fix affs parse_options()
[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 <linux/smp_lock.h>
20 #include "affs.h"
21
22 extern struct timezone sys_tz;
23
24 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
25 static int affs_remount (struct super_block *sb, int *flags, char *data);
26
27 static void
28 affs_commit_super(struct super_block *sb, int clean)
29 {
30         struct affs_sb_info *sbi = AFFS_SB(sb);
31         struct buffer_head *bh = sbi->s_root_bh;
32         struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
33
34         tail->bm_flag = cpu_to_be32(clean);
35         secs_to_datestamp(get_seconds(), &tail->disk_change);
36         affs_fix_checksum(sb, bh);
37         mark_buffer_dirty(bh);
38 }
39
40 static void
41 affs_put_super(struct super_block *sb)
42 {
43         struct affs_sb_info *sbi = AFFS_SB(sb);
44         pr_debug("AFFS: put_super()\n");
45
46         lock_kernel();
47
48         if (!(sb->s_flags & MS_RDONLY))
49                 affs_commit_super(sb, 1);
50
51         kfree(sbi->s_prefix);
52         affs_free_bitmap(sb);
53         affs_brelse(sbi->s_root_bh);
54         kfree(sbi);
55         sb->s_fs_info = NULL;
56
57         unlock_kernel();
58 }
59
60 static void
61 affs_write_super(struct super_block *sb)
62 {
63         int clean = 2;
64
65         lock_super(sb);
66         if (!(sb->s_flags & MS_RDONLY)) {
67                 //      if (sbi->s_bitmap[i].bm_bh) {
68                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
69                 //                      clean = 0;
70                 affs_commit_super(sb, clean);
71                 sb->s_dirt = !clean;    /* redo until bitmap synced */
72         } else
73                 sb->s_dirt = 0;
74         unlock_super(sb);
75
76         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
77 }
78
79 static int
80 affs_sync_fs(struct super_block *sb, int wait)
81 {
82         lock_super(sb);
83         affs_commit_super(sb, 2);
84         sb->s_dirt = 0;
85         unlock_super(sb);
86         return 0;
87 }
88
89 static struct kmem_cache * affs_inode_cachep;
90
91 static struct inode *affs_alloc_inode(struct super_block *sb)
92 {
93         struct affs_inode_info *i;
94
95         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
96         if (!i)
97                 return NULL;
98
99         i->vfs_inode.i_version = 1;
100         i->i_lc = NULL;
101         i->i_ext_bh = NULL;
102         i->i_pa_cnt = 0;
103
104         return &i->vfs_inode;
105 }
106
107 static void affs_destroy_inode(struct inode *inode)
108 {
109         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
110 }
111
112 static void init_once(void *foo)
113 {
114         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
115
116         init_MUTEX(&ei->i_link_lock);
117         init_MUTEX(&ei->i_ext_lock);
118         inode_init_once(&ei->vfs_inode);
119 }
120
121 static int init_inodecache(void)
122 {
123         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
124                                              sizeof(struct affs_inode_info),
125                                              0, (SLAB_RECLAIM_ACCOUNT|
126                                                 SLAB_MEM_SPREAD),
127                                              init_once);
128         if (affs_inode_cachep == NULL)
129                 return -ENOMEM;
130         return 0;
131 }
132
133 static void destroy_inodecache(void)
134 {
135         kmem_cache_destroy(affs_inode_cachep);
136 }
137
138 static const struct super_operations affs_sops = {
139         .alloc_inode    = affs_alloc_inode,
140         .destroy_inode  = affs_destroy_inode,
141         .write_inode    = affs_write_inode,
142         .delete_inode   = affs_delete_inode,
143         .clear_inode    = affs_clear_inode,
144         .put_super      = affs_put_super,
145         .write_super    = affs_write_super,
146         .sync_fs        = affs_sync_fs,
147         .statfs         = affs_statfs,
148         .remount_fs     = affs_remount,
149         .show_options   = generic_show_options,
150 };
151
152 enum {
153         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
154         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
155         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
156 };
157
158 static const match_table_t tokens = {
159         {Opt_bs, "bs=%u"},
160         {Opt_mode, "mode=%o"},
161         {Opt_mufs, "mufs"},
162         {Opt_prefix, "prefix=%s"},
163         {Opt_protect, "protect"},
164         {Opt_reserved, "reserved=%u"},
165         {Opt_root, "root=%u"},
166         {Opt_setgid, "setgid=%u"},
167         {Opt_setuid, "setuid=%u"},
168         {Opt_verbose, "verbose"},
169         {Opt_volume, "volume=%s"},
170         {Opt_ignore, "grpquota"},
171         {Opt_ignore, "noquota"},
172         {Opt_ignore, "quota"},
173         {Opt_ignore, "usrquota"},
174         {Opt_err, NULL},
175 };
176
177 static int
178 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
179                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
180 {
181         char *p;
182         substring_t args[MAX_OPT_ARGS];
183
184         /* Fill in defaults */
185
186         *uid        = current_uid();
187         *gid        = current_gid();
188         *reserved   = 2;
189         *root       = -1;
190         *blocksize  = -1;
191         volume[0]   = ':';
192         volume[1]   = 0;
193         *mount_opts = 0;
194         if (!options)
195                 return 1;
196
197         while ((p = strsep(&options, ",")) != NULL) {
198                 int token, n, option;
199                 if (!*p)
200                         continue;
201
202                 token = match_token(p, tokens, args);
203                 switch (token) {
204                 case Opt_bs:
205                         if (match_int(&args[0], &n))
206                                 return 0;
207                         if (n != 512 && n != 1024 && n != 2048
208                             && n != 4096) {
209                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
210                                 return 0;
211                         }
212                         *blocksize = n;
213                         break;
214                 case Opt_mode:
215                         if (match_octal(&args[0], &option))
216                                 return 0;
217                         *mode = option & 0777;
218                         *mount_opts |= SF_SETMODE;
219                         break;
220                 case Opt_mufs:
221                         *mount_opts |= SF_MUFS;
222                         break;
223                 case Opt_prefix:
224                         *prefix = match_strdup(&args[0]);
225                         if (!*prefix)
226                                 return 0;
227                         *mount_opts |= SF_PREFIX;
228                         break;
229                 case Opt_protect:
230                         *mount_opts |= SF_IMMUTABLE;
231                         break;
232                 case Opt_reserved:
233                         if (match_int(&args[0], reserved))
234                                 return 0;
235                         break;
236                 case Opt_root:
237                         if (match_int(&args[0], root))
238                                 return 0;
239                         break;
240                 case Opt_setgid:
241                         if (match_int(&args[0], &option))
242                                 return 0;
243                         *gid = option;
244                         *mount_opts |= SF_SETGID;
245                         break;
246                 case Opt_setuid:
247                         if (match_int(&args[0], &option))
248                                 return 0;
249                         *uid = option;
250                         *mount_opts |= SF_SETUID;
251                         break;
252                 case Opt_verbose:
253                         *mount_opts |= SF_VERBOSE;
254                         break;
255                 case Opt_volume: {
256                         char *vol = match_strdup(&args[0]);
257                         if (!vol)
258                                 return 0;
259                         strlcpy(volume, vol, 32);
260                         kfree(vol);
261                         break;
262                 }
263                 case Opt_ignore:
264                         /* Silently ignore the quota options */
265                         break;
266                 default:
267                         printk("AFFS: Unrecognized mount option \"%s\" "
268                                         "or missing value\n", p);
269                         return 0;
270                 }
271         }
272         return 1;
273 }
274
275 /* This function definitely needs to be split up. Some fine day I'll
276  * hopefully have the guts to do so. Until then: sorry for the mess.
277  */
278
279 static int affs_fill_super(struct super_block *sb, void *data, int silent)
280 {
281         struct affs_sb_info     *sbi;
282         struct buffer_head      *root_bh = NULL;
283         struct buffer_head      *boot_bh;
284         struct inode            *root_inode = NULL;
285         s32                      root_block;
286         int                      size, blocksize;
287         u32                      chksum;
288         int                      num_bm;
289         int                      i, j;
290         s32                      key;
291         uid_t                    uid;
292         gid_t                    gid;
293         int                      reserved;
294         unsigned long            mount_flags;
295         int                      tmp_flags;     /* fix remount prototype... */
296         u8                       sig[4];
297         int                      ret = -EINVAL;
298
299         save_mount_options(sb, data);
300
301         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
302
303         sb->s_magic             = AFFS_SUPER_MAGIC;
304         sb->s_op                = &affs_sops;
305         sb->s_flags |= MS_NODIRATIME;
306
307         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
308         if (!sbi)
309                 return -ENOMEM;
310         sb->s_fs_info = sbi;
311         mutex_init(&sbi->s_bmlock);
312         spin_lock_init(&sbi->symlink_lock);
313
314         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
315                                 &blocksize,&sbi->s_prefix,
316                                 sbi->s_volume, &mount_flags)) {
317                 printk(KERN_ERR "AFFS: Error parsing options\n");
318                 kfree(sbi->s_prefix);
319                 kfree(sbi);
320                 return -EINVAL;
321         }
322         /* N.B. after this point s_prefix must be released */
323
324         sbi->s_flags   = mount_flags;
325         sbi->s_mode    = i;
326         sbi->s_uid     = uid;
327         sbi->s_gid     = gid;
328         sbi->s_reserved= reserved;
329
330         /* Get the size of the device in 512-byte blocks.
331          * If we later see that the partition uses bigger
332          * blocks, we will have to change it.
333          */
334
335         size = sb->s_bdev->bd_inode->i_size >> 9;
336         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
337
338         affs_set_blocksize(sb, PAGE_SIZE);
339         /* Try to find root block. Its location depends on the block size. */
340
341         i = 512;
342         j = 4096;
343         if (blocksize > 0) {
344                 i = j = blocksize;
345                 size = size / (blocksize / 512);
346         }
347         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
348                 sbi->s_root_block = root_block;
349                 if (root_block < 0)
350                         sbi->s_root_block = (reserved + size - 1) / 2;
351                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
352                 affs_set_blocksize(sb, blocksize);
353                 sbi->s_partition_size = size;
354
355                 /* The root block location that was calculated above is not
356                  * correct if the partition size is an odd number of 512-
357                  * byte blocks, which will be rounded down to a number of
358                  * 1024-byte blocks, and if there were an even number of
359                  * reserved blocks. Ideally, all partition checkers should
360                  * report the real number of blocks of the real blocksize,
361                  * but since this just cannot be done, we have to try to
362                  * find the root block anyways. In the above case, it is one
363                  * block behind the calculated one. So we check this one, too.
364                  */
365                 for (num_bm = 0; num_bm < 2; num_bm++) {
366                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
367                                 "size=%d, reserved=%d\n",
368                                 sb->s_id,
369                                 sbi->s_root_block + num_bm,
370                                 blocksize, size, reserved);
371                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
372                         if (!root_bh)
373                                 continue;
374                         if (!affs_checksum_block(sb, root_bh) &&
375                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
376                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
377                                 sbi->s_hashsize    = blocksize / 4 - 56;
378                                 sbi->s_root_block += num_bm;
379                                 key                        = 1;
380                                 goto got_root;
381                         }
382                         affs_brelse(root_bh);
383                         root_bh = NULL;
384                 }
385         }
386         if (!silent)
387                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
388                         sb->s_id);
389         goto out_error;
390
391         /* N.B. after this point bh must be released */
392 got_root:
393         root_block = sbi->s_root_block;
394
395         /* Find out which kind of FS we have */
396         boot_bh = sb_bread(sb, 0);
397         if (!boot_bh) {
398                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
399                 goto out_error;
400         }
401         memcpy(sig, boot_bh->b_data, 4);
402         brelse(boot_bh);
403         chksum = be32_to_cpu(*(__be32 *)sig);
404
405         /* Dircache filesystems are compatible with non-dircache ones
406          * when reading. As long as they aren't supported, writing is
407          * not recommended.
408          */
409         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
410              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
411                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
412                         sb->s_id);
413                 sb->s_flags |= MS_RDONLY;
414         }
415         switch (chksum) {
416                 case MUFS_FS:
417                 case MUFS_INTLFFS:
418                 case MUFS_DCFFS:
419                         sbi->s_flags |= SF_MUFS;
420                         /* fall thru */
421                 case FS_INTLFFS:
422                 case FS_DCFFS:
423                         sbi->s_flags |= SF_INTL;
424                         break;
425                 case MUFS_FFS:
426                         sbi->s_flags |= SF_MUFS;
427                         break;
428                 case FS_FFS:
429                         break;
430                 case MUFS_OFS:
431                         sbi->s_flags |= SF_MUFS;
432                         /* fall thru */
433                 case FS_OFS:
434                         sbi->s_flags |= SF_OFS;
435                         sb->s_flags |= MS_NOEXEC;
436                         break;
437                 case MUFS_DCOFS:
438                 case MUFS_INTLOFS:
439                         sbi->s_flags |= SF_MUFS;
440                 case FS_DCOFS:
441                 case FS_INTLOFS:
442                         sbi->s_flags |= SF_INTL | SF_OFS;
443                         sb->s_flags |= MS_NOEXEC;
444                         break;
445                 default:
446                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
447                                 sb->s_id, chksum);
448                         goto out_error;
449         }
450
451         if (mount_flags & SF_VERBOSE) {
452                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
453                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
454                         len > 31 ? 31 : len,
455                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
456                         sig, sig[3] + '0', blocksize);
457         }
458
459         sb->s_flags |= MS_NODEV | MS_NOSUID;
460
461         sbi->s_data_blksize = sb->s_blocksize;
462         if (sbi->s_flags & SF_OFS)
463                 sbi->s_data_blksize -= 24;
464
465         /* Keep super block in cache */
466         sbi->s_root_bh = root_bh;
467         /* N.B. after this point s_root_bh must be released */
468
469         tmp_flags = sb->s_flags;
470         if (affs_init_bitmap(sb, &tmp_flags))
471                 goto out_error;
472         sb->s_flags = tmp_flags;
473
474         /* set up enough so that it can read an inode */
475
476         root_inode = affs_iget(sb, root_block);
477         if (IS_ERR(root_inode)) {
478                 ret = PTR_ERR(root_inode);
479                 goto out_error_noinode;
480         }
481
482         sb->s_root = d_alloc_root(root_inode);
483         if (!sb->s_root) {
484                 printk(KERN_ERR "AFFS: Get root inode failed\n");
485                 goto out_error;
486         }
487         sb->s_root->d_op = &affs_dentry_operations;
488
489         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
490         return 0;
491
492         /*
493          * Begin the cascaded cleanup ...
494          */
495 out_error:
496         if (root_inode)
497                 iput(root_inode);
498 out_error_noinode:
499         kfree(sbi->s_bitmap);
500         affs_brelse(root_bh);
501         kfree(sbi->s_prefix);
502         kfree(sbi);
503         sb->s_fs_info = NULL;
504         return ret;
505 }
506
507 static int
508 affs_remount(struct super_block *sb, int *flags, char *data)
509 {
510         struct affs_sb_info     *sbi = AFFS_SB(sb);
511         int                      blocksize;
512         uid_t                    uid;
513         gid_t                    gid;
514         int                      mode;
515         int                      reserved;
516         int                      root_block;
517         unsigned long            mount_flags;
518         int                      res = 0;
519         char                    *new_opts = kstrdup(data, GFP_KERNEL);
520         char                     volume[32];
521         char                    *prefix = NULL;
522
523         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
524
525         *flags |= MS_NODIRATIME;
526
527         memcpy(volume, sbi->s_volume, 32);
528         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
529                            &blocksize, &prefix, volume,
530                            &mount_flags)) {
531                 kfree(prefix);
532                 kfree(new_opts);
533                 return -EINVAL;
534         }
535         lock_kernel();
536         replace_mount_options(sb, new_opts);
537
538         sbi->s_flags = mount_flags;
539         sbi->s_mode  = mode;
540         sbi->s_uid   = uid;
541         sbi->s_gid   = gid;
542         /* protect against readers */
543         spin_lock(&sbi->symlink_lock);
544         if (prefix) {
545                 kfree(sbi->s_prefix);
546                 sbi->s_prefix = prefix;
547         }
548         memcpy(sbi->s_volume, volume, 32);
549         spin_unlock(&sbi->symlink_lock);
550
551         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
552                 unlock_kernel();
553                 return 0;
554         }
555         if (*flags & MS_RDONLY) {
556                 sb->s_dirt = 1;
557                 while (sb->s_dirt)
558                         affs_write_super(sb);
559                 affs_free_bitmap(sb);
560         } else
561                 res = affs_init_bitmap(sb, flags);
562
563         unlock_kernel();
564         return res;
565 }
566
567 static int
568 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
569 {
570         struct super_block *sb = dentry->d_sb;
571         int              free;
572         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
573
574         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
575              AFFS_SB(sb)->s_reserved);
576
577         free          = affs_count_free_blocks(sb);
578         buf->f_type    = AFFS_SUPER_MAGIC;
579         buf->f_bsize   = sb->s_blocksize;
580         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
581         buf->f_bfree   = free;
582         buf->f_bavail  = free;
583         buf->f_fsid.val[0] = (u32)id;
584         buf->f_fsid.val[1] = (u32)(id >> 32);
585         buf->f_namelen = 30;
586         return 0;
587 }
588
589 static int affs_get_sb(struct file_system_type *fs_type,
590         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
591 {
592         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
593                            mnt);
594 }
595
596 static struct file_system_type affs_fs_type = {
597         .owner          = THIS_MODULE,
598         .name           = "affs",
599         .get_sb         = affs_get_sb,
600         .kill_sb        = kill_block_super,
601         .fs_flags       = FS_REQUIRES_DEV,
602 };
603
604 static int __init init_affs_fs(void)
605 {
606         int err = init_inodecache();
607         if (err)
608                 goto out1;
609         err = register_filesystem(&affs_fs_type);
610         if (err)
611                 goto out;
612         return 0;
613 out:
614         destroy_inodecache();
615 out1:
616         return err;
617 }
618
619 static void __exit exit_affs_fs(void)
620 {
621         unregister_filesystem(&affs_fs_type);
622         destroy_inodecache();
623 }
624
625 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
626 MODULE_LICENSE("GPL");
627
628 module_init(init_affs_fs)
629 module_exit(exit_affs_fs)