Merge git://git.infradead.org/mtd-2.6
[linux-2.6] / 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         kfree(sbi->s_prefix);
39         affs_free_bitmap(sb);
40         affs_brelse(sbi->s_root_bh);
41         kfree(sbi);
42         sb->s_fs_info = NULL;
43         return;
44 }
45
46 static void
47 affs_write_super(struct super_block *sb)
48 {
49         int clean = 2;
50         struct affs_sb_info *sbi = AFFS_SB(sb);
51
52         if (!(sb->s_flags & MS_RDONLY)) {
53                 //      if (sbi->s_bitmap[i].bm_bh) {
54                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
55                 //                      clean = 0;
56                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
57                 secs_to_datestamp(get_seconds(),
58                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
59                 affs_fix_checksum(sb, sbi->s_root_bh);
60                 mark_buffer_dirty(sbi->s_root_bh);
61                 sb->s_dirt = !clean;    /* redo until bitmap synced */
62         } else
63                 sb->s_dirt = 0;
64
65         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
66 }
67
68 static kmem_cache_t * affs_inode_cachep;
69
70 static struct inode *affs_alloc_inode(struct super_block *sb)
71 {
72         struct affs_inode_info *ei;
73         ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, SLAB_KERNEL);
74         if (!ei)
75                 return NULL;
76         ei->vfs_inode.i_version = 1;
77         return &ei->vfs_inode;
78 }
79
80 static void affs_destroy_inode(struct inode *inode)
81 {
82         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
83 }
84
85 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
86 {
87         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
88
89         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
90             SLAB_CTOR_CONSTRUCTOR) {
91                 init_MUTEX(&ei->i_link_lock);
92                 init_MUTEX(&ei->i_ext_lock);
93                 inode_init_once(&ei->vfs_inode);
94         }
95 }
96
97 static int init_inodecache(void)
98 {
99         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
100                                              sizeof(struct affs_inode_info),
101                                              0, (SLAB_RECLAIM_ACCOUNT|
102                                                 SLAB_MEM_SPREAD),
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                         /* Free any previous prefix */
202                         kfree(*prefix);
203                         *prefix = NULL;
204                         *prefix = match_strdup(&args[0]);
205                         if (!*prefix)
206                                 return 0;
207                         *mount_opts |= SF_PREFIX;
208                         break;
209                 case Opt_protect:
210                         *mount_opts |= SF_IMMUTABLE;
211                         break;
212                 case Opt_reserved:
213                         if (match_int(&args[0], reserved))
214                                 return 1;
215                         break;
216                 case Opt_root:
217                         if (match_int(&args[0], root))
218                                 return 1;
219                         break;
220                 case Opt_setgid:
221                         if (match_int(&args[0], &option))
222                                 return 1;
223                         *gid = option;
224                         *mount_opts |= SF_SETGID;
225                         break;
226                 case Opt_setuid:
227                         if (match_int(&args[0], &option))
228                                 return -EINVAL;
229                         *uid = option;
230                         *mount_opts |= SF_SETUID;
231                         break;
232                 case Opt_verbose:
233                         *mount_opts |= SF_VERBOSE;
234                         break;
235                 case Opt_volume: {
236                         char *vol = match_strdup(&args[0]);
237                         strlcpy(volume, vol, 32);
238                         kfree(vol);
239                         break;
240                 }
241                 case Opt_ignore:
242                         /* Silently ignore the quota options */
243                         break;
244                 default:
245                         printk("AFFS: Unrecognized mount option \"%s\" "
246                                         "or missing value\n", p);
247                         return 0;
248                 }
249         }
250         return 1;
251 }
252
253 /* This function definitely needs to be split up. Some fine day I'll
254  * hopefully have the guts to do so. Until then: sorry for the mess.
255  */
256
257 static int affs_fill_super(struct super_block *sb, void *data, int silent)
258 {
259         struct affs_sb_info     *sbi;
260         struct buffer_head      *root_bh = NULL;
261         struct buffer_head      *boot_bh;
262         struct inode            *root_inode = NULL;
263         s32                      root_block;
264         int                      size, blocksize;
265         u32                      chksum;
266         int                      num_bm;
267         int                      i, j;
268         s32                      key;
269         uid_t                    uid;
270         gid_t                    gid;
271         int                      reserved;
272         unsigned long            mount_flags;
273         int                      tmp_flags;     /* fix remount prototype... */
274
275         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
276
277         sb->s_magic             = AFFS_SUPER_MAGIC;
278         sb->s_op                = &affs_sops;
279         sb->s_flags |= MS_NODIRATIME;
280
281         sbi = kmalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
282         if (!sbi)
283                 return -ENOMEM;
284         sb->s_fs_info = sbi;
285         memset(sbi, 0, sizeof(*sbi));
286         init_MUTEX(&sbi->s_bmlock);
287
288         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
289                                 &blocksize,&sbi->s_prefix,
290                                 sbi->s_volume, &mount_flags)) {
291                 printk(KERN_ERR "AFFS: Error parsing options\n");
292                 return -EINVAL;
293         }
294         /* N.B. after this point s_prefix must be released */
295
296         sbi->s_flags   = mount_flags;
297         sbi->s_mode    = i;
298         sbi->s_uid     = uid;
299         sbi->s_gid     = gid;
300         sbi->s_reserved= reserved;
301
302         /* Get the size of the device in 512-byte blocks.
303          * If we later see that the partition uses bigger
304          * blocks, we will have to change it.
305          */
306
307         size = sb->s_bdev->bd_inode->i_size >> 9;
308         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
309
310         affs_set_blocksize(sb, PAGE_SIZE);
311         /* Try to find root block. Its location depends on the block size. */
312
313         i = 512;
314         j = 4096;
315         if (blocksize > 0) {
316                 i = j = blocksize;
317                 size = size / (blocksize / 512);
318         }
319         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
320                 sbi->s_root_block = root_block;
321                 if (root_block < 0)
322                         sbi->s_root_block = (reserved + size - 1) / 2;
323                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
324                 affs_set_blocksize(sb, blocksize);
325                 sbi->s_partition_size = size;
326
327                 /* The root block location that was calculated above is not
328                  * correct if the partition size is an odd number of 512-
329                  * byte blocks, which will be rounded down to a number of
330                  * 1024-byte blocks, and if there were an even number of
331                  * reserved blocks. Ideally, all partition checkers should
332                  * report the real number of blocks of the real blocksize,
333                  * but since this just cannot be done, we have to try to
334                  * find the root block anyways. In the above case, it is one
335                  * block behind the calculated one. So we check this one, too.
336                  */
337                 for (num_bm = 0; num_bm < 2; num_bm++) {
338                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
339                                 "size=%d, reserved=%d\n",
340                                 sb->s_id,
341                                 sbi->s_root_block + num_bm,
342                                 blocksize, size, reserved);
343                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
344                         if (!root_bh)
345                                 continue;
346                         if (!affs_checksum_block(sb, root_bh) &&
347                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
348                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
349                                 sbi->s_hashsize    = blocksize / 4 - 56;
350                                 sbi->s_root_block += num_bm;
351                                 key                        = 1;
352                                 goto got_root;
353                         }
354                         affs_brelse(root_bh);
355                         root_bh = NULL;
356                 }
357         }
358         if (!silent)
359                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
360                         sb->s_id);
361         goto out_error;
362
363         /* N.B. after this point bh must be released */
364 got_root:
365         root_block = sbi->s_root_block;
366
367         /* Find out which kind of FS we have */
368         boot_bh = sb_bread(sb, 0);
369         if (!boot_bh) {
370                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
371                 goto out_error;
372         }
373         chksum = be32_to_cpu(*(__be32 *)boot_bh->b_data);
374         brelse(boot_bh);
375
376         /* Dircache filesystems are compatible with non-dircache ones
377          * when reading. As long as they aren't supported, writing is
378          * not recommended.
379          */
380         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
381              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
382                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
383                         sb->s_id);
384                 sb->s_flags |= MS_RDONLY;
385         }
386         switch (chksum) {
387                 case MUFS_FS:
388                 case MUFS_INTLFFS:
389                 case MUFS_DCFFS:
390                         sbi->s_flags |= SF_MUFS;
391                         /* fall thru */
392                 case FS_INTLFFS:
393                 case FS_DCFFS:
394                         sbi->s_flags |= SF_INTL;
395                         break;
396                 case MUFS_FFS:
397                         sbi->s_flags |= SF_MUFS;
398                         break;
399                 case FS_FFS:
400                         break;
401                 case MUFS_OFS:
402                         sbi->s_flags |= SF_MUFS;
403                         /* fall thru */
404                 case FS_OFS:
405                         sbi->s_flags |= SF_OFS;
406                         sb->s_flags |= MS_NOEXEC;
407                         break;
408                 case MUFS_DCOFS:
409                 case MUFS_INTLOFS:
410                         sbi->s_flags |= SF_MUFS;
411                 case FS_DCOFS:
412                 case FS_INTLOFS:
413                         sbi->s_flags |= SF_INTL | SF_OFS;
414                         sb->s_flags |= MS_NOEXEC;
415                         break;
416                 default:
417                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
418                                 sb->s_id, chksum);
419                         goto out_error;
420         }
421
422         if (mount_flags & SF_VERBOSE) {
423                 chksum = cpu_to_be32(chksum);
424                 printk(KERN_NOTICE "AFFS: Mounting volume \"%*s\": Type=%.3s\\%c, Blocksize=%d\n",
425                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0],
426                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
427                         (char *)&chksum,((char *)&chksum)[3] + '0',blocksize);
428         }
429
430         sb->s_flags |= MS_NODEV | MS_NOSUID;
431
432         sbi->s_data_blksize = sb->s_blocksize;
433         if (sbi->s_flags & SF_OFS)
434                 sbi->s_data_blksize -= 24;
435
436         /* Keep super block in cache */
437         sbi->s_root_bh = root_bh;
438         /* N.B. after this point s_root_bh must be released */
439
440         tmp_flags = sb->s_flags;
441         if (affs_init_bitmap(sb, &tmp_flags))
442                 goto out_error;
443         sb->s_flags = tmp_flags;
444
445         /* set up enough so that it can read an inode */
446
447         root_inode = iget(sb, root_block);
448         sb->s_root = d_alloc_root(root_inode);
449         if (!sb->s_root) {
450                 printk(KERN_ERR "AFFS: Get root inode failed\n");
451                 goto out_error;
452         }
453         sb->s_root->d_op = &affs_dentry_operations;
454
455         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
456         return 0;
457
458         /*
459          * Begin the cascaded cleanup ...
460          */
461 out_error:
462         if (root_inode)
463                 iput(root_inode);
464         kfree(sbi->s_bitmap);
465         affs_brelse(root_bh);
466         kfree(sbi->s_prefix);
467         kfree(sbi);
468         sb->s_fs_info = NULL;
469         return -EINVAL;
470 }
471
472 static int
473 affs_remount(struct super_block *sb, int *flags, char *data)
474 {
475         struct affs_sb_info     *sbi = AFFS_SB(sb);
476         int                      blocksize;
477         uid_t                    uid;
478         gid_t                    gid;
479         int                      mode;
480         int                      reserved;
481         int                      root_block;
482         unsigned long            mount_flags;
483         int                      res = 0;
484
485         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
486
487         *flags |= MS_NODIRATIME;
488
489         if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
490             &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
491                 return -EINVAL;
492         sbi->s_flags = mount_flags;
493         sbi->s_mode  = mode;
494         sbi->s_uid   = uid;
495         sbi->s_gid   = gid;
496
497         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
498                 return 0;
499         if (*flags & MS_RDONLY) {
500                 sb->s_dirt = 1;
501                 while (sb->s_dirt)
502                         affs_write_super(sb);
503                 affs_free_bitmap(sb);
504         } else
505                 res = affs_init_bitmap(sb, flags);
506
507         return res;
508 }
509
510 static int
511 affs_statfs(struct super_block *sb, struct kstatfs *buf)
512 {
513         int              free;
514
515         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
516              AFFS_SB(sb)->s_reserved);
517
518         free          = affs_count_free_blocks(sb);
519         buf->f_type    = AFFS_SUPER_MAGIC;
520         buf->f_bsize   = sb->s_blocksize;
521         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
522         buf->f_bfree   = free;
523         buf->f_bavail  = free;
524         return 0;
525 }
526
527 static struct super_block *affs_get_sb(struct file_system_type *fs_type,
528         int flags, const char *dev_name, void *data)
529 {
530         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super);
531 }
532
533 static struct file_system_type affs_fs_type = {
534         .owner          = THIS_MODULE,
535         .name           = "affs",
536         .get_sb         = affs_get_sb,
537         .kill_sb        = kill_block_super,
538         .fs_flags       = FS_REQUIRES_DEV,
539 };
540
541 static int __init init_affs_fs(void)
542 {
543         int err = init_inodecache();
544         if (err)
545                 goto out1;
546         err = register_filesystem(&affs_fs_type);
547         if (err)
548                 goto out;
549         return 0;
550 out:
551         destroy_inodecache();
552 out1:
553         return err;
554 }
555
556 static void __exit exit_affs_fs(void)
557 {
558         unregister_filesystem(&affs_fs_type);
559         destroy_inodecache();
560 }
561
562 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
563 MODULE_LICENSE("GPL");
564
565 module_init(init_affs_fs)
566 module_exit(exit_affs_fs)