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