blob: 75d9b5ba1d451c9bbdb40fc0baeb49bcd825cf78 [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>
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;
40 inode->i_mode = mode;
David Howellsc222d532008-11-14 10:38:59 +110041 inode->i_uid = current_fsuid();
42 inode->i_gid = current_fsgid();
Bob Copeland555e3772008-07-25 19:45:15 -070043 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
Christoph Hellwiga9185b42010-03-05 09:21:37 +010093static int __omfs_write_inode(struct inode *inode, int wait)
Bob Copeland555e3772008-07-25 19:45:15 -070094{
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
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100166static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
167{
168 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
169}
170
Bob Copeland555e3772008-07-25 19:45:15 -0700171int omfs_sync_inode(struct inode *inode)
172{
Christoph Hellwiga9185b42010-03-05 09:21:37 +0100173 return __omfs_write_inode(inode, 1);
Bob Copeland555e3772008-07-25 19:45:15 -0700174}
175
176/*
177 * called when an entry is deleted, need to clear the bits in the
178 * bitmaps.
179 */
180static void omfs_delete_inode(struct inode *inode)
181{
182 truncate_inode_pages(&inode->i_data, 0);
183
184 if (S_ISREG(inode->i_mode)) {
185 inode->i_size = 0;
186 omfs_shrink_inode(inode);
187 }
188
189 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
190 clear_inode(inode);
191}
192
193struct inode *omfs_iget(struct super_block *sb, ino_t ino)
194{
195 struct omfs_sb_info *sbi = OMFS_SB(sb);
196 struct omfs_inode *oi;
197 struct buffer_head *bh;
198 unsigned int block;
199 u64 ctime;
200 unsigned long nsecs;
201 struct inode *inode;
202
203 inode = iget_locked(sb, ino);
204 if (!inode)
205 return ERR_PTR(-ENOMEM);
206 if (!(inode->i_state & I_NEW))
207 return inode;
208
209 block = clus_to_blk(sbi, ino);
210 bh = sb_bread(inode->i_sb, block);
211 if (!bh)
212 goto iget_failed;
213
214 oi = (struct omfs_inode *)bh->b_data;
215
216 /* check self */
217 if (ino != be64_to_cpu(oi->i_head.h_self))
218 goto fail_bh;
219
220 inode->i_uid = sbi->s_uid;
221 inode->i_gid = sbi->s_gid;
222
223 ctime = be64_to_cpu(oi->i_ctime);
224 nsecs = do_div(ctime, 1000) * 1000L;
225
226 inode->i_atime.tv_sec = ctime;
227 inode->i_mtime.tv_sec = ctime;
228 inode->i_ctime.tv_sec = ctime;
229 inode->i_atime.tv_nsec = nsecs;
230 inode->i_mtime.tv_nsec = nsecs;
231 inode->i_ctime.tv_nsec = nsecs;
232
233 inode->i_mapping->a_ops = &omfs_aops;
234
235 switch (oi->i_type) {
236 case OMFS_DIR:
237 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
238 inode->i_op = &omfs_dir_inops;
239 inode->i_fop = &omfs_dir_operations;
Bob Copelandc9633432008-08-15 00:40:46 -0700240 inode->i_size = sbi->s_sys_blocksize;
Bob Copeland555e3772008-07-25 19:45:15 -0700241 inc_nlink(inode);
242 break;
243 case OMFS_FILE:
244 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
245 inode->i_fop = &omfs_file_operations;
246 inode->i_size = be64_to_cpu(oi->i_size);
247 break;
248 }
249 brelse(bh);
250 unlock_new_inode(inode);
251 return inode;
252fail_bh:
253 brelse(bh);
254iget_failed:
255 iget_failed(inode);
256 return ERR_PTR(-EIO);
257}
258
259static void omfs_put_super(struct super_block *sb)
260{
261 struct omfs_sb_info *sbi = OMFS_SB(sb);
262 kfree(sbi->s_imap);
263 kfree(sbi);
264 sb->s_fs_info = NULL;
265}
266
267static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
268{
269 struct super_block *s = dentry->d_sb;
270 struct omfs_sb_info *sbi = OMFS_SB(s);
Coly Li197e6712009-04-02 16:59:39 -0700271 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
272
Bob Copeland555e3772008-07-25 19:45:15 -0700273 buf->f_type = OMFS_MAGIC;
274 buf->f_bsize = sbi->s_blocksize;
275 buf->f_blocks = sbi->s_num_blocks;
276 buf->f_files = sbi->s_num_blocks;
277 buf->f_namelen = OMFS_NAMELEN;
Coly Li197e6712009-04-02 16:59:39 -0700278 buf->f_fsid.val[0] = (u32)id;
279 buf->f_fsid.val[1] = (u32)(id >> 32);
Bob Copeland555e3772008-07-25 19:45:15 -0700280
281 buf->f_bfree = buf->f_bavail = buf->f_ffree =
282 omfs_count_free(s);
Coly Li197e6712009-04-02 16:59:39 -0700283
Bob Copeland555e3772008-07-25 19:45:15 -0700284 return 0;
285}
286
Alexey Dobriyanb87221d2009-09-21 17:01:09 -0700287static const struct super_operations omfs_sops = {
Bob Copeland555e3772008-07-25 19:45:15 -0700288 .write_inode = omfs_write_inode,
289 .delete_inode = omfs_delete_inode,
290 .put_super = omfs_put_super,
291 .statfs = omfs_statfs,
292 .show_options = generic_show_options,
293};
294
295/*
296 * For Rio Karma, there is an on-disk free bitmap whose location is
297 * stored in the root block. For ReplayTV, there is no such free bitmap
298 * so we have to walk the tree. Both inodes and file data are allocated
299 * from the same map. This array can be big (300k) so we allocate
300 * in units of the blocksize.
301 */
302static int omfs_get_imap(struct super_block *sb)
303{
304 int bitmap_size;
305 int array_size;
306 int count;
307 struct omfs_sb_info *sbi = OMFS_SB(sb);
308 struct buffer_head *bh;
309 unsigned long **ptr;
310 sector_t block;
311
312 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
313 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
314
315 if (sbi->s_bitmap_ino == ~0ULL)
316 goto out;
317
318 sbi->s_imap_size = array_size;
319 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
320 if (!sbi->s_imap)
321 goto nomem;
322
323 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
324 ptr = sbi->s_imap;
325 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
326 bh = sb_bread(sb, block++);
327 if (!bh)
328 goto nomem_free;
329 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
330 if (!*ptr) {
331 brelse(bh);
332 goto nomem_free;
333 }
334 memcpy(*ptr, bh->b_data, sb->s_blocksize);
335 if (count < sb->s_blocksize)
336 memset((void *)*ptr + count, 0xff,
337 sb->s_blocksize - count);
338 brelse(bh);
339 ptr++;
340 }
341out:
342 return 0;
343
344nomem_free:
345 for (count = 0; count < array_size; count++)
346 kfree(sbi->s_imap[count]);
347
348 kfree(sbi->s_imap);
349nomem:
350 sbi->s_imap = NULL;
351 sbi->s_imap_size = 0;
352 return -ENOMEM;
353}
354
355enum {
356 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
357};
358
Steven Whitehousea447c092008-10-13 10:46:57 +0100359static const match_table_t tokens = {
Bob Copeland555e3772008-07-25 19:45:15 -0700360 {Opt_uid, "uid=%u"},
361 {Opt_gid, "gid=%u"},
362 {Opt_umask, "umask=%o"},
363 {Opt_dmask, "dmask=%o"},
364 {Opt_fmask, "fmask=%o"},
365};
366
367static int parse_options(char *options, struct omfs_sb_info *sbi)
368{
369 char *p;
370 substring_t args[MAX_OPT_ARGS];
371 int option;
372
373 if (!options)
374 return 1;
375
376 while ((p = strsep(&options, ",")) != NULL) {
377 int token;
378 if (!*p)
379 continue;
380
381 token = match_token(p, tokens, args);
382 switch (token) {
383 case Opt_uid:
384 if (match_int(&args[0], &option))
385 return 0;
386 sbi->s_uid = option;
387 break;
388 case Opt_gid:
389 if (match_int(&args[0], &option))
390 return 0;
391 sbi->s_gid = option;
392 break;
393 case Opt_umask:
394 if (match_octal(&args[0], &option))
395 return 0;
396 sbi->s_fmask = sbi->s_dmask = option;
397 break;
398 case Opt_dmask:
399 if (match_octal(&args[0], &option))
400 return 0;
401 sbi->s_dmask = option;
402 break;
403 case Opt_fmask:
404 if (match_octal(&args[0], &option))
405 return 0;
406 sbi->s_fmask = option;
407 break;
408 default:
409 return 0;
410 }
411 }
412 return 1;
413}
414
415static int omfs_fill_super(struct super_block *sb, void *data, int silent)
416{
417 struct buffer_head *bh, *bh2;
418 struct omfs_super_block *omfs_sb;
419 struct omfs_root_block *omfs_rb;
420 struct omfs_sb_info *sbi;
421 struct inode *root;
422 sector_t start;
423 int ret = -EINVAL;
424
425 save_mount_options(sb, (char *) data);
426
427 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
428 if (!sbi)
429 return -ENOMEM;
430
431 sb->s_fs_info = sbi;
432
David Howellsc222d532008-11-14 10:38:59 +1100433 sbi->s_uid = current_uid();
434 sbi->s_gid = current_gid();
Al Viroce3b0f82009-03-29 19:08:22 -0400435 sbi->s_dmask = sbi->s_fmask = current_umask();
Bob Copeland555e3772008-07-25 19:45:15 -0700436
437 if (!parse_options((char *) data, sbi))
438 goto end;
439
440 sb->s_maxbytes = 0xffffffff;
441
442 sb_set_blocksize(sb, 0x200);
443
444 bh = sb_bread(sb, 0);
445 if (!bh)
446 goto end;
447
448 omfs_sb = (struct omfs_super_block *)bh->b_data;
449
450 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
451 if (!silent)
452 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
453 omfs_sb->s_magic);
454 goto out_brelse_bh;
455 }
456 sb->s_magic = OMFS_MAGIC;
457
458 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
459 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
460 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
461 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
462 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
463 mutex_init(&sbi->s_bitmap_lock);
464
465 if (sbi->s_sys_blocksize > PAGE_SIZE) {
466 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
467 sbi->s_sys_blocksize);
468 goto out_brelse_bh;
469 }
470
471 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
472 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
473 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
474 sbi->s_blocksize);
475 goto out_brelse_bh;
476 }
477
478 /*
479 * Use sys_blocksize as the fs block since it is smaller than a
480 * page while the fs blocksize can be larger.
481 */
482 sb_set_blocksize(sb, sbi->s_sys_blocksize);
483
484 /*
485 * ...and the difference goes into a shift. sys_blocksize is always
486 * a power of two factor of blocksize.
487 */
488 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
489 get_bitmask_order(sbi->s_sys_blocksize);
490
491 start = clus_to_blk(sbi, be64_to_cpu(omfs_sb->s_root_block));
492 bh2 = sb_bread(sb, start);
493 if (!bh2)
494 goto out_brelse_bh;
495
496 omfs_rb = (struct omfs_root_block *)bh2->b_data;
497
498 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
499 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
500
501 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
502 printk(KERN_ERR "omfs: block count discrepancy between "
503 "super and root blocks (%llx, %llx)\n",
Alexander Beregalovdc60bf12008-08-05 13:01:33 -0700504 (unsigned long long)sbi->s_num_blocks,
505 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
Bob Copeland555e3772008-07-25 19:45:15 -0700506 goto out_brelse_bh2;
507 }
508
509 ret = omfs_get_imap(sb);
510 if (ret)
511 goto out_brelse_bh2;
512
513 sb->s_op = &omfs_sops;
514
515 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
516 if (IS_ERR(root)) {
517 ret = PTR_ERR(root);
518 goto out_brelse_bh2;
519 }
520
521 sb->s_root = d_alloc_root(root);
522 if (!sb->s_root) {
523 iput(root);
524 goto out_brelse_bh2;
525 }
526 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
527
528 ret = 0;
529out_brelse_bh2:
530 brelse(bh2);
531out_brelse_bh:
532 brelse(bh);
533end:
534 return ret;
535}
536
537static int omfs_get_sb(struct file_system_type *fs_type,
538 int flags, const char *dev_name,
539 void *data, struct vfsmount *m)
540{
541 return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
542}
543
544static struct file_system_type omfs_fs_type = {
545 .owner = THIS_MODULE,
546 .name = "omfs",
547 .get_sb = omfs_get_sb,
548 .kill_sb = kill_block_super,
549 .fs_flags = FS_REQUIRES_DEV,
550};
551
552static int __init init_omfs_fs(void)
553{
554 return register_filesystem(&omfs_fs_type);
555}
556
557static void __exit exit_omfs_fs(void)
558{
559 unregister_filesystem(&omfs_fs_type);
560}
561
562module_init(init_omfs_fs);
563module_exit(exit_omfs_fs);