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 <asm/unaligned.h>
32 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
33 /* if user don't select VFAT, this is undefined. */
34 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
37 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
38 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
41 static int fat_add_cluster(struct inode *inode)
45 err = fat_alloc_clusters(inode, &cluster, 1);
48 /* FIXME: this cluster should be added after data of this
49 * cluster is writed */
50 err = fat_chain_add(inode, cluster, 1);
52 fat_free_clusters(inode, cluster);
56 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
57 unsigned long *max_blocks,
58 struct buffer_head *bh_result, int create)
60 struct super_block *sb = inode->i_sb;
61 struct msdos_sb_info *sbi = MSDOS_SB(sb);
62 unsigned long mapped_blocks;
66 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
70 map_bh(bh_result, sb, phys);
71 *max_blocks = min(mapped_blocks, *max_blocks);
77 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
78 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
79 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
83 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
85 /* TODO: multiple cluster allocation would be desirable. */
86 err = fat_add_cluster(inode);
90 /* available blocks on this cluster */
91 mapped_blocks = sbi->sec_per_clus - offset;
93 *max_blocks = min(mapped_blocks, *max_blocks);
94 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
96 err = fat_bmap(inode, iblock, &phys, &mapped_blocks);
101 BUG_ON(*max_blocks != mapped_blocks);
102 set_buffer_new(bh_result);
103 map_bh(bh_result, sb, phys);
108 static int fat_get_block(struct inode *inode, sector_t iblock,
109 struct buffer_head *bh_result, int create)
111 struct super_block *sb = inode->i_sb;
112 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
115 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
118 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
122 static int fat_writepage(struct page *page, struct writeback_control *wbc)
124 return block_write_full_page(page, fat_get_block, wbc);
127 static int fat_writepages(struct address_space *mapping,
128 struct writeback_control *wbc)
130 return mpage_writepages(mapping, wbc, fat_get_block);
133 static int fat_readpage(struct file *file, struct page *page)
135 return mpage_readpage(page, fat_get_block);
138 static int fat_readpages(struct file *file, struct address_space *mapping,
139 struct list_head *pages, unsigned nr_pages)
141 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
144 static int fat_write_begin(struct file *file, struct address_space *mapping,
145 loff_t pos, unsigned len, unsigned flags,
146 struct page **pagep, void **fsdata)
149 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
151 &MSDOS_I(mapping->host)->mmu_private);
154 static int fat_write_end(struct file *file, struct address_space *mapping,
155 loff_t pos, unsigned len, unsigned copied,
156 struct page *pagep, void *fsdata)
158 struct inode *inode = mapping->host;
160 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
161 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
162 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
163 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
164 mark_inode_dirty(inode);
169 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
170 const struct iovec *iov,
171 loff_t offset, unsigned long nr_segs)
173 struct file *file = iocb->ki_filp;
174 struct inode *inode = file->f_mapping->host;
178 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
179 * so we need to update the ->mmu_private to block boundary.
181 * But we must fill the remaining area or hole by nul for
182 * updating ->mmu_private.
184 * Return 0, and fallback to normal buffered write.
186 loff_t size = offset + iov_length(iov, nr_segs);
187 if (MSDOS_I(inode)->mmu_private < size)
192 * FAT need to use the DIO_LOCKING for avoiding the race
193 * condition of fat_get_block() and ->truncate().
195 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
196 offset, nr_segs, fat_get_block, NULL);
199 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
201 return generic_block_bmap(mapping, block, fat_get_block);
204 static const struct address_space_operations fat_aops = {
205 .readpage = fat_readpage,
206 .readpages = fat_readpages,
207 .writepage = fat_writepage,
208 .writepages = fat_writepages,
209 .sync_page = block_sync_page,
210 .write_begin = fat_write_begin,
211 .write_end = fat_write_end,
212 .direct_IO = fat_direct_IO,
217 * New FAT inode stuff. We do the following:
218 * a) i_ino is constant and has nothing with on-disk location.
219 * b) FAT manages its own cache of directory entries.
220 * c) *This* cache is indexed by on-disk location.
221 * d) inode has an associated directory entry, all right, but
222 * it may be unhashed.
223 * e) currently entries are stored within struct inode. That should
225 * f) we deal with races in the following way:
226 * 1. readdir() and lookup() do FAT-dir-cache lookup.
227 * 2. rename() unhashes the F-d-c entry and rehashes it in
229 * 3. unlink() and rmdir() unhash F-d-c entry.
230 * 4. fat_write_inode() checks whether the thing is unhashed.
231 * If it is we silently return. If it isn't we do bread(),
232 * check if the location is still valid and retry if it
233 * isn't. Otherwise we do changes.
234 * 5. Spinlock is used to protect hash/unhash/location check/lookup
235 * 6. fat_clear_inode() unhashes the F-d-c entry.
236 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
237 * and consider negative result as cache miss.
240 static void fat_hash_init(struct super_block *sb)
242 struct msdos_sb_info *sbi = MSDOS_SB(sb);
245 spin_lock_init(&sbi->inode_hash_lock);
246 for (i = 0; i < FAT_HASH_SIZE; i++)
247 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
250 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
252 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
253 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
254 return tmp & FAT_HASH_MASK;
257 void fat_attach(struct inode *inode, loff_t i_pos)
259 struct super_block *sb = inode->i_sb;
260 struct msdos_sb_info *sbi = MSDOS_SB(sb);
262 spin_lock(&sbi->inode_hash_lock);
263 MSDOS_I(inode)->i_pos = i_pos;
264 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
265 sbi->inode_hashtable + fat_hash(sb, i_pos));
266 spin_unlock(&sbi->inode_hash_lock);
269 EXPORT_SYMBOL_GPL(fat_attach);
271 void fat_detach(struct inode *inode)
273 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
274 spin_lock(&sbi->inode_hash_lock);
275 MSDOS_I(inode)->i_pos = 0;
276 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
277 spin_unlock(&sbi->inode_hash_lock);
280 EXPORT_SYMBOL_GPL(fat_detach);
282 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
284 struct msdos_sb_info *sbi = MSDOS_SB(sb);
285 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
286 struct hlist_node *_p;
287 struct msdos_inode_info *i;
288 struct inode *inode = NULL;
290 spin_lock(&sbi->inode_hash_lock);
291 hlist_for_each_entry(i, _p, head, i_fat_hash) {
292 BUG_ON(i->vfs_inode.i_sb != sb);
293 if (i->i_pos != i_pos)
295 inode = igrab(&i->vfs_inode);
299 spin_unlock(&sbi->inode_hash_lock);
303 static int is_exec(unsigned char *extension)
305 unsigned char *exe_extensions = "EXECOMBAT", *walk;
307 for (walk = exe_extensions; *walk; walk += 3)
308 if (!strncmp(extension, walk, 3))
313 static int fat_calc_dir_size(struct inode *inode)
315 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
316 int ret, fclus, dclus;
319 if (MSDOS_I(inode)->i_start == 0)
322 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
325 inode->i_size = (fclus + 1) << sbi->cluster_bits;
330 /* doesn't deal with root inode */
331 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
333 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
336 MSDOS_I(inode)->i_pos = 0;
337 inode->i_uid = sbi->options.fs_uid;
338 inode->i_gid = sbi->options.fs_gid;
340 inode->i_generation = get_seconds();
342 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
343 inode->i_generation &= ~1;
344 inode->i_mode = MSDOS_MKMODE(de->attr,
345 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
346 inode->i_op = sbi->dir_ops;
347 inode->i_fop = &fat_dir_operations;
349 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
350 if (sbi->fat_bits == 32)
351 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
353 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
354 error = fat_calc_dir_size(inode);
357 MSDOS_I(inode)->mmu_private = inode->i_size;
359 inode->i_nlink = fat_subdirs(inode);
360 } else { /* not a directory */
361 inode->i_generation |= 1;
362 inode->i_mode = MSDOS_MKMODE(de->attr,
363 ((sbi->options.showexec && !is_exec(de->name + 8))
364 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
365 & ~sbi->options.fs_fmask) | S_IFREG;
366 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
367 if (sbi->fat_bits == 32)
368 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
370 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
371 inode->i_size = le32_to_cpu(de->size);
372 inode->i_op = &fat_file_inode_operations;
373 inode->i_fop = &fat_file_operations;
374 inode->i_mapping->a_ops = &fat_aops;
375 MSDOS_I(inode)->mmu_private = inode->i_size;
377 if (de->attr & ATTR_SYS) {
378 if (sbi->options.sys_immutable)
379 inode->i_flags |= S_IMMUTABLE;
381 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
382 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
383 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
385 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
386 if (sbi->options.isvfat) {
387 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
388 de->cdate, de->ctime_cs);
389 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
391 inode->i_ctime = inode->i_atime = inode->i_mtime;
396 struct inode *fat_build_inode(struct super_block *sb,
397 struct msdos_dir_entry *de, loff_t i_pos)
402 inode = fat_iget(sb, i_pos);
405 inode = new_inode(sb);
407 inode = ERR_PTR(-ENOMEM);
410 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
411 inode->i_version = 1;
412 err = fat_fill_inode(inode, de);
415 inode = ERR_PTR(err);
418 fat_attach(inode, i_pos);
419 insert_inode_hash(inode);
424 EXPORT_SYMBOL_GPL(fat_build_inode);
426 static void fat_delete_inode(struct inode *inode)
428 truncate_inode_pages(&inode->i_data, 0);
434 static void fat_clear_inode(struct inode *inode)
436 struct super_block *sb = inode->i_sb;
437 struct msdos_sb_info *sbi = MSDOS_SB(sb);
439 spin_lock(&sbi->inode_hash_lock);
440 fat_cache_inval_inode(inode);
441 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
442 spin_unlock(&sbi->inode_hash_lock);
445 static void fat_write_super(struct super_block *sb)
449 if (!(sb->s_flags & MS_RDONLY))
450 fat_clusters_flush(sb);
453 static void fat_put_super(struct super_block *sb)
455 struct msdos_sb_info *sbi = MSDOS_SB(sb);
458 unload_nls(sbi->nls_disk);
459 sbi->nls_disk = NULL;
460 sbi->options.codepage = fat_default_codepage;
463 unload_nls(sbi->nls_io);
466 if (sbi->options.iocharset != fat_default_iocharset) {
467 kfree(sbi->options.iocharset);
468 sbi->options.iocharset = fat_default_iocharset;
471 sb->s_fs_info = NULL;
475 static struct kmem_cache *fat_inode_cachep;
477 static struct inode *fat_alloc_inode(struct super_block *sb)
479 struct msdos_inode_info *ei;
480 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
483 return &ei->vfs_inode;
486 static void fat_destroy_inode(struct inode *inode)
488 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
491 static void init_once(void *foo)
493 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
495 spin_lock_init(&ei->cache_lru_lock);
497 ei->cache_valid_id = FAT_CACHE_VALID + 1;
498 INIT_LIST_HEAD(&ei->cache_lru);
499 INIT_HLIST_NODE(&ei->i_fat_hash);
500 inode_init_once(&ei->vfs_inode);
503 static int __init fat_init_inodecache(void)
505 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
506 sizeof(struct msdos_inode_info),
507 0, (SLAB_RECLAIM_ACCOUNT|
510 if (fat_inode_cachep == NULL)
515 static void __exit fat_destroy_inodecache(void)
517 kmem_cache_destroy(fat_inode_cachep);
520 static int fat_remount(struct super_block *sb, int *flags, char *data)
522 struct msdos_sb_info *sbi = MSDOS_SB(sb);
523 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
527 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
529 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
531 /* If the count of free cluster is still unknown, counts it here. */
532 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
533 int err = fat_count_free_clusters(dentry->d_sb);
538 buf->f_type = dentry->d_sb->s_magic;
539 buf->f_bsize = sbi->cluster_size;
540 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
541 buf->f_bfree = sbi->free_clusters;
542 buf->f_bavail = sbi->free_clusters;
543 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
548 static int fat_write_inode(struct inode *inode, int wait)
550 struct super_block *sb = inode->i_sb;
551 struct msdos_sb_info *sbi = MSDOS_SB(sb);
552 struct buffer_head *bh;
553 struct msdos_dir_entry *raw_entry;
558 i_pos = MSDOS_I(inode)->i_pos;
559 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
562 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
564 printk(KERN_ERR "FAT: unable to read inode block "
565 "for updating (i_pos %lld)\n", i_pos);
568 spin_lock(&sbi->inode_hash_lock);
569 if (i_pos != MSDOS_I(inode)->i_pos) {
570 spin_unlock(&sbi->inode_hash_lock);
575 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
576 [i_pos & (sbi->dir_per_block - 1)];
577 if (S_ISDIR(inode->i_mode))
580 raw_entry->size = cpu_to_le32(inode->i_size);
581 raw_entry->attr = fat_attr(inode);
582 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
583 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
584 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
585 &raw_entry->date, NULL);
586 if (sbi->options.isvfat) {
588 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
589 &raw_entry->cdate, &raw_entry->ctime_cs);
590 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
591 &raw_entry->adate, NULL);
593 spin_unlock(&sbi->inode_hash_lock);
594 mark_buffer_dirty(bh);
597 err = sync_dirty_buffer(bh);
602 int fat_sync_inode(struct inode *inode)
604 return fat_write_inode(inode, 1);
607 EXPORT_SYMBOL_GPL(fat_sync_inode);
609 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
610 static const struct super_operations fat_sops = {
611 .alloc_inode = fat_alloc_inode,
612 .destroy_inode = fat_destroy_inode,
613 .write_inode = fat_write_inode,
614 .delete_inode = fat_delete_inode,
615 .put_super = fat_put_super,
616 .write_super = fat_write_super,
617 .statfs = fat_statfs,
618 .clear_inode = fat_clear_inode,
619 .remount_fs = fat_remount,
621 .show_options = fat_show_options,
625 * a FAT file handle with fhtype 3 is
626 * 0/ i_ino - for fast, reliable lookup if still in the cache
627 * 1/ i_generation - to see if i_ino is still valid
628 * bit 0 == 0 iff directory
629 * 2/ i_pos(8-39) - if ino has changed, but still in cache
630 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
631 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
633 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
634 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
635 * of i_logstart is used to store the directory entry offset.
638 static struct dentry *fat_fh_to_dentry(struct super_block *sb,
639 struct fid *fid, int fh_len, int fh_type)
641 struct inode *inode = NULL;
642 struct dentry *result;
645 if (fh_len < 5 || fh_type != 3)
648 inode = ilookup(sb, fh[0]);
649 if (!inode || inode->i_generation != fh[1]) {
656 int i_logstart = fh[3] & 0x0fffffff;
658 i_pos = (loff_t)fh[2] << 8;
659 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
661 /* try 2 - see if i_pos is in F-d-c
662 * require i_logstart to be the same
663 * Will fail if you truncate and then re-write
666 inode = fat_iget(sb, i_pos);
667 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
674 * For now, do nothing if the inode is not found.
676 * What we could do is:
678 * - follow the file starting at fh[4], and record the ".." entry,
679 * and the name of the fh[2] entry.
680 * - then follow the ".." file finding the next step up.
682 * This way we build a path to the root of the tree. If this works, we
683 * lookup the path and so get this inode into the cache. Finally try
684 * the fat_iget lookup again. If that fails, then we are totally out
685 * of luck. But all that is for another day
687 result = d_obtain_alias(inode);
689 result->d_op = sb->s_root->d_op;
694 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
697 struct inode *inode = de->d_inode;
698 u32 ipos_h, ipos_m, ipos_l;
701 return 255; /* no room */
703 ipos_h = MSDOS_I(inode)->i_pos >> 8;
704 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
705 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
707 fh[0] = inode->i_ino;
708 fh[1] = inode->i_generation;
710 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
711 spin_lock(&de->d_lock);
712 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
713 spin_unlock(&de->d_lock);
717 static struct dentry *fat_get_parent(struct dentry *child)
719 struct super_block *sb = child->d_sb;
720 struct buffer_head *bh;
721 struct msdos_dir_entry *de;
723 struct dentry *parent;
729 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
731 parent = ERR_PTR(err);
734 inode = fat_build_inode(sb, de, i_pos);
737 parent = d_obtain_alias(inode);
744 static const struct export_operations fat_export_ops = {
745 .encode_fh = fat_encode_fh,
746 .fh_to_dentry = fat_fh_to_dentry,
747 .get_parent = fat_get_parent,
750 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
752 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
753 struct fat_mount_options *opts = &sbi->options;
754 int isvfat = opts->isvfat;
756 if (opts->fs_uid != 0)
757 seq_printf(m, ",uid=%u", opts->fs_uid);
758 if (opts->fs_gid != 0)
759 seq_printf(m, ",gid=%u", opts->fs_gid);
760 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
761 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
762 if (opts->allow_utime)
763 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
765 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
768 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
770 switch (opts->shortname) {
771 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
772 seq_puts(m, ",shortname=win95");
774 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
775 seq_puts(m, ",shortname=winnt");
777 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
778 seq_puts(m, ",shortname=mixed");
780 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
781 /* seq_puts(m, ",shortname=lower"); */
784 seq_puts(m, ",shortname=unknown");
788 if (opts->name_check != 'n')
789 seq_printf(m, ",check=%c", opts->name_check);
791 seq_puts(m, ",usefree");
793 seq_puts(m, ",quiet");
795 seq_puts(m, ",showexec");
796 if (opts->sys_immutable)
797 seq_puts(m, ",sys_immutable");
800 seq_puts(m, ",dotsOK=yes");
802 seq_puts(m, ",nocase");
805 seq_puts(m, ",utf8");
806 if (opts->unicode_xlate)
807 seq_puts(m, ",uni_xlate");
809 seq_puts(m, ",nonumtail");
811 if (sbi->options.flush)
812 seq_puts(m, ",flush");
814 seq_puts(m, ",tz=UTC");
820 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
821 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
822 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
823 Opt_immutable, Opt_dots, Opt_nodots,
824 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
825 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
826 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
827 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_err,
830 static const match_table_t fat_tokens = {
831 {Opt_check_r, "check=relaxed"},
832 {Opt_check_s, "check=strict"},
833 {Opt_check_n, "check=normal"},
834 {Opt_check_r, "check=r"},
835 {Opt_check_s, "check=s"},
836 {Opt_check_n, "check=n"},
839 {Opt_umask, "umask=%o"},
840 {Opt_dmask, "dmask=%o"},
841 {Opt_fmask, "fmask=%o"},
842 {Opt_allow_utime, "allow_utime=%o"},
843 {Opt_codepage, "codepage=%u"},
844 {Opt_usefree, "usefree"},
845 {Opt_nocase, "nocase"},
846 {Opt_quiet, "quiet"},
847 {Opt_showexec, "showexec"},
848 {Opt_debug, "debug"},
849 {Opt_immutable, "sys_immutable"},
850 {Opt_obsolate, "conv=binary"},
851 {Opt_obsolate, "conv=text"},
852 {Opt_obsolate, "conv=auto"},
853 {Opt_obsolate, "conv=b"},
854 {Opt_obsolate, "conv=t"},
855 {Opt_obsolate, "conv=a"},
856 {Opt_obsolate, "fat=%u"},
857 {Opt_obsolate, "blocksize=%u"},
858 {Opt_obsolate, "cvf_format=%20s"},
859 {Opt_obsolate, "cvf_options=%100s"},
860 {Opt_obsolate, "posix"},
861 {Opt_flush, "flush"},
862 {Opt_tz_utc, "tz=UTC"},
865 static const match_table_t msdos_tokens = {
866 {Opt_nodots, "nodots"},
867 {Opt_nodots, "dotsOK=no"},
869 {Opt_dots, "dotsOK=yes"},
872 static const match_table_t vfat_tokens = {
873 {Opt_charset, "iocharset=%s"},
874 {Opt_shortname_lower, "shortname=lower"},
875 {Opt_shortname_win95, "shortname=win95"},
876 {Opt_shortname_winnt, "shortname=winnt"},
877 {Opt_shortname_mixed, "shortname=mixed"},
878 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
879 {Opt_utf8_no, "utf8=no"},
880 {Opt_utf8_no, "utf8=false"},
881 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
882 {Opt_utf8_yes, "utf8=yes"},
883 {Opt_utf8_yes, "utf8=true"},
884 {Opt_utf8_yes, "utf8"},
885 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
886 {Opt_uni_xl_no, "uni_xlate=no"},
887 {Opt_uni_xl_no, "uni_xlate=false"},
888 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
889 {Opt_uni_xl_yes, "uni_xlate=yes"},
890 {Opt_uni_xl_yes, "uni_xlate=true"},
891 {Opt_uni_xl_yes, "uni_xlate"},
892 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
893 {Opt_nonumtail_no, "nonumtail=no"},
894 {Opt_nonumtail_no, "nonumtail=false"},
895 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
896 {Opt_nonumtail_yes, "nonumtail=yes"},
897 {Opt_nonumtail_yes, "nonumtail=true"},
898 {Opt_nonumtail_yes, "nonumtail"},
902 static int parse_options(char *options, int is_vfat, int silent, int *debug,
903 struct fat_mount_options *opts)
906 substring_t args[MAX_OPT_ARGS];
910 opts->isvfat = is_vfat;
912 opts->fs_uid = current->uid;
913 opts->fs_gid = current->gid;
914 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
915 opts->allow_utime = -1;
916 opts->codepage = fat_default_codepage;
917 opts->iocharset = fat_default_iocharset;
919 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
922 opts->name_check = 'n';
923 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
924 opts->utf8 = opts->unicode_xlate = 0;
926 opts->usefree = opts->nocase = 0;
933 while ((p = strsep(&options, ",")) != NULL) {
938 token = match_token(p, fat_tokens, args);
939 if (token == Opt_err) {
941 token = match_token(p, vfat_tokens, args);
943 token = match_token(p, msdos_tokens, args);
947 opts->name_check = 's';
950 opts->name_check = 'r';
953 opts->name_check = 'n';
962 /* for backward compatibility */
963 opts->shortname = VFAT_SFN_DISPLAY_WIN95
964 | VFAT_SFN_CREATE_WIN95;
977 opts->sys_immutable = 1;
980 if (match_int(&args[0], &option))
982 opts->fs_uid = option;
985 if (match_int(&args[0], &option))
987 opts->fs_gid = option;
990 if (match_octal(&args[0], &option))
992 opts->fs_fmask = opts->fs_dmask = option;
995 if (match_octal(&args[0], &option))
997 opts->fs_dmask = option;
1000 if (match_octal(&args[0], &option))
1002 opts->fs_fmask = option;
1004 case Opt_allow_utime:
1005 if (match_octal(&args[0], &option))
1007 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1010 if (match_int(&args[0], &option))
1012 opts->codepage = option;
1021 /* msdos specific */
1031 if (opts->iocharset != fat_default_iocharset)
1032 kfree(opts->iocharset);
1033 iocharset = match_strdup(&args[0]);
1036 opts->iocharset = iocharset;
1038 case Opt_shortname_lower:
1039 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1040 | VFAT_SFN_CREATE_WIN95;
1042 case Opt_shortname_win95:
1043 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1044 | VFAT_SFN_CREATE_WIN95;
1046 case Opt_shortname_winnt:
1047 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1048 | VFAT_SFN_CREATE_WINNT;
1050 case Opt_shortname_mixed:
1051 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1052 | VFAT_SFN_CREATE_WIN95;
1054 case Opt_utf8_no: /* 0 or no or false */
1057 case Opt_utf8_yes: /* empty or 1 or yes or true */
1060 case Opt_uni_xl_no: /* 0 or no or false */
1061 opts->unicode_xlate = 0;
1063 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1064 opts->unicode_xlate = 1;
1066 case Opt_nonumtail_no: /* 0 or no or false */
1067 opts->numtail = 1; /* negated option */
1069 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1070 opts->numtail = 0; /* negated option */
1073 /* obsolete mount options */
1075 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1076 "not supported now\n", p);
1078 /* unknown option */
1082 "FAT: Unrecognized mount option \"%s\" "
1083 "or missing value\n", p);
1090 /* UTF-8 doesn't provide FAT semantics */
1091 if (!strcmp(opts->iocharset, "utf8")) {
1092 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1093 " for FAT filesystems, filesystem will be "
1094 "case sensitive!\n");
1097 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1098 if (opts->allow_utime == (unsigned short)-1)
1099 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1100 if (opts->unicode_xlate)
1106 static int fat_read_root(struct inode *inode)
1108 struct super_block *sb = inode->i_sb;
1109 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1112 MSDOS_I(inode)->i_pos = 0;
1113 inode->i_uid = sbi->options.fs_uid;
1114 inode->i_gid = sbi->options.fs_gid;
1116 inode->i_generation = 0;
1117 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1118 inode->i_op = sbi->dir_ops;
1119 inode->i_fop = &fat_dir_operations;
1120 if (sbi->fat_bits == 32) {
1121 MSDOS_I(inode)->i_start = sbi->root_cluster;
1122 error = fat_calc_dir_size(inode);
1126 MSDOS_I(inode)->i_start = 0;
1127 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1129 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1130 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1131 MSDOS_I(inode)->i_logstart = 0;
1132 MSDOS_I(inode)->mmu_private = inode->i_size;
1134 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1135 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1136 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1137 inode->i_nlink = fat_subdirs(inode)+2;
1143 * Read the super block of an MS-DOS FS.
1145 int fat_fill_super(struct super_block *sb, void *data, int silent,
1146 const struct inode_operations *fs_dir_inode_ops, int isvfat)
1148 struct inode *root_inode = NULL;
1149 struct buffer_head *bh;
1150 struct fat_boot_sector *b;
1151 struct msdos_sb_info *sbi;
1152 u16 logical_sector_size;
1153 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1160 * GFP_KERNEL is ok here, because while we do hold the
1161 * supeblock lock, memory pressure can't call back into
1162 * the filesystem, since we're only just about to mount
1163 * it and have no inodes etc active!
1165 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1168 sb->s_fs_info = sbi;
1170 sb->s_flags |= MS_NODIRATIME;
1171 sb->s_magic = MSDOS_SUPER_MAGIC;
1172 sb->s_op = &fat_sops;
1173 sb->s_export_op = &fat_export_ops;
1174 sbi->dir_ops = fs_dir_inode_ops;
1176 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
1181 sb_min_blocksize(sb, 512);
1182 bh = sb_bread(sb, 0);
1184 printk(KERN_ERR "FAT: unable to read boot sector\n");
1188 b = (struct fat_boot_sector *) bh->b_data;
1191 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1197 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1203 * Earlier we checked here that b->secs_track and b->head are nonzero,
1204 * but it turns out valid FAT filesystems can have zero there.
1208 if (!fat_valid_media(media)) {
1210 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1215 logical_sector_size = get_unaligned_le16(&b->sector_size);
1216 if (!is_power_of_2(logical_sector_size)
1217 || (logical_sector_size < 512)
1218 || (logical_sector_size > 4096)) {
1220 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1221 logical_sector_size);
1225 sbi->sec_per_clus = b->sec_per_clus;
1226 if (!is_power_of_2(sbi->sec_per_clus)) {
1228 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1234 if (logical_sector_size < sb->s_blocksize) {
1235 printk(KERN_ERR "FAT: logical sector size too small for device"
1236 " (logical sector size = %u)\n", logical_sector_size);
1240 if (logical_sector_size > sb->s_blocksize) {
1243 if (!sb_set_blocksize(sb, logical_sector_size)) {
1244 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1245 logical_sector_size);
1248 bh = sb_bread(sb, 0);
1250 printk(KERN_ERR "FAT: unable to read boot sector"
1251 " (logical sector size = %lu)\n",
1255 b = (struct fat_boot_sector *) bh->b_data;
1258 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1259 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1260 sbi->fats = b->fats;
1261 sbi->fat_bits = 0; /* Don't know yet */
1262 sbi->fat_start = le16_to_cpu(b->reserved);
1263 sbi->fat_length = le16_to_cpu(b->fat_length);
1264 sbi->root_cluster = 0;
1265 sbi->free_clusters = -1; /* Don't know yet */
1266 sbi->free_clus_valid = 0;
1267 sbi->prev_free = FAT_START_ENT;
1269 if (!sbi->fat_length && b->fat32_length) {
1270 struct fat_boot_fsinfo *fsinfo;
1271 struct buffer_head *fsinfo_bh;
1275 sbi->fat_length = le32_to_cpu(b->fat32_length);
1276 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1278 sb->s_maxbytes = 0xffffffff;
1280 /* MC - if info_sector is 0, don't multiply by 0 */
1281 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1282 if (sbi->fsinfo_sector == 0)
1283 sbi->fsinfo_sector = 1;
1285 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1286 if (fsinfo_bh == NULL) {
1287 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1288 " (sector = %lu)\n", sbi->fsinfo_sector);
1293 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1294 if (!IS_FSINFO(fsinfo)) {
1295 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1296 "0x%08x, 0x%08x (sector = %lu)\n",
1297 le32_to_cpu(fsinfo->signature1),
1298 le32_to_cpu(fsinfo->signature2),
1299 sbi->fsinfo_sector);
1301 if (sbi->options.usefree)
1302 sbi->free_clus_valid = 1;
1303 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1304 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1310 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1311 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1313 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1314 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1315 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1317 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1318 " (%u)\n", sbi->dir_entries);
1323 rootdir_sectors = sbi->dir_entries
1324 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1325 sbi->data_start = sbi->dir_start + rootdir_sectors;
1326 total_sectors = get_unaligned_le16(&b->sectors);
1327 if (total_sectors == 0)
1328 total_sectors = le32_to_cpu(b->total_sect);
1330 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1332 if (sbi->fat_bits != 32)
1333 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1335 /* check that FAT table does not overflow */
1336 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1337 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1338 if (total_clusters > MAX_FAT(sb)) {
1340 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1346 sbi->max_cluster = total_clusters + FAT_START_ENT;
1347 /* check the free_clusters, it's not necessarily correct */
1348 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1349 sbi->free_clusters = -1;
1350 /* check the prev_free, it's not necessarily correct */
1351 sbi->prev_free %= sbi->max_cluster;
1352 if (sbi->prev_free < FAT_START_ENT)
1353 sbi->prev_free = FAT_START_ENT;
1357 /* set up enough so that it can read an inode */
1359 fat_ent_access_init(sb);
1362 * The low byte of FAT's first entry must have same value with
1363 * media-field. But in real world, too many devices is
1364 * writing wrong value. So, removed that validity check.
1366 * if (FAT_FIRST_ENT(sb, media) != first)
1370 sprintf(buf, "cp%d", sbi->options.codepage);
1371 sbi->nls_disk = load_nls(buf);
1372 if (!sbi->nls_disk) {
1373 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1377 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1378 if (sbi->options.isvfat) {
1379 sbi->nls_io = load_nls(sbi->options.iocharset);
1381 printk(KERN_ERR "FAT: IO charset %s not found\n",
1382 sbi->options.iocharset);
1388 root_inode = new_inode(sb);
1391 root_inode->i_ino = MSDOS_ROOT_INO;
1392 root_inode->i_version = 1;
1393 error = fat_read_root(root_inode);
1397 insert_inode_hash(root_inode);
1398 sb->s_root = d_alloc_root(root_inode);
1400 printk(KERN_ERR "FAT: get root inode failed\n");
1409 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1410 " on dev %s.\n", sb->s_id);
1416 unload_nls(sbi->nls_io);
1418 unload_nls(sbi->nls_disk);
1419 if (sbi->options.iocharset != fat_default_iocharset)
1420 kfree(sbi->options.iocharset);
1421 sb->s_fs_info = NULL;
1426 EXPORT_SYMBOL_GPL(fat_fill_super);
1429 * helper function for fat_flush_inodes. This writes both the inode
1430 * and the file data blocks, waiting for in flight data blocks before
1431 * the start of the call. It does not wait for any io started
1434 static int writeback_inode(struct inode *inode)
1438 struct address_space *mapping = inode->i_mapping;
1439 struct writeback_control wbc = {
1440 .sync_mode = WB_SYNC_NONE,
1443 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1444 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1445 * and filemap_fdatawrite is used for the data blocks
1447 ret = sync_inode(inode, &wbc);
1449 ret = filemap_fdatawrite(mapping);
1454 * write data and metadata corresponding to i1 and i2. The io is
1455 * started but we do not wait for any of it to finish.
1457 * filemap_flush is used for the block device, so if there is a dirty
1458 * page for a block already in flight, we will not wait and start the
1461 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1464 if (!MSDOS_SB(sb)->options.flush)
1467 ret = writeback_inode(i1);
1469 ret = writeback_inode(i2);
1471 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1472 ret = filemap_flush(mapping);
1476 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1478 static int __init init_fat_fs(void)
1482 err = fat_cache_init();
1486 err = fat_init_inodecache();
1493 fat_cache_destroy();
1497 static void __exit exit_fat_fs(void)
1499 fat_cache_destroy();
1500 fat_destroy_inodecache();
1503 module_init(init_fat_fs)
1504 module_exit(exit_fat_fs)
1506 MODULE_LICENSE("GPL");