2 * Optimized MPEG FS - inode and super operations.
3 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
4 * Released under GPL v2.
6 #include <linux/module.h>
7 #include <linux/sched.h>
8 #include <linux/slab.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/writeback.h>
15 #include <linux/crc-itu-t.h>
18 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
19 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
20 MODULE_LICENSE("GPL");
22 struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
24 struct omfs_sb_info *sbi = OMFS_SB(sb);
25 if (block >= sbi->s_num_blocks)
28 return sb_bread(sb, clus_to_blk(sbi, block));
31 struct inode *omfs_new_inode(struct inode *dir, int mode)
37 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
39 inode = new_inode(dir->i_sb);
41 return ERR_PTR(-ENOMEM);
43 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
48 inode->i_ino = new_block;
49 inode_init_owner(inode, NULL, mode);
50 inode->i_mapping->a_ops = &omfs_aops;
52 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
53 switch (mode & S_IFMT) {
55 inode->i_op = &omfs_dir_inops;
56 inode->i_fop = &omfs_dir_operations;
57 inode->i_size = sbi->s_sys_blocksize;
61 inode->i_op = &omfs_file_inops;
62 inode->i_fop = &omfs_file_operations;
67 insert_inode_hash(inode);
68 mark_inode_dirty(inode);
71 make_bad_inode(inode);
77 * Update the header checksums for a dirty inode based on its contents.
78 * Caller is expected to hold the buffer head underlying oi and mark it
81 static void omfs_update_checksums(struct omfs_inode *oi)
83 int xor, i, ofs = 0, count;
85 unsigned char *ptr = (unsigned char *) oi;
87 count = be32_to_cpu(oi->i_head.h_body_size);
88 ofs = sizeof(struct omfs_header);
90 crc = crc_itu_t(crc, ptr + ofs, count);
91 oi->i_head.h_crc = cpu_to_be16(crc);
94 for (i = 1; i < OMFS_XOR_COUNT; i++)
97 oi->i_head.h_check_xor = xor;
100 static int __omfs_write_inode(struct inode *inode, int wait)
102 struct omfs_inode *oi;
103 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
104 struct buffer_head *bh, *bh2;
110 /* get current inode since we may have written sibling ptrs etc. */
111 bh = omfs_bread(inode->i_sb, inode->i_ino);
115 oi = (struct omfs_inode *) bh->b_data;
117 oi->i_head.h_self = cpu_to_be64(inode->i_ino);
118 if (S_ISDIR(inode->i_mode))
119 oi->i_type = OMFS_DIR;
120 else if (S_ISREG(inode->i_mode))
121 oi->i_type = OMFS_FILE;
123 printk(KERN_WARNING "omfs: unknown file type: %d\n",
128 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
129 sizeof(struct omfs_header));
130 oi->i_head.h_version = 1;
131 oi->i_head.h_type = OMFS_INODE_NORMAL;
132 oi->i_head.h_magic = OMFS_IMAGIC;
133 oi->i_size = cpu_to_be64(inode->i_size);
135 ctime = inode->i_ctime.tv_sec * 1000LL +
136 ((inode->i_ctime.tv_nsec + 999)/1000);
137 oi->i_ctime = cpu_to_be64(ctime);
139 omfs_update_checksums(oi);
141 mark_buffer_dirty(bh);
143 sync_dirty_buffer(bh);
144 if (buffer_req(bh) && !buffer_uptodate(bh))
148 /* if mirroring writes, copy to next fsblock */
149 for (i = 1; i < sbi->s_mirrors; i++) {
150 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
154 memcpy(bh2->b_data, bh->b_data, bh->b_size);
155 mark_buffer_dirty(bh2);
157 sync_dirty_buffer(bh2);
158 if (buffer_req(bh2) && !buffer_uptodate(bh2))
163 ret = (sync_failed) ? -EIO : 0;
170 static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
172 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
175 int omfs_sync_inode(struct inode *inode)
177 return __omfs_write_inode(inode, 1);
181 * called when an entry is deleted, need to clear the bits in the
184 static void omfs_delete_inode(struct inode *inode)
186 truncate_inode_pages(&inode->i_data, 0);
188 if (S_ISREG(inode->i_mode)) {
190 omfs_shrink_inode(inode);
193 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
197 struct inode *omfs_iget(struct super_block *sb, ino_t ino)
199 struct omfs_sb_info *sbi = OMFS_SB(sb);
200 struct omfs_inode *oi;
201 struct buffer_head *bh;
206 inode = iget_locked(sb, ino);
208 return ERR_PTR(-ENOMEM);
209 if (!(inode->i_state & I_NEW))
212 bh = omfs_bread(inode->i_sb, ino);
216 oi = (struct omfs_inode *)bh->b_data;
219 if (ino != be64_to_cpu(oi->i_head.h_self))
222 inode->i_uid = sbi->s_uid;
223 inode->i_gid = sbi->s_gid;
225 ctime = be64_to_cpu(oi->i_ctime);
226 nsecs = do_div(ctime, 1000) * 1000L;
228 inode->i_atime.tv_sec = ctime;
229 inode->i_mtime.tv_sec = ctime;
230 inode->i_ctime.tv_sec = ctime;
231 inode->i_atime.tv_nsec = nsecs;
232 inode->i_mtime.tv_nsec = nsecs;
233 inode->i_ctime.tv_nsec = nsecs;
235 inode->i_mapping->a_ops = &omfs_aops;
237 switch (oi->i_type) {
239 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
240 inode->i_op = &omfs_dir_inops;
241 inode->i_fop = &omfs_dir_operations;
242 inode->i_size = sbi->s_sys_blocksize;
246 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
247 inode->i_fop = &omfs_file_operations;
248 inode->i_size = be64_to_cpu(oi->i_size);
252 unlock_new_inode(inode);
258 return ERR_PTR(-EIO);
261 static void omfs_put_super(struct super_block *sb)
263 struct omfs_sb_info *sbi = OMFS_SB(sb);
266 sb->s_fs_info = NULL;
269 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
271 struct super_block *s = dentry->d_sb;
272 struct omfs_sb_info *sbi = OMFS_SB(s);
273 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
275 buf->f_type = OMFS_MAGIC;
276 buf->f_bsize = sbi->s_blocksize;
277 buf->f_blocks = sbi->s_num_blocks;
278 buf->f_files = sbi->s_num_blocks;
279 buf->f_namelen = OMFS_NAMELEN;
280 buf->f_fsid.val[0] = (u32)id;
281 buf->f_fsid.val[1] = (u32)(id >> 32);
283 buf->f_bfree = buf->f_bavail = buf->f_ffree =
289 static const struct super_operations omfs_sops = {
290 .write_inode = omfs_write_inode,
291 .delete_inode = omfs_delete_inode,
292 .put_super = omfs_put_super,
293 .statfs = omfs_statfs,
294 .show_options = generic_show_options,
298 * For Rio Karma, there is an on-disk free bitmap whose location is
299 * stored in the root block. For ReplayTV, there is no such free bitmap
300 * so we have to walk the tree. Both inodes and file data are allocated
301 * from the same map. This array can be big (300k) so we allocate
302 * in units of the blocksize.
304 static int omfs_get_imap(struct super_block *sb)
309 struct omfs_sb_info *sbi = OMFS_SB(sb);
310 struct buffer_head *bh;
314 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
315 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
317 if (sbi->s_bitmap_ino == ~0ULL)
320 sbi->s_imap_size = array_size;
321 sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
325 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
326 if (block >= sbi->s_num_blocks)
330 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
331 bh = sb_bread(sb, block++);
334 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
339 memcpy(*ptr, bh->b_data, sb->s_blocksize);
340 if (count < sb->s_blocksize)
341 memset((void *)*ptr + count, 0xff,
342 sb->s_blocksize - count);
350 for (count = 0; count < array_size; count++)
351 kfree(sbi->s_imap[count]);
356 sbi->s_imap_size = 0;
361 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
364 static const match_table_t tokens = {
367 {Opt_umask, "umask=%o"},
368 {Opt_dmask, "dmask=%o"},
369 {Opt_fmask, "fmask=%o"},
372 static int parse_options(char *options, struct omfs_sb_info *sbi)
375 substring_t args[MAX_OPT_ARGS];
381 while ((p = strsep(&options, ",")) != NULL) {
386 token = match_token(p, tokens, args);
389 if (match_int(&args[0], &option))
394 if (match_int(&args[0], &option))
399 if (match_octal(&args[0], &option))
401 sbi->s_fmask = sbi->s_dmask = option;
404 if (match_octal(&args[0], &option))
406 sbi->s_dmask = option;
409 if (match_octal(&args[0], &option))
411 sbi->s_fmask = option;
420 static int omfs_fill_super(struct super_block *sb, void *data, int silent)
422 struct buffer_head *bh, *bh2;
423 struct omfs_super_block *omfs_sb;
424 struct omfs_root_block *omfs_rb;
425 struct omfs_sb_info *sbi;
429 save_mount_options(sb, (char *) data);
431 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
437 sbi->s_uid = current_uid();
438 sbi->s_gid = current_gid();
439 sbi->s_dmask = sbi->s_fmask = current_umask();
441 if (!parse_options((char *) data, sbi))
444 sb->s_maxbytes = 0xffffffff;
446 sb_set_blocksize(sb, 0x200);
448 bh = sb_bread(sb, 0);
452 omfs_sb = (struct omfs_super_block *)bh->b_data;
454 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
456 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
460 sb->s_magic = OMFS_MAGIC;
462 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
463 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
464 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
465 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
466 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
467 mutex_init(&sbi->s_bitmap_lock);
469 if (sbi->s_sys_blocksize > PAGE_SIZE) {
470 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
471 sbi->s_sys_blocksize);
475 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
476 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
477 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
483 * Use sys_blocksize as the fs block since it is smaller than a
484 * page while the fs blocksize can be larger.
486 sb_set_blocksize(sb, sbi->s_sys_blocksize);
489 * ...and the difference goes into a shift. sys_blocksize is always
490 * a power of two factor of blocksize.
492 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
493 get_bitmask_order(sbi->s_sys_blocksize);
495 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
499 omfs_rb = (struct omfs_root_block *)bh2->b_data;
501 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
502 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
504 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
505 printk(KERN_ERR "omfs: block count discrepancy between "
506 "super and root blocks (%llx, %llx)\n",
507 (unsigned long long)sbi->s_num_blocks,
508 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
512 if (sbi->s_bitmap_ino != ~0ULL &&
513 sbi->s_bitmap_ino > sbi->s_num_blocks) {
514 printk(KERN_ERR "omfs: free space bitmap location is corrupt "
515 "(%llx, total blocks %llx)\n",
516 (unsigned long long) sbi->s_bitmap_ino,
517 (unsigned long long) sbi->s_num_blocks);
521 ret = omfs_get_imap(sb);
525 sb->s_op = &omfs_sops;
527 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
533 sb->s_root = d_alloc_root(root);
538 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
551 static int omfs_get_sb(struct file_system_type *fs_type,
552 int flags, const char *dev_name,
553 void *data, struct vfsmount *m)
555 return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
558 static struct file_system_type omfs_fs_type = {
559 .owner = THIS_MODULE,
561 .get_sb = omfs_get_sb,
562 .kill_sb = kill_block_super,
563 .fs_flags = FS_REQUIRES_DEV,
566 static int __init init_omfs_fs(void)
568 return register_filesystem(&omfs_fs_type);
571 static void __exit exit_omfs_fs(void)
573 unregister_filesystem(&omfs_fs_type);
576 module_init(init_omfs_fs);
577 module_exit(exit_omfs_fs);