Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6] / fs / omfs / inode.c
1 /*
2  * Optimized MPEG FS - inode and super operations.
3  * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
4  * Released under GPL v2.
5  */
6 #include <linux/version.h>
7 #include <linux/module.h>
8 #include <linux/sched.h>
9 #include <linux/fs.h>
10 #include <linux/vfs.h>
11 #include <linux/parser.h>
12 #include <linux/buffer_head.h>
13 #include <linux/vmalloc.h>
14 #include <linux/crc-itu-t.h>
15 #include "omfs.h"
16
17 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
18 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
19 MODULE_LICENSE("GPL");
20
21 struct inode *omfs_new_inode(struct inode *dir, int mode)
22 {
23         struct inode *inode;
24         u64 new_block;
25         int err;
26         int len;
27         struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
28
29         inode = new_inode(dir->i_sb);
30         if (!inode)
31                 return ERR_PTR(-ENOMEM);
32
33         err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
34                         &new_block, &len);
35         if (err)
36                 goto fail;
37
38         inode->i_ino = new_block;
39         inode->i_mode = mode;
40         inode->i_uid = current->fsuid;
41         inode->i_gid = current->fsgid;
42         inode->i_blocks = 0;
43         inode->i_mapping->a_ops = &omfs_aops;
44
45         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
46         switch (mode & S_IFMT) {
47         case S_IFDIR:
48                 inode->i_op = &omfs_dir_inops;
49                 inode->i_fop = &omfs_dir_operations;
50                 inode->i_size = sbi->s_sys_blocksize;
51                 inc_nlink(inode);
52                 break;
53         case S_IFREG:
54                 inode->i_op = &omfs_file_inops;
55                 inode->i_fop = &omfs_file_operations;
56                 inode->i_size = 0;
57                 break;
58         }
59
60         insert_inode_hash(inode);
61         mark_inode_dirty(inode);
62         return inode;
63 fail:
64         make_bad_inode(inode);
65         iput(inode);
66         return ERR_PTR(err);
67 }
68
69 /*
70  * Update the header checksums for a dirty inode based on its contents.
71  * Caller is expected to hold the buffer head underlying oi and mark it
72  * dirty.
73  */
74 static void omfs_update_checksums(struct omfs_inode *oi)
75 {
76         int xor, i, ofs = 0, count;
77         u16 crc = 0;
78         unsigned char *ptr = (unsigned char *) oi;
79
80         count = be32_to_cpu(oi->i_head.h_body_size);
81         ofs = sizeof(struct omfs_header);
82
83         crc = crc_itu_t(crc, ptr + ofs, count);
84         oi->i_head.h_crc = cpu_to_be16(crc);
85
86         xor = ptr[0];
87         for (i = 1; i < OMFS_XOR_COUNT; i++)
88                 xor ^= ptr[i];
89
90         oi->i_head.h_check_xor = xor;
91 }
92
93 static int omfs_write_inode(struct inode *inode, int wait)
94 {
95         struct omfs_inode *oi;
96         struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
97         struct buffer_head *bh, *bh2;
98         unsigned int block;
99         u64 ctime;
100         int i;
101         int ret = -EIO;
102         int sync_failed = 0;
103
104         /* get current inode since we may have written sibling ptrs etc. */
105         block = clus_to_blk(sbi, inode->i_ino);
106         bh = sb_bread(inode->i_sb, block);
107         if (!bh)
108                 goto out;
109
110         oi = (struct omfs_inode *) bh->b_data;
111
112         oi->i_head.h_self = cpu_to_be64(inode->i_ino);
113         if (S_ISDIR(inode->i_mode))
114                 oi->i_type = OMFS_DIR;
115         else if (S_ISREG(inode->i_mode))
116                 oi->i_type = OMFS_FILE;
117         else {
118                 printk(KERN_WARNING "omfs: unknown file type: %d\n",
119                         inode->i_mode);
120                 goto out_brelse;
121         }
122
123         oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
124                 sizeof(struct omfs_header));
125         oi->i_head.h_version = 1;
126         oi->i_head.h_type = OMFS_INODE_NORMAL;
127         oi->i_head.h_magic = OMFS_IMAGIC;
128         oi->i_size = cpu_to_be64(inode->i_size);
129
130         ctime = inode->i_ctime.tv_sec * 1000LL +
131                 ((inode->i_ctime.tv_nsec + 999)/1000);
132         oi->i_ctime = cpu_to_be64(ctime);
133
134         omfs_update_checksums(oi);
135
136         mark_buffer_dirty(bh);
137         if (wait) {
138                 sync_dirty_buffer(bh);
139                 if (buffer_req(bh) && !buffer_uptodate(bh))
140                         sync_failed = 1;
141         }
142
143         /* if mirroring writes, copy to next fsblock */
144         for (i = 1; i < sbi->s_mirrors; i++) {
145                 bh2 = sb_bread(inode->i_sb, block + i *
146                         (sbi->s_blocksize / sbi->s_sys_blocksize));
147                 if (!bh2)
148                         goto out_brelse;
149
150                 memcpy(bh2->b_data, bh->b_data, bh->b_size);
151                 mark_buffer_dirty(bh2);
152                 if (wait) {
153                         sync_dirty_buffer(bh2);
154                         if (buffer_req(bh2) && !buffer_uptodate(bh2))
155                                 sync_failed = 1;
156                 }
157                 brelse(bh2);
158         }
159         ret = (sync_failed) ? -EIO : 0;
160 out_brelse:
161         brelse(bh);
162 out:
163         return ret;
164 }
165
166 int omfs_sync_inode(struct inode *inode)
167 {
168         return omfs_write_inode(inode, 1);
169 }
170
171 /*
172  * called when an entry is deleted, need to clear the bits in the
173  * bitmaps.
174  */
175 static void omfs_delete_inode(struct inode *inode)
176 {
177         truncate_inode_pages(&inode->i_data, 0);
178
179         if (S_ISREG(inode->i_mode)) {
180                 inode->i_size = 0;
181                 omfs_shrink_inode(inode);
182         }
183
184         omfs_clear_range(inode->i_sb, inode->i_ino, 2);
185         clear_inode(inode);
186 }
187
188 struct inode *omfs_iget(struct super_block *sb, ino_t ino)
189 {
190         struct omfs_sb_info *sbi = OMFS_SB(sb);
191         struct omfs_inode *oi;
192         struct buffer_head *bh;
193         unsigned int block;
194         u64 ctime;
195         unsigned long nsecs;
196         struct inode *inode;
197
198         inode = iget_locked(sb, ino);
199         if (!inode)
200                 return ERR_PTR(-ENOMEM);
201         if (!(inode->i_state & I_NEW))
202                 return inode;
203
204         block = clus_to_blk(sbi, ino);
205         bh = sb_bread(inode->i_sb, block);
206         if (!bh)
207                 goto iget_failed;
208
209         oi = (struct omfs_inode *)bh->b_data;
210
211         /* check self */
212         if (ino != be64_to_cpu(oi->i_head.h_self))
213                 goto fail_bh;
214
215         inode->i_uid = sbi->s_uid;
216         inode->i_gid = sbi->s_gid;
217
218         ctime = be64_to_cpu(oi->i_ctime);
219         nsecs = do_div(ctime, 1000) * 1000L;
220
221         inode->i_atime.tv_sec = ctime;
222         inode->i_mtime.tv_sec = ctime;
223         inode->i_ctime.tv_sec = ctime;
224         inode->i_atime.tv_nsec = nsecs;
225         inode->i_mtime.tv_nsec = nsecs;
226         inode->i_ctime.tv_nsec = nsecs;
227
228         inode->i_mapping->a_ops = &omfs_aops;
229
230         switch (oi->i_type) {
231         case OMFS_DIR:
232                 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
233                 inode->i_op = &omfs_dir_inops;
234                 inode->i_fop = &omfs_dir_operations;
235                 inode->i_size = sbi->s_sys_blocksize;
236                 inc_nlink(inode);
237                 break;
238         case OMFS_FILE:
239                 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
240                 inode->i_fop = &omfs_file_operations;
241                 inode->i_size = be64_to_cpu(oi->i_size);
242                 break;
243         }
244         brelse(bh);
245         unlock_new_inode(inode);
246         return inode;
247 fail_bh:
248         brelse(bh);
249 iget_failed:
250         iget_failed(inode);
251         return ERR_PTR(-EIO);
252 }
253
254 static void omfs_put_super(struct super_block *sb)
255 {
256         struct omfs_sb_info *sbi = OMFS_SB(sb);
257         kfree(sbi->s_imap);
258         kfree(sbi);
259         sb->s_fs_info = NULL;
260 }
261
262 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
263 {
264         struct super_block *s = dentry->d_sb;
265         struct omfs_sb_info *sbi = OMFS_SB(s);
266         buf->f_type = OMFS_MAGIC;
267         buf->f_bsize = sbi->s_blocksize;
268         buf->f_blocks = sbi->s_num_blocks;
269         buf->f_files = sbi->s_num_blocks;
270         buf->f_namelen = OMFS_NAMELEN;
271
272         buf->f_bfree = buf->f_bavail = buf->f_ffree =
273                 omfs_count_free(s);
274         return 0;
275 }
276
277 static struct super_operations omfs_sops = {
278         .write_inode    = omfs_write_inode,
279         .delete_inode   = omfs_delete_inode,
280         .put_super      = omfs_put_super,
281         .statfs         = omfs_statfs,
282         .show_options   = generic_show_options,
283 };
284
285 /*
286  * For Rio Karma, there is an on-disk free bitmap whose location is
287  * stored in the root block.  For ReplayTV, there is no such free bitmap
288  * so we have to walk the tree.  Both inodes and file data are allocated
289  * from the same map.  This array can be big (300k) so we allocate
290  * in units of the blocksize.
291  */
292 static int omfs_get_imap(struct super_block *sb)
293 {
294         int bitmap_size;
295         int array_size;
296         int count;
297         struct omfs_sb_info *sbi = OMFS_SB(sb);
298         struct buffer_head *bh;
299         unsigned long **ptr;
300         sector_t block;
301
302         bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
303         array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
304
305         if (sbi->s_bitmap_ino == ~0ULL)
306                 goto out;
307
308         sbi->s_imap_size = array_size;
309         sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
310         if (!sbi->s_imap)
311                 goto nomem;
312
313         block = clus_to_blk(sbi, sbi->s_bitmap_ino);
314         ptr = sbi->s_imap;
315         for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
316                 bh = sb_bread(sb, block++);
317                 if (!bh)
318                         goto nomem_free;
319                 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
320                 if (!*ptr) {
321                         brelse(bh);
322                         goto nomem_free;
323                 }
324                 memcpy(*ptr, bh->b_data, sb->s_blocksize);
325                 if (count < sb->s_blocksize)
326                         memset((void *)*ptr + count, 0xff,
327                                 sb->s_blocksize - count);
328                 brelse(bh);
329                 ptr++;
330         }
331 out:
332         return 0;
333
334 nomem_free:
335         for (count = 0; count < array_size; count++)
336                 kfree(sbi->s_imap[count]);
337
338         kfree(sbi->s_imap);
339 nomem:
340         sbi->s_imap = NULL;
341         sbi->s_imap_size = 0;
342         return -ENOMEM;
343 }
344
345 enum {
346         Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
347 };
348
349 static match_table_t tokens = {
350         {Opt_uid, "uid=%u"},
351         {Opt_gid, "gid=%u"},
352         {Opt_umask, "umask=%o"},
353         {Opt_dmask, "dmask=%o"},
354         {Opt_fmask, "fmask=%o"},
355 };
356
357 static int parse_options(char *options, struct omfs_sb_info *sbi)
358 {
359         char *p;
360         substring_t args[MAX_OPT_ARGS];
361         int option;
362
363         if (!options)
364                 return 1;
365
366         while ((p = strsep(&options, ",")) != NULL) {
367                 int token;
368                 if (!*p)
369                         continue;
370
371                 token = match_token(p, tokens, args);
372                 switch (token) {
373                 case Opt_uid:
374                         if (match_int(&args[0], &option))
375                                 return 0;
376                         sbi->s_uid = option;
377                         break;
378                 case Opt_gid:
379                         if (match_int(&args[0], &option))
380                                 return 0;
381                         sbi->s_gid = option;
382                         break;
383                 case Opt_umask:
384                         if (match_octal(&args[0], &option))
385                                 return 0;
386                         sbi->s_fmask = sbi->s_dmask = option;
387                         break;
388                 case Opt_dmask:
389                         if (match_octal(&args[0], &option))
390                                 return 0;
391                         sbi->s_dmask = option;
392                         break;
393                 case Opt_fmask:
394                         if (match_octal(&args[0], &option))
395                                 return 0;
396                         sbi->s_fmask = option;
397                         break;
398                 default:
399                         return 0;
400                 }
401         }
402         return 1;
403 }
404
405 static int omfs_fill_super(struct super_block *sb, void *data, int silent)
406 {
407         struct buffer_head *bh, *bh2;
408         struct omfs_super_block *omfs_sb;
409         struct omfs_root_block *omfs_rb;
410         struct omfs_sb_info *sbi;
411         struct inode *root;
412         sector_t start;
413         int ret = -EINVAL;
414
415         save_mount_options(sb, (char *) data);
416
417         sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
418         if (!sbi)
419                 return -ENOMEM;
420
421         sb->s_fs_info = sbi;
422
423         sbi->s_uid = current->uid;
424         sbi->s_gid = current->gid;
425         sbi->s_dmask = sbi->s_fmask = current->fs->umask;
426
427         if (!parse_options((char *) data, sbi))
428                 goto end;
429
430         sb->s_maxbytes = 0xffffffff;
431
432         sb_set_blocksize(sb, 0x200);
433
434         bh = sb_bread(sb, 0);
435         if (!bh)
436                 goto end;
437
438         omfs_sb = (struct omfs_super_block *)bh->b_data;
439
440         if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
441                 if (!silent)
442                         printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
443                                    omfs_sb->s_magic);
444                 goto out_brelse_bh;
445         }
446         sb->s_magic = OMFS_MAGIC;
447
448         sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
449         sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
450         sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
451         sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
452         sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
453         mutex_init(&sbi->s_bitmap_lock);
454
455         if (sbi->s_sys_blocksize > PAGE_SIZE) {
456                 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
457                         sbi->s_sys_blocksize);
458                 goto out_brelse_bh;
459         }
460
461         if (sbi->s_blocksize < sbi->s_sys_blocksize ||
462             sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
463                 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
464                         sbi->s_blocksize);
465                 goto out_brelse_bh;
466         }
467
468         /*
469          * Use sys_blocksize as the fs block since it is smaller than a
470          * page while the fs blocksize can be larger.
471          */
472         sb_set_blocksize(sb, sbi->s_sys_blocksize);
473
474         /*
475          * ...and the difference goes into a shift.  sys_blocksize is always
476          * a power of two factor of blocksize.
477          */
478         sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
479                 get_bitmask_order(sbi->s_sys_blocksize);
480
481         start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block));
482         bh2 = sb_bread(sb, start);
483         if (!bh2)
484                 goto out_brelse_bh;
485
486         omfs_rb = (struct omfs_root_block *)bh2->b_data;
487
488         sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
489         sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
490
491         if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
492                 printk(KERN_ERR "omfs: block count discrepancy between "
493                         "super and root blocks (%llx, %llx)\n",
494                         (unsigned long long)sbi->s_num_blocks,
495                         (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
496                 goto out_brelse_bh2;
497         }
498
499         ret = omfs_get_imap(sb);
500         if (ret)
501                 goto out_brelse_bh2;
502
503         sb->s_op = &omfs_sops;
504
505         root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
506         if (IS_ERR(root)) {
507                 ret = PTR_ERR(root);
508                 goto out_brelse_bh2;
509         }
510
511         sb->s_root = d_alloc_root(root);
512         if (!sb->s_root) {
513                 iput(root);
514                 goto out_brelse_bh2;
515         }
516         printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
517
518         ret = 0;
519 out_brelse_bh2:
520         brelse(bh2);
521 out_brelse_bh:
522         brelse(bh);
523 end:
524         return ret;
525 }
526
527 static int omfs_get_sb(struct file_system_type *fs_type,
528                         int flags, const char *dev_name,
529                         void *data, struct vfsmount *m)
530 {
531         return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
532 }
533
534 static struct file_system_type omfs_fs_type = {
535         .owner = THIS_MODULE,
536         .name = "omfs",
537         .get_sb = omfs_get_sb,
538         .kill_sb = kill_block_super,
539         .fs_flags = FS_REQUIRES_DEV,
540 };
541
542 static int __init init_omfs_fs(void)
543 {
544         return register_filesystem(&omfs_fs_type);
545 }
546
547 static void __exit exit_omfs_fs(void)
548 {
549         unregister_filesystem(&omfs_fs_type);
550 }
551
552 module_init(init_omfs_fs);
553 module_exit(exit_omfs_fs);