GNU Linux-libre 5.10.219-gnu1
[releases.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 = u64_to_fsid(id);
108         buf->f_namelen = HFS_NAMELEN;
109
110         return 0;
111 }
112
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
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
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
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
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  */
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  */
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_hfs_find;
424                 }
425                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
426         }
427         if (res)
428                 goto bail_hfs_find;
429         res = -EINVAL;
430         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
431         hfs_find_exit(&fd);
432         if (!root_inode)
433                 goto bail_no_root;
434
435         sb->s_d_op = &hfs_dentry_operations;
436         res = -ENOMEM;
437         sb->s_root = d_make_root(root_inode);
438         if (!sb->s_root)
439                 goto bail_no_root;
440
441         /* everything's okay */
442         return 0;
443
444 bail_hfs_find:
445         hfs_find_exit(&fd);
446 bail_no_root:
447         pr_err("get root inode failed\n");
448 bail:
449         hfs_mdb_put(sb);
450         return res;
451 }
452
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
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
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
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)