fs/affs/super.c: remove unused variable
[sfrench/cifs-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/slab.h>
20 #include <linux/writeback.h>
21 #include "affs.h"
22
23 extern struct timezone sys_tz;
24
25 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
26 static int affs_remount (struct super_block *sb, int *flags, char *data);
27
28 static void
29 affs_commit_super(struct super_block *sb, int wait)
30 {
31         struct affs_sb_info *sbi = AFFS_SB(sb);
32         struct buffer_head *bh = sbi->s_root_bh;
33         struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
34
35         lock_buffer(bh);
36         secs_to_datestamp(get_seconds(), &tail->disk_change);
37         affs_fix_checksum(sb, bh);
38         unlock_buffer(bh);
39
40         mark_buffer_dirty(bh);
41         if (wait)
42                 sync_dirty_buffer(bh);
43 }
44
45 static void
46 affs_put_super(struct super_block *sb)
47 {
48         struct affs_sb_info *sbi = AFFS_SB(sb);
49         pr_debug("%s()\n", __func__);
50
51         cancel_delayed_work_sync(&sbi->sb_work);
52 }
53
54 static int
55 affs_sync_fs(struct super_block *sb, int wait)
56 {
57         affs_commit_super(sb, wait);
58         return 0;
59 }
60
61 static void flush_superblock(struct work_struct *work)
62 {
63         struct affs_sb_info *sbi;
64         struct super_block *sb;
65
66         sbi = container_of(work, struct affs_sb_info, sb_work.work);
67         sb = sbi->sb;
68
69         spin_lock(&sbi->work_lock);
70         sbi->work_queued = 0;
71         spin_unlock(&sbi->work_lock);
72
73         affs_commit_super(sb, 1);
74 }
75
76 void affs_mark_sb_dirty(struct super_block *sb)
77 {
78         struct affs_sb_info *sbi = AFFS_SB(sb);
79         unsigned long delay;
80
81         if (sb->s_flags & MS_RDONLY)
82                return;
83
84         spin_lock(&sbi->work_lock);
85         if (!sbi->work_queued) {
86                delay = msecs_to_jiffies(dirty_writeback_interval * 10);
87                queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
88                sbi->work_queued = 1;
89         }
90         spin_unlock(&sbi->work_lock);
91 }
92
93 static struct kmem_cache * affs_inode_cachep;
94
95 static struct inode *affs_alloc_inode(struct super_block *sb)
96 {
97         struct affs_inode_info *i;
98
99         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
100         if (!i)
101                 return NULL;
102
103         i->vfs_inode.i_version = 1;
104         i->i_lc = NULL;
105         i->i_ext_bh = NULL;
106         i->i_pa_cnt = 0;
107
108         return &i->vfs_inode;
109 }
110
111 static void affs_i_callback(struct rcu_head *head)
112 {
113         struct inode *inode = container_of(head, struct inode, i_rcu);
114         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
115 }
116
117 static void affs_destroy_inode(struct inode *inode)
118 {
119         call_rcu(&inode->i_rcu, affs_i_callback);
120 }
121
122 static void init_once(void *foo)
123 {
124         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
125
126         sema_init(&ei->i_link_lock, 1);
127         sema_init(&ei->i_ext_lock, 1);
128         inode_init_once(&ei->vfs_inode);
129 }
130
131 static int __init init_inodecache(void)
132 {
133         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
134                                              sizeof(struct affs_inode_info),
135                                              0, (SLAB_RECLAIM_ACCOUNT|
136                                                 SLAB_MEM_SPREAD),
137                                              init_once);
138         if (affs_inode_cachep == NULL)
139                 return -ENOMEM;
140         return 0;
141 }
142
143 static void destroy_inodecache(void)
144 {
145         /*
146          * Make sure all delayed rcu free inodes are flushed before we
147          * destroy cache.
148          */
149         rcu_barrier();
150         kmem_cache_destroy(affs_inode_cachep);
151 }
152
153 static const struct super_operations affs_sops = {
154         .alloc_inode    = affs_alloc_inode,
155         .destroy_inode  = affs_destroy_inode,
156         .write_inode    = affs_write_inode,
157         .evict_inode    = affs_evict_inode,
158         .put_super      = affs_put_super,
159         .sync_fs        = affs_sync_fs,
160         .statfs         = affs_statfs,
161         .remount_fs     = affs_remount,
162         .show_options   = generic_show_options,
163 };
164
165 enum {
166         Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
167         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
168         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
169 };
170
171 static const match_table_t tokens = {
172         {Opt_bs, "bs=%u"},
173         {Opt_mode, "mode=%o"},
174         {Opt_mufs, "mufs"},
175         {Opt_notruncate, "nofilenametruncate"},
176         {Opt_prefix, "prefix=%s"},
177         {Opt_protect, "protect"},
178         {Opt_reserved, "reserved=%u"},
179         {Opt_root, "root=%u"},
180         {Opt_setgid, "setgid=%u"},
181         {Opt_setuid, "setuid=%u"},
182         {Opt_verbose, "verbose"},
183         {Opt_volume, "volume=%s"},
184         {Opt_ignore, "grpquota"},
185         {Opt_ignore, "noquota"},
186         {Opt_ignore, "quota"},
187         {Opt_ignore, "usrquota"},
188         {Opt_err, NULL},
189 };
190
191 static int
192 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
193                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
194 {
195         char *p;
196         substring_t args[MAX_OPT_ARGS];
197
198         /* Fill in defaults */
199
200         *uid        = current_uid();
201         *gid        = current_gid();
202         *reserved   = 2;
203         *root       = -1;
204         *blocksize  = -1;
205         volume[0]   = ':';
206         volume[1]   = 0;
207         *mount_opts = 0;
208         if (!options)
209                 return 1;
210
211         while ((p = strsep(&options, ",")) != NULL) {
212                 int token, n, option;
213                 if (!*p)
214                         continue;
215
216                 token = match_token(p, tokens, args);
217                 switch (token) {
218                 case Opt_bs:
219                         if (match_int(&args[0], &n))
220                                 return 0;
221                         if (n != 512 && n != 1024 && n != 2048
222                             && n != 4096) {
223                                 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
224                                 return 0;
225                         }
226                         *blocksize = n;
227                         break;
228                 case Opt_mode:
229                         if (match_octal(&args[0], &option))
230                                 return 0;
231                         *mode = option & 0777;
232                         *mount_opts |= SF_SETMODE;
233                         break;
234                 case Opt_mufs:
235                         *mount_opts |= SF_MUFS;
236                         break;
237                 case Opt_notruncate:
238                         *mount_opts |= SF_NO_TRUNCATE;
239                         break;
240                 case Opt_prefix:
241                         *prefix = match_strdup(&args[0]);
242                         if (!*prefix)
243                                 return 0;
244                         *mount_opts |= SF_PREFIX;
245                         break;
246                 case Opt_protect:
247                         *mount_opts |= SF_IMMUTABLE;
248                         break;
249                 case Opt_reserved:
250                         if (match_int(&args[0], reserved))
251                                 return 0;
252                         break;
253                 case Opt_root:
254                         if (match_int(&args[0], root))
255                                 return 0;
256                         break;
257                 case Opt_setgid:
258                         if (match_int(&args[0], &option))
259                                 return 0;
260                         *gid = make_kgid(current_user_ns(), option);
261                         if (!gid_valid(*gid))
262                                 return 0;
263                         *mount_opts |= SF_SETGID;
264                         break;
265                 case Opt_setuid:
266                         if (match_int(&args[0], &option))
267                                 return 0;
268                         *uid = make_kuid(current_user_ns(), option);
269                         if (!uid_valid(*uid))
270                                 return 0;
271                         *mount_opts |= SF_SETUID;
272                         break;
273                 case Opt_verbose:
274                         *mount_opts |= SF_VERBOSE;
275                         break;
276                 case Opt_volume: {
277                         char *vol = match_strdup(&args[0]);
278                         if (!vol)
279                                 return 0;
280                         strlcpy(volume, vol, 32);
281                         kfree(vol);
282                         break;
283                 }
284                 case Opt_ignore:
285                         /* Silently ignore the quota options */
286                         break;
287                 default:
288                         pr_warn("Unrecognized mount option \"%s\" or missing value\n",
289                                 p);
290                         return 0;
291                 }
292         }
293         return 1;
294 }
295
296 /* This function definitely needs to be split up. Some fine day I'll
297  * hopefully have the guts to do so. Until then: sorry for the mess.
298  */
299
300 static int affs_fill_super(struct super_block *sb, void *data, int silent)
301 {
302         struct affs_sb_info     *sbi;
303         struct buffer_head      *root_bh = NULL;
304         struct buffer_head      *boot_bh;
305         struct inode            *root_inode = NULL;
306         s32                      root_block;
307         int                      size, blocksize;
308         u32                      chksum;
309         int                      num_bm;
310         int                      i, j;
311         kuid_t                   uid;
312         kgid_t                   gid;
313         int                      reserved;
314         unsigned long            mount_flags;
315         int                      tmp_flags;     /* fix remount prototype... */
316         u8                       sig[4];
317         int                      ret;
318
319         save_mount_options(sb, data);
320
321         pr_debug("read_super(%s)\n", data ? (const char *)data : "no options");
322
323         sb->s_magic             = AFFS_SUPER_MAGIC;
324         sb->s_op                = &affs_sops;
325         sb->s_flags |= MS_NODIRATIME;
326
327         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
328         if (!sbi)
329                 return -ENOMEM;
330
331         sb->s_fs_info = sbi;
332         sbi->sb = sb;
333         mutex_init(&sbi->s_bmlock);
334         spin_lock_init(&sbi->symlink_lock);
335         spin_lock_init(&sbi->work_lock);
336         INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
337
338         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
339                                 &blocksize,&sbi->s_prefix,
340                                 sbi->s_volume, &mount_flags)) {
341                 pr_err("Error parsing options\n");
342                 return -EINVAL;
343         }
344         /* N.B. after this point s_prefix must be released */
345
346         sbi->s_flags   = mount_flags;
347         sbi->s_mode    = i;
348         sbi->s_uid     = uid;
349         sbi->s_gid     = gid;
350         sbi->s_reserved= reserved;
351
352         /* Get the size of the device in 512-byte blocks.
353          * If we later see that the partition uses bigger
354          * blocks, we will have to change it.
355          */
356
357         size = sb->s_bdev->bd_inode->i_size >> 9;
358         pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size);
359
360         affs_set_blocksize(sb, PAGE_SIZE);
361         /* Try to find root block. Its location depends on the block size. */
362
363         i = 512;
364         j = 4096;
365         if (blocksize > 0) {
366                 i = j = blocksize;
367                 size = size / (blocksize / 512);
368         }
369         for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) {
370                 sbi->s_root_block = root_block;
371                 if (root_block < 0)
372                         sbi->s_root_block = (reserved + size - 1) / 2;
373                 pr_debug("setting blocksize to %d\n", blocksize);
374                 affs_set_blocksize(sb, blocksize);
375                 sbi->s_partition_size = size;
376
377                 /* The root block location that was calculated above is not
378                  * correct if the partition size is an odd number of 512-
379                  * byte blocks, which will be rounded down to a number of
380                  * 1024-byte blocks, and if there were an even number of
381                  * reserved blocks. Ideally, all partition checkers should
382                  * report the real number of blocks of the real blocksize,
383                  * but since this just cannot be done, we have to try to
384                  * find the root block anyways. In the above case, it is one
385                  * block behind the calculated one. So we check this one, too.
386                  */
387                 for (num_bm = 0; num_bm < 2; num_bm++) {
388                         pr_debug("Dev %s, trying root=%u, bs=%d, "
389                                 "size=%d, reserved=%d\n",
390                                 sb->s_id,
391                                 sbi->s_root_block + num_bm,
392                                 blocksize, size, reserved);
393                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
394                         if (!root_bh)
395                                 continue;
396                         if (!affs_checksum_block(sb, root_bh) &&
397                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
398                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
399                                 sbi->s_hashsize    = blocksize / 4 - 56;
400                                 sbi->s_root_block += num_bm;
401                                 goto got_root;
402                         }
403                         affs_brelse(root_bh);
404                         root_bh = NULL;
405                 }
406         }
407         if (!silent)
408                 pr_err("No valid root block on device %s\n", sb->s_id);
409         return -EINVAL;
410
411         /* N.B. after this point bh must be released */
412 got_root:
413         /* Keep super block in cache */
414         sbi->s_root_bh = root_bh;
415         root_block = sbi->s_root_block;
416
417         /* Find out which kind of FS we have */
418         boot_bh = sb_bread(sb, 0);
419         if (!boot_bh) {
420                 pr_err("Cannot read boot block\n");
421                 return -EINVAL;
422         }
423         memcpy(sig, boot_bh->b_data, 4);
424         brelse(boot_bh);
425         chksum = be32_to_cpu(*(__be32 *)sig);
426
427         /* Dircache filesystems are compatible with non-dircache ones
428          * when reading. As long as they aren't supported, writing is
429          * not recommended.
430          */
431         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
432              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
433                 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id);
434                 sb->s_flags |= MS_RDONLY;
435         }
436         switch (chksum) {
437                 case MUFS_FS:
438                 case MUFS_INTLFFS:
439                 case MUFS_DCFFS:
440                         sbi->s_flags |= SF_MUFS;
441                         /* fall thru */
442                 case FS_INTLFFS:
443                 case FS_DCFFS:
444                         sbi->s_flags |= SF_INTL;
445                         break;
446                 case MUFS_FFS:
447                         sbi->s_flags |= SF_MUFS;
448                         break;
449                 case FS_FFS:
450                         break;
451                 case MUFS_OFS:
452                         sbi->s_flags |= SF_MUFS;
453                         /* fall thru */
454                 case FS_OFS:
455                         sbi->s_flags |= SF_OFS;
456                         sb->s_flags |= MS_NOEXEC;
457                         break;
458                 case MUFS_DCOFS:
459                 case MUFS_INTLOFS:
460                         sbi->s_flags |= SF_MUFS;
461                 case FS_DCOFS:
462                 case FS_INTLOFS:
463                         sbi->s_flags |= SF_INTL | SF_OFS;
464                         sb->s_flags |= MS_NOEXEC;
465                         break;
466                 default:
467                         pr_err("Unknown filesystem on device %s: %08X\n",
468                                sb->s_id, chksum);
469                         return -EINVAL;
470         }
471
472         if (mount_flags & SF_VERBOSE) {
473                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
474                 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
475                         len > 31 ? 31 : len,
476                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
477                         sig, sig[3] + '0', blocksize);
478         }
479
480         sb->s_flags |= MS_NODEV | MS_NOSUID;
481
482         sbi->s_data_blksize = sb->s_blocksize;
483         if (sbi->s_flags & SF_OFS)
484                 sbi->s_data_blksize -= 24;
485
486         tmp_flags = sb->s_flags;
487         ret = affs_init_bitmap(sb, &tmp_flags);
488         if (ret)
489                 return ret;
490         sb->s_flags = tmp_flags;
491
492         /* set up enough so that it can read an inode */
493
494         root_inode = affs_iget(sb, root_block);
495         if (IS_ERR(root_inode))
496                 return PTR_ERR(root_inode);
497
498         if (AFFS_SB(sb)->s_flags & SF_INTL)
499                 sb->s_d_op = &affs_intl_dentry_operations;
500         else
501                 sb->s_d_op = &affs_dentry_operations;
502
503         sb->s_root = d_make_root(root_inode);
504         if (!sb->s_root) {
505                 pr_err("AFFS: Get root inode failed\n");
506                 return -ENOMEM;
507         }
508
509         pr_debug("s_flags=%lX\n", sb->s_flags);
510         return 0;
511 }
512
513 static int
514 affs_remount(struct super_block *sb, int *flags, char *data)
515 {
516         struct affs_sb_info     *sbi = AFFS_SB(sb);
517         int                      blocksize;
518         kuid_t                   uid;
519         kgid_t                   gid;
520         int                      mode;
521         int                      reserved;
522         int                      root_block;
523         unsigned long            mount_flags;
524         int                      res = 0;
525         char                    *new_opts = kstrdup(data, GFP_KERNEL);
526         char                     volume[32];
527         char                    *prefix = NULL;
528
529         pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data);
530
531         sync_filesystem(sb);
532         *flags |= MS_NODIRATIME;
533
534         memcpy(volume, sbi->s_volume, 32);
535         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
536                            &blocksize, &prefix, volume,
537                            &mount_flags)) {
538                 kfree(prefix);
539                 kfree(new_opts);
540                 return -EINVAL;
541         }
542
543         flush_delayed_work(&sbi->sb_work);
544         replace_mount_options(sb, new_opts);
545
546         sbi->s_flags = mount_flags;
547         sbi->s_mode  = mode;
548         sbi->s_uid   = uid;
549         sbi->s_gid   = gid;
550         /* protect against readers */
551         spin_lock(&sbi->symlink_lock);
552         if (prefix) {
553                 kfree(sbi->s_prefix);
554                 sbi->s_prefix = prefix;
555         }
556         memcpy(sbi->s_volume, volume, 32);
557         spin_unlock(&sbi->symlink_lock);
558
559         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
560                 return 0;
561
562         if (*flags & MS_RDONLY)
563                 affs_free_bitmap(sb);
564         else
565                 res = affs_init_bitmap(sb, flags);
566
567         return res;
568 }
569
570 static int
571 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
572 {
573         struct super_block *sb = dentry->d_sb;
574         int              free;
575         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
576
577         pr_debug("%s() partsize=%d, reserved=%d\n",
578                  __func__, AFFS_SB(sb)->s_partition_size,
579                  AFFS_SB(sb)->s_reserved);
580
581         free          = affs_count_free_blocks(sb);
582         buf->f_type    = AFFS_SUPER_MAGIC;
583         buf->f_bsize   = sb->s_blocksize;
584         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
585         buf->f_bfree   = free;
586         buf->f_bavail  = free;
587         buf->f_fsid.val[0] = (u32)id;
588         buf->f_fsid.val[1] = (u32)(id >> 32);
589         buf->f_namelen = 30;
590         return 0;
591 }
592
593 static struct dentry *affs_mount(struct file_system_type *fs_type,
594         int flags, const char *dev_name, void *data)
595 {
596         return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
597 }
598
599 static void affs_kill_sb(struct super_block *sb)
600 {
601         struct affs_sb_info *sbi = AFFS_SB(sb);
602         kill_block_super(sb);
603         if (sbi) {
604                 affs_free_bitmap(sb);
605                 affs_brelse(sbi->s_root_bh);
606                 kfree(sbi->s_prefix);
607                 kfree(sbi);
608         }
609 }
610
611 static struct file_system_type affs_fs_type = {
612         .owner          = THIS_MODULE,
613         .name           = "affs",
614         .mount          = affs_mount,
615         .kill_sb        = affs_kill_sb,
616         .fs_flags       = FS_REQUIRES_DEV,
617 };
618 MODULE_ALIAS_FS("affs");
619
620 static int __init init_affs_fs(void)
621 {
622         int err = init_inodecache();
623         if (err)
624                 goto out1;
625         err = register_filesystem(&affs_fs_type);
626         if (err)
627                 goto out;
628         return 0;
629 out:
630         destroy_inodecache();
631 out1:
632         return err;
633 }
634
635 static void __exit exit_affs_fs(void)
636 {
637         unregister_filesystem(&affs_fs_type);
638         destroy_inodecache();
639 }
640
641 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
642 MODULE_LICENSE("GPL");
643
644 module_init(init_affs_fs)
645 module_exit(exit_affs_fs)