystem(&hfs_fs_type);
492         if (err)
493                 kmem_cache_destroy(hfs_inode_cachep);
494         return err;
495 }
496
497 static void __exit exit_hfs_fs(void)
498 {
499         unregister_filesystem(&hfs_fs_type);
500
501         /*
502          * Make sure all delayed rcu free inodes are flushed before we
503          * destroy cache.
504          */
505         rcu_barrier();
506         kmem_cache_destroy(hfs_inode_cachep);
507 }
508
509 module_init(init_hfs_fs)
510 module_exit(exit_hfs_fs)