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