fnctl: f_modown should call write_lock_irqsave/restore
[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 -EINVAL;
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 1;
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                         /* Free any previous prefix */
225                         kfree(*prefix);
226                         *prefix = match_strdup(&args[0]);
227                         if (!*prefix)
228                                 return 0;
229                         *mount_opts |= SF_PREFIX;
230                         break;
231                 case Opt_protect:
232                         *mount_opts |= SF_IMMUTABLE;
233                         break;
234                 case Opt_reserved:
235                         if (match_int(&args[0], reserved))
236                                 return 1;
237                         break;
238                 case Opt_root:
239                         if (match_int(&args[0], root))
240                                 return 1;
241                         break;
242                 case Opt_setgid:
243                         if (match_int(&args[0], &option))
244                                 return 1;
245                         *gid = option;
246                         *mount_opts |= SF_SETGID;
247                         break;
248                 case Opt_setuid:
249                         if (match_int(&args[0], &option))
250                                 return -EINVAL;
251                         *uid = option;
252                         *mount_opts |= SF_SETUID;
253                         break;
254                 case Opt_verbose:
255                         *mount_opts |= SF_VERBOSE;
256                         break;
257                 case Opt_volume: {
258                         char *vol = match_strdup(&args[0]);
259                         if (!vol)
260                                 return 0;
261                         strlcpy(volume, vol, 32);
262                         kfree(vol);
263                         break;
264                 }
265                 case Opt_ignore:
266                         /* Silently ignore the quota options */
267                         break;
268                 default:
269                         printk("AFFS: Unrecognized mount option \"%s\" "
270                                         "or missing value\n", p);
271                         return 0;
272                 }
273         }
274         return 1;
275 }
276
277 /* This function definitely needs to be split up. Some fine day I'll
278  * hopefully have the guts to do so. Until then: sorry for the mess.
279  */
280
281 static int affs_fill_super(struct super_block *sb, void *data, int silent)
282 {
283         struct affs_sb_info     *sbi;
284         struct buffer_head      *root_bh = NULL;
285         struct buffer_head      *boot_bh;
286         struct inode            *root_inode = NULL;
287         s32                      root_block;
288         int                      size, blocksize;
289         u32                      chksum;
290         int                      num_bm;
291         int                      i, j;
292         s32                      key;
293         uid_t                    uid;
294         gid_t                    gid;
295         int                      reserved;
296         unsigned long            mount_flags;
297         int                      tmp_flags;     /* fix remount prototype... */
298         u8                       sig[4];
299         int                      ret = -EINVAL;
300
301         save_mount_options(sb, data);
302
303         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
304
305         sb->s_magic             = AFFS_SUPER_MAGIC;
306         sb->s_op                = &affs_sops;
307         sb->s_flags |= MS_NODIRATIME;
308
309         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
310         if (!sbi)
311                 return -ENOMEM;
312         sb->s_fs_info = sbi;
313         mutex_init(&sbi->s_bmlock);
314
315         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
316                                 &blocksize,&sbi->s_prefix,
317                                 sbi->s_volume, &mount_flags)) {
318                 printk(KERN_ERR "AFFS: Error parsing options\n");
319                 return -EINVAL;
320         }
321         /* N.B. after this point s_prefix must be released */
322
323         sbi->s_flags   = mount_flags;
324         sbi->s_mode    = i;
325         sbi->s_uid     = uid;
326         sbi->s_gid     = gid;
327         sbi->s_reserved= reserved;
328
329         /* Get the size of the device in 512-byte blocks.
330          * If we later see that the partition uses bigger
331          * blocks, we will have to change it.
332          */
333
334         size = sb->s_bdev->bd_inode->i_size >> 9;
335         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
336
337         affs_set_blocksize(sb, PAGE_SIZE);
338         /* Try to find root block. Its location depends on the block size. */
339
340         i = 512;
341         j = 4096;
342         if (blocksize > 0) {
343                 i = j = blocksize;
344                 size = size / (blocksize / 512);
345         }
346         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
347                 sbi->s_root_block = root_block;
348                 if (root_block < 0)
349                         sbi->s_root_block = (reserved + size - 1) / 2;
350                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
351                 affs_set_blocksize(sb, blocksize);
352                 sbi->s_partition_size = size;
353
354                 /* The root block location that was calculated above is not
355                  * correct if the partition size is an odd number of 512-
356                  * byte blocks, which will be rounded down to a number of
357                  * 1024-byte blocks, and if there were an even number of
358                  * reserved blocks. Ideally, all partition checkers should
359                  * report the real number of blocks of the real blocksize,
360                  * but since this just cannot be done, we have to try to
361                  * find the root block anyways. In the above case, it is one
362                  * block behind the calculated one. So we check this one, too.
363                  */
364                 for (num_bm = 0; num_bm < 2; num_bm++) {
365                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
366                                 "size=%d, reserved=%d\n",
367                                 sb->s_id,
368                                 sbi->s_root_block + num_bm,
369                                 blocksize, size, reserved);
370                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
371                         if (!root_bh)
372                                 continue;
373                         if (!affs_checksum_block(sb, root_bh) &&
374                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
375                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
376                                 sbi->s_hashsize    = blocksize / 4 - 56;
377                                 sbi->s_root_block += num_bm;
378                                 key                        = 1;
379                                 goto got_root;
380                         }
381                         affs_brelse(root_bh);
382                         root_bh = NULL;
383                 }
384         }
385         if (!silent)
386                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
387                         sb->s_id);
388         goto out_error;
389
390         /* N.B. after this point bh must be released */
391 got_root:
392         root_block = sbi->s_root_block;
393
394         /* Find out which kind of FS we have */
395         boot_bh = sb_bread(sb, 0);
396         if (!boot_bh) {
397                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
398                 goto out_error;
399         }
400         memcpy(sig, boot_bh->b_data, 4);
401         brelse(boot_bh);
402         chksum = be32_to_cpu(*(__be32 *)sig);
403
404         /* Dircache filesystems are compatible with non-dircache ones
405          * when reading. As long as they aren't supported, writing is
406          * not recommended.
407          */
408         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
409              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
410                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
411                         sb->s_id);
412                 sb->s_flags |= MS_RDONLY;
413         }
414         switch (chksum) {
415                 case MUFS_FS:
416                 case MUFS_INTLFFS:
417                 case MUFS_DCFFS:
418                         sbi->s_flags |= SF_MUFS;
419                         /* fall thru */
420                 case FS_INTLFFS:
421                 case FS_DCFFS:
422                         sbi->s_flags |= SF_INTL;
423                         break;
424                 case MUFS_FFS:
425                         sbi->s_flags |= SF_MUFS;
426                         break;
427                 case FS_FFS:
428                         break;
429                 case MUFS_OFS:
430                         sbi->s_flags |= SF_MUFS;
431                         /* fall thru */
432                 case FS_OFS:
433                         sbi->s_flags |= SF_OFS;
434                         sb->s_flags |= MS_NOEXEC;
435                         break;
436                 case MUFS_DCOFS:
437                 case MUFS_INTLOFS:
438                         sbi->s_flags |= SF_MUFS;
439                 case FS_DCOFS:
440                 case FS_INTLOFS:
441                         sbi->s_flags |= SF_INTL | SF_OFS;
442                         sb->s_flags |= MS_NOEXEC;
443                         break;
444                 default:
445                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
446                                 sb->s_id, chksum);
447                         goto out_error;
448         }
449
450         if (mount_flags & SF_VERBOSE) {
451                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
452                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
453                         len > 31 ? 31 : len,
454                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
455                         sig, sig[3] + '0', blocksize);
456         }
457
458         sb->s_flags |= MS_NODEV | MS_NOSUID;
459
460         sbi->s_data_blksize = sb->s_blocksize;
461         if (sbi->s_flags & SF_OFS)
462                 sbi->s_data_blksize -= 24;
463
464         /* Keep super block in cache */
465         sbi->s_root_bh = root_bh;
466         /* N.B. after this point s_root_bh must be released */
467
468         tmp_flags = sb->s_flags;
469         if (affs_init_bitmap(sb, &tmp_flags))
470                 goto out_error;
471         sb->s_flags = tmp_flags;
472
473         /* set up enough so that it can read an inode */
474
475         root_inode = affs_iget(sb, root_block);
476         if (IS_ERR(root_inode)) {
477                 ret = PTR_ERR(root_inode);
478                 goto out_error_noinode;
479         }
480
481         sb->s_root = d_alloc_root(root_inode);
482         if (!sb->s_root) {
483                 printk(KERN_ERR "AFFS: Get root inode failed\n");
484                 goto out_error;
485         }
486         sb->s_root->d_op = &affs_dentry_operations;
487
488         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
489         return 0;
490
491         /*
492          * Begin the cascaded cleanup ...
493          */
494 out_error:
495         if (root_inode)
496                 iput(root_inode);
497 out_error_noinode:
498         kfree(sbi->s_bitmap);
499         affs_brelse(root_bh);
500         kfree(sbi->s_prefix);
501         kfree(sbi);
502         sb->s_fs_info = NULL;
503         return ret;
504 }
505
506 static int
507 affs_remount(struct super_block *sb, int *flags, char *data)
508 {
509         struct affs_sb_info     *sbi = AFFS_SB(sb);
510         int                      blocksize;
511         uid_t                    uid;
512         gid_t                    gid;
513         int                      mode;
514         int                      reserved;
515         int                      root_block;
516         unsigned long            mount_flags;
517         int                      res = 0;
518         char                    *new_opts = kstrdup(data, GFP_KERNEL);
519
520         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
521
522         *flags |= MS_NODIRATIME;
523
524         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
525                            &blocksize, &sbi->s_prefix, sbi->s_volume,
526                            &mount_flags)) {
527                 kfree(new_opts);
528                 return -EINVAL;
529         }
530         lock_kernel();
531         replace_mount_options(sb, new_opts);
532
533         sbi->s_flags = mount_flags;
534         sbi->s_mode  = mode;
535         sbi->s_uid   = uid;
536         sbi->s_gid   = gid;
537
538         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {
539                 unlock_kernel();
540                 return 0;
541         }
542         if (*flags & MS_RDONLY) {
543                 sb->s_dirt = 1;
544                 while (sb->s_dirt)
545                         affs_write_super(sb);
546                 affs_free_bitmap(sb);
547         } else
548                 res = affs_init_bitmap(sb, flags);
549
550         unlock_kernel();
551         return res;
552 }
553
554 static int
555 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
556 {
557         struct super_block *sb = dentry->d_sb;
558         int              free;
559         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
560
561         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
562              AFFS_SB(sb)->s_reserved);
563
564         free          = affs_count_free_blocks(sb);
565         buf->f_type    = AFFS_SUPER_MAGIC;
566         buf->f_bsize   = sb->s_blocksize;
567         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
568         buf->f_bfree   = free;
569         buf->f_bavail  = free;
570         buf->f_fsid.val[0] = (u32)id;
571         buf->f_fsid.val[1] = (u32)(id >> 32);
572         buf->f_namelen = 30;
573         return 0;
574 }
575
576 static int affs_get_sb(struct file_system_type *fs_type,
577         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
578 {
579         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
580                            mnt);
581 }
582
583 static struct file_system_type affs_fs_type = {
584         .owner          = THIS_MODULE,
585         .name           = "affs",
586         .get_sb         = affs_get_sb,
587         .kill_sb        = kill_block_super,
588         .fs_flags       = FS_REQUIRES_DEV,
589 };
590
591 static int __init init_affs_fs(void)
592 {
593         int err = init_inodecache();
594         if (err)
595                 goto out1;
596         err = register_filesystem(&affs_fs_type);
597         if (err)
598                 goto out;
599         return 0;
600 out:
601         destroy_inodecache();
602 out1:
603         return err;
604 }
605
606 static void __exit exit_affs_fs(void)
607 {
608         unregister_filesystem(&affs_fs_type);
609         destroy_inodecache();
610 }
611
612 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
613 MODULE_LICENSE("GPL");
614
615 module_init(init_affs_fs)
616 module_exit(exit_affs_fs)