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6#include <linux/module.h>
7#include <linux/sched.h>
8#include <linux/slab.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/writeback.h>
15#include <linux/crc-itu-t.h>
16#include "omfs.h"
17
18MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
19MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
20MODULE_LICENSE("GPL");
21
22struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
23{
24 struct omfs_sb_info *sbi = OMFS_SB(sb);
25 if (block >= sbi->s_num_blocks)
26 return NULL;
27
28 return sb_bread(sb, clus_to_blk(sbi, block));
29}
30
31struct inode *omfs_new_inode(struct inode *dir, int mode)
32{
33 struct inode *inode;
34 u64 new_block;
35 int err;
36 int len;
37 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
38
39 inode = new_inode(dir->i_sb);
40 if (!inode)
41 return ERR_PTR(-ENOMEM);
42
43 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
44 &new_block, &len);
45 if (err)
46 goto fail;
47
48 inode->i_ino = new_block;
49 inode_init_owner(inode, NULL, mode);
50 inode->i_mapping->a_ops = &omfs_aops;
51
52 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
53 switch (mode & S_IFMT) {
54 case S_IFDIR:
55 inode->i_op = &omfs_dir_inops;
56 inode->i_fop = &omfs_dir_operations;
57 inode->i_size = sbi->s_sys_blocksize;
58 inc_nlink(inode);
59 break;
60 case S_IFREG:
61 inode->i_op = &omfs_file_inops;
62 inode->i_fop = &omfs_file_operations;
63 inode->i_size = 0;
64 break;
65 }
66
67 insert_inode_hash(inode);
68 mark_inode_dirty(inode);
69 return inode;
70fail:
71 make_bad_inode(inode);
72 iput(inode);
73 return ERR_PTR(err);
74}
75
76
77
78
79
80
81static void omfs_update_checksums(struct omfs_inode *oi)
82{
83 int xor, i, ofs = 0, count;
84 u16 crc = 0;
85 unsigned char *ptr = (unsigned char *) oi;
86
87 count = be32_to_cpu(oi->i_head.h_body_size);
88 ofs = sizeof(struct omfs_header);
89
90 crc = crc_itu_t(crc, ptr + ofs, count);
91 oi->i_head.h_crc = cpu_to_be16(crc);
92
93 xor = ptr[0];
94 for (i = 1; i < OMFS_XOR_COUNT; i++)
95 xor ^= ptr[i];
96
97 oi->i_head.h_check_xor = xor;
98}
99
100static int __omfs_write_inode(struct inode *inode, int wait)
101{
102 struct omfs_inode *oi;
103 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
104 struct buffer_head *bh, *bh2;
105 u64 ctime;
106 int i;
107 int ret = -EIO;
108 int sync_failed = 0;
109
110
111 bh = omfs_bread(inode->i_sb, inode->i_ino);
112 if (!bh)
113 goto out;
114
115 oi = (struct omfs_inode *) bh->b_data;
116
117 oi->i_head.h_self = cpu_to_be64(inode->i_ino);
118 if (S_ISDIR(inode->i_mode))
119 oi->i_type = OMFS_DIR;
120 else if (S_ISREG(inode->i_mode))
121 oi->i_type = OMFS_FILE;
122 else {
123 printk(KERN_WARNING "omfs: unknown file type: %d\n",
124 inode->i_mode);
125 goto out_brelse;
126 }
127
128 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
129 sizeof(struct omfs_header));
130 oi->i_head.h_version = 1;
131 oi->i_head.h_type = OMFS_INODE_NORMAL;
132 oi->i_head.h_magic = OMFS_IMAGIC;
133 oi->i_size = cpu_to_be64(inode->i_size);
134
135 ctime = inode->i_ctime.tv_sec * 1000LL +
136 ((inode->i_ctime.tv_nsec + 999)/1000);
137 oi->i_ctime = cpu_to_be64(ctime);
138
139 omfs_update_checksums(oi);
140
141 mark_buffer_dirty(bh);
142 if (wait) {
143 sync_dirty_buffer(bh);
144 if (buffer_req(bh) && !buffer_uptodate(bh))
145 sync_failed = 1;
146 }
147
148
149 for (i = 1; i < sbi->s_mirrors; i++) {
150 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
151 if (!bh2)
152 goto out_brelse;
153
154 memcpy(bh2->b_data, bh->b_data, bh->b_size);
155 mark_buffer_dirty(bh2);
156 if (wait) {
157 sync_dirty_buffer(bh2);
158 if (buffer_req(bh2) && !buffer_uptodate(bh2))
159 sync_failed = 1;
160 }
161 brelse(bh2);
162 }
163 ret = (sync_failed) ? -EIO : 0;
164out_brelse:
165 brelse(bh);
166out:
167 return ret;
168}
169
170static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
171{
172 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
173}
174
175int omfs_sync_inode(struct inode *inode)
176{
177 return __omfs_write_inode(inode, 1);
178}
179
180
181
182
183
184static void omfs_evict_inode(struct inode *inode)
185{
186 truncate_inode_pages(&inode->i_data, 0);
187 end_writeback(inode);
188
189 if (inode->i_nlink)
190 return;
191
192 if (S_ISREG(inode->i_mode)) {
193 inode->i_size = 0;
194 omfs_shrink_inode(inode);
195 }
196
197 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
198}
199
200struct inode *omfs_iget(struct super_block *sb, ino_t ino)
201{
202 struct omfs_sb_info *sbi = OMFS_SB(sb);
203 struct omfs_inode *oi;
204 struct buffer_head *bh;
205 u64 ctime;
206 unsigned long nsecs;
207 struct inode *inode;
208
209 inode = iget_locked(sb, ino);
210 if (!inode)
211 return ERR_PTR(-ENOMEM);
212 if (!(inode->i_state & I_NEW))
213 return inode;
214
215 bh = omfs_bread(inode->i_sb, ino);
216 if (!bh)
217 goto iget_failed;
218
219 oi = (struct omfs_inode *)bh->b_data;
220
221
222 if (ino != be64_to_cpu(oi->i_head.h_self))
223 goto fail_bh;
224
225 inode->i_uid = sbi->s_uid;
226 inode->i_gid = sbi->s_gid;
227
228 ctime = be64_to_cpu(oi->i_ctime);
229 nsecs = do_div(ctime, 1000) * 1000L;
230
231 inode->i_atime.tv_sec = ctime;
232 inode->i_mtime.tv_sec = ctime;
233 inode->i_ctime.tv_sec = ctime;
234 inode->i_atime.tv_nsec = nsecs;
235 inode->i_mtime.tv_nsec = nsecs;
236 inode->i_ctime.tv_nsec = nsecs;
237
238 inode->i_mapping->a_ops = &omfs_aops;
239
240 switch (oi->i_type) {
241 case OMFS_DIR:
242 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
243 inode->i_op = &omfs_dir_inops;
244 inode->i_fop = &omfs_dir_operations;
245 inode->i_size = sbi->s_sys_blocksize;
246 inc_nlink(inode);
247 break;
248 case OMFS_FILE:
249 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
250 inode->i_fop = &omfs_file_operations;
251 inode->i_size = be64_to_cpu(oi->i_size);
252 break;
253 }
254 brelse(bh);
255 unlock_new_inode(inode);
256 return inode;
257fail_bh:
258 brelse(bh);
259iget_failed:
260 iget_failed(inode);
261 return ERR_PTR(-EIO);
262}
263
264static void omfs_put_super(struct super_block *sb)
265{
266 struct omfs_sb_info *sbi = OMFS_SB(sb);
267 kfree(sbi->s_imap);
268 kfree(sbi);
269 sb->s_fs_info = NULL;
270}
271
272static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
273{
274 struct super_block *s = dentry->d_sb;
275 struct omfs_sb_info *sbi = OMFS_SB(s);
276 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
277
278 buf->f_type = OMFS_MAGIC;
279 buf->f_bsize = sbi->s_blocksize;
280 buf->f_blocks = sbi->s_num_blocks;
281 buf->f_files = sbi->s_num_blocks;
282 buf->f_namelen = OMFS_NAMELEN;
283 buf->f_fsid.val[0] = (u32)id;
284 buf->f_fsid.val[1] = (u32)(id >> 32);
285
286 buf->f_bfree = buf->f_bavail = buf->f_ffree =
287 omfs_count_free(s);
288
289 return 0;
290}
291
292static const struct super_operations omfs_sops = {
293 .write_inode = omfs_write_inode,
294 .evict_inode = omfs_evict_inode,
295 .put_super = omfs_put_super,
296 .statfs = omfs_statfs,
297 .show_options = generic_show_options,
298};
299
300
301
302
303
304
305
306
307static int omfs_get_imap(struct super_block *sb)
308{
309 int bitmap_size;
310 int array_size;
311 int count;
312 struct omfs_sb_info *sbi = OMFS_SB(sb);
313 struct buffer_head *bh;
314 unsigned long **ptr;
315 sector_t block;
316
317 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
318 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
319
320 if (sbi->s_bitmap_ino == ~0ULL)
321 goto out;
322
323 sbi->s_imap_size = array_size;
324 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
325 if (!sbi->s_imap)
326 goto nomem;
327
328 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
329 if (block >= sbi->s_num_blocks)
330 goto nomem;
331
332 ptr = sbi->s_imap;
333 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
334 bh = sb_bread(sb, block++);
335 if (!bh)
336 goto nomem_free;
337 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
338 if (!*ptr) {
339 brelse(bh);
340 goto nomem_free;
341 }
342 memcpy(*ptr, bh->b_data, sb->s_blocksize);
343 if (count < sb->s_blocksize)
344 memset((void *)*ptr + count, 0xff,
345 sb->s_blocksize - count);
346 brelse(bh);
347 ptr++;
348 }
349out:
350 return 0;
351
352nomem_free:
353 for (count = 0; count < array_size; count++)
354 kfree(sbi->s_imap[count]);
355
356 kfree(sbi->s_imap);
357nomem:
358 sbi->s_imap = NULL;
359 sbi->s_imap_size = 0;
360 return -ENOMEM;
361}
362
363enum {
364 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
365};
366
367static const match_table_t tokens = {
368 {Opt_uid, "uid=%u"},
369 {Opt_gid, "gid=%u"},
370 {Opt_umask, "umask=%o"},
371 {Opt_dmask, "dmask=%o"},
372 {Opt_fmask, "fmask=%o"},
373};
374
375static int parse_options(char *options, struct omfs_sb_info *sbi)
376{
377 char *p;
378 substring_t args[MAX_OPT_ARGS];
379 int option;
380
381 if (!options)
382 return 1;
383
384 while ((p = strsep(&options, ",")) != NULL) {
385 int token;
386 if (!*p)
387 continue;
388
389 token = match_token(p, tokens, args);
390 switch (token) {
391 case Opt_uid:
392 if (match_int(&args[0], &option))
393 return 0;
394 sbi->s_uid = option;
395 break;
396 case Opt_gid:
397 if (match_int(&args[0], &option))
398 return 0;
399 sbi->s_gid = option;
400 break;
401 case Opt_umask:
402 if (match_octal(&args[0], &option))
403 return 0;
404 sbi->s_fmask = sbi->s_dmask = option;
405 break;
406 case Opt_dmask:
407 if (match_octal(&args[0], &option))
408 return 0;
409 sbi->s_dmask = option;
410 break;
411 case Opt_fmask:
412 if (match_octal(&args[0], &option))
413 return 0;
414 sbi->s_fmask = option;
415 break;
416 default:
417 return 0;
418 }
419 }
420 return 1;
421}
422
423static int omfs_fill_super(struct super_block *sb, void *data, int silent)
424{
425 struct buffer_head *bh, *bh2;
426 struct omfs_super_block *omfs_sb;
427 struct omfs_root_block *omfs_rb;
428 struct omfs_sb_info *sbi;
429 struct inode *root;
430 int ret = -EINVAL;
431
432 save_mount_options(sb, (char *) data);
433
434 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
435 if (!sbi)
436 return -ENOMEM;
437
438 sb->s_fs_info = sbi;
439
440 sbi->s_uid = current_uid();
441 sbi->s_gid = current_gid();
442 sbi->s_dmask = sbi->s_fmask = current_umask();
443
444 if (!parse_options((char *) data, sbi))
445 goto end;
446
447 sb->s_maxbytes = 0xffffffff;
448
449 sb_set_blocksize(sb, 0x200);
450
451 bh = sb_bread(sb, 0);
452 if (!bh)
453 goto end;
454
455 omfs_sb = (struct omfs_super_block *)bh->b_data;
456
457 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
458 if (!silent)
459 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
460 omfs_sb->s_magic);
461 goto out_brelse_bh;
462 }
463 sb->s_magic = OMFS_MAGIC;
464
465 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
466 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
467 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
468 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
469 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
470 mutex_init(&sbi->s_bitmap_lock);
471
472 if (sbi->s_sys_blocksize > PAGE_SIZE) {
473 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
474 sbi->s_sys_blocksize);
475 goto out_brelse_bh;
476 }
477
478 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
479 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
480 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
481 sbi->s_blocksize);
482 goto out_brelse_bh;
483 }
484
485
486
487
488
489 sb_set_blocksize(sb, sbi->s_sys_blocksize);
490
491
492
493
494
495 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
496 get_bitmask_order(sbi->s_sys_blocksize);
497
498 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
499 if (!bh2)
500 goto out_brelse_bh;
501
502 omfs_rb = (struct omfs_root_block *)bh2->b_data;
503
504 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
505 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
506
507 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
508 printk(KERN_ERR "omfs: block count discrepancy between "
509 "super and root blocks (%llx, %llx)\n",
510 (unsigned long long)sbi->s_num_blocks,
511 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
512 goto out_brelse_bh2;
513 }
514
515 if (sbi->s_bitmap_ino != ~0ULL &&
516 sbi->s_bitmap_ino > sbi->s_num_blocks) {
517 printk(KERN_ERR "omfs: free space bitmap location is corrupt "
518 "(%llx, total blocks %llx)\n",
519 (unsigned long long) sbi->s_bitmap_ino,
520 (unsigned long long) sbi->s_num_blocks);
521 goto out_brelse_bh2;
522 }
523 if (sbi->s_clustersize < 1 ||
524 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
525 printk(KERN_ERR "omfs: cluster size out of range (%d)",
526 sbi->s_clustersize);
527 goto out_brelse_bh2;
528 }
529
530 ret = omfs_get_imap(sb);
531 if (ret)
532 goto out_brelse_bh2;
533
534 sb->s_op = &omfs_sops;
535
536 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
537 if (IS_ERR(root)) {
538 ret = PTR_ERR(root);
539 goto out_brelse_bh2;
540 }
541
542 sb->s_root = d_alloc_root(root);
543 if (!sb->s_root) {
544 iput(root);
545 goto out_brelse_bh2;
546 }
547 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
548
549 ret = 0;
550out_brelse_bh2:
551 brelse(bh2);
552out_brelse_bh:
553 brelse(bh);
554end:
555 if (ret)
556 kfree(sbi);
557 return ret;
558}
559
560static struct dentry *omfs_mount(struct file_system_type *fs_type,
561 int flags, const char *dev_name, void *data)
562{
563 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
564}
565
566static struct file_system_type omfs_fs_type = {
567 .owner = THIS_MODULE,
568 .name = "omfs",
569 .mount = omfs_mount,
570 .kill_sb = kill_block_super,
571 .fs_flags = FS_REQUIRES_DEV,
572};
573
574static int __init init_omfs_fs(void)
575{
576 return register_filesystem(&omfs_fs_type);
577}
578
579static void __exit exit_omfs_fs(void)
580{
581 unregister_filesystem(&omfs_fs_type);
582}
583
584module_init(init_omfs_fs);
585module_exit(exit_omfs_fs);
586
