mount options: fix affs
[linux-2.6.git] / fs / affs / super.c
1 /*
2  *  linux/fs/affs/inode.c
3  *
4  *  (c) 1996  Hans-Joachim Widmaier - Rewritten
5  *
6  *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
7  *
8  *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
9  *
10  *  (C) 1991  Linus Torvalds - minix filesystem
11  */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/statfs.h>
16 #include <linux/parser.h>
17 #include <linux/magic.h>
18 #include <linux/sched.h>
19 #include "affs.h"
20
21 extern struct timezone sys_tz;
22
23 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
24 static int affs_remount (struct super_block *sb, int *flags, char *data);
25
26 static void
27 affs_put_super(struct super_block *sb)
28 {
29         struct affs_sb_info *sbi = AFFS_SB(sb);
30         pr_debug("AFFS: put_super()\n");
31
32         if (!(sb->s_flags & MS_RDONLY)) {
33                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
34                 secs_to_datestamp(get_seconds(),
35                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
36                 affs_fix_checksum(sb, sbi->s_root_bh);
37                 mark_buffer_dirty(sbi->s_root_bh);
38         }
39
40         kfree(sbi->s_prefix);
41         affs_free_bitmap(sb);
42         affs_brelse(sbi->s_root_bh);
43         kfree(sbi);
44         sb->s_fs_info = NULL;
45         return;
46 }
47
48 static void
49 affs_write_super(struct super_block *sb)
50 {
51         int clean = 2;
52         struct affs_sb_info *sbi = AFFS_SB(sb);
53
54         if (!(sb->s_flags & MS_RDONLY)) {
55                 //      if (sbi->s_bitmap[i].bm_bh) {
56                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
57                 //                      clean = 0;
58                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
59                 secs_to_datestamp(get_seconds(),
60                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
61                 affs_fix_checksum(sb, sbi->s_root_bh);
62                 mark_buffer_dirty(sbi->s_root_bh);
63                 sb->s_dirt = !clean;    /* redo until bitmap synced */
64         } else
65                 sb->s_dirt = 0;
66
67         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
68 }
69
70 static struct kmem_cache * affs_inode_cachep;
71
72 static struct inode *affs_alloc_inode(struct super_block *sb)
73 {
74         struct affs_inode_info *ei;
75         ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
76         if (!ei)
77                 return NULL;
78         ei->vfs_inode.i_version = 1;
79         return &ei->vfs_inode;
80 }
81
82 static void affs_destroy_inode(struct inode *inode)
83 {
84         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
85 }
86
87 static void init_once(struct kmem_cache *cachep, void *foo)
88 {
89         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
90
91         init_MUTEX(&ei->i_link_lock);
92         init_MUTEX(&ei->i_ext_lock);
93         inode_init_once(&ei->vfs_inode);
94 }
95
96 static int init_inodecache(void)
97 {
98         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
99                                              sizeof(struct affs_inode_info),
100                                              0, (SLAB_RECLAIM_ACCOUNT|
101                                                 SLAB_MEM_SPREAD),
102                                              init_once);
103         if (affs_inode_cachep == NULL)
104                 return -ENOMEM;
105         return 0;
106 }
107
108 static void destroy_inodecache(void)
109 {
110         kmem_cache_destroy(affs_inode_cachep);
111 }
112
113 static const struct super_operations affs_sops = {
114         .alloc_inode    = affs_alloc_inode,
115         .destroy_inode  = affs_destroy_inode,
116         .write_inode    = affs_write_inode,
117         .put_inode      = affs_put_inode,
118         .drop_inode     = affs_drop_inode,
119         .delete_inode   = affs_delete_inode,
120         .clear_inode    = affs_clear_inode,
121         .put_super      = affs_put_super,
122         .write_super    = affs_write_super,
123         .statfs         = affs_statfs,
124         .remount_fs     = affs_remount,
125         .show_options   = generic_show_options,
126 };
127
128 enum {
129         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
130         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
131         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
132 };
133
134 static match_table_t tokens = {
135         {Opt_bs, "bs=%u"},
136         {Opt_mode, "mode=%o"},
137         {Opt_mufs, "mufs"},
138         {Opt_prefix, "prefix=%s"},
139         {Opt_protect, "protect"},
140         {Opt_reserved, "reserved=%u"},
141         {Opt_root, "root=%u"},
142         {Opt_setgid, "setgid=%u"},
143         {Opt_setuid, "setuid=%u"},
144         {Opt_verbose, "verbose"},
145         {Opt_volume, "volume=%s"},
146         {Opt_ignore, "grpquota"},
147         {Opt_ignore, "noquota"},
148         {Opt_ignore, "quota"},
149         {Opt_ignore, "usrquota"},
150         {Opt_err, NULL},
151 };
152
153 static int
154 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
155                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
156 {
157         char *p;
158         substring_t args[MAX_OPT_ARGS];
159
160         /* Fill in defaults */
161
162         *uid        = current->uid;
163         *gid        = current->gid;
164         *reserved   = 2;
165         *root       = -1;
166         *blocksize  = -1;
167         volume[0]   = ':';
168         volume[1]   = 0;
169         *mount_opts = 0;
170         if (!options)
171                 return 1;
172
173         while ((p = strsep(&options, ",")) != NULL) {
174                 int token, n, option;
175                 if (!*p)
176                         continue;
177
178                 token = match_token(p, tokens, args);
179                 switch (token) {
180                 case Opt_bs:
181                         if (match_int(&args[0], &n))
182                                 return -EINVAL;
183                         if (n != 512 && n != 1024 && n != 2048
184                             && n != 4096) {
185                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
186                                 return 0;
187                         }
188                         *blocksize = n;
189                         break;
190                 case Opt_mode:
191                         if (match_octal(&args[0], &option))
192                                 return 1;
193                         *mode = option & 0777;
194                         *mount_opts |= SF_SETMODE;
195                         break;
196                 case Opt_mufs:
197                         *mount_opts |= SF_MUFS;
198                         break;
199                 case Opt_prefix:
200                         /* Free any previous prefix */
201                         kfree(*prefix);
202                         *prefix = NULL;
203                         *prefix = match_strdup(&args[0]);
204                         if (!*prefix)
205                                 return 0;
206                         *mount_opts |= SF_PREFIX;
207                         break;
208                 case Opt_protect:
209                         *mount_opts |= SF_IMMUTABLE;
210                         break;
211                 case Opt_reserved:
212                         if (match_int(&args[0], reserved))
213                                 return 1;
214                         break;
215                 case Opt_root:
216                         if (match_int(&args[0], root))
217                                 return 1;
218                         break;
219                 case Opt_setgid:
220                         if (match_int(&args[0], &option))
221                                 return 1;
222                         *gid = option;
223                         *mount_opts |= SF_SETGID;
224                         break;
225                 case Opt_setuid:
226                         if (match_int(&args[0], &option))
227                                 return -EINVAL;
228                         *uid = option;
229                         *mount_opts |= SF_SETUID;
230                         break;
231                 case Opt_verbose:
232                         *mount_opts |= SF_VERBOSE;
233                         break;
234                 case Opt_volume: {
235                         char *vol = match_strdup(&args[0]);
236                         strlcpy(volume, vol, 32);
237                         kfree(vol);
238                         break;
239                 }
240                 case Opt_ignore:
241                         /* Silently ignore the quota options */
242                         break;
243                 default:
244                         printk("AFFS: Unrecognized mount option \"%s\" "
245                                         "or missing value\n", p);
246                         return 0;
247                 }
248         }
249         return 1;
250 }
251
252 /* This function definitely needs to be split up. Some fine day I'll
253  * hopefully have the guts to do so. Until then: sorry for the mess.
254  */
255
256 static int affs_fill_super(struct super_block *sb, void *data, int silent)
257 {
258         struct affs_sb_info     *sbi;
259         struct buffer_head      *root_bh = NULL;
260         struct buffer_head      *boot_bh;
261         struct inode            *root_inode = NULL;
262         s32                      root_block;
263         int                      size, blocksize;
264         u32                      chksum;
265         int                      num_bm;
266         int                      i, j;
267         s32                      key;
268         uid_t                    uid;
269         gid_t                    gid;
270         int                      reserved;
271         unsigned long            mount_flags;
272         int                      tmp_flags;     /* fix remount prototype... */
273         u8                       sig[4];
274         int                      ret = -EINVAL;
275
276         save_mount_options(sb, data);
277
278         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
279
280         sb->s_magic             = AFFS_SUPER_MAGIC;
281         sb->s_op                = &affs_sops;
282         sb->s_flags |= MS_NODIRATIME;
283
284         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
285         if (!sbi)
286                 return -ENOMEM;
287         sb->s_fs_info = sbi;
288         init_MUTEX(&sbi->s_bmlock);
289
290         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
291                                 &blocksize,&sbi->s_prefix,
292                                 sbi->s_volume, &mount_flags)) {
293                 printk(KERN_ERR "AFFS: Error parsing options\n");
294                 return -EINVAL;
295         }
296         /* N.B. after this point s_prefix must be released */
297
298         sbi->s_flags   = mount_flags;
299         sbi->s_mode    = i;
300         sbi->s_uid     = uid;
301         sbi->s_gid     = gid;
302         sbi->s_reserved= reserved;
303
304         /* Get the size of the device in 512-byte blocks.
305          * If we later see that the partition uses bigger
306          * blocks, we will have to change it.
307          */
308
309         size = sb->s_bdev->bd_inode->i_size >> 9;
310         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
311
312         affs_set_blocksize(sb, PAGE_SIZE);
313         /* Try to find root block. Its location depends on the block size. */
314
315         i = 512;
316         j = 4096;
317         if (blocksize > 0) {
318                 i = j = blocksize;
319                 size = size / (blocksize / 512);
320         }
321         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
322                 sbi->s_root_block = root_block;
323                 if (root_block < 0)
324                         sbi->s_root_block = (reserved + size - 1) / 2;
325                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
326                 affs_set_blocksize(sb, blocksize);
327                 sbi->s_partition_size = size;
328
329                 /* The root block location that was calculated above is not
330                  * correct if the partition size is an odd number of 512-
331                  * byte blocks, which will be rounded down to a number of
332                  * 1024-byte blocks, and if there were an even number of
333                  * reserved blocks. Ideally, all partition checkers should
334                  * report the real number of blocks of the real blocksize,
335                  * but since this just cannot be done, we have to try to
336                  * find the root block anyways. In the above case, it is one
337                  * block behind the calculated one. So we check this one, too.
338                  */
339                 for (num_bm = 0; num_bm < 2; num_bm++) {
340                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
341                                 "size=%d, reserved=%d\n",
342                                 sb->s_id,
343                                 sbi->s_root_block + num_bm,
344                                 blocksize, size, reserved);
345                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
346                         if (!root_bh)
347                                 continue;
348                         if (!affs_checksum_block(sb, root_bh) &&
349                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
350                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
351                                 sbi->s_hashsize    = blocksize / 4 - 56;
352                                 sbi->s_root_block += num_bm;
353                                 key                        = 1;
354                                 goto got_root;
355                         }
356                         affs_brelse(root_bh);
357                         root_bh = NULL;
358                 }
359         }
360         if (!silent)
361                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
362                         sb->s_id);
363         goto out_error;
364
365         /* N.B. after this point bh must be released */
366 got_root:
367         root_block = sbi->s_root_block;
368
369         /* Find out which kind of FS we have */
370         boot_bh = sb_bread(sb, 0);
371         if (!boot_bh) {
372                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
373                 goto out_error;
374         }
375         memcpy(sig, boot_bh->b_data, 4);
376         brelse(boot_bh);
377         chksum = be32_to_cpu(*(__be32 *)sig);
378
379         /* Dircache filesystems are compatible with non-dircache ones
380          * when reading. As long as they aren't supported, writing is
381          * not recommended.
382          */
383         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
384              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
385                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
386                         sb->s_id);
387                 sb->s_flags |= MS_RDONLY;
388         }
389         switch (chksum) {
390                 case MUFS_FS:
391                 case MUFS_INTLFFS:
392                 case MUFS_DCFFS:
393                         sbi->s_flags |= SF_MUFS;
394                         /* fall thru */
395                 case FS_INTLFFS:
396                 case FS_DCFFS:
397                         sbi->s_flags |= SF_INTL;
398                         break;
399                 case MUFS_FFS:
400                         sbi->s_flags |= SF_MUFS;
401                         break;
402                 case FS_FFS:
403                         break;
404                 case MUFS_OFS:
405                         sbi->s_flags |= SF_MUFS;
406                         /* fall thru */
407                 case FS_OFS:
408                         sbi->s_flags |= SF_OFS;
409                         sb->s_flags |= MS_NOEXEC;
410                         break;
411                 case MUFS_DCOFS:
412                 case MUFS_INTLOFS:
413                         sbi->s_flags |= SF_MUFS;
414                 case FS_DCOFS:
415                 case FS_INTLOFS:
416                         sbi->s_flags |= SF_INTL | SF_OFS;
417                         sb->s_flags |= MS_NOEXEC;
418                         break;
419                 default:
420                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
421                                 sb->s_id, chksum);
422                         goto out_error;
423         }
424
425         if (mount_flags & SF_VERBOSE) {
426                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
427                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
428                         len > 31 ? 31 : len,
429                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
430                         sig, sig[3] + '0', blocksize);
431         }
432
433         sb->s_flags |= MS_NODEV | MS_NOSUID;
434
435         sbi->s_data_blksize = sb->s_blocksize;
436         if (sbi->s_flags & SF_OFS)
437                 sbi->s_data_blksize -= 24;
438
439         /* Keep super block in cache */
440         sbi->s_root_bh = root_bh;
441         /* N.B. after this point s_root_bh must be released */
442
443         tmp_flags = sb->s_flags;
444         if (affs_init_bitmap(sb, &tmp_flags))
445                 goto out_error;
446         sb->s_flags = tmp_flags;
447
448         /* set up enough so that it can read an inode */
449
450         root_inode = affs_iget(sb, root_block);
451         if (IS_ERR(root_inode)) {
452                 ret = PTR_ERR(root_inode);
453                 goto out_error_noinode;
454         }
455
456         sb->s_root = d_alloc_root(root_inode);
457         if (!sb->s_root) {
458                 printk(KERN_ERR "AFFS: Get root inode failed\n");
459                 goto out_error;
460         }
461         sb->s_root->d_op = &affs_dentry_operations;
462
463         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
464         return 0;
465
466         /*
467          * Begin the cascaded cleanup ...
468          */
469 out_error:
470         if (root_inode)
471                 iput(root_inode);
472 out_error_noinode:
473         kfree(sbi->s_bitmap);
474         affs_brelse(root_bh);
475         kfree(sbi->s_prefix);
476         kfree(sbi);
477         sb->s_fs_info = NULL;
478         return ret;
479 }
480
481 static int
482 affs_remount(struct super_block *sb, int *flags, char *data)
483 {
484         struct affs_sb_info     *sbi = AFFS_SB(sb);
485         int                      blocksize;
486         uid_t                    uid;
487         gid_t                    gid;
488         int                      mode;
489         int                      reserved;
490         int                      root_block;
491         unsigned long            mount_flags;
492         int                      res = 0;
493         char                    *new_opts = kstrdup(data, GFP_KERNEL);
494
495         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
496
497         *flags |= MS_NODIRATIME;
498
499         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
500                            &blocksize, &sbi->s_prefix, sbi->s_volume,
501                            &mount_flags)) {
502                 kfree(new_opts);
503                 return -EINVAL;
504         }
505         kfree(sb->s_options);
506         sb->s_options = new_opts;
507
508         sbi->s_flags = mount_flags;
509         sbi->s_mode  = mode;
510         sbi->s_uid   = uid;
511         sbi->s_gid   = gid;
512
513         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
514                 return 0;
515         if (*flags & MS_RDONLY) {
516                 sb->s_dirt = 1;
517                 while (sb->s_dirt)
518                         affs_write_super(sb);
519                 affs_free_bitmap(sb);
520         } else
521                 res = affs_init_bitmap(sb, flags);
522
523         return res;
524 }
525
526 static int
527 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
528 {
529         struct super_block *sb = dentry->d_sb;
530         int              free;
531
532         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
533              AFFS_SB(sb)->s_reserved);
534
535         free          = affs_count_free_blocks(sb);
536         buf->f_type    = AFFS_SUPER_MAGIC;
537         buf->f_bsize   = sb->s_blocksize;
538         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
539         buf->f_bfree   = free;
540         buf->f_bavail  = free;
541         return 0;
542 }
543
544 static int affs_get_sb(struct file_system_type *fs_type,
545         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
546 {
547         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
548                            mnt);
549 }
550
551 static struct file_system_type affs_fs_type = {
552         .owner          = THIS_MODULE,
553         .name           = "affs",
554         .get_sb         = affs_get_sb,
555         .kill_sb        = kill_block_super,
556         .fs_flags       = FS_REQUIRES_DEV,
557 };
558
559 static int __init init_affs_fs(void)
560 {
561         int err = init_inodecache();
562         if (err)
563                 goto out1;
564         err = register_filesystem(&affs_fs_type);
565         if (err)
566                 goto out;
567         return 0;
568 out:
569         destroy_inodecache();
570 out1:
571         return err;
572 }
573
574 static void __exit exit_affs_fs(void)
575 {
576         unregister_filesystem(&affs_fs_type);
577         destroy_inodecache();
578 }
579
580 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
581 MODULE_LICENSE("GPL");
582
583 module_init(init_affs_fs)
584 module_exit(exit_affs_fs)