blob: d865f553543651edda75b2039952f3c2c882a3ff [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 */
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
17MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
18MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
19MODULE_LICENSE("GPL");
20
21struct 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;
63fail:
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 */
74static 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
93static 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;
160out_brelse:
161 brelse(bh);
162out:
163 return ret;
164}
165
166int 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 */
175static 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
188struct 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 = be32_to_cpu(oi->i_head.h_body_size) +
236 sizeof(struct omfs_header);
237 inc_nlink(inode);
238 break;
239 case OMFS_FILE:
240 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
241 inode->i_fop = &omfs_file_operations;
242 inode->i_size = be64_to_cpu(oi->i_size);
243 break;
244 }
245 brelse(bh);
246 unlock_new_inode(inode);
247 return inode;
248fail_bh:
249 brelse(bh);
250iget_failed:
251 iget_failed(inode);
252 return ERR_PTR(-EIO);
253}
254
255static void omfs_put_super(struct super_block *sb)
256{
257 struct omfs_sb_info *sbi = OMFS_SB(sb);
258 kfree(sbi->s_imap);
259 kfree(sbi);
260 sb->s_fs_info = NULL;
261}
262
263static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
264{
265 struct super_block *s = dentry->d_sb;
266 struct omfs_sb_info *sbi = OMFS_SB(s);
267 buf->f_type = OMFS_MAGIC;
268 buf->f_bsize = sbi->s_blocksize;
269 buf->f_blocks = sbi->s_num_blocks;
270 buf->f_files = sbi->s_num_blocks;
271 buf->f_namelen = OMFS_NAMELEN;
272
273 buf->f_bfree = buf->f_bavail = buf->f_ffree =
274 omfs_count_free(s);
275 return 0;
276}
277
278static struct super_operations omfs_sops = {
279 .write_inode = omfs_write_inode,
280 .delete_inode = omfs_delete_inode,
281 .put_super = omfs_put_super,
282 .statfs = omfs_statfs,
283 .show_options = generic_show_options,
284};
285
286/*
287 * For Rio Karma, there is an on-disk free bitmap whose location is
288 * stored in the root block. For ReplayTV, there is no such free bitmap
289 * so we have to walk the tree. Both inodes and file data are allocated
290 * from the same map. This array can be big (300k) so we allocate
291 * in units of the blocksize.
292 */
293static int omfs_get_imap(struct super_block *sb)
294{
295 int bitmap_size;
296 int array_size;
297 int count;
298 struct omfs_sb_info *sbi = OMFS_SB(sb);
299 struct buffer_head *bh;
300 unsigned long **ptr;
301 sector_t block;
302
303 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
304 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
305
306 if (sbi->s_bitmap_ino == ~0ULL)
307 goto out;
308
309 sbi->s_imap_size = array_size;
310 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
311 if (!sbi->s_imap)
312 goto nomem;
313
314 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
315 ptr = sbi->s_imap;
316 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
317 bh = sb_bread(sb, block++);
318 if (!bh)
319 goto nomem_free;
320 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
321 if (!*ptr) {
322 brelse(bh);
323 goto nomem_free;
324 }
325 memcpy(*ptr, bh->b_data, sb->s_blocksize);
326 if (count < sb->s_blocksize)
327 memset((void *)*ptr + count, 0xff,
328 sb->s_blocksize - count);
329 brelse(bh);
330 ptr++;
331 }
332out:
333 return 0;
334
335nomem_free:
336 for (count = 0; count < array_size; count++)
337 kfree(sbi->s_imap[count]);
338
339 kfree(sbi->s_imap);
340nomem:
341 sbi->s_imap = NULL;
342 sbi->s_imap_size = 0;
343 return -ENOMEM;
344}
345
346enum {
347 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
348};
349
350static match_table_t tokens = {
351 {Opt_uid, "uid=%u"},
352 {Opt_gid, "gid=%u"},
353 {Opt_umask, "umask=%o"},
354 {Opt_dmask, "dmask=%o"},
355 {Opt_fmask, "fmask=%o"},
356};
357
358static int parse_options(char *options, struct omfs_sb_info *sbi)
359{
360 char *p;
361 substring_t args[MAX_OPT_ARGS];
362 int option;
363
364 if (!options)
365 return 1;
366
367 while ((p = strsep(&options, ",")) != NULL) {
368 int token;
369 if (!*p)
370 continue;
371
372 token = match_token(p, tokens, args);
373 switch (token) {
374 case Opt_uid:
375 if (match_int(&args[0], &option))
376 return 0;
377 sbi->s_uid = option;
378 break;
379 case Opt_gid:
380 if (match_int(&args[0], &option))
381 return 0;
382 sbi->s_gid = option;
383 break;
384 case Opt_umask:
385 if (match_octal(&args[0], &option))
386 return 0;
387 sbi->s_fmask = sbi->s_dmask = option;
388 break;
389 case Opt_dmask:
390 if (match_octal(&args[0], &option))
391 return 0;
392 sbi->s_dmask = option;
393 break;
394 case Opt_fmask:
395 if (match_octal(&args[0], &option))
396 return 0;
397 sbi->s_fmask = option;
398 break;
399 default:
400 return 0;
401 }
402 }
403 return 1;
404}
405
406static int omfs_fill_super(struct super_block *sb, void *data, int silent)
407{
408 struct buffer_head *bh, *bh2;
409 struct omfs_super_block *omfs_sb;
410 struct omfs_root_block *omfs_rb;
411 struct omfs_sb_info *sbi;
412 struct inode *root;
413 sector_t start;
414 int ret = -EINVAL;
415
416 save_mount_options(sb, (char *) data);
417
418 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
419 if (!sbi)
420 return -ENOMEM;
421
422 sb->s_fs_info = sbi;
423
424 sbi->s_uid = current->uid;
425 sbi->s_gid = current->gid;
426 sbi->s_dmask = sbi->s_fmask = current->fs->umask;
427
428 if (!parse_options((char *) data, sbi))
429 goto end;
430
431 sb->s_maxbytes = 0xffffffff;
432
433 sb_set_blocksize(sb, 0x200);
434
435 bh = sb_bread(sb, 0);
436 if (!bh)
437 goto end;
438
439 omfs_sb = (struct omfs_super_block *)bh->b_data;
440
441 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
442 if (!silent)
443 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
444 omfs_sb->s_magic);
445 goto out_brelse_bh;
446 }
447 sb->s_magic = OMFS_MAGIC;
448
449 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
450 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
451 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
452 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
453 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
454 mutex_init(&sbi->s_bitmap_lock);
455
456 if (sbi->s_sys_blocksize > PAGE_SIZE) {
457 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
458 sbi->s_sys_blocksize);
459 goto out_brelse_bh;
460 }
461
462 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
463 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
464 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
465 sbi->s_blocksize);
466 goto out_brelse_bh;
467 }
468
469 /*
470 * Use sys_blocksize as the fs block since it is smaller than a
471 * page while the fs blocksize can be larger.
472 */
473 sb_set_blocksize(sb, sbi->s_sys_blocksize);
474
475 /*
476 * ...and the difference goes into a shift. sys_blocksize is always
477 * a power of two factor of blocksize.
478 */
479 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
480 get_bitmask_order(sbi->s_sys_blocksize);
481
482 start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block));
483 bh2 = sb_bread(sb, start);
484 if (!bh2)
485 goto out_brelse_bh;
486
487 omfs_rb = (struct omfs_root_block *)bh2->b_data;
488
489 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
490 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
491
492 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
493 printk(KERN_ERR "omfs: block count discrepancy between "
494 "super and root blocks (%llx, %llx)\n",
495 sbi->s_num_blocks, 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;
519out_brelse_bh2:
520 brelse(bh2);
521out_brelse_bh:
522 brelse(bh);
523end:
524 return ret;
525}
526
527static 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
534static 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
542static int __init init_omfs_fs(void)
543{
544 return register_filesystem(&omfs_fs_type);
545}
546
547static void __exit exit_omfs_fs(void)
548{
549 unregister_filesystem(&omfs_fs_type);
550}
551
552module_init(init_omfs_fs);
553module_exit(exit_omfs_fs);