->write_super lock_super pushdown
[linux-3.10.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         lock_kernel();
33
34         if (!(sb->s_flags & MS_RDONLY)) {
35                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
36                 secs_to_datestamp(get_seconds(),
37                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
38                 affs_fix_checksum(sb, sbi->s_root_bh);
39                 mark_buffer_dirty(sbi->s_root_bh);
40         }
41
42         kfree(sbi->s_prefix);
43         affs_free_bitmap(sb);
44         affs_brelse(sbi->s_root_bh);
45         kfree(sbi);
46         sb->s_fs_info = NULL;
47
48         unlock_kernel();
49 }
50
51 static void
52 affs_write_super(struct super_block *sb)
53 {
54         int clean = 2;
55         struct affs_sb_info *sbi = AFFS_SB(sb);
56
57         lock_super(sb);
58         if (!(sb->s_flags & MS_RDONLY)) {
59                 //      if (sbi->s_bitmap[i].bm_bh) {
60                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
61                 //                      clean = 0;
62                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
63                 secs_to_datestamp(get_seconds(),
64                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
65                 affs_fix_checksum(sb, sbi->s_root_bh);
66                 mark_buffer_dirty(sbi->s_root_bh);
67                 sb->s_dirt = !clean;    /* redo until bitmap synced */
68         } else
69                 sb->s_dirt = 0;
70         unlock_super(sb);
71
72         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
73 }
74
75 static struct kmem_cache * affs_inode_cachep;
76
77 static struct inode *affs_alloc_inode(struct super_block *sb)
78 {
79         struct affs_inode_info *i;
80
81         i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
82         if (!i)
83                 return NULL;
84
85         i->vfs_inode.i_version = 1;
86         i->i_lc = NULL;
87         i->i_ext_bh = NULL;
88         i->i_pa_cnt = 0;
89
90         return &i->vfs_inode;
91 }
92
93 static void affs_destroy_inode(struct inode *inode)
94 {
95         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
96 }
97
98 static void init_once(void *foo)
99 {
100         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
101
102         init_MUTEX(&ei->i_link_lock);
103         init_MUTEX(&ei->i_ext_lock);
104         inode_init_once(&ei->vfs_inode);
105 }
106
107 static int init_inodecache(void)
108 {
109         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
110                                              sizeof(struct affs_inode_info),
111                                              0, (SLAB_RECLAIM_ACCOUNT|
112                                                 SLAB_MEM_SPREAD),
113                                              init_once);
114         if (affs_inode_cachep == NULL)
115                 return -ENOMEM;
116         return 0;
117 }
118
119 static void destroy_inodecache(void)
120 {
121         kmem_cache_destroy(affs_inode_cachep);
122 }
123
124 static const struct super_operations affs_sops = {
125         .alloc_inode    = affs_alloc_inode,
126         .destroy_inode  = affs_destroy_inode,
127         .write_inode    = affs_write_inode,
128         .delete_inode   = affs_delete_inode,
129         .clear_inode    = affs_clear_inode,
130         .put_super      = affs_put_super,
131         .write_super    = affs_write_super,
132         .statfs         = affs_statfs,
133         .remount_fs     = affs_remount,
134         .show_options   = generic_show_options,
135 };
136
137 enum {
138         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
139         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
140         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
141 };
142
143 static const match_table_t tokens = {
144         {Opt_bs, "bs=%u"},
145         {Opt_mode, "mode=%o"},
146         {Opt_mufs, "mufs"},
147         {Opt_prefix, "prefix=%s"},
148         {Opt_protect, "protect"},
149         {Opt_reserved, "reserved=%u"},
150         {Opt_root, "root=%u"},
151         {Opt_setgid, "setgid=%u"},
152         {Opt_setuid, "setuid=%u"},
153         {Opt_verbose, "verbose"},
154         {Opt_volume, "volume=%s"},
155         {Opt_ignore, "grpquota"},
156         {Opt_ignore, "noquota"},
157         {Opt_ignore, "quota"},
158         {Opt_ignore, "usrquota"},
159         {Opt_err, NULL},
160 };
161
162 static int
163 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
164                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
165 {
166         char *p;
167         substring_t args[MAX_OPT_ARGS];
168
169         /* Fill in defaults */
170
171         *uid        = current_uid();
172         *gid        = current_gid();
173         *reserved   = 2;
174         *root       = -1;
175         *blocksize  = -1;
176         volume[0]   = ':';
177         volume[1]   = 0;
178         *mount_opts = 0;
179         if (!options)
180                 return 1;
181
182         while ((p = strsep(&options, ",")) != NULL) {
183                 int token, n, option;
184                 if (!*p)
185                         continue;
186
187                 token = match_token(p, tokens, args);
188                 switch (token) {
189                 case Opt_bs:
190                         if (match_int(&args[0], &n))
191                                 return -EINVAL;
192                         if (n != 512 && n != 1024 && n != 2048
193                             && n != 4096) {
194                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
195                                 return 0;
196                         }
197                         *blocksize = n;
198                         break;
199                 case Opt_mode:
200                         if (match_octal(&args[0], &option))
201                                 return 1;
202                         *mode = option & 0777;
203                         *mount_opts |= SF_SETMODE;
204                         break;
205                 case Opt_mufs:
206                         *mount_opts |= SF_MUFS;
207                         break;
208                 case Opt_prefix:
209                         /* Free any previous prefix */
210                         kfree(*prefix);
211                         *prefix = match_strdup(&args[0]);
212                         if (!*prefix)
213                                 return 0;
214                         *mount_opts |= SF_PREFIX;
215                         break;
216                 case Opt_protect:
217                         *mount_opts |= SF_IMMUTABLE;
218                         break;
219                 case Opt_reserved:
220                         if (match_int(&args[0], reserved))
221                                 return 1;
222                         break;
223                 case Opt_root:
224                         if (match_int(&args[0], root))
225                                 return 1;
226                         break;
227                 case Opt_setgid:
228                         if (match_int(&args[0], &option))
229                                 return 1;
230                         *gid = option;
231                         *mount_opts |= SF_SETGID;
232                         break;
233                 case Opt_setuid:
234                         if (match_int(&args[0], &option))
235                                 return -EINVAL;
236                         *uid = option;
237                         *mount_opts |= SF_SETUID;
238                         break;
239                 case Opt_verbose:
240                         *mount_opts |= SF_VERBOSE;
241                         break;
242                 case Opt_volume: {
243                         char *vol = match_strdup(&args[0]);
244                         if (!vol)
245                                 return 0;
246                         strlcpy(volume, vol, 32);
247                         kfree(vol);
248                         break;
249                 }
250                 case Opt_ignore:
251                         /* Silently ignore the quota options */
252                         break;
253                 default:
254                         printk("AFFS: Unrecognized mount option \"%s\" "
255                                         "or missing value\n", p);
256                         return 0;
257                 }
258         }
259         return 1;
260 }
261
262 /* This function definitely needs to be split up. Some fine day I'll
263  * hopefully have the guts to do so. Until then: sorry for the mess.
264  */
265
266 static int affs_fill_super(struct super_block *sb, void *data, int silent)
267 {
268         struct affs_sb_info     *sbi;
269         struct buffer_head      *root_bh = NULL;
270         struct buffer_head      *boot_bh;
271         struct inode            *root_inode = NULL;
272         s32                      root_block;
273         int                      size, blocksize;
274         u32                      chksum;
275         int                      num_bm;
276         int                      i, j;
277         s32                      key;
278         uid_t                    uid;
279         gid_t                    gid;
280         int                      reserved;
281         unsigned long            mount_flags;
282         int                      tmp_flags;     /* fix remount prototype... */
283         u8                       sig[4];
284         int                      ret = -EINVAL;
285
286         save_mount_options(sb, data);
287
288         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
289
290         sb->s_magic             = AFFS_SUPER_MAGIC;
291         sb->s_op                = &affs_sops;
292         sb->s_flags |= MS_NODIRATIME;
293
294         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
295         if (!sbi)
296                 return -ENOMEM;
297         sb->s_fs_info = sbi;
298         mutex_init(&sbi->s_bmlock);
299
300         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
301                                 &blocksize,&sbi->s_prefix,
302                                 sbi->s_volume, &mount_flags)) {
303                 printk(KERN_ERR "AFFS: Error parsing options\n");
304                 return -EINVAL;
305         }
306         /* N.B. after this point s_prefix must be released */
307
308         sbi->s_flags   = mount_flags;
309         sbi->s_mode    = i;
310         sbi->s_uid     = uid;
311         sbi->s_gid     = gid;
312         sbi->s_reserved= reserved;
313
314         /* Get the size of the device in 512-byte blocks.
315          * If we later see that the partition uses bigger
316          * blocks, we will have to change it.
317          */
318
319         size = sb->s_bdev->bd_inode->i_size >> 9;
320         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
321
322         affs_set_blocksize(sb, PAGE_SIZE);
323         /* Try to find root block. Its location depends on the block size. */
324
325         i = 512;
326         j = 4096;
327         if (blocksize > 0) {
328                 i = j = blocksize;
329                 size = size / (blocksize / 512);
330         }
331         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
332                 sbi->s_root_block = root_block;
333                 if (root_block < 0)
334                         sbi->s_root_block = (reserved + size - 1) / 2;
335                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
336                 affs_set_blocksize(sb, blocksize);
337                 sbi->s_partition_size = size;
338
339                 /* The root block location that was calculated above is not
340                  * correct if the partition size is an odd number of 512-
341                  * byte blocks, which will be rounded down to a number of
342                  * 1024-byte blocks, and if there were an even number of
343                  * reserved blocks. Ideally, all partition checkers should
344                  * report the real number of blocks of the real blocksize,
345                  * but since this just cannot be done, we have to try to
346                  * find the root block anyways. In the above case, it is one
347                  * block behind the calculated one. So we check this one, too.
348                  */
349                 for (num_bm = 0; num_bm < 2; num_bm++) {
350                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
351                                 "size=%d, reserved=%d\n",
352                                 sb->s_id,
353                                 sbi->s_root_block + num_bm,
354                                 blocksize, size, reserved);
355                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
356                         if (!root_bh)
357                                 continue;
358                         if (!affs_checksum_block(sb, root_bh) &&
359                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
360                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
361                                 sbi->s_hashsize    = blocksize / 4 - 56;
362                                 sbi->s_root_block += num_bm;
363                                 key                        = 1;
364                                 goto got_root;
365                         }
366                         affs_brelse(root_bh);
367                         root_bh = NULL;
368                 }
369         }
370         if (!silent)
371                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
372                         sb->s_id);
373         goto out_error;
374
375         /* N.B. after this point bh must be released */
376 got_root:
377         root_block = sbi->s_root_block;
378
379         /* Find out which kind of FS we have */
380         boot_bh = sb_bread(sb, 0);
381         if (!boot_bh) {
382                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
383                 goto out_error;
384         }
385         memcpy(sig, boot_bh->b_data, 4);
386         brelse(boot_bh);
387         chksum = be32_to_cpu(*(__be32 *)sig);
388
389         /* Dircache filesystems are compatible with non-dircache ones
390          * when reading. As long as they aren't supported, writing is
391          * not recommended.
392          */
393         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
394              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
395                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
396                         sb->s_id);
397                 sb->s_flags |= MS_RDONLY;
398         }
399         switch (chksum) {
400                 case MUFS_FS:
401                 case MUFS_INTLFFS:
402                 case MUFS_DCFFS:
403                         sbi->s_flags |= SF_MUFS;
404                         /* fall thru */
405                 case FS_INTLFFS:
406                 case FS_DCFFS:
407                         sbi->s_flags |= SF_INTL;
408                         break;
409                 case MUFS_FFS:
410                         sbi->s_flags |= SF_MUFS;
411                         break;
412                 case FS_FFS:
413                         break;
414                 case MUFS_OFS:
415                         sbi->s_flags |= SF_MUFS;
416                         /* fall thru */
417                 case FS_OFS:
418                         sbi->s_flags |= SF_OFS;
419                         sb->s_flags |= MS_NOEXEC;
420                         break;
421                 case MUFS_DCOFS:
422                 case MUFS_INTLOFS:
423                         sbi->s_flags |= SF_MUFS;
424                 case FS_DCOFS:
425                 case FS_INTLOFS:
426                         sbi->s_flags |= SF_INTL | SF_OFS;
427                         sb->s_flags |= MS_NOEXEC;
428                         break;
429                 default:
430                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
431                                 sb->s_id, chksum);
432                         goto out_error;
433         }
434
435         if (mount_flags & SF_VERBOSE) {
436                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
437                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
438                         len > 31 ? 31 : len,
439                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
440                         sig, sig[3] + '0', blocksize);
441         }
442
443         sb->s_flags |= MS_NODEV | MS_NOSUID;
444
445         sbi->s_data_blksize = sb->s_blocksize;
446         if (sbi->s_flags & SF_OFS)
447                 sbi->s_data_blksize -= 24;
448
449         /* Keep super block in cache */
450         sbi->s_root_bh = root_bh;
451         /* N.B. after this point s_root_bh must be released */
452
453         tmp_flags = sb->s_flags;
454         if (affs_init_bitmap(sb, &tmp_flags))
455                 goto out_error;
456         sb->s_flags = tmp_flags;
457
458         /* set up enough so that it can read an inode */
459
460         root_inode = affs_iget(sb, root_block);
461         if (IS_ERR(root_inode)) {
462                 ret = PTR_ERR(root_inode);
463                 goto out_error_noinode;
464         }
465
466         sb->s_root = d_alloc_root(root_inode);
467         if (!sb->s_root) {
468                 printk(KERN_ERR "AFFS: Get root inode failed\n");
469                 goto out_error;
470         }
471         sb->s_root->d_op = &affs_dentry_operations;
472
473         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
474         return 0;
475
476         /*
477          * Begin the cascaded cleanup ...
478          */
479 out_error:
480         if (root_inode)
481                 iput(root_inode);
482 out_error_noinode:
483         kfree(sbi->s_bitmap);
484         affs_brelse(root_bh);
485         kfree(sbi->s_prefix);
486         kfree(sbi);
487         sb->s_fs_info = NULL;
488         return ret;
489 }
490
491 static int
492 affs_remount(struct super_block *sb, int *flags, char *data)
493 {
494         struct affs_sb_info     *sbi = AFFS_SB(sb);
495         int                      blocksize;
496         uid_t                    uid;
497         gid_t                    gid;
498         int                      mode;
499         int                      reserved;
500         int                      root_block;
501         unsigned long            mount_flags;
502         int                      res = 0;
503         char                    *new_opts = kstrdup(data, GFP_KERNEL);
504
505         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
506
507         *flags |= MS_NODIRATIME;
508
509         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
510                            &blocksize, &sbi->s_prefix, sbi->s_volume,
511                            &mount_flags)) {
512                 kfree(new_opts);
513                 return -EINVAL;
514         }
515         replace_mount_options(sb, new_opts);
516
517         sbi->s_flags = mount_flags;
518         sbi->s_mode  = mode;
519         sbi->s_uid   = uid;
520         sbi->s_gid   = gid;
521
522         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
523                 return 0;
524         if (*flags & MS_RDONLY) {
525                 sb->s_dirt = 1;
526                 while (sb->s_dirt)
527                         affs_write_super(sb);
528                 affs_free_bitmap(sb);
529         } else
530                 res = affs_init_bitmap(sb, flags);
531
532         return res;
533 }
534
535 static int
536 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
537 {
538         struct super_block *sb = dentry->d_sb;
539         int              free;
540         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
541
542         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
543              AFFS_SB(sb)->s_reserved);
544
545         free          = affs_count_free_blocks(sb);
546         buf->f_type    = AFFS_SUPER_MAGIC;
547         buf->f_bsize   = sb->s_blocksize;
548         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
549         buf->f_bfree   = free;
550         buf->f_bavail  = free;
551         buf->f_fsid.val[0] = (u32)id;
552         buf->f_fsid.val[1] = (u32)(id >> 32);
553         buf->f_namelen = 30;
554         return 0;
555 }
556
557 static int affs_get_sb(struct file_system_type *fs_type,
558         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
559 {
560         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
561                            mnt);
562 }
563
564 static struct file_system_type affs_fs_type = {
565         .owner          = THIS_MODULE,
566         .name           = "affs",
567         .get_sb         = affs_get_sb,
568         .kill_sb        = kill_block_super,
569         .fs_flags       = FS_REQUIRES_DEV,
570 };
571
572 static int __init init_affs_fs(void)
573 {
574         int err = init_inodecache();
575         if (err)
576                 goto out1;
577         err = register_filesystem(&affs_fs_type);
578         if (err)
579                 goto out;
580         return 0;
581 out:
582         destroy_inodecache();
583 out1:
584         return err;
585 }
586
587 static void __exit exit_affs_fs(void)
588 {
589         unregister_filesystem(&affs_fs_type);
590         destroy_inodecache();
591 }
592
593 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
594 MODULE_LICENSE("GPL");
595
596 module_init(init_affs_fs)
597 module_exit(exit_affs_fs)