8989c93193ed227e84c786e629f1fd4f1e81ce4c
[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 *i;
75
76         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
77         if (!i)
78                 return NULL;
79
80         i->vfs_inode.i_version = 1;
81         i->i_lc = NULL;
82         i->i_ext_bh = NULL;
83         i->i_pa_cnt = 0;
84
85         return &i->vfs_inode;
86 }
87
88 static void affs_destroy_inode(struct inode *inode)
89 {
90         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
91 }
92
93 static void init_once(void *foo)
94 {
95         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
96
97         init_MUTEX(&ei->i_link_lock);
98         init_MUTEX(&ei->i_ext_lock);
99         inode_init_once(&ei->vfs_inode);
100 }
101
102 static int init_inodecache(void)
103 {
104         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
105                                              sizeof(struct affs_inode_info),
106                                              0, (SLAB_RECLAIM_ACCOUNT|
107                                                 SLAB_MEM_SPREAD),
108                                              init_once);
109         if (affs_inode_cachep == NULL)
110                 return -ENOMEM;
111         return 0;
112 }
113
114 static void destroy_inodecache(void)
115 {
116         kmem_cache_destroy(affs_inode_cachep);
117 }
118
119 static const struct super_operations affs_sops = {
120         .alloc_inode    = affs_alloc_inode,
121         .destroy_inode  = affs_destroy_inode,
122         .write_inode    = affs_write_inode,
123         .delete_inode   = affs_delete_inode,
124         .clear_inode    = affs_clear_inode,
125         .put_super      = affs_put_super,
126         .write_super    = affs_write_super,
127         .statfs         = affs_statfs,
128         .remount_fs     = affs_remount,
129         .show_options   = generic_show_options,
130 };
131
132 enum {
133         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
134         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
135         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
136 };
137
138 static const match_table_t tokens = {
139         {Opt_bs, "bs=%u"},
140         {Opt_mode, "mode=%o"},
141         {Opt_mufs, "mufs"},
142         {Opt_prefix, "prefix=%s"},
143         {Opt_protect, "protect"},
144         {Opt_reserved, "reserved=%u"},
145         {Opt_root, "root=%u"},
146         {Opt_setgid, "setgid=%u"},
147         {Opt_setuid, "setuid=%u"},
148         {Opt_verbose, "verbose"},
149         {Opt_volume, "volume=%s"},
150         {Opt_ignore, "grpquota"},
151         {Opt_ignore, "noquota"},
152         {Opt_ignore, "quota"},
153         {Opt_ignore, "usrquota"},
154         {Opt_err, NULL},
155 };
156
157 static int
158 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
159                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
160 {
161         char *p;
162         substring_t args[MAX_OPT_ARGS];
163
164         /* Fill in defaults */
165
166         *uid        = current->uid;
167         *gid        = current->gid;
168         *reserved   = 2;
169         *root       = -1;
170         *blocksize  = -1;
171         volume[0]   = ':';
172         volume[1]   = 0;
173         *mount_opts = 0;
174         if (!options)
175                 return 1;
176
177         while ((p = strsep(&options, ",")) != NULL) {
178                 int token, n, option;
179                 if (!*p)
180                         continue;
181
182                 token = match_token(p, tokens, args);
183                 switch (token) {
184                 case Opt_bs:
185                         if (match_int(&args[0], &n))
186                                 return -EINVAL;
187                         if (n != 512 && n != 1024 && n != 2048
188                             && n != 4096) {
189                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
190                                 return 0;
191                         }
192                         *blocksize = n;
193                         break;
194                 case Opt_mode:
195                         if (match_octal(&args[0], &option))
196                                 return 1;
197                         *mode = option & 0777;
198                         *mount_opts |= SF_SETMODE;
199                         break;
200                 case Opt_mufs:
201                         *mount_opts |= SF_MUFS;
202                         break;
203                 case Opt_prefix:
204                         /* Free any previous prefix */
205                         kfree(*prefix);
206                         *prefix = match_strdup(&args[0]);
207                         if (!*prefix)
208                                 return 0;
209                         *mount_opts |= SF_PREFIX;
210                         break;
211                 case Opt_protect:
212                         *mount_opts |= SF_IMMUTABLE;
213                         break;
214                 case Opt_reserved:
215                         if (match_int(&args[0], reserved))
216                                 return 1;
217                         break;
218                 case Opt_root:
219                         if (match_int(&args[0], root))
220                                 return 1;
221                         break;
222                 case Opt_setgid:
223                         if (match_int(&args[0], &option))
224                                 return 1;
225                         *gid = option;
226                         *mount_opts |= SF_SETGID;
227                         break;
228                 case Opt_setuid:
229                         if (match_int(&args[0], &option))
230                                 return -EINVAL;
231                         *uid = option;
232                         *mount_opts |= SF_SETUID;
233                         break;
234                 case Opt_verbose:
235                         *mount_opts |= SF_VERBOSE;
236                         break;
237                 case Opt_volume: {
238                         char *vol = match_strdup(&args[0]);
239                         if (!vol)
240                                 return 0;
241                         strlcpy(volume, vol, 32);
242                         kfree(vol);
243                         break;
244                 }
245                 case Opt_ignore:
246                         /* Silently ignore the quota options */
247                         break;
248                 default:
249                         printk("AFFS: Unrecognized mount option \"%s\" "
250                                         "or missing value\n", p);
251                         return 0;
252                 }
253         }
254         return 1;
255 }
256
257 /* This function definitely needs to be split up. Some fine day I'll
258  * hopefully have the guts to do so. Until then: sorry for the mess.
259  */
260
261 static int affs_fill_super(struct super_block *sb, void *data, int silent)
262 {
263         struct affs_sb_info     *sbi;
264         struct buffer_head      *root_bh = NULL;
265         struct buffer_head      *boot_bh;
266         struct inode            *root_inode = NULL;
267         s32                      root_block;
268         int                      size, blocksize;
269         u32                      chksum;
270         int                      num_bm;
271         int                      i, j;
272         s32                      key;
273         uid_t                    uid;
274         gid_t                    gid;
275         int                      reserved;
276         unsigned long            mount_flags;
277         int                      tmp_flags;     /* fix remount prototype... */
278         u8                       sig[4];
279         int                      ret = -EINVAL;
280
281         save_mount_options(sb, data);
282
283         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
284
285         sb->s_magic             = AFFS_SUPER_MAGIC;
286         sb->s_op                = &affs_sops;
287         sb->s_flags |= MS_NODIRATIME;
288
289         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
290         if (!sbi)
291                 return -ENOMEM;
292         sb->s_fs_info = sbi;
293         mutex_init(&sbi->s_bmlock);
294
295         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
296                                 &blocksize,&sbi->s_prefix,
297                                 sbi->s_volume, &mount_flags)) {
298                 printk(KERN_ERR "AFFS: Error parsing options\n");
299                 return -EINVAL;
300         }
301         /* N.B. after this point s_prefix must be released */
302
303         sbi->s_flags   = mount_flags;
304         sbi->s_mode    = i;
305         sbi->s_uid     = uid;
306         sbi->s_gid     = gid;
307         sbi->s_reserved= reserved;
308
309         /* Get the size of the device in 512-byte blocks.
310          * If we later see that the partition uses bigger
311          * blocks, we will have to change it.
312          */
313
314         size = sb->s_bdev->bd_inode->i_size >> 9;
315         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
316
317         affs_set_blocksize(sb, PAGE_SIZE);
318         /* Try to find root block. Its location depends on the block size. */
319
320         i = 512;
321         j = 4096;
322         if (blocksize > 0) {
323                 i = j = blocksize;
324                 size = size / (blocksize / 512);
325         }
326         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
327                 sbi->s_root_block = root_block;
328                 if (root_block < 0)
329                         sbi->s_root_block = (reserved + size - 1) / 2;
330                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
331                 affs_set_blocksize(sb, blocksize);
332                 sbi->s_partition_size = size;
333
334                 /* The root block location that was calculated above is not
335                  * correct if the partition size is an odd number of 512-
336                  * byte blocks, which will be rounded down to a number of
337                  * 1024-byte blocks, and if there were an even number of
338                  * reserved blocks. Ideally, all partition checkers should
339                  * report the real number of blocks of the real blocksize,
340                  * but since this just cannot be done, we have to try to
341                  * find the root block anyways. In the above case, it is one
342                  * block behind the calculated one. So we check this one, too.
343                  */
344                 for (num_bm = 0; num_bm < 2; num_bm++) {
345                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
346                                 "size=%d, reserved=%d\n",
347                                 sb->s_id,
348                                 sbi->s_root_block + num_bm,
349                                 blocksize, size, reserved);
350                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
351                         if (!root_bh)
352                                 continue;
353                         if (!affs_checksum_block(sb, root_bh) &&
354                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
355                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
356                                 sbi->s_hashsize    = blocksize / 4 - 56;
357                                 sbi->s_root_block += num_bm;
358                                 key                        = 1;
359                                 goto got_root;
360                         }
361                         affs_brelse(root_bh);
362                         root_bh = NULL;
363                 }
364         }
365         if (!silent)
366                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
367                         sb->s_id);
368         goto out_error;
369
370         /* N.B. after this point bh must be released */
371 got_root:
372         root_block = sbi->s_root_block;
373
374         /* Find out which kind of FS we have */
375         boot_bh = sb_bread(sb, 0);
376         if (!boot_bh) {
377                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
378                 goto out_error;
379         }
380         memcpy(sig, boot_bh->b_data, 4);
381         brelse(boot_bh);
382         chksum = be32_to_cpu(*(__be32 *)sig);
383
384         /* Dircache filesystems are compatible with non-dircache ones
385          * when reading. As long as they aren't supported, writing is
386          * not recommended.
387          */
388         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
389              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
390                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
391                         sb->s_id);
392                 sb->s_flags |= MS_RDONLY;
393         }
394         switch (chksum) {
395                 case MUFS_FS:
396                 case MUFS_INTLFFS:
397                 case MUFS_DCFFS:
398                         sbi->s_flags |= SF_MUFS;
399                         /* fall thru */
400                 case FS_INTLFFS:
401                 case FS_DCFFS:
402                         sbi->s_flags |= SF_INTL;
403                         break;
404                 case MUFS_FFS:
405                         sbi->s_flags |= SF_MUFS;
406                         break;
407                 case FS_FFS:
408                         break;
409                 case MUFS_OFS:
410                         sbi->s_flags |= SF_MUFS;
411                         /* fall thru */
412                 case FS_OFS:
413                         sbi->s_flags |= SF_OFS;
414                         sb->s_flags |= MS_NOEXEC;
415                         break;
416                 case MUFS_DCOFS:
417                 case MUFS_INTLOFS:
418                         sbi->s_flags |= SF_MUFS;
419                 case FS_DCOFS:
420                 case FS_INTLOFS:
421                         sbi->s_flags |= SF_INTL | SF_OFS;
422                         sb->s_flags |= MS_NOEXEC;
423                         break;
424                 default:
425                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
426                                 sb->s_id, chksum);
427                         goto out_error;
428         }
429
430         if (mount_flags & SF_VERBOSE) {
431                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
432                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
433                         len > 31 ? 31 : len,
434                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
435                         sig, sig[3] + '0', blocksize);
436         }
437
438         sb->s_flags |= MS_NODEV | MS_NOSUID;
439
440         sbi->s_data_blksize = sb->s_blocksize;
441         if (sbi->s_flags & SF_OFS)
442                 sbi->s_data_blksize -= 24;
443
444         /* Keep super block in cache */
445         sbi->s_root_bh = root_bh;
446         /* N.B. after this point s_root_bh must be released */
447
448         tmp_flags = sb->s_flags;
449         if (affs_init_bitmap(sb, &tmp_flags))
450                 goto out_error;
451         sb->s_flags = tmp_flags;
452
453         /* set up enough so that it can read an inode */
454
455         root_inode = affs_iget(sb, root_block);
456         if (IS_ERR(root_inode)) {
457                 ret = PTR_ERR(root_inode);
458                 goto out_error_noinode;
459         }
460
461         sb->s_root = d_alloc_root(root_inode);
462         if (!sb->s_root) {
463                 printk(KERN_ERR "AFFS: Get root inode failed\n");
464                 goto out_error;
465         }
466         sb->s_root->d_op = &affs_dentry_operations;
467
468         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
469         return 0;
470
471         /*
472          * Begin the cascaded cleanup ...
473          */
474 out_error:
475         if (root_inode)
476                 iput(root_inode);
477 out_error_noinode:
478         kfree(sbi->s_bitmap);
479         affs_brelse(root_bh);
480         kfree(sbi->s_prefix);
481         kfree(sbi);
482         sb->s_fs_info = NULL;
483         return ret;
484 }
485
486 static int
487 affs_remount(struct super_block *sb, int *flags, char *data)
488 {
489         struct affs_sb_info     *sbi = AFFS_SB(sb);
490         int                      blocksize;
491         uid_t                    uid;
492         gid_t                    gid;
493         int                      mode;
494         int                      reserved;
495         int                      root_block;
496         unsigned long            mount_flags;
497         int                      res = 0;
498         char                    *new_opts = kstrdup(data, GFP_KERNEL);
499
500         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
501
502         *flags |= MS_NODIRATIME;
503
504         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
505                            &blocksize, &sbi->s_prefix, sbi->s_volume,
506                            &mount_flags)) {
507                 kfree(new_opts);
508                 return -EINVAL;
509         }
510         kfree(sb->s_options);
511         sb->s_options = new_opts;
512
513         sbi->s_flags = mount_flags;
514         sbi->s_mode  = mode;
515         sbi->s_uid   = uid;
516         sbi->s_gid   = gid;
517
518         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
519                 return 0;
520         if (*flags & MS_RDONLY) {
521                 sb->s_dirt = 1;
522                 while (sb->s_dirt)
523                         affs_write_super(sb);
524                 affs_free_bitmap(sb);
525         } else
526                 res = affs_init_bitmap(sb, flags);
527
528         return res;
529 }
530
531 static int
532 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
533 {
534         struct super_block *sb = dentry->d_sb;
535         int              free;
536
537         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
538              AFFS_SB(sb)->s_reserved);
539
540         free          = affs_count_free_blocks(sb);
541         buf->f_type    = AFFS_SUPER_MAGIC;
542         buf->f_bsize   = sb->s_blocksize;
543         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
544         buf->f_bfree   = free;
545         buf->f_bavail  = free;
546         return 0;
547 }
548
549 static int affs_get_sb(struct file_system_type *fs_type,
550         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
551 {
552         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
553                            mnt);
554 }
555
556 static struct file_system_type affs_fs_type = {
557         .owner          = THIS_MODULE,
558         .name           = "affs",
559         .get_sb         = affs_get_sb,
560         .kill_sb        = kill_block_super,
561         .fs_flags       = FS_REQUIRES_DEV,
562 };
563
564 static int __init init_affs_fs(void)
565 {
566         int err = init_inodecache();
567         if (err)
568                 goto out1;
569         err = register_filesystem(&affs_fs_type);
570         if (err)
571                 goto out;
572         return 0;
573 out:
574         destroy_inodecache();
575 out1:
576         return err;
577 }
578
579 static void __exit exit_affs_fs(void)
580 {
581         unregister_filesystem(&affs_fs_type);
582         destroy_inodecache();
583 }
584
585 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
586 MODULE_LICENSE("GPL");
587
588 module_init(init_affs_fs)
589 module_exit(exit_affs_fs)