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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(&init_user_ns, 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 = u64_to_fsid(id);
286
287 buf->f_bfree = buf->f_bavail = buf->f_ffree =
288 omfs_count_free(s);
289
290 return 0;
291}
292
293
294
295
296static int omfs_show_options(struct seq_file *m, struct dentry *root)
297{
298 struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
299 umode_t cur_umask = current_umask();
300
301 if (!uid_eq(sbi->s_uid, current_uid()))
302 seq_printf(m, ",uid=%u",
303 from_kuid_munged(&init_user_ns, sbi->s_uid));
304 if (!gid_eq(sbi->s_gid, current_gid()))
305 seq_printf(m, ",gid=%u",
306 from_kgid_munged(&init_user_ns, sbi->s_gid));
307
308 if (sbi->s_dmask == sbi->s_fmask) {
309 if (sbi->s_fmask != cur_umask)
310 seq_printf(m, ",umask=%o", sbi->s_fmask);
311 } else {
312 if (sbi->s_dmask != cur_umask)
313 seq_printf(m, ",dmask=%o", sbi->s_dmask);
314 if (sbi->s_fmask != cur_umask)
315 seq_printf(m, ",fmask=%o", sbi->s_fmask);
316 }
317
318 return 0;
319}
320
321static const struct super_operations omfs_sops = {
322 .write_inode = omfs_write_inode,
323 .evict_inode = omfs_evict_inode,
324 .put_super = omfs_put_super,
325 .statfs = omfs_statfs,
326 .show_options = omfs_show_options,
327};
328
329
330
331
332
333
334
335
336static int omfs_get_imap(struct super_block *sb)
337{
338 unsigned int bitmap_size, array_size;
339 int count;
340 struct omfs_sb_info *sbi = OMFS_SB(sb);
341 struct buffer_head *bh;
342 unsigned long **ptr;
343 sector_t block;
344
345 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
346 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
347
348 if (sbi->s_bitmap_ino == ~0ULL)
349 goto out;
350
351 sbi->s_imap_size = array_size;
352 sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL);
353 if (!sbi->s_imap)
354 goto nomem;
355
356 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
357 if (block >= sbi->s_num_blocks)
358 goto nomem;
359
360 ptr = sbi->s_imap;
361 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
362 bh = sb_bread(sb, block++);
363 if (!bh)
364 goto nomem_free;
365 *ptr = kmemdup(bh->b_data, sb->s_blocksize, GFP_KERNEL);
366 if (!*ptr) {
367 brelse(bh);
368 goto nomem_free;
369 }
370 if (count < sb->s_blocksize)
371 memset((void *)*ptr + count, 0xff,
372 sb->s_blocksize - count);
373 brelse(bh);
374 ptr++;
375 }
376out:
377 return 0;
378
379nomem_free:
380 for (count = 0; count < array_size; count++)
381 kfree(sbi->s_imap[count]);
382
383 kfree(sbi->s_imap);
384nomem:
385 sbi->s_imap = NULL;
386 sbi->s_imap_size = 0;
387 return -ENOMEM;
388}
389
390enum {
391 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err
392};
393
394static const match_table_t tokens = {
395 {Opt_uid, "uid=%u"},
396 {Opt_gid, "gid=%u"},
397 {Opt_umask, "umask=%o"},
398 {Opt_dmask, "dmask=%o"},
399 {Opt_fmask, "fmask=%o"},
400 {Opt_err, NULL},
401};
402
403static int parse_options(char *options, struct omfs_sb_info *sbi)
404{
405 char *p;
406 substring_t args[MAX_OPT_ARGS];
407 int option;
408
409 if (!options)
410 return 1;
411
412 while ((p = strsep(&options, ",")) != NULL) {
413 int token;
414 if (!*p)
415 continue;
416
417 token = match_token(p, tokens, args);
418 switch (token) {
419 case Opt_uid:
420 if (match_int(&args[0], &option))
421 return 0;
422 sbi->s_uid = make_kuid(current_user_ns(), option);
423 if (!uid_valid(sbi->s_uid))
424 return 0;
425 break;
426 case Opt_gid:
427 if (match_int(&args[0], &option))
428 return 0;
429 sbi->s_gid = make_kgid(current_user_ns(), option);
430 if (!gid_valid(sbi->s_gid))
431 return 0;
432 break;
433 case Opt_umask:
434 if (match_octal(&args[0], &option))
435 return 0;
436 sbi->s_fmask = sbi->s_dmask = option;
437 break;
438 case Opt_dmask:
439 if (match_octal(&args[0], &option))
440 return 0;
441 sbi->s_dmask = option;
442 break;
443 case Opt_fmask:
444 if (match_octal(&args[0], &option))
445 return 0;
446 sbi->s_fmask = option;
447 break;
448 default:
449 return 0;
450 }
451 }
452 return 1;
453}
454
455static int omfs_fill_super(struct super_block *sb, void *data, int silent)
456{
457 struct buffer_head *bh, *bh2;
458 struct omfs_super_block *omfs_sb;
459 struct omfs_root_block *omfs_rb;
460 struct omfs_sb_info *sbi;
461 struct inode *root;
462 int ret = -EINVAL;
463
464 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
465 if (!sbi)
466 return -ENOMEM;
467
468 sb->s_fs_info = sbi;
469
470 sbi->s_uid = current_uid();
471 sbi->s_gid = current_gid();
472 sbi->s_dmask = sbi->s_fmask = current_umask();
473
474 if (!parse_options((char *) data, sbi))
475 goto end;
476
477 sb->s_maxbytes = 0xffffffff;
478
479 sb->s_time_gran = NSEC_PER_MSEC;
480 sb->s_time_min = 0;
481 sb->s_time_max = U64_MAX / MSEC_PER_SEC;
482
483 sb_set_blocksize(sb, 0x200);
484
485 bh = sb_bread(sb, 0);
486 if (!bh)
487 goto end;
488
489 omfs_sb = (struct omfs_super_block *)bh->b_data;
490
491 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
492 if (!silent)
493 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
494 omfs_sb->s_magic);
495 goto out_brelse_bh;
496 }
497 sb->s_magic = OMFS_MAGIC;
498
499 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
500 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
501 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
502 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
503 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
504 mutex_init(&sbi->s_bitmap_lock);
505
506 if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) {
507 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n",
508 (unsigned long long)sbi->s_num_blocks);
509 goto out_brelse_bh;
510 }
511
512 if (sbi->s_sys_blocksize > PAGE_SIZE) {
513 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
514 sbi->s_sys_blocksize);
515 goto out_brelse_bh;
516 }
517
518 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
519 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
520 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
521 sbi->s_blocksize);
522 goto out_brelse_bh;
523 }
524
525
526
527
528
529 sb_set_blocksize(sb, sbi->s_sys_blocksize);
530
531
532
533
534
535 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
536 get_bitmask_order(sbi->s_sys_blocksize);
537
538 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
539 if (!bh2)
540 goto out_brelse_bh;
541
542 omfs_rb = (struct omfs_root_block *)bh2->b_data;
543
544 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
545 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
546
547 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
548 printk(KERN_ERR "omfs: block count discrepancy between "
549 "super and root blocks (%llx, %llx)\n",
550 (unsigned long long)sbi->s_num_blocks,
551 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
552 goto out_brelse_bh2;
553 }
554
555 if (sbi->s_bitmap_ino != ~0ULL &&
556 sbi->s_bitmap_ino > sbi->s_num_blocks) {
557 printk(KERN_ERR "omfs: free space bitmap location is corrupt "
558 "(%llx, total blocks %llx)\n",
559 (unsigned long long) sbi->s_bitmap_ino,
560 (unsigned long long) sbi->s_num_blocks);
561 goto out_brelse_bh2;
562 }
563 if (sbi->s_clustersize < 1 ||
564 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
565 printk(KERN_ERR "omfs: cluster size out of range (%d)",
566 sbi->s_clustersize);
567 goto out_brelse_bh2;
568 }
569
570 ret = omfs_get_imap(sb);
571 if (ret)
572 goto out_brelse_bh2;
573
574 sb->s_op = &omfs_sops;
575
576 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
577 if (IS_ERR(root)) {
578 ret = PTR_ERR(root);
579 goto out_brelse_bh2;
580 }
581
582 sb->s_root = d_make_root(root);
583 if (!sb->s_root) {
584 ret = -ENOMEM;
585 goto out_brelse_bh2;
586 }
587 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
588
589 ret = 0;
590out_brelse_bh2:
591 brelse(bh2);
592out_brelse_bh:
593 brelse(bh);
594end:
595 if (ret)
596 kfree(sbi);
597 return ret;
598}
599
600static struct dentry *omfs_mount(struct file_system_type *fs_type,
601 int flags, const char *dev_name, void *data)
602{
603 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
604}
605
606static struct file_system_type omfs_fs_type = {
607 .owner = THIS_MODULE,
608 .name = "omfs",
609 .mount = omfs_mount,
610 .kill_sb = kill_block_super,
611 .fs_flags = FS_REQUIRES_DEV,
612};
613MODULE_ALIAS_FS("omfs");
614
615static int __init init_omfs_fs(void)
616{
617 return register_filesystem(&omfs_fs_type);
618}
619
620static void __exit exit_omfs_fs(void)
621{
622 unregister_filesystem(&omfs_fs_type);
623}
624
625module_init(init_omfs_fs);
626module_exit(exit_omfs_fs);
627
