blob: 633e9dc972bbc63edb052e89cd924aad8e25e8c3 [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;
David Howellsc222d532008-11-14 10:38:59 +110040 inode->i_uid = current_fsuid();
41 inode->i_gid = current_fsgid();
Bob Copeland555e3772008-07-25 19:45:15 -070042 inode->i_mapping->a_ops = &omfs_aops;
43
44 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
45 switch (mode & S_IFMT) {
46 case S_IFDIR:
47 inode->i_op = &omfs_dir_inops;
48 inode->i_fop = &omfs_dir_operations;
49 inode->i_size = sbi->s_sys_blocksize;
50 inc_nlink(inode);
51 break;
52 case S_IFREG:
53 inode->i_op = &omfs_file_inops;
54 inode->i_fop = &omfs_file_operations;
55 inode->i_size = 0;
56 break;
57 }
58
59 insert_inode_hash(inode);
60 mark_inode_dirty(inode);
61 return inode;
62fail:
63 make_bad_inode(inode);
64 iput(inode);
65 return ERR_PTR(err);
66}
67
68/*
69 * Update the header checksums for a dirty inode based on its contents.
70 * Caller is expected to hold the buffer head underlying oi and mark it
71 * dirty.
72 */
73static void omfs_update_checksums(struct omfs_inode *oi)
74{
75 int xor, i, ofs = 0, count;
76 u16 crc = 0;
77 unsigned char *ptr = (unsigned char *) oi;
78
79 count = be32_to_cpu(oi->i_head.h_body_size);
80 ofs = sizeof(struct omfs_header);
81
82 crc = crc_itu_t(crc, ptr + ofs, count);
83 oi->i_head.h_crc = cpu_to_be16(crc);
84
85 xor = ptr[0];
86 for (i = 1; i < OMFS_XOR_COUNT; i++)
87 xor ^= ptr[i];
88
89 oi->i_head.h_check_xor = xor;
90}
91
92static int omfs_write_inode(struct inode *inode, int wait)
93{
94 struct omfs_inode *oi;
95 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
96 struct buffer_head *bh, *bh2;
97 unsigned int block;
98 u64 ctime;
99 int i;
100 int ret = -EIO;
101 int sync_failed = 0;
102
103 /* get current inode since we may have written sibling ptrs etc. */
104 block = clus_to_blk(sbi, inode->i_ino);
105 bh = sb_bread(inode->i_sb, block);
106 if (!bh)
107 goto out;
108
109 oi = (struct omfs_inode *) bh->b_data;
110
111 oi->i_head.h_self = cpu_to_be64(inode->i_ino);
112 if (S_ISDIR(inode->i_mode))
113 oi->i_type = OMFS_DIR;
114 else if (S_ISREG(inode->i_mode))
115 oi->i_type = OMFS_FILE;
116 else {
117 printk(KERN_WARNING "omfs: unknown file type: %d\n",
118 inode->i_mode);
119 goto out_brelse;
120 }
121
122 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
123 sizeof(struct omfs_header));
124 oi->i_head.h_version = 1;
125 oi->i_head.h_type = OMFS_INODE_NORMAL;
126 oi->i_head.h_magic = OMFS_IMAGIC;
127 oi->i_size = cpu_to_be64(inode->i_size);
128
129 ctime = inode->i_ctime.tv_sec * 1000LL +
130 ((inode->i_ctime.tv_nsec + 999)/1000);
131 oi->i_ctime = cpu_to_be64(ctime);
132
133 omfs_update_checksums(oi);
134
135 mark_buffer_dirty(bh);
136 if (wait) {
137 sync_dirty_buffer(bh);
138 if (buffer_req(bh) && !buffer_uptodate(bh))
139 sync_failed = 1;
140 }
141
142 /* if mirroring writes, copy to next fsblock */
143 for (i = 1; i < sbi->s_mirrors; i++) {
144 bh2 = sb_bread(inode->i_sb, block + i *
145 (sbi->s_blocksize / sbi->s_sys_blocksize));
146 if (!bh2)
147 goto out_brelse;
148
149 memcpy(bh2->b_data, bh->b_data, bh->b_size);
150 mark_buffer_dirty(bh2);
151 if (wait) {
152 sync_dirty_buffer(bh2);
153 if (buffer_req(bh2) && !buffer_uptodate(bh2))
154 sync_failed = 1;
155 }
156 brelse(bh2);
157 }
158 ret = (sync_failed) ? -EIO : 0;
159out_brelse:
160 brelse(bh);
161out:
162 return ret;
163}
164
165int omfs_sync_inode(struct inode *inode)
166{
167 return omfs_write_inode(inode, 1);
168}
169
170/*
171 * called when an entry is deleted, need to clear the bits in the
172 * bitmaps.
173 */
174static void omfs_delete_inode(struct inode *inode)
175{
176 truncate_inode_pages(&inode->i_data, 0);
177
178 if (S_ISREG(inode->i_mode)) {
179 inode->i_size = 0;
180 omfs_shrink_inode(inode);
181 }
182
183 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
184 clear_inode(inode);
185}
186
187struct inode *omfs_iget(struct super_block *sb, ino_t ino)
188{
189 struct omfs_sb_info *sbi = OMFS_SB(sb);
190 struct omfs_inode *oi;
191 struct buffer_head *bh;
192 unsigned int block;
193 u64 ctime;
194 unsigned long nsecs;
195 struct inode *inode;
196
197 inode = iget_locked(sb, ino);
198 if (!inode)
199 return ERR_PTR(-ENOMEM);
200 if (!(inode->i_state & I_NEW))
201 return inode;
202
203 block = clus_to_blk(sbi, ino);
204 bh = sb_bread(inode->i_sb, block);
205 if (!bh)
206 goto iget_failed;
207
208 oi = (struct omfs_inode *)bh->b_data;
209
210 /* check self */
211 if (ino != be64_to_cpu(oi->i_head.h_self))
212 goto fail_bh;
213
214 inode->i_uid = sbi->s_uid;
215 inode->i_gid = sbi->s_gid;
216
217 ctime = be64_to_cpu(oi->i_ctime);
218 nsecs = do_div(ctime, 1000) * 1000L;
219
220 inode->i_atime.tv_sec = ctime;
221 inode->i_mtime.tv_sec = ctime;
222 inode->i_ctime.tv_sec = ctime;
223 inode->i_atime.tv_nsec = nsecs;
224 inode->i_mtime.tv_nsec = nsecs;
225 inode->i_ctime.tv_nsec = nsecs;
226
227 inode->i_mapping->a_ops = &omfs_aops;
228
229 switch (oi->i_type) {
230 case OMFS_DIR:
231 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
232 inode->i_op = &omfs_dir_inops;
233 inode->i_fop = &omfs_dir_operations;
Bob Copelandc9633432008-08-15 00:40:46 -0700234 inode->i_size = sbi->s_sys_blocksize;
Bob Copeland555e3772008-07-25 19:45:15 -0700235 inc_nlink(inode);
236 break;
237 case OMFS_FILE:
238 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
239 inode->i_fop = &omfs_file_operations;
240 inode->i_size = be64_to_cpu(oi->i_size);
241 break;
242 }
243 brelse(bh);
244 unlock_new_inode(inode);
245 return inode;
246fail_bh:
247 brelse(bh);
248iget_failed:
249 iget_failed(inode);
250 return ERR_PTR(-EIO);
251}
252
253static void omfs_put_super(struct super_block *sb)
254{
255 struct omfs_sb_info *sbi = OMFS_SB(sb);
256 kfree(sbi->s_imap);
257 kfree(sbi);
258 sb->s_fs_info = NULL;
259}
260
261static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
262{
263 struct super_block *s = dentry->d_sb;
264 struct omfs_sb_info *sbi = OMFS_SB(s);
265 buf->f_type = OMFS_MAGIC;
266 buf->f_bsize = sbi->s_blocksize;
267 buf->f_blocks = sbi->s_num_blocks;
268 buf->f_files = sbi->s_num_blocks;
269 buf->f_namelen = OMFS_NAMELEN;
270
271 buf->f_bfree = buf->f_bavail = buf->f_ffree =
272 omfs_count_free(s);
273 return 0;
274}
275
276static struct super_operations omfs_sops = {
277 .write_inode = omfs_write_inode,
278 .delete_inode = omfs_delete_inode,
279 .put_super = omfs_put_super,
280 .statfs = omfs_statfs,
281 .show_options = generic_show_options,
282};
283
284/*
285 * For Rio Karma, there is an on-disk free bitmap whose location is
286 * stored in the root block. For ReplayTV, there is no such free bitmap
287 * so we have to walk the tree. Both inodes and file data are allocated
288 * from the same map. This array can be big (300k) so we allocate
289 * in units of the blocksize.
290 */
291static int omfs_get_imap(struct super_block *sb)
292{
293 int bitmap_size;
294 int array_size;
295 int count;
296 struct omfs_sb_info *sbi = OMFS_SB(sb);
297 struct buffer_head *bh;
298 unsigned long **ptr;
299 sector_t block;
300
301 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
302 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
303
304 if (sbi->s_bitmap_ino == ~0ULL)
305 goto out;
306
307 sbi->s_imap_size = array_size;
308 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
309 if (!sbi->s_imap)
310 goto nomem;
311
312 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
313 ptr = sbi->s_imap;
314 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
315 bh = sb_bread(sb, block++);
316 if (!bh)
317 goto nomem_free;
318 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
319 if (!*ptr) {
320 brelse(bh);
321 goto nomem_free;
322 }
323 memcpy(*ptr, bh->b_data, sb->s_blocksize);
324 if (count < sb->s_blocksize)
325 memset((void *)*ptr + count, 0xff,
326 sb->s_blocksize - count);
327 brelse(bh);
328 ptr++;
329 }
330out:
331 return 0;
332
333nomem_free:
334 for (count = 0; count < array_size; count++)
335 kfree(sbi->s_imap[count]);
336
337 kfree(sbi->s_imap);
338nomem:
339 sbi->s_imap = NULL;
340 sbi->s_imap_size = 0;
341 return -ENOMEM;
342}
343
344enum {
345 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
346};
347
Steven Whitehousea447c092008-10-13 10:46:57 +0100348static const match_table_t tokens = {
Bob Copeland555e3772008-07-25 19:45:15 -0700349 {Opt_uid, "uid=%u"},
350 {Opt_gid, "gid=%u"},
351 {Opt_umask, "umask=%o"},
352 {Opt_dmask, "dmask=%o"},
353 {Opt_fmask, "fmask=%o"},
354};
355
356static int parse_options(char *options, struct omfs_sb_info *sbi)
357{
358 char *p;
359 substring_t args[MAX_OPT_ARGS];
360 int option;
361
362 if (!options)
363 return 1;
364
365 while ((p = strsep(&options, ",")) != NULL) {
366 int token;
367 if (!*p)
368 continue;
369
370 token = match_token(p, tokens, args);
371 switch (token) {
372 case Opt_uid:
373 if (match_int(&args[0], &option))
374 return 0;
375 sbi->s_uid = option;
376 break;
377 case Opt_gid:
378 if (match_int(&args[0], &option))
379 return 0;
380 sbi->s_gid = option;
381 break;
382 case Opt_umask:
383 if (match_octal(&args[0], &option))
384 return 0;
385 sbi->s_fmask = sbi->s_dmask = option;
386 break;
387 case Opt_dmask:
388 if (match_octal(&args[0], &option))
389 return 0;
390 sbi->s_dmask = option;
391 break;
392 case Opt_fmask:
393 if (match_octal(&args[0], &option))
394 return 0;
395 sbi->s_fmask = option;
396 break;
397 default:
398 return 0;
399 }
400 }
401 return 1;
402}
403
404static int omfs_fill_super(struct super_block *sb, void *data, int silent)
405{
406 struct buffer_head *bh, *bh2;
407 struct omfs_super_block *omfs_sb;
408 struct omfs_root_block *omfs_rb;
409 struct omfs_sb_info *sbi;
410 struct inode *root;
411 sector_t start;
412 int ret = -EINVAL;
413
414 save_mount_options(sb, (char *) data);
415
416 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
417 if (!sbi)
418 return -ENOMEM;
419
420 sb->s_fs_info = sbi;
421
David Howellsc222d532008-11-14 10:38:59 +1100422 sbi->s_uid = current_uid();
423 sbi->s_gid = current_gid();
Bob Copeland555e3772008-07-25 19:45:15 -0700424 sbi->s_dmask = sbi->s_fmask = current->fs->umask;
425
426 if (!parse_options((char *) data, sbi))
427 goto end;
428
429 sb->s_maxbytes = 0xffffffff;
430
431 sb_set_blocksize(sb, 0x200);
432
433 bh = sb_bread(sb, 0);
434 if (!bh)
435 goto end;
436
437 omfs_sb = (struct omfs_super_block *)bh->b_data;
438
439 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
440 if (!silent)
441 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
442 omfs_sb->s_magic);
443 goto out_brelse_bh;
444 }
445 sb->s_magic = OMFS_MAGIC;
446
447 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
448 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
449 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
450 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
451 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
452 mutex_init(&sbi->s_bitmap_lock);
453
454 if (sbi->s_sys_blocksize > PAGE_SIZE) {
455 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
456 sbi->s_sys_blocksize);
457 goto out_brelse_bh;
458 }
459
460 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
461 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
462 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
463 sbi->s_blocksize);
464 goto out_brelse_bh;
465 }
466
467 /*
468 * Use sys_blocksize as the fs block since it is smaller than a
469 * page while the fs blocksize can be larger.
470 */
471 sb_set_blocksize(sb, sbi->s_sys_blocksize);
472
473 /*
474 * ...and the difference goes into a shift. sys_blocksize is always
475 * a power of two factor of blocksize.
476 */
477 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
478 get_bitmask_order(sbi->s_sys_blocksize);
479
480 start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block));
481 bh2 = sb_bread(sb, start);
482 if (!bh2)
483 goto out_brelse_bh;
484
485 omfs_rb = (struct omfs_root_block *)bh2->b_data;
486
487 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
488 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
489
490 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
491 printk(KERN_ERR "omfs: block count discrepancy between "
492 "super and root blocks (%llx, %llx)\n",
Alexander Beregalovdc60bf12008-08-05 13:01:33 -0700493 (unsigned long long)sbi->s_num_blocks,
494 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
Bob Copeland555e3772008-07-25 19:45:15 -0700495 goto out_brelse_bh2;
496 }
497
498 ret = omfs_get_imap(sb);
499 if (ret)
500 goto out_brelse_bh2;
501
502 sb->s_op = &omfs_sops;
503
504 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
505 if (IS_ERR(root)) {
506 ret = PTR_ERR(root);
507 goto out_brelse_bh2;
508 }
509
510 sb->s_root = d_alloc_root(root);
511 if (!sb->s_root) {
512 iput(root);
513 goto out_brelse_bh2;
514 }
515 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
516
517 ret = 0;
518out_brelse_bh2:
519 brelse(bh2);
520out_brelse_bh:
521 brelse(bh);
522end:
523 return ret;
524}
525
526static int omfs_get_sb(struct file_system_type *fs_type,
527 int flags, const char *dev_name,
528 void *data, struct vfsmount *m)
529{
530 return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
531}
532
533static struct file_system_type omfs_fs_type = {
534 .owner = THIS_MODULE,
535 .name = "omfs",
536 .get_sb = omfs_get_sb,
537 .kill_sb = kill_block_super,
538 .fs_flags = FS_REQUIRES_DEV,
539};
540
541static int __init init_omfs_fs(void)
542{
543 return register_filesystem(&omfs_fs_type);
544}
545
546static void __exit exit_omfs_fs(void)
547{
548 unregister_filesystem(&omfs_fs_type);
549}
550
551module_init(init_omfs_fs);
552module_exit(exit_omfs_fs);