Linux-2.6.12-rc2
[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 "affs.h"
18
19 extern struct timezone sys_tz;
20
21 static int affs_statfs(struct super_block *sb, struct kstatfs *buf);
22 static int affs_remount (struct super_block *sb, int *flags, char *data);
23
24 static void
25 affs_put_super(struct super_block *sb)
26 {
27         struct affs_sb_info *sbi = AFFS_SB(sb);
28         pr_debug("AFFS: put_super()\n");
29
30         if (!(sb->s_flags & MS_RDONLY)) {
31                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
32                 secs_to_datestamp(get_seconds(),
33                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
34                 affs_fix_checksum(sb, sbi->s_root_bh);
35                 mark_buffer_dirty(sbi->s_root_bh);
36         }
37
38         if (sbi->s_prefix)
39                 kfree(sbi->s_prefix);
40         affs_free_bitmap(sb);
41         affs_brelse(sbi->s_root_bh);
42         kfree(sbi);
43         sb->s_fs_info = NULL;
44         return;
45 }
46
47 static void
48 affs_write_super(struct super_block *sb)
49 {
50         int clean = 2;
51         struct affs_sb_info *sbi = AFFS_SB(sb);
52
53         if (!(sb->s_flags & MS_RDONLY)) {
54                 //      if (sbi->s_bitmap[i].bm_bh) {
55                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
56                 //                      clean = 0;
57                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
58                 secs_to_datestamp(get_seconds(),
59                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
60                 affs_fix_checksum(sb, sbi->s_root_bh);
61                 mark_buffer_dirty(sbi->s_root_bh);
62                 sb->s_dirt = !clean;    /* redo until bitmap synced */
63         } else
64                 sb->s_dirt = 0;
65
66         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
67 }
68
69 static kmem_cache_t * affs_inode_cachep;
70
71 static struct inode *affs_alloc_inode(struct super_block *sb)
72 {
73         struct affs_inode_info *ei;
74         ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, SLAB_KERNEL);
75         if (!ei)
76                 return NULL;
77         ei->vfs_inode.i_version = 1;
78         return &ei->vfs_inode;
79 }
80
81 static void affs_destroy_inode(struct inode *inode)
82 {
83         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
84 }
85
86 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
87 {
88         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
89
90         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
91             SLAB_CTOR_CONSTRUCTOR) {
92                 init_MUTEX(&ei->i_link_lock);
93                 init_MUTEX(&ei->i_ext_lock);
94                 inode_init_once(&ei->vfs_inode);
95         }
96 }
97
98 static int init_inodecache(void)
99 {
100         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
101                                              sizeof(struct affs_inode_info),
102                                              0, SLAB_RECLAIM_ACCOUNT,
103                                              init_once, NULL);
104         if (affs_inode_cachep == NULL)
105                 return -ENOMEM;
106         return 0;
107 }
108
109 static void destroy_inodecache(void)
110 {
111         if (kmem_cache_destroy(affs_inode_cachep))
112                 printk(KERN_INFO "affs_inode_cache: not all structures were freed\n");
113 }
114
115 static struct super_operations affs_sops = {
116         .alloc_inode    = affs_alloc_inode,
117         .destroy_inode  = affs_destroy_inode,
118         .read_inode     = affs_read_inode,
119         .write_inode    = affs_write_inode,
120         .put_inode      = affs_put_inode,
121         .delete_inode   = affs_delete_inode,
122         .clear_inode    = affs_clear_inode,
123         .put_super      = affs_put_super,
124         .write_super    = affs_write_super,
125         .statfs         = affs_statfs,
126         .remount_fs     = affs_remount,
127 };
128
129 enum {
130         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
131         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
132         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
133 };
134
135 static match_table_t tokens = {
136         {Opt_bs, "bs=%u"},
137         {Opt_mode, "mode=%o"},
138         {Opt_mufs, "mufs"},
139         {Opt_prefix, "prefix=%s"},
140         {Opt_protect, "protect"},
141         {Opt_reserved, "reserved=%u"},
142         {Opt_root, "root=%u"},
143         {Opt_setgid, "setgid=%u"},
144         {Opt_setuid, "setuid=%u"},
145         {Opt_verbose, "verbose"},
146         {Opt_volume, "volume=%s"},
147         {Opt_ignore, "grpquota"},
148         {Opt_ignore, "noquota"},
149         {Opt_ignore, "quota"},
150         {Opt_ignore, "usrquota"},
151         {Opt_err, NULL},
152 };
153
154 static int
155 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
156                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
157 {
158         char *p;
159         substring_t args[MAX_OPT_ARGS];
160
161         /* Fill in defaults */
162
163         *uid        = current->uid;
164         *gid        = current->gid;
165         *reserved   = 2;
166         *root       = -1;
167         *blocksize  = -1;
168         volume[0]   = ':';
169         volume[1]   = 0;
170         *mount_opts = 0;
171         if (!options)
172                 return 1;
173
174         while ((p = strsep(&options, ",")) != NULL) {
175                 int token, n, option;
176                 if (!*p)
177                         continue;
178
179                 token = match_token(p, tokens, args);
180                 switch (token) {
181                 case Opt_bs:
182                         if (match_int(&args[0], &n))
183                                 return -EINVAL;
184                         if (n != 512 && n != 1024 && n != 2048
185                             && n != 4096) {
186                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
187                                 return 0;
188                         }
189                         *blocksize = n;
190                         break;
191                 case Opt_mode:
192                         if (match_octal(&args[0], &option))
193                                 return 1;
194                         *mode = option & 0777;
195                         *mount_opts |= SF_SETMODE;
196                         break;
197                 case Opt_mufs:
198                         *mount_opts |= SF_MUFS;
199                         break;
200                 case Opt_prefix:
201                         if (*prefix) {          /* Free any previous prefix */
202                                 kfree(*prefix);
203                                 *prefix = NULL;
204                         }
205                         *prefix = match_strdup(&args[0]);
206                         if (!*prefix)
207                                 return 0;
208                         *mount_opts |= SF_PREFIX;
209                         break;
210                 case Opt_protect:
211                         *mount_opts |= SF_IMMUTABLE;
212                         break;
213                 case Opt_reserved:
214                         if (match_int(&args[0], reserved))
215                                 return 1;
216                         break;
217                 case Opt_root:
218                         if (match_int(&args[0], root))
219                                 return 1;
220                         break;
221                 case Opt_setgid:
222                         if (match_int(&args[0], &option))
223                                 return 1;
224                         *gid = option;
225                         *mount_opts |= SF_SETGID;
226                         break;
227                 case Opt_setuid:
228                         if (match_int(&args[0], &option))
229                                 return -EINVAL;
230                         *uid = option;
231                         *mount_opts |= SF_SETUID;
232                         break;
233                 case Opt_verbose:
234                         *mount_opts |= SF_VERBOSE;
235                         break;
236                 case Opt_volume: {
237                         char *vol = match_strdup(&args[0]);
238                         strlcpy(volume, vol, 32);
239                         kfree(vol);
240                         break;
241                 }
242                 case Opt_ignore:
243                         /* Silently ignore the quota options */
244                         break;
245                 default:
246                         printk("AFFS: Unrecognized mount option \"%s\" "
247                                         "or missing value\n", p);
248                         return 0;
249                 }
250         }
251         return 1;
252 }
253
254 /* This function definitely needs to be split up. Some fine day I'll
255  * hopefully have the guts to do so. Until then: sorry for the mess.
256  */
257
258 static int affs_fill_super(struct super_block *sb, void *data, int silent)
259 {
260         struct affs_sb_info     *sbi;
261         struct buffer_head      *root_bh = NULL;
262         struct buffer_head      *boot_bh;
263         struct inode            *root_inode = NULL;
264         s32                      root_block;
265         int                      size, blocksize;
266         u32                      chksum;
267         int                      num_bm;
268         int                      i, j;
269         s32                      key;
270         uid_t                    uid;
271         gid_t                    gid;
272         int                      reserved;
273         unsigned long            mount_flags;
274         int                      tmp_flags;     /* fix remount prototype... */
275
276         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
277
278         sb->s_magic             = AFFS_SUPER_MAGIC;
279         sb->s_op                = &affs_sops;
280         sb->s_flags |= MS_NODIRATIME;
281
282         sbi = kmalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
283         if (!sbi)
284                 return -ENOMEM;
285         sb->s_fs_info = sbi;
286         memset(sbi, 0, sizeof(*sbi));
287         init_MUTEX(&sbi->s_bmlock);
288
289         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
290                                 &blocksize,&sbi->s_prefix,
291                                 sbi->s_volume, &mount_flags)) {
292                 printk(KERN_ERR "AFFS: Error parsing options\n");
293                 return -EINVAL;
294         }
295         /* N.B. after this point s_prefix must be released */
296
297         sbi->s_flags   = mount_flags;
298         sbi->s_mode    = i;
299         sbi->s_uid     = uid;
300         sbi->s_gid     = gid;
301         sbi->s_reserved= reserved;
302
303         /* Get the size of the device in 512-byte blocks.
304          * If we later see that the partition uses bigger
305          * blocks, we will have to change it.
306          */
307
308         size = sb->s_bdev->bd_inode->i_size >> 9;
309         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
310
311         affs_set_blocksize(sb, PAGE_SIZE);
312         /* Try to find root block. Its location depends on the block size. */
313
314         i = 512;
315         j = 4096;
316         if (blocksize > 0) {
317                 i = j = blocksize;
318                 size = size / (blocksize / 512);
319         }
320         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
321                 sbi->s_root_block = root_block;
322                 if (root_block < 0)
323                         sbi->s_root_block = (reserved + size - 1) / 2;
324                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
325                 affs_set_blocksize(sb, blocksize);
326                 sbi->s_partition_size = size;
327
328                 /* The root block location that was calculated above is not
329                  * correct if the partition size is an odd number of 512-
330                  * byte blocks, which will be rounded down to a number of
331                  * 1024-byte blocks, and if there were an even number of
332                  * reserved blocks. Ideally, all partition checkers should
333                  * report the real number of blocks of the real blocksize,
334                  * but since this just cannot be done, we have to try to
335                  * find the root block anyways. In the above case, it is one
336                  * block behind the calculated one. So we check this one, too.
337                  */
338                 for (num_bm = 0; num_bm < 2; num_bm++) {
339                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
340                                 "size=%d, reserved=%d\n",
341                                 sb->s_id,
342                                 sbi->s_root_block + num_bm,
343                                 blocksize, size, reserved);
344                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
345                         if (!root_bh)
346                                 continue;
347                         if (!affs_checksum_block(sb, root_bh) &&
348                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
349                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
350                                 sbi->s_hashsize    = blocksize / 4 - 56;
351                                 sbi->s_root_block += num_bm;
352                                 key                        = 1;
353                                 goto got_root;
354                         }
355                         affs_brelse(root_bh);
356                         root_bh = NULL;
357                 }
358         }
359         if (!silent)
360                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
361                         sb->s_id);
362         goto out_error;
363
364         /* N.B. after this point bh must be released */
365 got_root:
366         root_block = sbi->s_root_block;
367
368         /* Find out which kind of FS we have */
369         boot_bh = sb_bread(sb, 0);
370         if (!boot_bh) {
371                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
372                 goto out_error;
373         }
374         chksum = be32_to_cpu(*(__be32 *)boot_bh->b_data);
375         brelse(boot_bh);
376
377         /* Dircache filesystems are compatible with non-dircache ones
378          * when reading. As long as they aren't supported, writing is
379          * not recommended.
380          */
381         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
382              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
383                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
384                         sb->s_id);
385                 sb->s_flags |= MS_RDONLY;
386         }
387         switch (chksum) {
388                 case MUFS_FS:
389                 case MUFS_INTLFFS:
390                 case MUFS_DCFFS:
391                         sbi->s_flags |= SF_MUFS;
392                         /* fall thru */
393                 case FS_INTLFFS:
394                 case FS_DCFFS:
395                         sbi->s_flags |= SF_INTL;
396                         break;
397                 case MUFS_FFS:
398                         sbi->s_flags |= SF_MUFS;
399                         break;
400                 case FS_FFS:
401                         break;
402                 case MUFS_OFS:
403                         sbi->s_flags |= SF_MUFS;
404                         /* fall thru */
405                 case FS_OFS:
406                         sbi->s_flags |= SF_OFS;
407                         sb->s_flags |= MS_NOEXEC;
408                         break;
409                 case MUFS_DCOFS:
410                 case MUFS_INTLOFS:
411                         sbi->s_flags |= SF_MUFS;
412                 case FS_DCOFS:
413                 case FS_INTLOFS:
414                         sbi->s_flags |= SF_INTL | SF_OFS;
415                         sb->s_flags |= MS_NOEXEC;
416                         break;
417                 default:
418                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
419                                 sb->s_id, chksum);
420                         goto out_error;
421         }
422
423         if (mount_flags & SF_VERBOSE) {
424                 chksum = cpu_to_be32(chksum);
425                 printk(KERN_NOTICE "AFFS: Mounting volume \"%*s\": Type=%.3s\\%c, Blocksize=%d\n",
426                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0],
427                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
428                         (char *)&chksum,((char *)&chksum)[3] + '0',blocksize);
429         }
430
431         sb->s_flags |= MS_NODEV | MS_NOSUID;
432
433         sbi->s_data_blksize = sb->s_blocksize;
434         if (sbi->s_flags & SF_OFS)
435                 sbi->s_data_blksize -= 24;
436
437         /* Keep super block in cache */
438         sbi->s_root_bh = root_bh;
439         /* N.B. after this point s_root_bh must be released */
440
441         tmp_flags = sb->s_flags;
442         if (affs_init_bitmap(sb, &tmp_flags))
443                 goto out_error;
444         sb->s_flags = tmp_flags;
445
446         /* set up enough so that it can read an inode */
447
448         root_inode = iget(sb, root_block);
449         sb->s_root = d_alloc_root(root_inode);
450         if (!sb->s_root) {
451                 printk(KERN_ERR "AFFS: Get root inode failed\n");
452                 goto out_error;
453         }
454         sb->s_root->d_op = &affs_dentry_operations;
455
456         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
457         return 0;
458
459         /*
460          * Begin the cascaded cleanup ...
461          */
462 out_error:
463         if (root_inode)
464                 iput(root_inode);
465         if (sbi->s_bitmap)
466                 kfree(sbi->s_bitmap);
467         affs_brelse(root_bh);
468         if (sbi->s_prefix)
469                 kfree(sbi->s_prefix);
470         kfree(sbi);
471         sb->s_fs_info = NULL;
472         return -EINVAL;
473 }
474
475 static int
476 affs_remount(struct super_block *sb, int *flags, char *data)
477 {
478         struct affs_sb_info     *sbi = AFFS_SB(sb);
479         int                      blocksize;
480         uid_t                    uid;
481         gid_t                    gid;
482         int                      mode;
483         int                      reserved;
484         int                      root_block;
485         unsigned long            mount_flags;
486         int                      res = 0;
487
488         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
489
490         *flags |= MS_NODIRATIME;
491
492         if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
493             &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
494                 return -EINVAL;
495         sbi->s_flags = mount_flags;
496         sbi->s_mode  = mode;
497         sbi->s_uid   = uid;
498         sbi->s_gid   = gid;
499
500         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
501                 return 0;
502         if (*flags & MS_RDONLY) {
503                 sb->s_dirt = 1;
504                 while (sb->s_dirt)
505                         affs_write_super(sb);
506                 affs_free_bitmap(sb);
507         } else
508                 res = affs_init_bitmap(sb, flags);
509
510         return res;
511 }
512
513 static int
514 affs_statfs(struct super_block *sb, struct kstatfs *buf)
515 {
516         int              free;
517
518         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
519              AFFS_SB(sb)->s_reserved);
520
521         free          = affs_count_free_blocks(sb);
522         buf->f_type    = AFFS_SUPER_MAGIC;
523         buf->f_bsize   = sb->s_blocksize;
524         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
525         buf->f_bfree   = free;
526         buf->f_bavail  = free;
527         return 0;
528 }
529
530 static struct super_block *affs_get_sb(struct file_system_type *fs_type,
531         int flags, const char *dev_name, void *data)
532 {
533         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super);
534 }
535
536 static struct file_system_type affs_fs_type = {
537         .owner          = THIS_MODULE,
538         .name           = "affs",
539         .get_sb         = affs_get_sb,
540         .kill_sb        = kill_block_super,
541         .fs_flags       = FS_REQUIRES_DEV,
542 };
543
544 static int __init init_affs_fs(void)
545 {
546         int err = init_inodecache();
547         if (err)
548                 goto out1;
549         err = register_filesystem(&affs_fs_type);
550         if (err)
551                 goto out;
552         return 0;
553 out:
554         destroy_inodecache();
555 out1:
556         return err;
557 }
558
559 static void __exit exit_affs_fs(void)
560 {
561         unregister_filesystem(&affs_fs_type);
562         destroy_inodecache();
563 }
564
565 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
566 MODULE_LICENSE("GPL");
567
568 module_init(init_affs_fs)
569 module_exit(exit_affs_fs)