hfs: add ->sync_fs
[linux-2.6.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/mount.h>
18 #include <linux/init.h>
19 #include <linux/nls.h>
20 #include <linux/parser.h>
21 #include <linux/seq_file.h>
22 #include <linux/vfs.h>
23
24 #include "hfs_fs.h"
25 #include "btree.h"
26
27 static struct kmem_cache *hfs_inode_cachep;
28
29 MODULE_LICENSE("GPL");
30
31 /*
32  * hfs_write_super()
33  *
34  * Description:
35  *   This function is called by the VFS only. When the filesystem
36  *   is mounted r/w it updates the MDB on disk.
37  * Input Variable(s):
38  *   struct super_block *sb: Pointer to the hfs superblock
39  * Output Variable(s):
40  *   NONE
41  * Returns:
42  *   void
43  * Preconditions:
44  *   'sb' points to a "valid" (struct super_block).
45  * Postconditions:
46  *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
47  *   (hfs_put_super() must set this flag!). Some MDB fields are updated
48  *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
49  */
50 static void hfs_write_super(struct super_block *sb)
51 {
52         lock_super(sb);
53         sb->s_dirt = 0;
54
55         /* sync everything to the buffers */
56         if (!(sb->s_flags & MS_RDONLY))
57                 hfs_mdb_commit(sb);
58         unlock_super(sb);
59 }
60
61 static int hfs_sync_fs(struct super_block *sb, int wait)
62 {
63         lock_super(sb);
64         hfs_mdb_commit(sb);
65         sb->s_dirt = 0;
66         unlock_super(sb);
67
68         return 0;
69 }
70
71 /*
72  * hfs_put_super()
73  *
74  * This is the put_super() entry in the super_operations structure for
75  * HFS filesystems.  The purpose is to release the resources
76  * associated with the superblock sb.
77  */
78 static void hfs_put_super(struct super_block *sb)
79 {
80         lock_kernel();
81
82         if (sb->s_dirt)
83                 hfs_write_super(sb);
84         hfs_mdb_close(sb);
85         /* release the MDB's resources */
86         hfs_mdb_put(sb);
87
88         unlock_kernel();
89 }
90
91 /*
92  * hfs_statfs()
93  *
94  * This is the statfs() entry in the super_operations structure for
95  * HFS filesystems.  The purpose is to return various data about the
96  * filesystem.
97  *
98  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
99  */
100 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
101 {
102         struct super_block *sb = dentry->d_sb;
103         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
104
105         buf->f_type = HFS_SUPER_MAGIC;
106         buf->f_bsize = sb->s_blocksize;
107         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
108         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
109         buf->f_bavail = buf->f_bfree;
110         buf->f_files = HFS_SB(sb)->fs_ablocks;
111         buf->f_ffree = HFS_SB(sb)->free_ablocks;
112         buf->f_fsid.val[0] = (u32)id;
113         buf->f_fsid.val[1] = (u32)(id >> 32);
114         buf->f_namelen = HFS_NAMELEN;
115
116         return 0;
117 }
118
119 static int hfs_remount(struct super_block *sb, int *flags, char *data)
120 {
121         *flags |= MS_NODIRATIME;
122         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
123                 return 0;
124         if (!(*flags & MS_RDONLY)) {
125                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
126                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
127                                "running fsck.hfs is recommended.  leaving read-only.\n");
128                         sb->s_flags |= MS_RDONLY;
129                         *flags |= MS_RDONLY;
130                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
131                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
132                         sb->s_flags |= MS_RDONLY;
133                         *flags |= MS_RDONLY;
134                 }
135         }
136         return 0;
137 }
138
139 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
140 {
141         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
142
143         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
144                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
145         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
146                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
147         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
148         if (sbi->s_file_umask != 0133)
149                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
150         if (sbi->s_dir_umask != 0022)
151                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
152         if (sbi->part >= 0)
153                 seq_printf(seq, ",part=%u", sbi->part);
154         if (sbi->session >= 0)
155                 seq_printf(seq, ",session=%u", sbi->session);
156         if (sbi->nls_disk)
157                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
158         if (sbi->nls_io)
159                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
160         if (sbi->s_quiet)
161                 seq_printf(seq, ",quiet");
162         return 0;
163 }
164
165 static struct inode *hfs_alloc_inode(struct super_block *sb)
166 {
167         struct hfs_inode_info *i;
168
169         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
170         return i ? &i->vfs_inode : NULL;
171 }
172
173 static void hfs_destroy_inode(struct inode *inode)
174 {
175         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
176 }
177
178 static const struct super_operations hfs_super_operations = {
179         .alloc_inode    = hfs_alloc_inode,
180         .destroy_inode  = hfs_destroy_inode,
181         .write_inode    = hfs_write_inode,
182         .clear_inode    = hfs_clear_inode,
183         .put_super      = hfs_put_super,
184         .write_super    = hfs_write_super,
185         .sync_fs        = hfs_sync_fs,
186         .statfs         = hfs_statfs,
187         .remount_fs     = hfs_remount,
188         .show_options   = hfs_show_options,
189 };
190
191 enum {
192         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
193         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
194         opt_codepage, opt_iocharset,
195         opt_err
196 };
197
198 static const match_table_t tokens = {
199         { opt_uid, "uid=%u" },
200         { opt_gid, "gid=%u" },
201         { opt_umask, "umask=%o" },
202         { opt_file_umask, "file_umask=%o" },
203         { opt_dir_umask, "dir_umask=%o" },
204         { opt_part, "part=%u" },
205         { opt_session, "session=%u" },
206         { opt_type, "type=%s" },
207         { opt_creator, "creator=%s" },
208         { opt_quiet, "quiet" },
209         { opt_codepage, "codepage=%s" },
210         { opt_iocharset, "iocharset=%s" },
211         { opt_err, NULL }
212 };
213
214 static inline int match_fourchar(substring_t *arg, u32 *result)
215 {
216         if (arg->to - arg->from != 4)
217                 return -EINVAL;
218         memcpy(result, arg->from, 4);
219         return 0;
220 }
221
222 /*
223  * parse_options()
224  *
225  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
226  * This function is called by hfs_read_super() to parse the mount options.
227  */
228 static int parse_options(char *options, struct hfs_sb_info *hsb)
229 {
230         char *p;
231         substring_t args[MAX_OPT_ARGS];
232         int tmp, token;
233
234         /* initialize the sb with defaults */
235         hsb->s_uid = current_uid();
236         hsb->s_gid = current_gid();
237         hsb->s_file_umask = 0133;
238         hsb->s_dir_umask = 0022;
239         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
240         hsb->s_quiet = 0;
241         hsb->part = -1;
242         hsb->session = -1;
243
244         if (!options)
245                 return 1;
246
247         while ((p = strsep(&options, ",")) != NULL) {
248                 if (!*p)
249                         continue;
250
251                 token = match_token(p, tokens, args);
252                 switch (token) {
253                 case opt_uid:
254                         if (match_int(&args[0], &tmp)) {
255                                 printk(KERN_ERR "hfs: uid requires an argument\n");
256                                 return 0;
257                         }
258                         hsb->s_uid = (uid_t)tmp;
259                         break;
260                 case opt_gid:
261                         if (match_int(&args[0], &tmp)) {
262                                 printk(KERN_ERR "hfs: gid requires an argument\n");
263                                 return 0;
264                         }
265                         hsb->s_gid = (gid_t)tmp;
266                         break;
267                 case opt_umask:
268                         if (match_octal(&args[0], &tmp)) {
269                                 printk(KERN_ERR "hfs: umask requires a value\n");
270                                 return 0;
271                         }
272                         hsb->s_file_umask = (umode_t)tmp;
273                         hsb->s_dir_umask = (umode_t)tmp;
274                         break;
275                 case opt_file_umask:
276                         if (match_octal(&args[0], &tmp)) {
277                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
278                                 return 0;
279                         }
280                         hsb->s_file_umask = (umode_t)tmp;
281                         break;
282                 case opt_dir_umask:
283                         if (match_octal(&args[0], &tmp)) {
284                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
285                                 return 0;
286                         }
287                         hsb->s_dir_umask = (umode_t)tmp;
288                         break;
289                 case opt_part:
290                         if (match_int(&args[0], &hsb->part)) {
291                                 printk(KERN_ERR "hfs: part requires an argument\n");
292                                 return 0;
293                         }
294                         break;
295                 case opt_session:
296                         if (match_int(&args[0], &hsb->session)) {
297                                 printk(KERN_ERR "hfs: session requires an argument\n");
298                                 return 0;
299                         }
300                         break;
301                 case opt_type:
302                         if (match_fourchar(&args[0], &hsb->s_type)) {
303                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
304                                 return 0;
305                         }
306                         break;
307                 case opt_creator:
308                         if (match_fourchar(&args[0], &hsb->s_creator)) {
309                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
310                                 return 0;
311                         }
312                         break;
313                 case opt_quiet:
314                         hsb->s_quiet = 1;
315                         break;
316                 case opt_codepage:
317                         if (hsb->nls_disk) {
318                                 printk(KERN_ERR "hfs: unable to change codepage\n");
319                                 return 0;
320                         }
321                         p = match_strdup(&args[0]);
322                         if (p)
323                                 hsb->nls_disk = load_nls(p);
324                         if (!hsb->nls_disk) {
325                                 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
326                                 kfree(p);
327                                 return 0;
328                         }
329                         kfree(p);
330                         break;
331                 case opt_iocharset:
332                         if (hsb->nls_io) {
333                                 printk(KERN_ERR "hfs: unable to change iocharset\n");
334                                 return 0;
335                         }
336                         p = match_strdup(&args[0]);
337                         if (p)
338                                 hsb->nls_io = load_nls(p);
339                         if (!hsb->nls_io) {
340                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
341                                 kfree(p);
342                                 return 0;
343                         }
344                         kfree(p);
345                         break;
346                 default:
347                         return 0;
348                 }
349         }
350
351         if (hsb->nls_disk && !hsb->nls_io) {
352                 hsb->nls_io = load_nls_default();
353                 if (!hsb->nls_io) {
354                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
355                         return 0;
356                 }
357         }
358         hsb->s_dir_umask &= 0777;
359         hsb->s_file_umask &= 0577;
360
361         return 1;
362 }
363
364 /*
365  * hfs_read_super()
366  *
367  * This is the function that is responsible for mounting an HFS
368  * filesystem.  It performs all the tasks necessary to get enough data
369  * from the disk to read the root inode.  This includes parsing the
370  * mount options, dealing with Macintosh partitions, reading the
371  * superblock and the allocation bitmap blocks, calling
372  * hfs_btree_init() to get the necessary data about the extents and
373  * catalog B-trees and, finally, reading the root inode into memory.
374  */
375 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
376 {
377         struct hfs_sb_info *sbi;
378         struct hfs_find_data fd;
379         hfs_cat_rec rec;
380         struct inode *root_inode;
381         int res;
382
383         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
384         if (!sbi)
385                 return -ENOMEM;
386         sb->s_fs_info = sbi;
387         INIT_HLIST_HEAD(&sbi->rsrc_inodes);
388
389         res = -EINVAL;
390         if (!parse_options((char *)data, sbi)) {
391                 printk(KERN_ERR "hfs: unable to parse mount options.\n");
392                 goto bail;
393         }
394
395         sb->s_op = &hfs_super_operations;
396         sb->s_flags |= MS_NODIRATIME;
397         mutex_init(&sbi->bitmap_lock);
398
399         res = hfs_mdb_get(sb);
400         if (res) {
401                 if (!silent)
402                         printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
403                                 hfs_mdb_name(sb));
404                 res = -EINVAL;
405                 goto bail;
406         }
407
408         /* try to get the root inode */
409         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
410         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
411         if (!res)
412                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
413         if (res) {
414                 hfs_find_exit(&fd);
415                 goto bail_no_root;
416         }
417         res = -EINVAL;
418         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
419         hfs_find_exit(&fd);
420         if (!root_inode)
421                 goto bail_no_root;
422
423         res = -ENOMEM;
424         sb->s_root = d_alloc_root(root_inode);
425         if (!sb->s_root)
426                 goto bail_iput;
427
428         sb->s_root->d_op = &hfs_dentry_operations;
429
430         /* everything's okay */
431         return 0;
432
433 bail_iput:
434         iput(root_inode);
435 bail_no_root:
436         printk(KERN_ERR "hfs: get root inode failed.\n");
437 bail:
438         hfs_mdb_put(sb);
439         return res;
440 }
441
442 static int hfs_get_sb(struct file_system_type *fs_type,
443                       int flags, const char *dev_name, void *data,
444                       struct vfsmount *mnt)
445 {
446         return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
447 }
448
449 static struct file_system_type hfs_fs_type = {
450         .owner          = THIS_MODULE,
451         .name           = "hfs",
452         .get_sb         = hfs_get_sb,
453         .kill_sb        = kill_block_super,
454         .fs_flags       = FS_REQUIRES_DEV,
455 };
456
457 static void hfs_init_once(void *p)
458 {
459         struct hfs_inode_info *i = p;
460
461         inode_init_once(&i->vfs_inode);
462 }
463
464 static int __init init_hfs_fs(void)
465 {
466         int err;
467
468         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
469                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
470                 hfs_init_once);
471         if (!hfs_inode_cachep)
472                 return -ENOMEM;
473         err = register_filesystem(&hfs_fs_type);
474         if (err)
475                 kmem_cache_destroy(hfs_inode_cachep);
476         return err;
477 }
478
479 static void __exit exit_hfs_fs(void)
480 {
481         unregister_filesystem(&hfs_fs_type);
482         kmem_cache_destroy(hfs_inode_cachep);
483 }
484
485 module_init(init_hfs_fs)
486 module_exit(exit_hfs_fs)