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/pagemap.h>
20 #include <linux/mpage.h>
21 #include <linux/buffer_head.h>
22 #include <linux/exportfs.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 <linux/log2.h>
29 #include <linux/hash.h>
30 #include <asm/unaligned.h>
33 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
34 /* if user don't select VFAT, this is undefined. */
35 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
38 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
39 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
42 static int fat_add_cluster(struct inode *inode)
46 err = fat_alloc_clusters(inode, &cluster, 1);
49 /* FIXME: this cluster should be added after data of this
50 * cluster is writed */
51 err = fat_chain_add(inode, cluster, 1);
53 fat_free_clusters(inode, cluster);
57 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
58 unsigned long *max_blocks,
59 struct buffer_head *bh_result, int create)
61 struct super_block *sb = inode->i_sb;
62 struct msdos_sb_info *sbi = MSDOS_SB(sb);
63 unsigned long mapped_blocks;
67 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
71 map_bh(bh_result, sb, phys);
72 *max_blocks = min(mapped_blocks, *max_blocks);
78 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
79 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
80 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
84 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
86 /* TODO: multiple cluster allocation would be desirable. */
87 err = fat_add_cluster(inode);
91 /* available blocks on this cluster */
92 mapped_blocks = sbi->sec_per_clus - offset;
94 *max_blocks = min(mapped_blocks, *max_blocks);
95 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
97 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
102 BUG_ON(*max_blocks != mapped_blocks);
103 set_buffer_new(bh_result);
104 map_bh(bh_result, sb, phys);
109 static int fat_get_block(struct inode *inode, sector_t iblock,
110 struct buffer_head *bh_result, int create)
112 struct super_block *sb = inode->i_sb;
113 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
116 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
119 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
123 static int fat_writepage(struct page *page, struct writeback_control *wbc)
125 return block_write_full_page(page, fat_get_block, wbc);
128 static int fat_writepages(struct address_space *mapping,
129 struct writeback_control *wbc)
131 return mpage_writepages(mapping, wbc, fat_get_block);
134 static int fat_readpage(struct file *file, struct page *page)
136 return mpage_readpage(page, fat_get_block);
139 static int fat_readpages(struct file *file, struct address_space *mapping,
140 struct list_head *pages, unsigned nr_pages)
142 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
145 static int fat_write_begin(struct file *file, struct address_space *mapping,
146 loff_t pos, unsigned len, unsigned flags,
147 struct page **pagep, void **fsdata)
150 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
152 &MSDOS_I(mapping->host)->mmu_private);
155 static int fat_write_end(struct file *file, struct address_space *mapping,
156 loff_t pos, unsigned len, unsigned copied,
157 struct page *pagep, void *fsdata)
159 struct inode *inode = mapping->host;
161 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
162 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
163 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
164 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
165 mark_inode_dirty(inode);
170 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
171 const struct iovec *iov,
172 loff_t offset, unsigned long nr_segs)
174 struct file *file = iocb->ki_filp;
175 struct inode *inode = file->f_mapping->host;
179 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
180 * so we need to update the ->mmu_private to block boundary.
182 * But we must fill the remaining area or hole by nul for
183 * updating ->mmu_private.
185 * Return 0, and fallback to normal buffered write.
187 loff_t size = offset + iov_length(iov, nr_segs);
188 if (MSDOS_I(inode)->mmu_private < size)
193 * FAT need to use the DIO_LOCKING for avoiding the race
194 * condition of fat_get_block() and ->truncate().
196 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
197 offset, nr_segs, fat_get_block, NULL);
200 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
202 return generic_block_bmap(mapping, block, fat_get_block);
205 static const struct address_space_operations fat_aops = {
206 .readpage = fat_readpage,
207 .readpages = fat_readpages,
208 .writepage = fat_writepage,
209 .writepages = fat_writepages,
210 .sync_page = block_sync_page,
211 .write_begin = fat_write_begin,
212 .write_end = fat_write_end,
213 .direct_IO = fat_direct_IO,
218 * New FAT inode stuff. We do the following:
219 * a) i_ino is constant and has nothing with on-disk location.
220 * b) FAT manages its own cache of directory entries.
221 * c) *This* cache is indexed by on-disk location.
222 * d) inode has an associated directory entry, all right, but
223 * it may be unhashed.
224 * e) currently entries are stored within struct inode. That should
226 * f) we deal with races in the following way:
227 * 1. readdir() and lookup() do FAT-dir-cache lookup.
228 * 2. rename() unhashes the F-d-c entry and rehashes it in
230 * 3. unlink() and rmdir() unhash F-d-c entry.
231 * 4. fat_write_inode() checks whether the thing is unhashed.
232 * If it is we silently return. If it isn't we do bread(),
233 * check if the location is still valid and retry if it
234 * isn't. Otherwise we do changes.
235 * 5. Spinlock is used to protect hash/unhash/location check/lookup
236 * 6. fat_clear_inode() unhashes the F-d-c entry.
237 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
238 * and consider negative result as cache miss.
241 static void fat_hash_init(struct super_block *sb)
243 struct msdos_sb_info *sbi = MSDOS_SB(sb);
246 spin_lock_init(&sbi->inode_hash_lock);
247 for (i = 0; i < FAT_HASH_SIZE; i++)
248 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
251 static inline unsigned long fat_hash(loff_t i_pos)
253 return hash_32(i_pos, FAT_HASH_BITS);
256 void fat_attach(struct inode *inode, loff_t i_pos)
258 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
259 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
261 spin_lock(&sbi->inode_hash_lock);
262 MSDOS_I(inode)->i_pos = i_pos;
263 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
264 spin_unlock(&sbi->inode_hash_lock);
266 EXPORT_SYMBOL_GPL(fat_attach);
268 void fat_detach(struct inode *inode)
270 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
271 spin_lock(&sbi->inode_hash_lock);
272 MSDOS_I(inode)->i_pos = 0;
273 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
274 spin_unlock(&sbi->inode_hash_lock);
276 EXPORT_SYMBOL_GPL(fat_detach);
278 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
280 struct msdos_sb_info *sbi = MSDOS_SB(sb);
281 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
282 struct hlist_node *_p;
283 struct msdos_inode_info *i;
284 struct inode *inode = NULL;
286 spin_lock(&sbi->inode_hash_lock);
287 hlist_for_each_entry(i, _p, head, i_fat_hash) {
288 BUG_ON(i->vfs_inode.i_sb != sb);
289 if (i->i_pos != i_pos)
291 inode = igrab(&i->vfs_inode);
295 spin_unlock(&sbi->inode_hash_lock);
299 static int is_exec(unsigned char *extension)
301 unsigned char *exe_extensions = "EXECOMBAT", *walk;
303 for (walk = exe_extensions; *walk; walk += 3)
304 if (!strncmp(extension, walk, 3))
309 static int fat_calc_dir_size(struct inode *inode)
311 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
312 int ret, fclus, dclus;
315 if (MSDOS_I(inode)->i_start == 0)
318 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
321 inode->i_size = (fclus + 1) << sbi->cluster_bits;
326 /* doesn't deal with root inode */
327 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
329 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
332 MSDOS_I(inode)->i_pos = 0;
333 inode->i_uid = sbi->options.fs_uid;
334 inode->i_gid = sbi->options.fs_gid;
336 inode->i_generation = get_seconds();
338 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
339 inode->i_generation &= ~1;
340 inode->i_mode = MSDOS_MKMODE(de->attr,
341 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
342 inode->i_op = sbi->dir_ops;
343 inode->i_fop = &fat_dir_operations;
345 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
346 if (sbi->fat_bits == 32)
347 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
349 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
350 error = fat_calc_dir_size(inode);
353 MSDOS_I(inode)->mmu_private = inode->i_size;
355 inode->i_nlink = fat_subdirs(inode);
356 } else { /* not a directory */
357 inode->i_generation |= 1;
358 inode->i_mode = MSDOS_MKMODE(de->attr,
359 ((sbi->options.showexec && !is_exec(de->name + 8))
360 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
361 & ~sbi->options.fs_fmask) | S_IFREG;
362 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
363 if (sbi->fat_bits == 32)
364 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
366 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
367 inode->i_size = le32_to_cpu(de->size);
368 inode->i_op = &fat_file_inode_operations;
369 inode->i_fop = &fat_file_operations;
370 inode->i_mapping->a_ops = &fat_aops;
371 MSDOS_I(inode)->mmu_private = inode->i_size;
373 if (de->attr & ATTR_SYS) {
374 if (sbi->options.sys_immutable)
375 inode->i_flags |= S_IMMUTABLE;
377 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
378 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
379 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
381 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
382 if (sbi->options.isvfat) {
383 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
384 de->cdate, de->ctime_cs);
385 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
387 inode->i_ctime = inode->i_atime = inode->i_mtime;
392 struct inode *fat_build_inode(struct super_block *sb,
393 struct msdos_dir_entry *de, loff_t i_pos)
398 inode = fat_iget(sb, i_pos);
401 inode = new_inode(sb);
403 inode = ERR_PTR(-ENOMEM);
406 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
407 inode->i_version = 1;
408 err = fat_fill_inode(inode, de);
411 inode = ERR_PTR(err);
414 fat_attach(inode, i_pos);
415 insert_inode_hash(inode);
420 EXPORT_SYMBOL_GPL(fat_build_inode);
422 static void fat_delete_inode(struct inode *inode)
424 truncate_inode_pages(&inode->i_data, 0);
430 static void fat_clear_inode(struct inode *inode)
432 struct super_block *sb = inode->i_sb;
433 struct msdos_sb_info *sbi = MSDOS_SB(sb);
435 spin_lock(&sbi->inode_hash_lock);
436 fat_cache_inval_inode(inode);
437 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
438 spin_unlock(&sbi->inode_hash_lock);
441 static void fat_write_super(struct super_block *sb)
445 if (!(sb->s_flags & MS_RDONLY))
446 fat_clusters_flush(sb);
449 static void fat_put_super(struct super_block *sb)
451 struct msdos_sb_info *sbi = MSDOS_SB(sb);
454 unload_nls(sbi->nls_disk);
455 sbi->nls_disk = NULL;
456 sbi->options.codepage = fat_default_codepage;
459 unload_nls(sbi->nls_io);
462 if (sbi->options.iocharset != fat_default_iocharset) {
463 kfree(sbi->options.iocharset);
464 sbi->options.iocharset = fat_default_iocharset;
467 sb->s_fs_info = NULL;
471 static struct kmem_cache *fat_inode_cachep;
473 static struct inode *fat_alloc_inode(struct super_block *sb)
475 struct msdos_inode_info *ei;
476 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
479 return &ei->vfs_inode;
482 static void fat_destroy_inode(struct inode *inode)
484 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
487 static void init_once(void *foo)
489 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
491 spin_lock_init(&ei->cache_lru_lock);
493 ei->cache_valid_id = FAT_CACHE_VALID + 1;
494 INIT_LIST_HEAD(&ei->cache_lru);
495 INIT_HLIST_NODE(&ei->i_fat_hash);
496 inode_init_once(&ei->vfs_inode);
499 static int __init fat_init_inodecache(void)
501 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
502 sizeof(struct msdos_inode_info),
503 0, (SLAB_RECLAIM_ACCOUNT|
506 if (fat_inode_cachep == NULL)
511 static void __exit fat_destroy_inodecache(void)
513 kmem_cache_destroy(fat_inode_cachep);
516 static int fat_remount(struct super_block *sb, int *flags, char *data)
518 struct msdos_sb_info *sbi = MSDOS_SB(sb);
519 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
523 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
525 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
527 /* If the count of free cluster is still unknown, counts it here. */
528 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
529 int err = fat_count_free_clusters(dentry->d_sb);
534 buf->f_type = dentry->d_sb->s_magic;
535 buf->f_bsize = sbi->cluster_size;
536 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
537 buf->f_bfree = sbi->free_clusters;
538 buf->f_bavail = sbi->free_clusters;
539 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
544 static int fat_write_inode(struct inode *inode, int wait)
546 struct super_block *sb = inode->i_sb;
547 struct msdos_sb_info *sbi = MSDOS_SB(sb);
548 struct buffer_head *bh;
549 struct msdos_dir_entry *raw_entry;
554 i_pos = MSDOS_I(inode)->i_pos;
555 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
558 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
560 printk(KERN_ERR "FAT: unable to read inode block "
561 "for updating (i_pos %lld)\n", i_pos);
564 spin_lock(&sbi->inode_hash_lock);
565 if (i_pos != MSDOS_I(inode)->i_pos) {
566 spin_unlock(&sbi->inode_hash_lock);
571 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
572 [i_pos & (sbi->dir_per_block - 1)];
573 if (S_ISDIR(inode->i_mode))
576 raw_entry->size = cpu_to_le32(inode->i_size);
577 raw_entry->attr = fat_attr(inode);
578 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
579 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
580 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
581 &raw_entry->date, NULL);
582 if (sbi->options.isvfat) {
584 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
585 &raw_entry->cdate, &raw_entry->ctime_cs);
586 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
587 &raw_entry->adate, NULL);
589 spin_unlock(&sbi->inode_hash_lock);
590 mark_buffer_dirty(bh);
593 err = sync_dirty_buffer(bh);
598 int fat_sync_inode(struct inode *inode)
600 return fat_write_inode(inode, 1);
603 EXPORT_SYMBOL_GPL(fat_sync_inode);
605 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
606 static const struct super_operations fat_sops = {
607 .alloc_inode = fat_alloc_inode,
608 .destroy_inode = fat_destroy_inode,
609 .write_inode = fat_write_inode,
610 .delete_inode = fat_delete_inode,
611 .put_super = fat_put_super,
612 .write_super = fat_write_super,
613 .statfs = fat_statfs,
614 .clear_inode = fat_clear_inode,
615 .remount_fs = fat_remount,
617 .show_options = fat_show_options,
621 * a FAT file handle with fhtype 3 is
622 * 0/ i_ino - for fast, reliable lookup if still in the cache
623 * 1/ i_generation - to see if i_ino is still valid
624 * bit 0 == 0 iff directory
625 * 2/ i_pos(8-39) - if ino has changed, but still in cache
626 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
627 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
629 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
630 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
631 * of i_logstart is used to store the directory entry offset.
634 static struct dentry *fat_fh_to_dentry(struct super_block *sb,
635 struct fid *fid, int fh_len, int fh_type)
637 struct inode *inode = NULL;
638 struct dentry *result;
641 if (fh_len < 5 || fh_type != 3)
644 inode = ilookup(sb, fh[0]);
645 if (!inode || inode->i_generation != fh[1]) {
652 int i_logstart = fh[3] & 0x0fffffff;
654 i_pos = (loff_t)fh[2] << 8;
655 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
657 /* try 2 - see if i_pos is in F-d-c
658 * require i_logstart to be the same
659 * Will fail if you truncate and then re-write
662 inode = fat_iget(sb, i_pos);
663 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
670 * For now, do nothing if the inode is not found.
672 * What we could do is:
674 * - follow the file starting at fh[4], and record the ".." entry,
675 * and the name of the fh[2] entry.
676 * - then follow the ".." file finding the next step up.
678 * This way we build a path to the root of the tree. If this works, we
679 * lookup the path and so get this inode into the cache. Finally try
680 * the fat_iget lookup again. If that fails, then we are totally out
681 * of luck. But all that is for another day
683 result = d_obtain_alias(inode);
685 result->d_op = sb->s_root->d_op;
690 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
693 struct inode *inode = de->d_inode;
694 u32 ipos_h, ipos_m, ipos_l;
697 return 255; /* no room */
699 ipos_h = MSDOS_I(inode)->i_pos >> 8;
700 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
701 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
703 fh[0] = inode->i_ino;
704 fh[1] = inode->i_generation;
706 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
707 spin_lock(&de->d_lock);
708 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
709 spin_unlock(&de->d_lock);
713 static struct dentry *fat_get_parent(struct dentry *child)
715 struct super_block *sb = child->d_sb;
716 struct buffer_head *bh;
717 struct msdos_dir_entry *de;
719 struct dentry *parent;
725 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
727 parent = ERR_PTR(err);
730 inode = fat_build_inode(sb, de, i_pos);
733 parent = d_obtain_alias(inode);
740 static const struct export_operations fat_export_ops = {
741 .encode_fh = fat_encode_fh,
742 .fh_to_dentry = fat_fh_to_dentry,
743 .get_parent = fat_get_parent,
746 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
748 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
749 struct fat_mount_options *opts = &sbi->options;
750 int isvfat = opts->isvfat;
752 if (opts->fs_uid != 0)
753 seq_printf(m, ",uid=%u", opts->fs_uid);
754 if (opts->fs_gid != 0)
755 seq_printf(m, ",gid=%u", opts->fs_gid);
756 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
757 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
758 if (opts->allow_utime)
759 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
761 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
764 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
766 switch (opts->shortname) {
767 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
768 seq_puts(m, ",shortname=win95");
770 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
771 seq_puts(m, ",shortname=winnt");
773 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
774 seq_puts(m, ",shortname=mixed");
776 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
777 /* seq_puts(m, ",shortname=lower"); */
780 seq_puts(m, ",shortname=unknown");
784 if (opts->name_check != 'n')
785 seq_printf(m, ",check=%c", opts->name_check);
787 seq_puts(m, ",usefree");
789 seq_puts(m, ",quiet");
791 seq_puts(m, ",showexec");
792 if (opts->sys_immutable)
793 seq_puts(m, ",sys_immutable");
796 seq_puts(m, ",dotsOK=yes");
798 seq_puts(m, ",nocase");
801 seq_puts(m, ",utf8");
802 if (opts->unicode_xlate)
803 seq_puts(m, ",uni_xlate");
805 seq_puts(m, ",nonumtail");
807 if (sbi->options.flush)
808 seq_puts(m, ",flush");
810 seq_puts(m, ",tz=UTC");
816 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
817 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
818 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
819 Opt_immutable, Opt_dots, Opt_nodots,
820 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
821 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
822 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
823 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_err,
826 static const match_table_t fat_tokens = {
827 {Opt_check_r, "check=relaxed"},
828 {Opt_check_s, "check=strict"},
829 {Opt_check_n, "check=normal"},
830 {Opt_check_r, "check=r"},
831 {Opt_check_s, "check=s"},
832 {Opt_check_n, "check=n"},
835 {Opt_umask, "umask=%o"},
836 {Opt_dmask, "dmask=%o"},
837 {Opt_fmask, "fmask=%o"},
838 {Opt_allow_utime, "allow_utime=%o"},
839 {Opt_codepage, "codepage=%u"},
840 {Opt_usefree, "usefree"},
841 {Opt_nocase, "nocase"},
842 {Opt_quiet, "quiet"},
843 {Opt_showexec, "showexec"},
844 {Opt_debug, "debug"},
845 {Opt_immutable, "sys_immutable"},
846 {Opt_obsolate, "conv=binary"},
847 {Opt_obsolate, "conv=text"},
848 {Opt_obsolate, "conv=auto"},
849 {Opt_obsolate, "conv=b"},
850 {Opt_obsolate, "conv=t"},
851 {Opt_obsolate, "conv=a"},
852 {Opt_obsolate, "fat=%u"},
853 {Opt_obsolate, "blocksize=%u"},
854 {Opt_obsolate, "cvf_format=%20s"},
855 {Opt_obsolate, "cvf_options=%100s"},
856 {Opt_obsolate, "posix"},
857 {Opt_flush, "flush"},
858 {Opt_tz_utc, "tz=UTC"},
861 static const match_table_t msdos_tokens = {
862 {Opt_nodots, "nodots"},
863 {Opt_nodots, "dotsOK=no"},
865 {Opt_dots, "dotsOK=yes"},
868 static const match_table_t vfat_tokens = {
869 {Opt_charset, "iocharset=%s"},
870 {Opt_shortname_lower, "shortname=lower"},
871 {Opt_shortname_win95, "shortname=win95"},
872 {Opt_shortname_winnt, "shortname=winnt"},
873 {Opt_shortname_mixed, "shortname=mixed"},
874 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
875 {Opt_utf8_no, "utf8=no"},
876 {Opt_utf8_no, "utf8=false"},
877 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
878 {Opt_utf8_yes, "utf8=yes"},
879 {Opt_utf8_yes, "utf8=true"},
880 {Opt_utf8_yes, "utf8"},
881 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
882 {Opt_uni_xl_no, "uni_xlate=no"},
883 {Opt_uni_xl_no, "uni_xlate=false"},
884 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
885 {Opt_uni_xl_yes, "uni_xlate=yes"},
886 {Opt_uni_xl_yes, "uni_xlate=true"},
887 {Opt_uni_xl_yes, "uni_xlate"},
888 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
889 {Opt_nonumtail_no, "nonumtail=no"},
890 {Opt_nonumtail_no, "nonumtail=false"},
891 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
892 {Opt_nonumtail_yes, "nonumtail=yes"},
893 {Opt_nonumtail_yes, "nonumtail=true"},
894 {Opt_nonumtail_yes, "nonumtail"},
898 static int parse_options(char *options, int is_vfat, int silent, int *debug,
899 struct fat_mount_options *opts)
902 substring_t args[MAX_OPT_ARGS];
906 opts->isvfat = is_vfat;
908 opts->fs_uid = current->uid;
909 opts->fs_gid = current->gid;
910 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
911 opts->allow_utime = -1;
912 opts->codepage = fat_default_codepage;
913 opts->iocharset = fat_default_iocharset;
915 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
918 opts->name_check = 'n';
919 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
920 opts->utf8 = opts->unicode_xlate = 0;
922 opts->usefree = opts->nocase = 0;
929 while ((p = strsep(&options, ",")) != NULL) {
934 token = match_token(p, fat_tokens, args);
935 if (token == Opt_err) {
937 token = match_token(p, vfat_tokens, args);
939 token = match_token(p, msdos_tokens, args);
943 opts->name_check = 's';
946 opts->name_check = 'r';
949 opts->name_check = 'n';
958 /* for backward compatibility */
959 opts->shortname = VFAT_SFN_DISPLAY_WIN95
960 | VFAT_SFN_CREATE_WIN95;
973 opts->sys_immutable = 1;
976 if (match_int(&args[0], &option))
978 opts->fs_uid = option;
981 if (match_int(&args[0], &option))
983 opts->fs_gid = option;
986 if (match_octal(&args[0], &option))
988 opts->fs_fmask = opts->fs_dmask = option;
991 if (match_octal(&args[0], &option))
993 opts->fs_dmask = option;
996 if (match_octal(&args[0], &option))
998 opts->fs_fmask = option;
1000 case Opt_allow_utime:
1001 if (match_octal(&args[0], &option))
1003 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1006 if (match_int(&args[0], &option))
1008 opts->codepage = option;
1017 /* msdos specific */
1027 if (opts->iocharset != fat_default_iocharset)
1028 kfree(opts->iocharset);
1029 iocharset = match_strdup(&args[0]);
1032 opts->iocharset = iocharset;
1034 case Opt_shortname_lower:
1035 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1036 | VFAT_SFN_CREATE_WIN95;
1038 case Opt_shortname_win95:
1039 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1040 | VFAT_SFN_CREATE_WIN95;
1042 case Opt_shortname_winnt:
1043 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1044 | VFAT_SFN_CREATE_WINNT;
1046 case Opt_shortname_mixed:
1047 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1048 | VFAT_SFN_CREATE_WIN95;
1050 case Opt_utf8_no: /* 0 or no or false */
1053 case Opt_utf8_yes: /* empty or 1 or yes or true */
1056 case Opt_uni_xl_no: /* 0 or no or false */
1057 opts->unicode_xlate = 0;
1059 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1060 opts->unicode_xlate = 1;
1062 case Opt_nonumtail_no: /* 0 or no or false */
1063 opts->numtail = 1; /* negated option */
1065 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1066 opts->numtail = 0; /* negated option */
1069 /* obsolete mount options */
1071 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1072 "not supported now\n", p);
1074 /* unknown option */
1078 "FAT: Unrecognized mount option \"%s\" "
1079 "or missing value\n", p);
1086 /* UTF-8 doesn't provide FAT semantics */
1087 if (!strcmp(opts->iocharset, "utf8")) {
1088 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1089 " for FAT filesystems, filesystem will be "
1090 "case sensitive!\n");
1093 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1094 if (opts->allow_utime == (unsigned short)-1)
1095 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1096 if (opts->unicode_xlate)
1102 static int fat_read_root(struct inode *inode)
1104 struct super_block *sb = inode->i_sb;
1105 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1108 MSDOS_I(inode)->i_pos = 0;
1109 inode->i_uid = sbi->options.fs_uid;
1110 inode->i_gid = sbi->options.fs_gid;
1112 inode->i_generation = 0;
1113 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1114 inode->i_op = sbi->dir_ops;
1115 inode->i_fop = &fat_dir_operations;
1116 if (sbi->fat_bits == 32) {
1117 MSDOS_I(inode)->i_start = sbi->root_cluster;
1118 error = fat_calc_dir_size(inode);
1122 MSDOS_I(inode)->i_start = 0;
1123 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1125 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1126 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1127 MSDOS_I(inode)->i_logstart = 0;
1128 MSDOS_I(inode)->mmu_private = inode->i_size;
1130 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1131 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1132 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1133 inode->i_nlink = fat_subdirs(inode)+2;
1139 * Read the super block of an MS-DOS FS.
1141 int fat_fill_super(struct super_block *sb, void *data, int silent,
1142 const struct inode_operations *fs_dir_inode_ops, int isvfat)
1144 struct inode *root_inode = NULL;
1145 struct buffer_head *bh;
1146 struct fat_boot_sector *b;
1147 struct msdos_sb_info *sbi;
1148 u16 logical_sector_size;
1149 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1156 * GFP_KERNEL is ok here, because while we do hold the
1157 * supeblock lock, memory pressure can't call back into
1158 * the filesystem, since we're only just about to mount
1159 * it and have no inodes etc active!
1161 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1164 sb->s_fs_info = sbi;
1166 sb->s_flags |= MS_NODIRATIME;
1167 sb->s_magic = MSDOS_SUPER_MAGIC;
1168 sb->s_op = &fat_sops;
1169 sb->s_export_op = &fat_export_ops;
1170 sbi->dir_ops = fs_dir_inode_ops;
1172 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
1177 sb_min_blocksize(sb, 512);
1178 bh = sb_bread(sb, 0);
1180 printk(KERN_ERR "FAT: unable to read boot sector\n");
1184 b = (struct fat_boot_sector *) bh->b_data;
1187 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1193 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1199 * Earlier we checked here that b->secs_track and b->head are nonzero,
1200 * but it turns out valid FAT filesystems can have zero there.
1204 if (!fat_valid_media(media)) {
1206 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1211 logical_sector_size = get_unaligned_le16(&b->sector_size);
1212 if (!is_power_of_2(logical_sector_size)
1213 || (logical_sector_size < 512)
1214 || (logical_sector_size > 4096)) {
1216 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1217 logical_sector_size);
1221 sbi->sec_per_clus = b->sec_per_clus;
1222 if (!is_power_of_2(sbi->sec_per_clus)) {
1224 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1230 if (logical_sector_size < sb->s_blocksize) {
1231 printk(KERN_ERR "FAT: logical sector size too small for device"
1232 " (logical sector size = %u)\n", logical_sector_size);
1236 if (logical_sector_size > sb->s_blocksize) {
1239 if (!sb_set_blocksize(sb, logical_sector_size)) {
1240 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1241 logical_sector_size);
1244 bh = sb_bread(sb, 0);
1246 printk(KERN_ERR "FAT: unable to read boot sector"
1247 " (logical sector size = %lu)\n",
1251 b = (struct fat_boot_sector *) bh->b_data;
1254 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1255 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1256 sbi->fats = b->fats;
1257 sbi->fat_bits = 0; /* Don't know yet */
1258 sbi->fat_start = le16_to_cpu(b->reserved);
1259 sbi->fat_length = le16_to_cpu(b->fat_length);
1260 sbi->root_cluster = 0;
1261 sbi->free_clusters = -1; /* Don't know yet */
1262 sbi->free_clus_valid = 0;
1263 sbi->prev_free = FAT_START_ENT;
1265 if (!sbi->fat_length && b->fat32_length) {
1266 struct fat_boot_fsinfo *fsinfo;
1267 struct buffer_head *fsinfo_bh;
1271 sbi->fat_length = le32_to_cpu(b->fat32_length);
1272 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1274 sb->s_maxbytes = 0xffffffff;
1276 /* MC - if info_sector is 0, don't multiply by 0 */
1277 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1278 if (sbi->fsinfo_sector == 0)
1279 sbi->fsinfo_sector = 1;
1281 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1282 if (fsinfo_bh == NULL) {
1283 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1284 " (sector = %lu)\n", sbi->fsinfo_sector);
1289 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1290 if (!IS_FSINFO(fsinfo)) {
1291 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1292 "0x%08x, 0x%08x (sector = %lu)\n",
1293 le32_to_cpu(fsinfo->signature1),
1294 le32_to_cpu(fsinfo->signature2),
1295 sbi->fsinfo_sector);
1297 if (sbi->options.usefree)
1298 sbi->free_clus_valid = 1;
1299 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1300 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1306 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1307 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1309 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1310 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1311 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1313 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1314 " (%u)\n", sbi->dir_entries);
1319 rootdir_sectors = sbi->dir_entries
1320 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1321 sbi->data_start = sbi->dir_start + rootdir_sectors;
1322 total_sectors = get_unaligned_le16(&b->sectors);
1323 if (total_sectors == 0)
1324 total_sectors = le32_to_cpu(b->total_sect);
1326 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1328 if (sbi->fat_bits != 32)
1329 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1331 /* check that FAT table does not overflow */
1332 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1333 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1334 if (total_clusters > MAX_FAT(sb)) {
1336 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1342 sbi->max_cluster = total_clusters + FAT_START_ENT;
1343 /* check the free_clusters, it's not necessarily correct */
1344 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1345 sbi->free_clusters = -1;
1346 /* check the prev_free, it's not necessarily correct */
1347 sbi->prev_free %= sbi->max_cluster;
1348 if (sbi->prev_free < FAT_START_ENT)
1349 sbi->prev_free = FAT_START_ENT;
1353 /* set up enough so that it can read an inode */
1355 fat_ent_access_init(sb);
1358 * The low byte of FAT's first entry must have same value with
1359 * media-field. But in real world, too many devices is
1360 * writing wrong value. So, removed that validity check.
1362 * if (FAT_FIRST_ENT(sb, media) != first)
1366 sprintf(buf, "cp%d", sbi->options.codepage);
1367 sbi->nls_disk = load_nls(buf);
1368 if (!sbi->nls_disk) {
1369 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1373 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1374 if (sbi->options.isvfat) {
1375 sbi->nls_io = load_nls(sbi->options.iocharset);
1377 printk(KERN_ERR "FAT: IO charset %s not found\n",
1378 sbi->options.iocharset);
1384 root_inode = new_inode(sb);
1387 root_inode->i_ino = MSDOS_ROOT_INO;
1388 root_inode->i_version = 1;
1389 error = fat_read_root(root_inode);
1393 insert_inode_hash(root_inode);
1394 sb->s_root = d_alloc_root(root_inode);
1396 printk(KERN_ERR "FAT: get root inode failed\n");
1405 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1406 " on dev %s.\n", sb->s_id);
1412 unload_nls(sbi->nls_io);
1414 unload_nls(sbi->nls_disk);
1415 if (sbi->options.iocharset != fat_default_iocharset)
1416 kfree(sbi->options.iocharset);
1417 sb->s_fs_info = NULL;
1422 EXPORT_SYMBOL_GPL(fat_fill_super);
1425 * helper function for fat_flush_inodes. This writes both the inode
1426 * and the file data blocks, waiting for in flight data blocks before
1427 * the start of the call. It does not wait for any io started
1430 static int writeback_inode(struct inode *inode)
1434 struct address_space *mapping = inode->i_mapping;
1435 struct writeback_control wbc = {
1436 .sync_mode = WB_SYNC_NONE,
1439 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1440 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1441 * and filemap_fdatawrite is used for the data blocks
1443 ret = sync_inode(inode, &wbc);
1445 ret = filemap_fdatawrite(mapping);
1450 * write data and metadata corresponding to i1 and i2. The io is
1451 * started but we do not wait for any of it to finish.
1453 * filemap_flush is used for the block device, so if there is a dirty
1454 * page for a block already in flight, we will not wait and start the
1457 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1460 if (!MSDOS_SB(sb)->options.flush)
1463 ret = writeback_inode(i1);
1465 ret = writeback_inode(i2);
1467 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1468 ret = filemap_flush(mapping);
1472 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1474 static int __init init_fat_fs(void)
1478 err = fat_cache_init();
1482 err = fat_init_inodecache();
1489 fat_cache_destroy();
1493 static void __exit exit_fat_fs(void)
1495 fat_cache_destroy();
1496 fat_destroy_inodecache();
1499 module_init(init_fat_fs)
1500 module_exit(exit_fat_fs)
1502 MODULE_LICENSE("GPL");