blob: 089839a6cc6404e46715df5543d4be0d9162c702 [file] [log] [blame]
Bob Copeland555e3772008-07-25 19:45:15 -07001/*
2 * Optimized MPEG FS - inode and super operations.
3 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
4 * Released under GPL v2.
5 */
Bob Copeland555e3772008-07-25 19:45:15 -07006#include <linux/module.h>
7#include <linux/sched.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09008#include <linux/slab.h>
Bob Copeland555e3772008-07-25 19:45:15 -07009#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>
Christoph Hellwiga9185b42010-03-05 09:21:37 +010014#include <linux/writeback.h>
Bob Copeland555e3772008-07-25 19:45:15 -070015#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 inode *omfs_new_inode(struct inode *dir, int mode)
23{
24 struct inode *inode;
25 u64 new_block;
26 int err;
27 int len;
28 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
29
30 inode = new_inode(dir->i_sb);
31 if (!inode)
32 return ERR_PTR(-ENOMEM);
33
34 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
35 &new_block, &len);
36 if (err)
37 goto fail;
38
39 inode->i_ino = new_block;
Dmitry Monakhov6a9e6522010-03-04 17:32:17 +030040 inode_init_owner(inode, NULL, mode);
Bob Copeland555e3772008-07-25 19:45:15 -070041 inode->i_mapping->a_ops = &omfs_aops;
42
43 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
44 switch (mode & S_IFMT) {
45 case S_IFDIR:
46 inode->i_op = &omfs_dir_inops;
47 inode->i_fop = &omfs_dir_operations;
48 inode->i_size = sbi->s_sys_blocksize;
49 inc_nlink(inode);
50 break;
51 case S_IFREG:
52 inode->i_op = &omfs_file_inops;
53 inode->i_fop = &omfs_file_operations;
54 inode->i_size = 0;
55 break;
56 }
57
58 insert_inode_hash(inode);
59 mark_inode_dirty(inode);
60 return inode;
61fail:
62 make_bad_inode(inode);
63 iput(inode);
64 return ERR_PTR(err);
65}
66
67/*
68 * Update the header checksums for a dirty inode based on its contents.
69 * Caller is expected to hold the buffer head underlying oi and mark it
70 * dirty.
71 */
72static void omfs_update_checksums(struct omfs_inode *oi)
73{
74 int xor, i, ofs = 0, count;
75 u16 crc = 0;
76 unsigned char *ptr = (unsigned char *) oi;
77
78 count = be32_to_cpu(oi->i_head.h_body_size);
79 ofs = sizeof(struct omfs_header);
80
81 crc = crc_itu_t(crc, ptr + ofs, count);
82 oi->i_head.h_crc = cpu_to_be16(crc);
83
84 xor = ptr[0];
85 for (i = 1; i < OMFS_XOR_COUNT; i++)
86 xor ^= ptr[i];
87
88 oi->i_head.h_check_xor = xor;
89}
90
Christoph Hellwiga9185b42010-03-05 09:21:37 +010091static int __omfs_write_inode(struct inode *inode, int wait)
Bob Copeland555e3772008-07-25 19:45:15 -070092{
93 struct omfs_inode *oi;
94 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
95 struct buffer_head *bh, *bh2;
96 unsigned int block;
97 u64 ctime;
98 int i;
99 int ret = -EIO;
100 int sync_failed = 0;
101
102 /* get current inode since we may have written sibling ptrs etc. */
103 block = clus_to_blk(sbi, inode->i_ino);
104 bh = sb_bread(inode->i_sb, block);
105 if (!bh)
106 goto out;
107
108 oi = (struct omfs_inode *) bh->b_data;
109
110 oi->i_head.h_self = cpu_to_be64(inode->i_ino);
111 if (S_ISDIR(inode->i_mode))
112 oi->i_type = OMFS_DIR;
113 else if (S_ISREG(inode->i_mode))
114 oi->i_type = OMFS_FILE;
115 else {
116 printk(KERN_WARNING "omfs: unknown file type: %d\n",
117 inode->i_mode);
118 goto out_brelse;
119 }
120
121 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
122 sizeof(struct omfs_header));
123 oi->i_head.h_version = 1;
124 oi->i_head.h_type = OMFS_INODE_NORMAL;
125 oi->i_head.h_magic = OMFS_IMAGIC;
126 oi->i_size = cpu_to_be64(inode->i_size);
127
128 ctime = inode->i_ctime.tv_sec * 1000LL +
129 ((inode->i_ctime.tv_nsec + 999)/1000);
130 oi->i_ctime = cpu_to_be64(ctime);
131
132 omfs_update_checksums(oi);
133
134 mark_buffer_dirty(bh);
135 if (wait) {
136 sync_dirty_buffer(bh);
137 if (buffer_req(bh) && !buffer_uptodate(bh))
138 sync_failed = 1;
139 }
140
141 /* if mirroring writes, copy to next fsblock */
142 for (i = 1; i < sbi->s_mirrors; i++) {
143 bh2 = sb_bread(inode->i_sb, block + i *
144 (sbi->s_blocksize / sbi->s_sys_blocksize));
145 if (!bh2)
146 goto out_brelse;
147
148 memcpy(bh2->b_data, bh->b_data, bh->b_size);
149 mark_buffer_dirty(bh2);
150 if (wait) {
151 sync_dirty_buffer(bh2);
152 if (buffer_req(bh2) && !buffer_uptodate(bh2))
153 sync_failed = 1;
154 }
155 brelse(bh2);
156 }
157 ret = (sync_failed) ? -EIO : 0;
158out_brelse:
159 brelse(bh);
160out:
161 return ret;
162}
163
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100164static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
165{
166 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
167}
168
Bob Copeland555e3772008-07-25 19:45:15 -0700169int omfs_sync_inode(struct inode *inode)
170{
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100171 return __omfs_write_inode(inode, 1);
Bob Copeland555e3772008-07-25 19:45:15 -0700172}
173
174/*
175 * called when an entry is deleted, need to clear the bits in the
176 * bitmaps.
177 */
178static void omfs_delete_inode(struct inode *inode)
179{
180 truncate_inode_pages(&inode->i_data, 0);
181
182 if (S_ISREG(inode->i_mode)) {
183 inode->i_size = 0;
184 omfs_shrink_inode(inode);
185 }
186
187 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
188 clear_inode(inode);
189}
190
191struct inode *omfs_iget(struct super_block *sb, ino_t ino)
192{
193 struct omfs_sb_info *sbi = OMFS_SB(sb);
194 struct omfs_inode *oi;
195 struct buffer_head *bh;
196 unsigned int block;
197 u64 ctime;
198 unsigned long nsecs;
199 struct inode *inode;
200
201 inode = iget_locked(sb, ino);
202 if (!inode)
203 return ERR_PTR(-ENOMEM);
204 if (!(inode->i_state & I_NEW))
205 return inode;
206
207 block = clus_to_blk(sbi, ino);
208 bh = sb_bread(inode->i_sb, block);
209 if (!bh)
210 goto iget_failed;
211
212 oi = (struct omfs_inode *)bh->b_data;
213
214 /* check self */
215 if (ino != be64_to_cpu(oi->i_head.h_self))
216 goto fail_bh;
217
218 inode->i_uid = sbi->s_uid;
219 inode->i_gid = sbi->s_gid;
220
221 ctime = be64_to_cpu(oi->i_ctime);
222 nsecs = do_div(ctime, 1000) * 1000L;
223
224 inode->i_atime.tv_sec = ctime;
225 inode->i_mtime.tv_sec = ctime;
226 inode->i_ctime.tv_sec = ctime;
227 inode->i_atime.tv_nsec = nsecs;
228 inode->i_mtime.tv_nsec = nsecs;
229 inode->i_ctime.tv_nsec = nsecs;
230
231 inode->i_mapping->a_ops = &omfs_aops;
232
233 switch (oi->i_type) {
234 case OMFS_DIR:
235 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
236 inode->i_op = &omfs_dir_inops;
237 inode->i_fop = &omfs_dir_operations;
Bob Copelandc9633432008-08-15 00:40:46 -0700238 inode->i_size = sbi->s_sys_blocksize;
Bob Copeland555e3772008-07-25 19:45:15 -0700239 inc_nlink(inode);
240 break;
241 case OMFS_FILE:
242 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
243 inode->i_fop = &omfs_file_operations;
244 inode->i_size = be64_to_cpu(oi->i_size);
245 break;
246 }
247 brelse(bh);
248 unlock_new_inode(inode);
249 return inode;
250fail_bh:
251 brelse(bh);
252iget_failed:
253 iget_failed(inode);
254 return ERR_PTR(-EIO);
255}
256
257static void omfs_put_super(struct super_block *sb)
258{
259 struct omfs_sb_info *sbi = OMFS_SB(sb);
260 kfree(sbi->s_imap);
261 kfree(sbi);
262 sb->s_fs_info = NULL;
263}
264
265static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
266{
267 struct super_block *s = dentry->d_sb;
268 struct omfs_sb_info *sbi = OMFS_SB(s);
Coly Li197e6712009-04-02 16:59:39 -0700269 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
270
Bob Copeland555e3772008-07-25 19:45:15 -0700271 buf->f_type = OMFS_MAGIC;
272 buf->f_bsize = sbi->s_blocksize;
273 buf->f_blocks = sbi->s_num_blocks;
274 buf->f_files = sbi->s_num_blocks;
275 buf->f_namelen = OMFS_NAMELEN;
Coly Li197e6712009-04-02 16:59:39 -0700276 buf->f_fsid.val[0] = (u32)id;
277 buf->f_fsid.val[1] = (u32)(id >> 32);
Bob Copeland555e3772008-07-25 19:45:15 -0700278
279 buf->f_bfree = buf->f_bavail = buf->f_ffree =
280 omfs_count_free(s);
Coly Li197e6712009-04-02 16:59:39 -0700281
Bob Copeland555e3772008-07-25 19:45:15 -0700282 return 0;
283}
284
Alexey Dobriyanb87221d2009-09-21 17:01:09 -0700285static const struct super_operations omfs_sops = {
Bob Copeland555e3772008-07-25 19:45:15 -0700286 .write_inode = omfs_write_inode,
287 .delete_inode = omfs_delete_inode,
288 .put_super = omfs_put_super,
289 .statfs = omfs_statfs,
290 .show_options = generic_show_options,
291};
292
293/*
294 * For Rio Karma, there is an on-disk free bitmap whose location is
295 * stored in the root block. For ReplayTV, there is no such free bitmap
296 * so we have to walk the tree. Both inodes and file data are allocated
297 * from the same map. This array can be big (300k) so we allocate
298 * in units of the blocksize.
299 */
300static int omfs_get_imap(struct super_block *sb)
301{
302 int bitmap_size;
303 int array_size;
304 int count;
305 struct omfs_sb_info *sbi = OMFS_SB(sb);
306 struct buffer_head *bh;
307 unsigned long **ptr;
308 sector_t block;
309
310 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
311 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
312
313 if (sbi->s_bitmap_ino == ~0ULL)
314 goto out;
315
316 sbi->s_imap_size = array_size;
317 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
318 if (!sbi->s_imap)
319 goto nomem;
320
321 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
322 ptr = sbi->s_imap;
323 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
324 bh = sb_bread(sb, block++);
325 if (!bh)
326 goto nomem_free;
327 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
328 if (!*ptr) {
329 brelse(bh);
330 goto nomem_free;
331 }
332 memcpy(*ptr, bh->b_data, sb->s_blocksize);
333 if (count < sb->s_blocksize)
334 memset((void *)*ptr + count, 0xff,
335 sb->s_blocksize - count);
336 brelse(bh);
337 ptr++;
338 }
339out:
340 return 0;
341
342nomem_free:
343 for (count = 0; count < array_size; count++)
344 kfree(sbi->s_imap[count]);
345
346 kfree(sbi->s_imap);
347nomem:
348 sbi->s_imap = NULL;
349 sbi->s_imap_size = 0;
350 return -ENOMEM;
351}
352
353enum {
354 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
355};
356
Steven Whitehousea447c092008-10-13 10:46:57 +0100357static const match_table_t tokens = {
Bob Copeland555e3772008-07-25 19:45:15 -0700358 {Opt_uid, "uid=%u"},
359 {Opt_gid, "gid=%u"},
360 {Opt_umask, "umask=%o"},
361 {Opt_dmask, "dmask=%o"},
362 {Opt_fmask, "fmask=%o"},
363};
364
365static int parse_options(char *options, struct omfs_sb_info *sbi)
366{
367 char *p;
368 substring_t args[MAX_OPT_ARGS];
369 int option;
370
371 if (!options)
372 return 1;
373
374 while ((p = strsep(&options, ",")) != NULL) {
375 int token;
376 if (!*p)
377 continue;
378
379 token = match_token(p, tokens, args);
380 switch (token) {
381 case Opt_uid:
382 if (match_int(&args[0], &option))
383 return 0;
384 sbi->s_uid = option;
385 break;
386 case Opt_gid:
387 if (match_int(&args[0], &option))
388 return 0;
389 sbi->s_gid = option;
390 break;
391 case Opt_umask:
392 if (match_octal(&args[0], &option))
393 return 0;
394 sbi->s_fmask = sbi->s_dmask = option;
395 break;
396 case Opt_dmask:
397 if (match_octal(&args[0], &option))
398 return 0;
399 sbi->s_dmask = option;
400 break;
401 case Opt_fmask:
402 if (match_octal(&args[0], &option))
403 return 0;
404 sbi->s_fmask = option;
405 break;
406 default:
407 return 0;
408 }
409 }
410 return 1;
411}
412
413static int omfs_fill_super(struct super_block *sb, void *data, int silent)
414{
415 struct buffer_head *bh, *bh2;
416 struct omfs_super_block *omfs_sb;
417 struct omfs_root_block *omfs_rb;
418 struct omfs_sb_info *sbi;
419 struct inode *root;
420 sector_t start;
421 int ret = -EINVAL;
422
423 save_mount_options(sb, (char *) data);
424
425 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
426 if (!sbi)
427 return -ENOMEM;
428
429 sb->s_fs_info = sbi;
430
David Howellsc222d532008-11-14 10:38:59 +1100431 sbi->s_uid = current_uid();
432 sbi->s_gid = current_gid();
Al Viroce3b0f82009-03-29 19:08:22 -0400433 sbi->s_dmask = sbi->s_fmask = current_umask();
Bob Copeland555e3772008-07-25 19:45:15 -0700434
435 if (!parse_options((char *) data, sbi))
436 goto end;
437
438 sb->s_maxbytes = 0xffffffff;
439
440 sb_set_blocksize(sb, 0x200);
441
442 bh = sb_bread(sb, 0);
443 if (!bh)
444 goto end;
445
446 omfs_sb = (struct omfs_super_block *)bh->b_data;
447
448 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
449 if (!silent)
450 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
451 omfs_sb->s_magic);
452 goto out_brelse_bh;
453 }
454 sb->s_magic = OMFS_MAGIC;
455
456 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
457 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
458 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
459 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
460 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
461 mutex_init(&sbi->s_bitmap_lock);
462
463 if (sbi->s_sys_blocksize > PAGE_SIZE) {
464 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
465 sbi->s_sys_blocksize);
466 goto out_brelse_bh;
467 }
468
469 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
470 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
471 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
472 sbi->s_blocksize);
473 goto out_brelse_bh;
474 }
475
476 /*
477 * Use sys_blocksize as the fs block since it is smaller than a
478 * page while the fs blocksize can be larger.
479 */
480 sb_set_blocksize(sb, sbi->s_sys_blocksize);
481
482 /*
483 * ...and the difference goes into a shift. sys_blocksize is always
484 * a power of two factor of blocksize.
485 */
486 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
487 get_bitmask_order(sbi->s_sys_blocksize);
488
489 start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block));
490 bh2 = sb_bread(sb, start);
491 if (!bh2)
492 goto out_brelse_bh;
493
494 omfs_rb = (struct omfs_root_block *)bh2->b_data;
495
496 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
497 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
498
499 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
500 printk(KERN_ERR "omfs: block count discrepancy between "
501 "super and root blocks (%llx, %llx)\n",
Alexander Beregalovdc60bf12008-08-05 13:01:33 -0700502 (unsigned long long)sbi->s_num_blocks,
503 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
Bob Copeland555e3772008-07-25 19:45:15 -0700504 goto out_brelse_bh2;
505 }
506
507 ret = omfs_get_imap(sb);
508 if (ret)
509 goto out_brelse_bh2;
510
511 sb->s_op = &omfs_sops;
512
513 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
514 if (IS_ERR(root)) {
515 ret = PTR_ERR(root);
516 goto out_brelse_bh2;
517 }
518
519 sb->s_root = d_alloc_root(root);
520 if (!sb->s_root) {
521 iput(root);
522 goto out_brelse_bh2;
523 }
524 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
525
526 ret = 0;
527out_brelse_bh2:
528 brelse(bh2);
529out_brelse_bh:
530 brelse(bh);
531end:
532 return ret;
533}
534
535static int omfs_get_sb(struct file_system_type *fs_type,
536 int flags, const char *dev_name,
537 void *data, struct vfsmount *m)
538{
539 return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
540}
541
542static struct file_system_type omfs_fs_type = {
543 .owner = THIS_MODULE,
544 .name = "omfs",
545 .get_sb = omfs_get_sb,
546 .kill_sb = kill_block_super,
547 .fs_flags = FS_REQUIRES_DEV,
548};
549
550static int __init init_omfs_fs(void)
551{
552 return register_filesystem(&omfs_fs_type);
553}
554
555static void __exit exit_omfs_fs(void)
556{
557 unregister_filesystem(&omfs_fs_type);
558}
559
560module_init(init_omfs_fs);
561module_exit(exit_omfs_fs);