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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/cred.h>
12#include <linux/parser.h>
13#include <linux/buffer_head.h>
14#include <linux/vmalloc.h>
15#include <linux/writeback.h>
16#include <linux/seq_file.h>
17#include <linux/crc-itu-t.h>
18#include "omfs.h"
19
20MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
21MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
22MODULE_LICENSE("GPL");
23
24struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
25{
26 struct omfs_sb_info *sbi = OMFS_SB(sb);
27 if (block >= sbi->s_num_blocks)
28 return NULL;
29
30 return sb_bread(sb, clus_to_blk(sbi, block));
31}
32
33struct inode *omfs_new_inode(struct inode *dir, umode_t mode)
34{
35 struct inode *inode;
36 u64 new_block;
37 int err;
38 int len;
39 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
40
41 inode = new_inode(dir->i_sb);
42 if (!inode)
43 return ERR_PTR(-ENOMEM);
44
45 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
46 &new_block, &len);
47 if (err)
48 goto fail;
49
50 inode->i_ino = new_block;
51 inode_init_owner(inode, NULL, mode);
52 inode->i_mapping->a_ops = &omfs_aops;
53
54 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
55 switch (mode & S_IFMT) {
56 case S_IFDIR:
57 inode->i_op = &omfs_dir_inops;
58 inode->i_fop = &omfs_dir_operations;
59 inode->i_size = sbi->s_sys_blocksize;
60 inc_nlink(inode);
61 break;
62 case S_IFREG:
63 inode->i_op = &omfs_file_inops;
64 inode->i_fop = &omfs_file_operations;
65 inode->i_size = 0;
66 break;
67 }
68
69 insert_inode_hash(inode);
70 mark_inode_dirty(inode);
71 return inode;
72fail:
73 make_bad_inode(inode);
74 iput(inode);
75 return ERR_PTR(err);
76}
77
78
79
80
81
82
83static void omfs_update_checksums(struct omfs_inode *oi)
84{
85 int xor, i, ofs = 0, count;
86 u16 crc = 0;
87 unsigned char *ptr = (unsigned char *) oi;
88
89 count = be32_to_cpu(oi->i_head.h_body_size);
90 ofs = sizeof(struct omfs_header);
91
92 crc = crc_itu_t(crc, ptr + ofs, count);
93 oi->i_head.h_crc = cpu_to_be16(crc);
94
95 xor = ptr[0];
96 for (i = 1; i < OMFS_XOR_COUNT; i++)
97 xor ^= ptr[i];
98
99 oi->i_head.h_check_xor = xor;
100}
101
102static int __omfs_write_inode(struct inode *inode, int wait)
103{
104 struct omfs_inode *oi;
105 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
106 struct buffer_head *bh, *bh2;
107 u64 ctime;
108 int i;
109 int ret = -EIO;
110 int sync_failed = 0;
111
112
113 bh = omfs_bread(inode->i_sb, inode->i_ino);
114 if (!bh)
115 goto out;
116
117 oi = (struct omfs_inode *) bh->b_data;
118
119 oi->i_head.h_self = cpu_to_be64(inode->i_ino);
120 if (S_ISDIR(inode->i_mode))
121 oi->i_type = OMFS_DIR;
122 else if (S_ISREG(inode->i_mode))
123 oi->i_type = OMFS_FILE;
124 else {
125 printk(KERN_WARNING "omfs: unknown file type: %d\n",
126 inode->i_mode);
127 goto out_brelse;
128 }
129
130 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
131 sizeof(struct omfs_header));
132 oi->i_head.h_version = 1;
133 oi->i_head.h_type = OMFS_INODE_NORMAL;
134 oi->i_head.h_magic = OMFS_IMAGIC;
135 oi->i_size = cpu_to_be64(inode->i_size);
136
137 ctime = inode->i_ctime.tv_sec * 1000LL +
138 ((inode->i_ctime.tv_nsec + 999)/1000);
139 oi->i_ctime = cpu_to_be64(ctime);
140
141 omfs_update_checksums(oi);
142
143 mark_buffer_dirty(bh);
144 if (wait) {
145 sync_dirty_buffer(bh);
146 if (buffer_req(bh) && !buffer_uptodate(bh))
147 sync_failed = 1;
148 }
149
150
151 for (i = 1; i < sbi->s_mirrors; i++) {
152 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
153 if (!bh2)
154 goto out_brelse;
155
156 memcpy(bh2->b_data, bh->b_data, bh->b_size);
157 mark_buffer_dirty(bh2);
158 if (wait) {
159 sync_dirty_buffer(bh2);
160 if (buffer_req(bh2) && !buffer_uptodate(bh2))
161 sync_failed = 1;
162 }
163 brelse(bh2);
164 }
165 ret = (sync_failed) ? -EIO : 0;
166out_brelse:
167 brelse(bh);
168out:
169 return ret;
170}
171
172static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
173{
174 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
175}
176
177int omfs_sync_inode(struct inode *inode)
178{
179 return __omfs_write_inode(inode, 1);
180}
181
182
183
184
185
186static void omfs_evict_inode(struct inode *inode)
187{
188 truncate_inode_pages_final(&inode->i_data);
189 clear_inode(inode);
190
191 if (inode->i_nlink)
192 return;
193
194 if (S_ISREG(inode->i_mode)) {
195 inode->i_size = 0;
196 omfs_shrink_inode(inode);
197 }
198
199 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
200}
201
202struct inode *omfs_iget(struct super_block *sb, ino_t ino)
203{
204 struct omfs_sb_info *sbi = OMFS_SB(sb);
205 struct omfs_inode *oi;
206 struct buffer_head *bh;
207 u64 ctime;
208 unsigned long nsecs;
209 struct inode *inode;
210
211 inode = iget_locked(sb, ino);
212 if (!inode)
213 return ERR_PTR(-ENOMEM);
214 if (!(inode->i_state & I_NEW))
215 return inode;
216
217 bh = omfs_bread(inode->i_sb, ino);
218 if (!bh)
219 goto iget_failed;
220
221 oi = (struct omfs_inode *)bh->b_data;
222
223
224 if (ino != be64_to_cpu(oi->i_head.h_self))
225 goto fail_bh;
226
227 inode->i_uid = sbi->s_uid;
228 inode->i_gid = sbi->s_gid;
229
230 ctime = be64_to_cpu(oi->i_ctime);
231 nsecs = do_div(ctime, 1000) * 1000L;
232
233 inode->i_atime.tv_sec = ctime;
234 inode->i_mtime.tv_sec = ctime;
235 inode->i_ctime.tv_sec = ctime;
236 inode->i_atime.tv_nsec = nsecs;
237 inode->i_mtime.tv_nsec = nsecs;
238 inode->i_ctime.tv_nsec = nsecs;
239
240 inode->i_mapping->a_ops = &omfs_aops;
241
242 switch (oi->i_type) {
243 case OMFS_DIR:
244 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
245 inode->i_op = &omfs_dir_inops;
246 inode->i_fop = &omfs_dir_operations;
247 inode->i_size = sbi->s_sys_blocksize;
248 inc_nlink(inode);
249 break;
250 case OMFS_FILE:
251 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
252 inode->i_fop = &omfs_file_operations;
253 inode->i_size = be64_to_cpu(oi->i_size);
254 break;
255 }
256 brelse(bh);
257 unlock_new_inode(inode);
258 return inode;
259fail_bh:
260 brelse(bh);
261iget_failed:
262 iget_failed(inode);
263 return ERR_PTR(-EIO);
264}
265
266static void omfs_put_super(struct super_block *sb)
267{
268 struct omfs_sb_info *sbi = OMFS_SB(sb);
269 kfree(sbi->s_imap);
270 kfree(sbi);
271 sb->s_fs_info = NULL;
272}
273
274static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
275{
276 struct super_block *s = dentry->d_sb;
277 struct omfs_sb_info *sbi = OMFS_SB(s);
278 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
279
280 buf->f_type = OMFS_MAGIC;
281 buf->f_bsize = sbi->s_blocksize;
282 buf->f_blocks = sbi->s_num_blocks;
283 buf->f_files = sbi->s_num_blocks;
284 buf->f_namelen = OMFS_NAMELEN;
285 buf->f_fsid.val[0] = (u32)id;
286 buf->f_fsid.val[1] = (u32)(id >> 32);
287
288 buf->f_bfree = buf->f_bavail = buf->f_ffree =
289 omfs_count_free(s);
290
291 return 0;
292}
293
294
295
296
297static int omfs_show_options(struct seq_file *m, struct dentry *root)
298{
299 struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
300 umode_t cur_umask = current_umask();
301
302 if (!uid_eq(sbi->s_uid, current_uid()))
303 seq_printf(m, ",uid=%u",
304 from_kuid_munged(&init_user_ns, sbi->s_uid));
305 if (!gid_eq(sbi->s_gid, current_gid()))
306 seq_printf(m, ",gid=%u",
307 from_kgid_munged(&init_user_ns, sbi->s_gid));
308
309 if (sbi->s_dmask == sbi->s_fmask) {
310 if (sbi->s_fmask != cur_umask)
311 seq_printf(m, ",umask=%o", sbi->s_fmask);
312 } else {
313 if (sbi->s_dmask != cur_umask)
314 seq_printf(m, ",dmask=%o", sbi->s_dmask);
315 if (sbi->s_fmask != cur_umask)
316 seq_printf(m, ",fmask=%o", sbi->s_fmask);
317 }
318
319 return 0;
320}
321
322static const struct super_operations omfs_sops = {
323 .write_inode = omfs_write_inode,
324 .evict_inode = omfs_evict_inode,
325 .put_super = omfs_put_super,
326 .statfs = omfs_statfs,
327 .show_options = omfs_show_options,
328};
329
330
331
332
333
334
335
336
337static int omfs_get_imap(struct super_block *sb)
338{
339 unsigned int bitmap_size, array_size;
340 int count;
341 struct omfs_sb_info *sbi = OMFS_SB(sb);
342 struct buffer_head *bh;
343 unsigned long **ptr;
344 sector_t block;
345
346 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
347 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
348
349 if (sbi->s_bitmap_ino == ~0ULL)
350 goto out;
351
352 sbi->s_imap_size = array_size;
353 sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL);
354 if (!sbi->s_imap)
355 goto nomem;
356
357 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
358 if (block >= sbi->s_num_blocks)
359 goto nomem;
360
361 ptr = sbi->s_imap;
362 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
363 bh = sb_bread(sb, block++);
364 if (!bh)
365 goto nomem_free;
366 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
367 if (!*ptr) {
368 brelse(bh);
369 goto nomem_free;
370 }
371 memcpy(*ptr, bh->b_data, sb->s_blocksize);
372 if (count < sb->s_blocksize)
373 memset((void *)*ptr + count, 0xff,
374 sb->s_blocksize - count);
375 brelse(bh);
376 ptr++;
377 }
378out:
379 return 0;
380
381nomem_free:
382 for (count = 0; count < array_size; count++)
383 kfree(sbi->s_imap[count]);
384
385 kfree(sbi->s_imap);
386nomem:
387 sbi->s_imap = NULL;
388 sbi->s_imap_size = 0;
389 return -ENOMEM;
390}
391
392enum {
393 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err
394};
395
396static const match_table_t tokens = {
397 {Opt_uid, "uid=%u"},
398 {Opt_gid, "gid=%u"},
399 {Opt_umask, "umask=%o"},
400 {Opt_dmask, "dmask=%o"},
401 {Opt_fmask, "fmask=%o"},
402 {Opt_err, NULL},
403};
404
405static int parse_options(char *options, struct omfs_sb_info *sbi)
406{
407 char *p;
408 substring_t args[MAX_OPT_ARGS];
409 int option;
410
411 if (!options)
412 return 1;
413
414 while ((p = strsep(&options, ",")) != NULL) {
415 int token;
416 if (!*p)
417 continue;
418
419 token = match_token(p, tokens, args);
420 switch (token) {
421 case Opt_uid:
422 if (match_int(&args[0], &option))
423 return 0;
424 sbi->s_uid = make_kuid(current_user_ns(), option);
425 if (!uid_valid(sbi->s_uid))
426 return 0;
427 break;
428 case Opt_gid:
429 if (match_int(&args[0], &option))
430 return 0;
431 sbi->s_gid = make_kgid(current_user_ns(), option);
432 if (!gid_valid(sbi->s_gid))
433 return 0;
434 break;
435 case Opt_umask:
436 if (match_octal(&args[0], &option))
437 return 0;
438 sbi->s_fmask = sbi->s_dmask = option;
439 break;
440 case Opt_dmask:
441 if (match_octal(&args[0], &option))
442 return 0;
443 sbi->s_dmask = option;
444 break;
445 case Opt_fmask:
446 if (match_octal(&args[0], &option))
447 return 0;
448 sbi->s_fmask = option;
449 break;
450 default:
451 return 0;
452 }
453 }
454 return 1;
455}
456
457static int omfs_fill_super(struct super_block *sb, void *data, int silent)
458{
459 struct buffer_head *bh, *bh2;
460 struct omfs_super_block *omfs_sb;
461 struct omfs_root_block *omfs_rb;
462 struct omfs_sb_info *sbi;
463 struct inode *root;
464 int ret = -EINVAL;
465
466 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
467 if (!sbi)
468 return -ENOMEM;
469
470 sb->s_fs_info = sbi;
471
472 sbi->s_uid = current_uid();
473 sbi->s_gid = current_gid();
474 sbi->s_dmask = sbi->s_fmask = current_umask();
475
476 if (!parse_options((char *) data, sbi))
477 goto end;
478
479 sb->s_maxbytes = 0xffffffff;
480
481 sb->s_time_gran = NSEC_PER_MSEC;
482 sb->s_time_min = 0;
483 sb->s_time_max = U64_MAX / MSEC_PER_SEC;
484
485 sb_set_blocksize(sb, 0x200);
486
487 bh = sb_bread(sb, 0);
488 if (!bh)
489 goto end;
490
491 omfs_sb = (struct omfs_super_block *)bh->b_data;
492
493 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
494 if (!silent)
495 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
496 omfs_sb->s_magic);
497 goto out_brelse_bh;
498 }
499 sb->s_magic = OMFS_MAGIC;
500
501 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
502 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
503 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
504 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
505 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
506 mutex_init(&sbi->s_bitmap_lock);
507
508 if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) {
509 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n",
510 (unsigned long long)sbi->s_num_blocks);
511 goto out_brelse_bh;
512 }
513
514 if (sbi->s_sys_blocksize > PAGE_SIZE) {
515 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
516 sbi->s_sys_blocksize);
517 goto out_brelse_bh;
518 }
519
520 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
521 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
522 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
523 sbi->s_blocksize);
524 goto out_brelse_bh;
525 }
526
527
528
529
530
531 sb_set_blocksize(sb, sbi->s_sys_blocksize);
532
533
534
535
536
537 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
538 get_bitmask_order(sbi->s_sys_blocksize);
539
540 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
541 if (!bh2)
542 goto out_brelse_bh;
543
544 omfs_rb = (struct omfs_root_block *)bh2->b_data;
545
546 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
547 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
548
549 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
550 printk(KERN_ERR "omfs: block count discrepancy between "
551 "super and root blocks (%llx, %llx)\n",
552 (unsigned long long)sbi->s_num_blocks,
553 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
554 goto out_brelse_bh2;
555 }
556
557 if (sbi->s_bitmap_ino != ~0ULL &&
558 sbi->s_bitmap_ino > sbi->s_num_blocks) {
559 printk(KERN_ERR "omfs: free space bitmap location is corrupt "
560 "(%llx, total blocks %llx)\n",
561 (unsigned long long) sbi->s_bitmap_ino,
562 (unsigned long long) sbi->s_num_blocks);
563 goto out_brelse_bh2;
564 }
565 if (sbi->s_clustersize < 1 ||
566 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
567 printk(KERN_ERR "omfs: cluster size out of range (%d)",
568 sbi->s_clustersize);
569 goto out_brelse_bh2;
570 }
571
572 ret = omfs_get_imap(sb);
573 if (ret)
574 goto out_brelse_bh2;
575
576 sb->s_op = &omfs_sops;
577
578 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
579 if (IS_ERR(root)) {
580 ret = PTR_ERR(root);
581 goto out_brelse_bh2;
582 }
583
584 sb->s_root = d_make_root(root);
585 if (!sb->s_root) {
586 ret = -ENOMEM;
587 goto out_brelse_bh2;
588 }
589 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
590
591 ret = 0;
592out_brelse_bh2:
593 brelse(bh2);
594out_brelse_bh:
595 brelse(bh);
596end:
597 if (ret)
598 kfree(sbi);
599 return ret;
600}
601
602static struct dentry *omfs_mount(struct file_system_type *fs_type,
603 int flags, const char *dev_name, void *data)
604{
605 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
606}
607
608static struct file_system_type omfs_fs_type = {
609 .owner = THIS_MODULE,
610 .name = "omfs",
611 .mount = omfs_mount,
612 .kill_sb = kill_block_super,
613 .fs_flags = FS_REQUIRES_DEV,
614};
615MODULE_ALIAS_FS("omfs");
616
617static int __init init_omfs_fs(void)
618{
619 return register_filesystem(&omfs_fs_type);
620}
621
622static void __exit exit_omfs_fs(void)
623{
624 unregister_filesystem(&omfs_fs_type);
625}
626
627module_init(init_omfs_fs);
628module_exit(exit_omfs_fs);
629
