4 * Written 1992,1993 by Werner Almesberger
5 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
6 * Rewritten for the constant inumbers support by Al Viro
10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/time.h>
16 #include <linux/slab.h>
17 #include <linux/smp_lock.h>
18 #include <linux/seq_file.h>
19 #include <linux/msdos_fs.h>
20 #include <linux/pagemap.h>
21 #include <linux/mpage.h>
22 #include <linux/buffer_head.h>
23 #include <linux/mount.h>
24 #include <linux/vfs.h>
25 #include <linux/parser.h>
26 #include <linux/uio.h>
27 #include <linux/writeback.h>
28 #include <asm/unaligned.h>
30 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
31 /* if user don't select VFAT, this is undefined. */
32 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
35 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
36 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
39 static int fat_add_cluster(struct inode *inode)
43 err = fat_alloc_clusters(inode, &cluster, 1);
46 /* FIXME: this cluster should be added after data of this
47 * cluster is writed */
48 err = fat_chain_add(inode, cluster, 1);
50 fat_free_clusters(inode, cluster);
54 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
55 unsigned long *max_blocks,
56 struct buffer_head *bh_result, int create)
58 struct super_block *sb = inode->i_sb;
59 struct msdos_sb_info *sbi = MSDOS_SB(sb);
60 unsigned long mapped_blocks;
64 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
68 map_bh(bh_result, sb, phys);
69 *max_blocks = min(mapped_blocks, *max_blocks);
75 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
76 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
77 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
81 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
83 /* TODO: multiple cluster allocation would be desirable. */
84 err = fat_add_cluster(inode);
88 /* available blocks on this cluster */
89 mapped_blocks = sbi->sec_per_clus - offset;
91 *max_blocks = min(mapped_blocks, *max_blocks);
92 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
94 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
99 BUG_ON(*max_blocks != mapped_blocks);
100 set_buffer_new(bh_result);
101 map_bh(bh_result, sb, phys);
106 static int fat_get_block(struct inode *inode, sector_t iblock,
107 struct buffer_head *bh_result, int create)
109 struct super_block *sb = inode->i_sb;
110 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
113 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
116 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
120 static int fat_writepage(struct page *page, struct writeback_control *wbc)
122 return block_write_full_page(page, fat_get_block, wbc);
125 static int fat_writepages(struct address_space *mapping,
126 struct writeback_control *wbc)
128 return mpage_writepages(mapping, wbc, fat_get_block);
131 static int fat_readpage(struct file *file, struct page *page)
133 return mpage_readpage(page, fat_get_block);
136 static int fat_readpages(struct file *file, struct address_space *mapping,
137 struct list_head *pages, unsigned nr_pages)
139 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
142 static int fat_prepare_write(struct file *file, struct page *page,
143 unsigned from, unsigned to)
145 return cont_prepare_write(page, from, to, fat_get_block,
146 &MSDOS_I(page->mapping->host)->mmu_private);
149 static int fat_commit_write(struct file *file, struct page *page,
150 unsigned from, unsigned to)
152 struct inode *inode = page->mapping->host;
153 int err = generic_commit_write(file, page, from, to);
154 if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
155 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
156 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
157 mark_inode_dirty(inode);
162 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
163 const struct iovec *iov,
164 loff_t offset, unsigned long nr_segs)
166 struct file *file = iocb->ki_filp;
167 struct inode *inode = file->f_mapping->host;
171 * FIXME: blockdev_direct_IO() doesn't use ->prepare_write(),
172 * so we need to update the ->mmu_private to block boundary.
174 * But we must fill the remaining area or hole by nul for
175 * updating ->mmu_private.
177 * Return 0, and fallback to normal buffered write.
179 loff_t size = offset + iov_length(iov, nr_segs);
180 if (MSDOS_I(inode)->mmu_private < size)
185 * FAT need to use the DIO_LOCKING for avoiding the race
186 * condition of fat_get_block() and ->truncate().
188 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
189 offset, nr_segs, fat_get_block, NULL);
192 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
194 return generic_block_bmap(mapping, block, fat_get_block);
197 static const struct address_space_operations fat_aops = {
198 .readpage = fat_readpage,
199 .readpages = fat_readpages,
200 .writepage = fat_writepage,
201 .writepages = fat_writepages,
202 .sync_page = block_sync_page,
203 .prepare_write = fat_prepare_write,
204 .commit_write = fat_commit_write,
205 .direct_IO = fat_direct_IO,
210 * New FAT inode stuff. We do the following:
211 * a) i_ino is constant and has nothing with on-disk location.
212 * b) FAT manages its own cache of directory entries.
213 * c) *This* cache is indexed by on-disk location.
214 * d) inode has an associated directory entry, all right, but
215 * it may be unhashed.
216 * e) currently entries are stored within struct inode. That should
218 * f) we deal with races in the following way:
219 * 1. readdir() and lookup() do FAT-dir-cache lookup.
220 * 2. rename() unhashes the F-d-c entry and rehashes it in
222 * 3. unlink() and rmdir() unhash F-d-c entry.
223 * 4. fat_write_inode() checks whether the thing is unhashed.
224 * If it is we silently return. If it isn't we do bread(),
225 * check if the location is still valid and retry if it
226 * isn't. Otherwise we do changes.
227 * 5. Spinlock is used to protect hash/unhash/location check/lookup
228 * 6. fat_clear_inode() unhashes the F-d-c entry.
229 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
230 * and consider negative result as cache miss.
233 static void fat_hash_init(struct super_block *sb)
235 struct msdos_sb_info *sbi = MSDOS_SB(sb);
238 spin_lock_init(&sbi->inode_hash_lock);
239 for (i = 0; i < FAT_HASH_SIZE; i++)
240 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
243 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
245 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
246 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
247 return tmp & FAT_HASH_MASK;
250 void fat_attach(struct inode *inode, loff_t i_pos)
252 struct super_block *sb = inode->i_sb;
253 struct msdos_sb_info *sbi = MSDOS_SB(sb);
255 spin_lock(&sbi->inode_hash_lock);
256 MSDOS_I(inode)->i_pos = i_pos;
257 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
258 sbi->inode_hashtable + fat_hash(sb, i_pos));
259 spin_unlock(&sbi->inode_hash_lock);
262 EXPORT_SYMBOL_GPL(fat_attach);
264 void fat_detach(struct inode *inode)
266 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
267 spin_lock(&sbi->inode_hash_lock);
268 MSDOS_I(inode)->i_pos = 0;
269 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
270 spin_unlock(&sbi->inode_hash_lock);
273 EXPORT_SYMBOL_GPL(fat_detach);
275 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
277 struct msdos_sb_info *sbi = MSDOS_SB(sb);
278 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
279 struct hlist_node *_p;
280 struct msdos_inode_info *i;
281 struct inode *inode = NULL;
283 spin_lock(&sbi->inode_hash_lock);
284 hlist_for_each_entry(i, _p, head, i_fat_hash) {
285 BUG_ON(i->vfs_inode.i_sb != sb);
286 if (i->i_pos != i_pos)
288 inode = igrab(&i->vfs_inode);
292 spin_unlock(&sbi->inode_hash_lock);
296 static int is_exec(unsigned char *extension)
298 unsigned char *exe_extensions = "EXECOMBAT", *walk;
300 for (walk = exe_extensions; *walk; walk += 3)
301 if (!strncmp(extension, walk, 3))
306 static int fat_calc_dir_size(struct inode *inode)
308 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
309 int ret, fclus, dclus;
312 if (MSDOS_I(inode)->i_start == 0)
315 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
318 inode->i_size = (fclus + 1) << sbi->cluster_bits;
323 /* doesn't deal with root inode */
324 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
326 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
329 MSDOS_I(inode)->i_pos = 0;
330 inode->i_uid = sbi->options.fs_uid;
331 inode->i_gid = sbi->options.fs_gid;
333 inode->i_generation = get_seconds();
335 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
336 inode->i_generation &= ~1;
337 inode->i_mode = MSDOS_MKMODE(de->attr,
338 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
339 inode->i_op = sbi->dir_ops;
340 inode->i_fop = &fat_dir_operations;
342 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
343 if (sbi->fat_bits == 32)
344 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
346 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
347 error = fat_calc_dir_size(inode);
350 MSDOS_I(inode)->mmu_private = inode->i_size;
352 inode->i_nlink = fat_subdirs(inode);
353 } else { /* not a directory */
354 inode->i_generation |= 1;
355 inode->i_mode = MSDOS_MKMODE(de->attr,
356 ((sbi->options.showexec &&
358 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
359 & ~sbi->options.fs_fmask) | S_IFREG;
360 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
361 if (sbi->fat_bits == 32)
362 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
364 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
365 inode->i_size = le32_to_cpu(de->size);
366 inode->i_op = &fat_file_inode_operations;
367 inode->i_fop = &fat_file_operations;
368 inode->i_mapping->a_ops = &fat_aops;
369 MSDOS_I(inode)->mmu_private = inode->i_size;
371 if (de->attr & ATTR_SYS) {
372 if (sbi->options.sys_immutable)
373 inode->i_flags |= S_IMMUTABLE;
375 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
376 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
377 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
378 inode->i_mtime.tv_sec =
379 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
380 inode->i_mtime.tv_nsec = 0;
381 if (sbi->options.isvfat) {
382 int secs = de->ctime_cs / 100;
383 int csecs = de->ctime_cs % 100;
384 inode->i_ctime.tv_sec =
385 date_dos2unix(le16_to_cpu(de->ctime),
386 le16_to_cpu(de->cdate)) + secs;
387 inode->i_ctime.tv_nsec = csecs * 10000000;
388 inode->i_atime.tv_sec =
389 date_dos2unix(0, le16_to_cpu(de->adate));
390 inode->i_atime.tv_nsec = 0;
392 inode->i_ctime = inode->i_atime = inode->i_mtime;
397 struct inode *fat_build_inode(struct super_block *sb,
398 struct msdos_dir_entry *de, loff_t i_pos)
403 inode = fat_iget(sb, i_pos);
406 inode = new_inode(sb);
408 inode = ERR_PTR(-ENOMEM);
411 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
412 inode->i_version = 1;
413 err = fat_fill_inode(inode, de);
416 inode = ERR_PTR(err);
419 fat_attach(inode, i_pos);
420 insert_inode_hash(inode);
425 EXPORT_SYMBOL_GPL(fat_build_inode);
427 static void fat_delete_inode(struct inode *inode)
429 truncate_inode_pages(&inode->i_data, 0);
431 if (!is_bad_inode(inode)) {
438 static void fat_clear_inode(struct inode *inode)
440 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
442 if (is_bad_inode(inode))
445 spin_lock(&sbi->inode_hash_lock);
446 fat_cache_inval_inode(inode);
447 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
448 spin_unlock(&sbi->inode_hash_lock);
452 static void fat_write_super(struct super_block *sb)
456 if (!(sb->s_flags & MS_RDONLY))
457 fat_clusters_flush(sb);
460 static void fat_put_super(struct super_block *sb)
462 struct msdos_sb_info *sbi = MSDOS_SB(sb);
465 unload_nls(sbi->nls_disk);
466 sbi->nls_disk = NULL;
467 sbi->options.codepage = fat_default_codepage;
470 unload_nls(sbi->nls_io);
473 if (sbi->options.iocharset != fat_default_iocharset) {
474 kfree(sbi->options.iocharset);
475 sbi->options.iocharset = fat_default_iocharset;
478 sb->s_fs_info = NULL;
482 static struct kmem_cache *fat_inode_cachep;
484 static struct inode *fat_alloc_inode(struct super_block *sb)
486 struct msdos_inode_info *ei;
487 ei = kmem_cache_alloc(fat_inode_cachep, GFP_KERNEL);
490 return &ei->vfs_inode;
493 static void fat_destroy_inode(struct inode *inode)
495 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
498 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
500 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
502 if (flags & SLAB_CTOR_CONSTRUCTOR) {
503 spin_lock_init(&ei->cache_lru_lock);
505 ei->cache_valid_id = FAT_CACHE_VALID + 1;
506 INIT_LIST_HEAD(&ei->cache_lru);
507 INIT_HLIST_NODE(&ei->i_fat_hash);
508 inode_init_once(&ei->vfs_inode);
512 static int __init fat_init_inodecache(void)
514 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
515 sizeof(struct msdos_inode_info),
516 0, (SLAB_RECLAIM_ACCOUNT|
519 if (fat_inode_cachep == NULL)
524 static void __exit fat_destroy_inodecache(void)
526 kmem_cache_destroy(fat_inode_cachep);
529 static int fat_remount(struct super_block *sb, int *flags, char *data)
531 struct msdos_sb_info *sbi = MSDOS_SB(sb);
532 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
536 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
538 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
540 /* If the count of free cluster is still unknown, counts it here. */
541 if (sbi->free_clusters == -1) {
542 int err = fat_count_free_clusters(dentry->d_sb);
547 buf->f_type = dentry->d_sb->s_magic;
548 buf->f_bsize = sbi->cluster_size;
549 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
550 buf->f_bfree = sbi->free_clusters;
551 buf->f_bavail = sbi->free_clusters;
552 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
557 static int fat_write_inode(struct inode *inode, int wait)
559 struct super_block *sb = inode->i_sb;
560 struct msdos_sb_info *sbi = MSDOS_SB(sb);
561 struct buffer_head *bh;
562 struct msdos_dir_entry *raw_entry;
567 i_pos = MSDOS_I(inode)->i_pos;
568 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
572 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
574 printk(KERN_ERR "FAT: unable to read inode block "
575 "for updating (i_pos %lld)\n", i_pos);
579 spin_lock(&sbi->inode_hash_lock);
580 if (i_pos != MSDOS_I(inode)->i_pos) {
581 spin_unlock(&sbi->inode_hash_lock);
587 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
588 [i_pos & (sbi->dir_per_block - 1)];
589 if (S_ISDIR(inode->i_mode))
592 raw_entry->size = cpu_to_le32(inode->i_size);
593 raw_entry->attr = fat_attr(inode);
594 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
595 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
596 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
597 if (sbi->options.isvfat) {
599 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
600 fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate);
601 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
602 inode->i_ctime.tv_nsec / 10000000;
604 spin_unlock(&sbi->inode_hash_lock);
605 mark_buffer_dirty(bh);
607 err = sync_dirty_buffer(bh);
614 int fat_sync_inode(struct inode *inode)
616 return fat_write_inode(inode, 1);
619 EXPORT_SYMBOL_GPL(fat_sync_inode);
621 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
622 static const struct super_operations fat_sops = {
623 .alloc_inode = fat_alloc_inode,
624 .destroy_inode = fat_destroy_inode,
625 .write_inode = fat_write_inode,
626 .delete_inode = fat_delete_inode,
627 .put_super = fat_put_super,
628 .write_super = fat_write_super,
629 .statfs = fat_statfs,
630 .clear_inode = fat_clear_inode,
631 .remount_fs = fat_remount,
633 .read_inode = make_bad_inode,
635 .show_options = fat_show_options,
639 * a FAT file handle with fhtype 3 is
640 * 0/ i_ino - for fast, reliable lookup if still in the cache
641 * 1/ i_generation - to see if i_ino is still valid
642 * bit 0 == 0 iff directory
643 * 2/ i_pos(8-39) - if ino has changed, but still in cache
644 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
645 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
647 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
648 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
649 * of i_logstart is used to store the directory entry offset.
652 static struct dentry *
653 fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
654 int (*acceptable)(void *context, struct dentry *de),
658 return ERR_PTR(-ESTALE);
660 return ERR_PTR(-ESTALE);
662 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
665 static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
667 struct inode *inode = NULL;
668 struct dentry *result;
671 inode = iget(sb, fh[0]);
672 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
679 int i_logstart = fh[3] & 0x0fffffff;
681 i_pos = (loff_t)fh[2] << 8;
682 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
684 /* try 2 - see if i_pos is in F-d-c
685 * require i_logstart to be the same
686 * Will fail if you truncate and then re-write
689 inode = fat_iget(sb, i_pos);
690 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
696 /* For now, do nothing
697 * What we could do is:
698 * follow the file starting at fh[4], and record
699 * the ".." entry, and the name of the fh[2] entry.
700 * The follow the ".." file finding the next step up.
701 * This way we build a path to the root of
702 * the tree. If this works, we lookup the path and so
703 * get this inode into the cache.
704 * Finally try the fat_iget lookup again
705 * If that fails, then weare totally out of luck
706 * But all that is for another day
710 return ERR_PTR(-ESTALE);
713 /* now to find a dentry.
714 * If possible, get a well-connected one
716 result = d_alloc_anon(inode);
717 if (result == NULL) {
719 return ERR_PTR(-ENOMEM);
721 result->d_op = sb->s_root->d_op;
726 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
729 struct inode *inode = de->d_inode;
730 u32 ipos_h, ipos_m, ipos_l;
733 return 255; /* no room */
735 ipos_h = MSDOS_I(inode)->i_pos >> 8;
736 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
737 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
739 fh[0] = inode->i_ino;
740 fh[1] = inode->i_generation;
742 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
743 spin_lock(&de->d_lock);
744 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
745 spin_unlock(&de->d_lock);
749 static struct dentry *fat_get_parent(struct dentry *child)
751 struct buffer_head *bh;
752 struct msdos_dir_entry *de;
754 struct dentry *parent;
760 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
762 parent = ERR_PTR(err);
765 inode = fat_build_inode(child->d_sb, de, i_pos);
768 parent = ERR_PTR(PTR_ERR(inode));
771 parent = d_alloc_anon(inode);
774 parent = ERR_PTR(-ENOMEM);
782 static struct export_operations fat_export_ops = {
783 .decode_fh = fat_decode_fh,
784 .encode_fh = fat_encode_fh,
785 .get_dentry = fat_get_dentry,
786 .get_parent = fat_get_parent,
789 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
791 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
792 struct fat_mount_options *opts = &sbi->options;
793 int isvfat = opts->isvfat;
795 if (opts->fs_uid != 0)
796 seq_printf(m, ",uid=%u", opts->fs_uid);
797 if (opts->fs_gid != 0)
798 seq_printf(m, ",gid=%u", opts->fs_gid);
799 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
800 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
802 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
805 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
807 switch (opts->shortname) {
808 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
809 seq_puts(m, ",shortname=win95");
811 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
812 seq_puts(m, ",shortname=winnt");
814 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
815 seq_puts(m, ",shortname=mixed");
817 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
818 /* seq_puts(m, ",shortname=lower"); */
821 seq_puts(m, ",shortname=unknown");
825 if (opts->name_check != 'n')
826 seq_printf(m, ",check=%c", opts->name_check);
828 seq_puts(m, ",quiet");
830 seq_puts(m, ",showexec");
831 if (opts->sys_immutable)
832 seq_puts(m, ",sys_immutable");
835 seq_puts(m, ",dotsOK=yes");
837 seq_puts(m, ",nocase");
840 seq_puts(m, ",utf8");
841 if (opts->unicode_xlate)
842 seq_puts(m, ",uni_xlate");
844 seq_puts(m, ",nonumtail");
851 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
852 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
853 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
854 Opt_dots, Opt_nodots,
855 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
856 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
857 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
858 Opt_obsolate, Opt_flush, Opt_err,
861 static match_table_t fat_tokens = {
862 {Opt_check_r, "check=relaxed"},
863 {Opt_check_s, "check=strict"},
864 {Opt_check_n, "check=normal"},
865 {Opt_check_r, "check=r"},
866 {Opt_check_s, "check=s"},
867 {Opt_check_n, "check=n"},
870 {Opt_umask, "umask=%o"},
871 {Opt_dmask, "dmask=%o"},
872 {Opt_fmask, "fmask=%o"},
873 {Opt_codepage, "codepage=%u"},
874 {Opt_nocase, "nocase"},
875 {Opt_quiet, "quiet"},
876 {Opt_showexec, "showexec"},
877 {Opt_debug, "debug"},
878 {Opt_immutable, "sys_immutable"},
879 {Opt_obsolate, "conv=binary"},
880 {Opt_obsolate, "conv=text"},
881 {Opt_obsolate, "conv=auto"},
882 {Opt_obsolate, "conv=b"},
883 {Opt_obsolate, "conv=t"},
884 {Opt_obsolate, "conv=a"},
885 {Opt_obsolate, "fat=%u"},
886 {Opt_obsolate, "blocksize=%u"},
887 {Opt_obsolate, "cvf_format=%20s"},
888 {Opt_obsolate, "cvf_options=%100s"},
889 {Opt_obsolate, "posix"},
890 {Opt_flush, "flush"},
893 static match_table_t msdos_tokens = {
894 {Opt_nodots, "nodots"},
895 {Opt_nodots, "dotsOK=no"},
897 {Opt_dots, "dotsOK=yes"},
900 static match_table_t vfat_tokens = {
901 {Opt_charset, "iocharset=%s"},
902 {Opt_shortname_lower, "shortname=lower"},
903 {Opt_shortname_win95, "shortname=win95"},
904 {Opt_shortname_winnt, "shortname=winnt"},
905 {Opt_shortname_mixed, "shortname=mixed"},
906 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
907 {Opt_utf8_no, "utf8=no"},
908 {Opt_utf8_no, "utf8=false"},
909 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
910 {Opt_utf8_yes, "utf8=yes"},
911 {Opt_utf8_yes, "utf8=true"},
912 {Opt_utf8_yes, "utf8"},
913 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
914 {Opt_uni_xl_no, "uni_xlate=no"},
915 {Opt_uni_xl_no, "uni_xlate=false"},
916 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
917 {Opt_uni_xl_yes, "uni_xlate=yes"},
918 {Opt_uni_xl_yes, "uni_xlate=true"},
919 {Opt_uni_xl_yes, "uni_xlate"},
920 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
921 {Opt_nonumtail_no, "nonumtail=no"},
922 {Opt_nonumtail_no, "nonumtail=false"},
923 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
924 {Opt_nonumtail_yes, "nonumtail=yes"},
925 {Opt_nonumtail_yes, "nonumtail=true"},
926 {Opt_nonumtail_yes, "nonumtail"},
930 static int parse_options(char *options, int is_vfat, int silent, int *debug,
931 struct fat_mount_options *opts)
934 substring_t args[MAX_OPT_ARGS];
938 opts->isvfat = is_vfat;
940 opts->fs_uid = current->uid;
941 opts->fs_gid = current->gid;
942 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
943 opts->codepage = fat_default_codepage;
944 opts->iocharset = fat_default_iocharset;
946 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
949 opts->name_check = 'n';
950 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
951 opts->utf8 = opts->unicode_xlate = 0;
959 while ((p = strsep(&options, ",")) != NULL) {
964 token = match_token(p, fat_tokens, args);
965 if (token == Opt_err) {
967 token = match_token(p, vfat_tokens, args);
969 token = match_token(p, msdos_tokens, args);
973 opts->name_check = 's';
976 opts->name_check = 'r';
979 opts->name_check = 'n';
985 /* for backward compatibility */
986 opts->shortname = VFAT_SFN_DISPLAY_WIN95
987 | VFAT_SFN_CREATE_WIN95;
1000 opts->sys_immutable = 1;
1003 if (match_int(&args[0], &option))
1005 opts->fs_uid = option;
1008 if (match_int(&args[0], &option))
1010 opts->fs_gid = option;
1013 if (match_octal(&args[0], &option))
1015 opts->fs_fmask = opts->fs_dmask = option;
1018 if (match_octal(&args[0], &option))
1020 opts->fs_dmask = option;
1023 if (match_octal(&args[0], &option))
1025 opts->fs_fmask = option;
1028 if (match_int(&args[0], &option))
1030 opts->codepage = option;
1036 /* msdos specific */
1046 if (opts->iocharset != fat_default_iocharset)
1047 kfree(opts->iocharset);
1048 iocharset = match_strdup(&args[0]);
1051 opts->iocharset = iocharset;
1053 case Opt_shortname_lower:
1054 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1055 | VFAT_SFN_CREATE_WIN95;
1057 case Opt_shortname_win95:
1058 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1059 | VFAT_SFN_CREATE_WIN95;
1061 case Opt_shortname_winnt:
1062 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1063 | VFAT_SFN_CREATE_WINNT;
1065 case Opt_shortname_mixed:
1066 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1067 | VFAT_SFN_CREATE_WIN95;
1069 case Opt_utf8_no: /* 0 or no or false */
1072 case Opt_utf8_yes: /* empty or 1 or yes or true */
1075 case Opt_uni_xl_no: /* 0 or no or false */
1076 opts->unicode_xlate = 0;
1078 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1079 opts->unicode_xlate = 1;
1081 case Opt_nonumtail_no: /* 0 or no or false */
1082 opts->numtail = 1; /* negated option */
1084 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1085 opts->numtail = 0; /* negated option */
1088 /* obsolete mount options */
1090 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1091 "not supported now\n", p);
1093 /* unknown option */
1097 "FAT: Unrecognized mount option \"%s\" "
1098 "or missing value\n", p);
1103 /* UTF-8 doesn't provide FAT semantics */
1104 if (!strcmp(opts->iocharset, "utf8")) {
1105 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1106 " for FAT filesystems, filesystem will be case sensitive!\n");
1109 if (opts->unicode_xlate)
1115 static int fat_read_root(struct inode *inode)
1117 struct super_block *sb = inode->i_sb;
1118 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1121 MSDOS_I(inode)->i_pos = 0;
1122 inode->i_uid = sbi->options.fs_uid;
1123 inode->i_gid = sbi->options.fs_gid;
1125 inode->i_generation = 0;
1126 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1127 inode->i_op = sbi->dir_ops;
1128 inode->i_fop = &fat_dir_operations;
1129 if (sbi->fat_bits == 32) {
1130 MSDOS_I(inode)->i_start = sbi->root_cluster;
1131 error = fat_calc_dir_size(inode);
1135 MSDOS_I(inode)->i_start = 0;
1136 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1138 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1139 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1140 MSDOS_I(inode)->i_logstart = 0;
1141 MSDOS_I(inode)->mmu_private = inode->i_size;
1143 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1144 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1145 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1146 inode->i_nlink = fat_subdirs(inode)+2;
1152 * Read the super block of an MS-DOS FS.
1154 int fat_fill_super(struct super_block *sb, void *data, int silent,
1155 const struct inode_operations *fs_dir_inode_ops, int isvfat)
1157 struct inode *root_inode = NULL;
1158 struct buffer_head *bh;
1159 struct fat_boot_sector *b;
1160 struct msdos_sb_info *sbi;
1161 u16 logical_sector_size;
1162 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1168 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1171 sb->s_fs_info = sbi;
1173 sb->s_flags |= MS_NODIRATIME;
1174 sb->s_magic = MSDOS_SUPER_MAGIC;
1175 sb->s_op = &fat_sops;
1176 sb->s_export_op = &fat_export_ops;
1177 sbi->dir_ops = fs_dir_inode_ops;
1179 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
1184 sb_min_blocksize(sb, 512);
1185 bh = sb_bread(sb, 0);
1187 printk(KERN_ERR "FAT: unable to read boot sector\n");
1191 b = (struct fat_boot_sector *) bh->b_data;
1194 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1200 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1206 * Earlier we checked here that b->secs_track and b->head are nonzero,
1207 * but it turns out valid FAT filesystems can have zero there.
1211 if (!FAT_VALID_MEDIA(media)) {
1213 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1218 logical_sector_size =
1219 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
1220 if (!logical_sector_size
1221 || (logical_sector_size & (logical_sector_size - 1))
1222 || (logical_sector_size < 512)
1223 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1225 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1226 logical_sector_size);
1230 sbi->sec_per_clus = b->sec_per_clus;
1231 if (!sbi->sec_per_clus
1232 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
1234 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1240 if (logical_sector_size < sb->s_blocksize) {
1241 printk(KERN_ERR "FAT: logical sector size too small for device"
1242 " (logical sector size = %u)\n", logical_sector_size);
1246 if (logical_sector_size > sb->s_blocksize) {
1249 if (!sb_set_blocksize(sb, logical_sector_size)) {
1250 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1251 logical_sector_size);
1254 bh = sb_bread(sb, 0);
1256 printk(KERN_ERR "FAT: unable to read boot sector"
1257 " (logical sector size = %lu)\n",
1261 b = (struct fat_boot_sector *) bh->b_data;
1264 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1265 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1266 sbi->fats = b->fats;
1267 sbi->fat_bits = 0; /* Don't know yet */
1268 sbi->fat_start = le16_to_cpu(b->reserved);
1269 sbi->fat_length = le16_to_cpu(b->fat_length);
1270 sbi->root_cluster = 0;
1271 sbi->free_clusters = -1; /* Don't know yet */
1272 sbi->prev_free = FAT_START_ENT;
1274 if (!sbi->fat_length && b->fat32_length) {
1275 struct fat_boot_fsinfo *fsinfo;
1276 struct buffer_head *fsinfo_bh;
1280 sbi->fat_length = le32_to_cpu(b->fat32_length);
1281 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1283 sb->s_maxbytes = 0xffffffff;
1285 /* MC - if info_sector is 0, don't multiply by 0 */
1286 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1287 if (sbi->fsinfo_sector == 0)
1288 sbi->fsinfo_sector = 1;
1290 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1291 if (fsinfo_bh == NULL) {
1292 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1293 " (sector = %lu)\n", sbi->fsinfo_sector);
1298 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1299 if (!IS_FSINFO(fsinfo)) {
1301 "FAT: Did not find valid FSINFO signature.\n"
1302 " Found signature1 0x%08x signature2 0x%08x"
1303 " (sector = %lu)\n",
1304 le32_to_cpu(fsinfo->signature1),
1305 le32_to_cpu(fsinfo->signature2),
1306 sbi->fsinfo_sector);
1308 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1309 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1315 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1316 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1318 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1320 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1321 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1323 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1324 " (%u)\n", sbi->dir_entries);
1329 rootdir_sectors = sbi->dir_entries
1330 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1331 sbi->data_start = sbi->dir_start + rootdir_sectors;
1332 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1333 if (total_sectors == 0)
1334 total_sectors = le32_to_cpu(b->total_sect);
1336 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1338 if (sbi->fat_bits != 32)
1339 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1341 /* check that FAT table does not overflow */
1342 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1343 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1344 if (total_clusters > MAX_FAT(sb)) {
1346 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1352 sbi->max_cluster = total_clusters + FAT_START_ENT;
1353 /* check the free_clusters, it's not necessarily correct */
1354 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1355 sbi->free_clusters = -1;
1356 /* check the prev_free, it's not necessarily correct */
1357 sbi->prev_free %= sbi->max_cluster;
1358 if (sbi->prev_free < FAT_START_ENT)
1359 sbi->prev_free = FAT_START_ENT;
1363 /* set up enough so that it can read an inode */
1365 fat_ent_access_init(sb);
1368 * The low byte of FAT's first entry must have same value with
1369 * media-field. But in real world, too many devices is
1370 * writing wrong value. So, removed that validity check.
1372 * if (FAT_FIRST_ENT(sb, media) != first)
1376 sprintf(buf, "cp%d", sbi->options.codepage);
1377 sbi->nls_disk = load_nls(buf);
1378 if (!sbi->nls_disk) {
1379 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1383 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1384 if (sbi->options.isvfat) {
1385 sbi->nls_io = load_nls(sbi->options.iocharset);
1387 printk(KERN_ERR "FAT: IO charset %s not found\n",
1388 sbi->options.iocharset);
1394 root_inode = new_inode(sb);
1397 root_inode->i_ino = MSDOS_ROOT_INO;
1398 root_inode->i_version = 1;
1399 error = fat_read_root(root_inode);
1403 insert_inode_hash(root_inode);
1404 sb->s_root = d_alloc_root(root_inode);
1406 printk(KERN_ERR "FAT: get root inode failed\n");
1415 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1416 " on dev %s.\n", sb->s_id);
1422 unload_nls(sbi->nls_io);
1424 unload_nls(sbi->nls_disk);
1425 if (sbi->options.iocharset != fat_default_iocharset)
1426 kfree(sbi->options.iocharset);
1427 sb->s_fs_info = NULL;
1432 EXPORT_SYMBOL_GPL(fat_fill_super);
1435 * helper function for fat_flush_inodes. This writes both the inode
1436 * and the file data blocks, waiting for in flight data blocks before
1437 * the start of the call. It does not wait for any io started
1440 static int writeback_inode(struct inode *inode)
1444 struct address_space *mapping = inode->i_mapping;
1445 struct writeback_control wbc = {
1446 .sync_mode = WB_SYNC_NONE,
1449 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1450 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1451 * and filemap_fdatawrite is used for the data blocks
1453 ret = sync_inode(inode, &wbc);
1455 ret = filemap_fdatawrite(mapping);
1460 * write data and metadata corresponding to i1 and i2. The io is
1461 * started but we do not wait for any of it to finish.
1463 * filemap_flush is used for the block device, so if there is a dirty
1464 * page for a block already in flight, we will not wait and start the
1467 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1470 if (!MSDOS_SB(sb)->options.flush)
1473 ret = writeback_inode(i1);
1475 ret = writeback_inode(i2);
1477 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1478 ret = filemap_flush(mapping);
1482 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1484 static int __init init_fat_fs(void)
1488 err = fat_cache_init();
1492 err = fat_init_inodecache();
1499 fat_cache_destroy();
1503 static void __exit exit_fat_fs(void)
1505 fat_cache_destroy();
1506 fat_destroy_inodecache();
1509 module_init(init_fat_fs)
1510 module_exit(exit_fat_fs)
1512 MODULE_LICENSE("GPL");