1 // SPDX-License-Identifier: GPL-2.0-only
3 * Optimized MPEG FS - inode and super operations.
4 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
6 #include <linux/module.h>
7 #include <linux/sched.h>
8 #include <linux/slab.h>
10 #include <linux/vfs.h>
11 #include <linux/cred.h>
12 #include <linux/parser.h>
13 #include <linux/buffer_head.h>
14 #include <linux/vmalloc.h>
15 #include <linux/writeback.h>
16 #include <linux/seq_file.h>
17 #include <linux/crc-itu-t.h>
20 MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
21 MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
22 MODULE_LICENSE("GPL");
24 struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
26 struct omfs_sb_info *sbi = OMFS_SB(sb);
27 if (block >= sbi->s_num_blocks)
30 return sb_bread(sb, clus_to_blk(sbi, block));
33 struct inode *omfs_new_inode(struct inode *dir, umode_t mode)
39 struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
41 inode = new_inode(dir->i_sb);
43 return ERR_PTR(-ENOMEM);
45 err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
50 inode->i_ino = new_block;
51 inode_init_owner(inode, NULL, mode);
52 inode->i_mapping->a_ops = &omfs_aops;
54 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
55 switch (mode & S_IFMT) {
57 inode->i_op = &omfs_dir_inops;
58 inode->i_fop = &omfs_dir_operations;
59 inode->i_size = sbi->s_sys_blocksize;
63 inode->i_op = &omfs_file_inops;
64 inode->i_fop = &omfs_file_operations;
69 insert_inode_hash(inode);
70 mark_inode_dirty(inode);
73 make_bad_inode(inode);
79 * Update the header checksums for a dirty inode based on its contents.
80 * Caller is expected to hold the buffer head underlying oi and mark it
83 static void omfs_update_checksums(struct omfs_inode *oi)
85 int xor, i, ofs = 0, count;
87 unsigned char *ptr = (unsigned char *) oi;
89 count = be32_to_cpu(oi->i_head.h_body_size);
90 ofs = sizeof(struct omfs_header);
92 crc = crc_itu_t(crc, ptr + ofs, count);
93 oi->i_head.h_crc = cpu_to_be16(crc);
96 for (i = 1; i < OMFS_XOR_COUNT; i++)
99 oi->i_head.h_check_xor = xor;
102 static int __omfs_write_inode(struct inode *inode, int wait)
104 struct omfs_inode *oi;
105 struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
106 struct buffer_head *bh, *bh2;
112 /* get current inode since we may have written sibling ptrs etc. */
113 bh = omfs_bread(inode->i_sb, inode->i_ino);
117 oi = (struct omfs_inode *) bh->b_data;
119 oi->i_head.h_self = cpu_to_be64(inode->i_ino);
120 if (S_ISDIR(inode->i_mode))
121 oi->i_type = OMFS_DIR;
122 else if (S_ISREG(inode->i_mode))
123 oi->i_type = OMFS_FILE;
125 printk(KERN_WARNING "omfs: unknown file type: %d\n",
130 oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
131 sizeof(struct omfs_header));
132 oi->i_head.h_version = 1;
133 oi->i_head.h_type = OMFS_INODE_NORMAL;
134 oi->i_head.h_magic = OMFS_IMAGIC;
135 oi->i_size = cpu_to_be64(inode->i_size);
137 ctime = inode->i_ctime.tv_sec * 1000LL +
138 ((inode->i_ctime.tv_nsec + 999)/1000);
139 oi->i_ctime = cpu_to_be64(ctime);
141 omfs_update_checksums(oi);
143 mark_buffer_dirty(bh);
145 sync_dirty_buffer(bh);
146 if (buffer_req(bh) && !buffer_uptodate(bh))
150 /* if mirroring writes, copy to next fsblock */
151 for (i = 1; i < sbi->s_mirrors; i++) {
152 bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
156 memcpy(bh2->b_data, bh->b_data, bh->b_size);
157 mark_buffer_dirty(bh2);
159 sync_dirty_buffer(bh2);
160 if (buffer_req(bh2) && !buffer_uptodate(bh2))
165 ret = (sync_failed) ? -EIO : 0;
172 static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
174 return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
177 int omfs_sync_inode(struct inode *inode)
179 return __omfs_write_inode(inode, 1);
183 * called when an entry is deleted, need to clear the bits in the
186 static void omfs_evict_inode(struct inode *inode)
188 truncate_inode_pages_final(&inode->i_data);
194 if (S_ISREG(inode->i_mode)) {
196 omfs_shrink_inode(inode);
199 omfs_clear_range(inode->i_sb, inode->i_ino, 2);
202 struct inode *omfs_iget(struct super_block *sb, ino_t ino)
204 struct omfs_sb_info *sbi = OMFS_SB(sb);
205 struct omfs_inode *oi;
206 struct buffer_head *bh;
211 inode = iget_locked(sb, ino);
213 return ERR_PTR(-ENOMEM);
214 if (!(inode->i_state & I_NEW))
217 bh = omfs_bread(inode->i_sb, ino);
221 oi = (struct omfs_inode *)bh->b_data;
224 if (ino != be64_to_cpu(oi->i_head.h_self))
227 inode->i_uid = sbi->s_uid;
228 inode->i_gid = sbi->s_gid;
230 ctime = be64_to_cpu(oi->i_ctime);
231 nsecs = do_div(ctime, 1000) * 1000L;
233 inode->i_atime.tv_sec = ctime;
234 inode->i_mtime.tv_sec = ctime;
235 inode->i_ctime.tv_sec = ctime;
236 inode->i_atime.tv_nsec = nsecs;
237 inode->i_mtime.tv_nsec = nsecs;
238 inode->i_ctime.tv_nsec = nsecs;
240 inode->i_mapping->a_ops = &omfs_aops;
242 switch (oi->i_type) {
244 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
245 inode->i_op = &omfs_dir_inops;
246 inode->i_fop = &omfs_dir_operations;
247 inode->i_size = sbi->s_sys_blocksize;
251 inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
252 inode->i_fop = &omfs_file_operations;
253 inode->i_size = be64_to_cpu(oi->i_size);
257 unlock_new_inode(inode);
263 return ERR_PTR(-EIO);
266 static void omfs_put_super(struct super_block *sb)
268 struct omfs_sb_info *sbi = OMFS_SB(sb);
271 sb->s_fs_info = NULL;
274 static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
276 struct super_block *s = dentry->d_sb;
277 struct omfs_sb_info *sbi = OMFS_SB(s);
278 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
280 buf->f_type = OMFS_MAGIC;
281 buf->f_bsize = sbi->s_blocksize;
282 buf->f_blocks = sbi->s_num_blocks;
283 buf->f_files = sbi->s_num_blocks;
284 buf->f_namelen = OMFS_NAMELEN;
285 buf->f_fsid.val[0] = (u32)id;
286 buf->f_fsid.val[1] = (u32)(id >> 32);
288 buf->f_bfree = buf->f_bavail = buf->f_ffree =
295 * Display the mount options in /proc/mounts.
297 static int omfs_show_options(struct seq_file *m, struct dentry *root)
299 struct omfs_sb_info *sbi = OMFS_SB(root->d_sb);
300 umode_t cur_umask = current_umask();
302 if (!uid_eq(sbi->s_uid, current_uid()))
303 seq_printf(m, ",uid=%u",
304 from_kuid_munged(&init_user_ns, sbi->s_uid));
305 if (!gid_eq(sbi->s_gid, current_gid()))
306 seq_printf(m, ",gid=%u",
307 from_kgid_munged(&init_user_ns, sbi->s_gid));
309 if (sbi->s_dmask == sbi->s_fmask) {
310 if (sbi->s_fmask != cur_umask)
311 seq_printf(m, ",umask=%o", sbi->s_fmask);
313 if (sbi->s_dmask != cur_umask)
314 seq_printf(m, ",dmask=%o", sbi->s_dmask);
315 if (sbi->s_fmask != cur_umask)
316 seq_printf(m, ",fmask=%o", sbi->s_fmask);
322 static const struct super_operations omfs_sops = {
323 .write_inode = omfs_write_inode,
324 .evict_inode = omfs_evict_inode,
325 .put_super = omfs_put_super,
326 .statfs = omfs_statfs,
327 .show_options = omfs_show_options,
331 * For Rio Karma, there is an on-disk free bitmap whose location is
332 * stored in the root block. For ReplayTV, there is no such free bitmap
333 * so we have to walk the tree. Both inodes and file data are allocated
334 * from the same map. This array can be big (300k) so we allocate
335 * in units of the blocksize.
337 static int omfs_get_imap(struct super_block *sb)
339 unsigned int bitmap_size, array_size;
341 struct omfs_sb_info *sbi = OMFS_SB(sb);
342 struct buffer_head *bh;
346 bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
347 array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
349 if (sbi->s_bitmap_ino == ~0ULL)
352 sbi->s_imap_size = array_size;
353 sbi->s_imap = kcalloc(array_size, sizeof(unsigned long *), GFP_KERNEL);
357 block = clus_to_blk(sbi, sbi->s_bitmap_ino);
358 if (block >= sbi->s_num_blocks)
362 for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
363 bh = sb_bread(sb, block++);
366 *ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
371 memcpy(*ptr, bh->b_data, sb->s_blocksize);
372 if (count < sb->s_blocksize)
373 memset((void *)*ptr + count, 0xff,
374 sb->s_blocksize - count);
382 for (count = 0; count < array_size; count++)
383 kfree(sbi->s_imap[count]);
388 sbi->s_imap_size = 0;
393 Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_err
396 static const match_table_t tokens = {
399 {Opt_umask, "umask=%o"},
400 {Opt_dmask, "dmask=%o"},
401 {Opt_fmask, "fmask=%o"},
405 static int parse_options(char *options, struct omfs_sb_info *sbi)
408 substring_t args[MAX_OPT_ARGS];
414 while ((p = strsep(&options, ",")) != NULL) {
419 token = match_token(p, tokens, args);
422 if (match_int(&args[0], &option))
424 sbi->s_uid = make_kuid(current_user_ns(), option);
425 if (!uid_valid(sbi->s_uid))
429 if (match_int(&args[0], &option))
431 sbi->s_gid = make_kgid(current_user_ns(), option);
432 if (!gid_valid(sbi->s_gid))
436 if (match_octal(&args[0], &option))
438 sbi->s_fmask = sbi->s_dmask = option;
441 if (match_octal(&args[0], &option))
443 sbi->s_dmask = option;
446 if (match_octal(&args[0], &option))
448 sbi->s_fmask = option;
457 static int omfs_fill_super(struct super_block *sb, void *data, int silent)
459 struct buffer_head *bh, *bh2;
460 struct omfs_super_block *omfs_sb;
461 struct omfs_root_block *omfs_rb;
462 struct omfs_sb_info *sbi;
466 sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
472 sbi->s_uid = current_uid();
473 sbi->s_gid = current_gid();
474 sbi->s_dmask = sbi->s_fmask = current_umask();
476 if (!parse_options((char *) data, sbi))
479 sb->s_maxbytes = 0xffffffff;
481 sb->s_time_gran = NSEC_PER_MSEC;
483 sb->s_time_max = U64_MAX / MSEC_PER_SEC;
485 sb_set_blocksize(sb, 0x200);
487 bh = sb_bread(sb, 0);
491 omfs_sb = (struct omfs_super_block *)bh->b_data;
493 if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
495 printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
499 sb->s_magic = OMFS_MAGIC;
501 sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
502 sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
503 sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
504 sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
505 sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
506 mutex_init(&sbi->s_bitmap_lock);
508 if (sbi->s_num_blocks > OMFS_MAX_BLOCKS) {
509 printk(KERN_ERR "omfs: sysblock number (%llx) is out of range\n",
510 (unsigned long long)sbi->s_num_blocks);
514 if (sbi->s_sys_blocksize > PAGE_SIZE) {
515 printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
516 sbi->s_sys_blocksize);
520 if (sbi->s_blocksize < sbi->s_sys_blocksize ||
521 sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
522 printk(KERN_ERR "omfs: block size (%d) is out of range\n",
528 * Use sys_blocksize as the fs block since it is smaller than a
529 * page while the fs blocksize can be larger.
531 sb_set_blocksize(sb, sbi->s_sys_blocksize);
534 * ...and the difference goes into a shift. sys_blocksize is always
535 * a power of two factor of blocksize.
537 sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
538 get_bitmask_order(sbi->s_sys_blocksize);
540 bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
544 omfs_rb = (struct omfs_root_block *)bh2->b_data;
546 sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
547 sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
549 if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
550 printk(KERN_ERR "omfs: block count discrepancy between "
551 "super and root blocks (%llx, %llx)\n",
552 (unsigned long long)sbi->s_num_blocks,
553 (unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
557 if (sbi->s_bitmap_ino != ~0ULL &&
558 sbi->s_bitmap_ino > sbi->s_num_blocks) {
559 printk(KERN_ERR "omfs: free space bitmap location is corrupt "
560 "(%llx, total blocks %llx)\n",
561 (unsigned long long) sbi->s_bitmap_ino,
562 (unsigned long long) sbi->s_num_blocks);
565 if (sbi->s_clustersize < 1 ||
566 sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
567 printk(KERN_ERR "omfs: cluster size out of range (%d)",
572 ret = omfs_get_imap(sb);
576 sb->s_op = &omfs_sops;
578 root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
584 sb->s_root = d_make_root(root);
589 printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
602 static struct dentry *omfs_mount(struct file_system_type *fs_type,
603 int flags, const char *dev_name, void *data)
605 return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
608 static struct file_system_type omfs_fs_type = {
609 .owner = THIS_MODULE,
612 .kill_sb = kill_block_super,
613 .fs_flags = FS_REQUIRES_DEV,
615 MODULE_ALIAS_FS("omfs");
617 static int __init init_omfs_fs(void)
619 return register_filesystem(&omfs_fs_type);
622 static void __exit exit_omfs_fs(void)
624 unregister_filesystem(&omfs_fs_type);
627 module_init(init_omfs_fs);
628 module_exit(exit_omfs_fs);