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/seq_file.h>
18 #include <linux/pagemap.h>
19 #include <linux/mpage.h>
20 #include <linux/buffer_head.h>
21 #include <linux/exportfs.h>
22 #include <linux/mount.h>
23 #include <linux/vfs.h>
24 #include <linux/parser.h>
25 #include <linux/uio.h>
26 #include <linux/writeback.h>
27 #include <linux/log2.h>
28 #include <linux/hash.h>
29 #include <linux/blkdev.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, create);
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_error(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, create);
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 void fat_write_failed(struct address_space *mapping, loff_t to)
147 struct inode *inode = mapping->host;
149 if (to > inode->i_size) {
150 truncate_pagecache(inode, to, inode->i_size);
151 fat_truncate_blocks(inode, inode->i_size);
155 static int fat_write_begin(struct file *file, struct address_space *mapping,
156 loff_t pos, unsigned len, unsigned flags,
157 struct page **pagep, void **fsdata)
162 err = cont_write_begin(file, mapping, pos, len, flags,
163 pagep, fsdata, fat_get_block,
164 &MSDOS_I(mapping->host)->mmu_private);
166 fat_write_failed(mapping, pos + len);
170 static int fat_write_end(struct file *file, struct address_space *mapping,
171 loff_t pos, unsigned len, unsigned copied,
172 struct page *pagep, void *fsdata)
174 struct inode *inode = mapping->host;
176 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
178 fat_write_failed(mapping, pos + len);
179 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
180 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
181 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
182 mark_inode_dirty(inode);
187 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
188 const struct iovec *iov,
189 loff_t offset, unsigned long nr_segs)
191 struct file *file = iocb->ki_filp;
192 struct address_space *mapping = file->f_mapping;
193 struct inode *inode = mapping->host;
198 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
199 * so we need to update the ->mmu_private to block boundary.
201 * But we must fill the remaining area or hole by nul for
202 * updating ->mmu_private.
204 * Return 0, and fallback to normal buffered write.
206 loff_t size = offset + iov_length(iov, nr_segs);
207 if (MSDOS_I(inode)->mmu_private < size)
212 * FAT need to use the DIO_LOCKING for avoiding the race
213 * condition of fat_get_block() and ->truncate().
215 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
217 if (ret < 0 && (rw & WRITE))
218 fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
223 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
227 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
228 down_read(&MSDOS_I(mapping->host)->truncate_lock);
229 blocknr = generic_block_bmap(mapping, block, fat_get_block);
230 up_read(&MSDOS_I(mapping->host)->truncate_lock);
235 static const struct address_space_operations fat_aops = {
236 .readpage = fat_readpage,
237 .readpages = fat_readpages,
238 .writepage = fat_writepage,
239 .writepages = fat_writepages,
240 .write_begin = fat_write_begin,
241 .write_end = fat_write_end,
242 .direct_IO = fat_direct_IO,
247 * New FAT inode stuff. We do the following:
248 * a) i_ino is constant and has nothing with on-disk location.
249 * b) FAT manages its own cache of directory entries.
250 * c) *This* cache is indexed by on-disk location.
251 * d) inode has an associated directory entry, all right, but
252 * it may be unhashed.
253 * e) currently entries are stored within struct inode. That should
255 * f) we deal with races in the following way:
256 * 1. readdir() and lookup() do FAT-dir-cache lookup.
257 * 2. rename() unhashes the F-d-c entry and rehashes it in
259 * 3. unlink() and rmdir() unhash F-d-c entry.
260 * 4. fat_write_inode() checks whether the thing is unhashed.
261 * If it is we silently return. If it isn't we do bread(),
262 * check if the location is still valid and retry if it
263 * isn't. Otherwise we do changes.
264 * 5. Spinlock is used to protect hash/unhash/location check/lookup
265 * 6. fat_evict_inode() unhashes the F-d-c entry.
266 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
267 * and consider negative result as cache miss.
270 static void fat_hash_init(struct super_block *sb)
272 struct msdos_sb_info *sbi = MSDOS_SB(sb);
275 spin_lock_init(&sbi->inode_hash_lock);
276 for (i = 0; i < FAT_HASH_SIZE; i++)
277 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
280 static inline unsigned long fat_hash(loff_t i_pos)
282 return hash_32(i_pos, FAT_HASH_BITS);
285 static void dir_hash_init(struct super_block *sb)
287 struct msdos_sb_info *sbi = MSDOS_SB(sb);
290 spin_lock_init(&sbi->dir_hash_lock);
291 for (i = 0; i < FAT_HASH_SIZE; i++)
292 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
295 void fat_attach(struct inode *inode, loff_t i_pos)
297 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
299 if (inode->i_ino != MSDOS_ROOT_INO) {
300 struct hlist_head *head = sbi->inode_hashtable
303 spin_lock(&sbi->inode_hash_lock);
304 MSDOS_I(inode)->i_pos = i_pos;
305 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
306 spin_unlock(&sbi->inode_hash_lock);
309 /* If NFS support is enabled, cache the mapping of start cluster
310 * to directory inode. This is used during reconnection of
311 * dentries to the filesystem root.
313 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
314 struct hlist_head *d_head = sbi->dir_hashtable;
315 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
317 spin_lock(&sbi->dir_hash_lock);
318 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
319 spin_unlock(&sbi->dir_hash_lock);
322 EXPORT_SYMBOL_GPL(fat_attach);
324 void fat_detach(struct inode *inode)
326 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
327 spin_lock(&sbi->inode_hash_lock);
328 MSDOS_I(inode)->i_pos = 0;
329 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
330 spin_unlock(&sbi->inode_hash_lock);
332 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
333 spin_lock(&sbi->dir_hash_lock);
334 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
335 spin_unlock(&sbi->dir_hash_lock);
338 EXPORT_SYMBOL_GPL(fat_detach);
340 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
342 struct msdos_sb_info *sbi = MSDOS_SB(sb);
343 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
344 struct hlist_node *_p;
345 struct msdos_inode_info *i;
346 struct inode *inode = NULL;
348 spin_lock(&sbi->inode_hash_lock);
349 hlist_for_each_entry(i, _p, head, i_fat_hash) {
350 BUG_ON(i->vfs_inode.i_sb != sb);
351 if (i->i_pos != i_pos)
353 inode = igrab(&i->vfs_inode);
357 spin_unlock(&sbi->inode_hash_lock);
361 static int is_exec(unsigned char *extension)
363 unsigned char *exe_extensions = "EXECOMBAT", *walk;
365 for (walk = exe_extensions; *walk; walk += 3)
366 if (!strncmp(extension, walk, 3))
371 static int fat_calc_dir_size(struct inode *inode)
373 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
374 int ret, fclus, dclus;
377 if (MSDOS_I(inode)->i_start == 0)
380 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
383 inode->i_size = (fclus + 1) << sbi->cluster_bits;
388 /* doesn't deal with root inode */
389 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
391 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
394 MSDOS_I(inode)->i_pos = 0;
395 inode->i_uid = sbi->options.fs_uid;
396 inode->i_gid = sbi->options.fs_gid;
398 inode->i_generation = get_seconds();
400 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
401 inode->i_generation &= ~1;
402 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
403 inode->i_op = sbi->dir_ops;
404 inode->i_fop = &fat_dir_operations;
406 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
407 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
408 error = fat_calc_dir_size(inode);
411 MSDOS_I(inode)->mmu_private = inode->i_size;
413 set_nlink(inode, fat_subdirs(inode));
414 } else { /* not a directory */
415 inode->i_generation |= 1;
416 inode->i_mode = fat_make_mode(sbi, de->attr,
417 ((sbi->options.showexec && !is_exec(de->name + 8))
418 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
419 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
421 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
422 inode->i_size = le32_to_cpu(de->size);
423 inode->i_op = &fat_file_inode_operations;
424 inode->i_fop = &fat_file_operations;
425 inode->i_mapping->a_ops = &fat_aops;
426 MSDOS_I(inode)->mmu_private = inode->i_size;
428 if (de->attr & ATTR_SYS) {
429 if (sbi->options.sys_immutable)
430 inode->i_flags |= S_IMMUTABLE;
432 fat_save_attrs(inode, de->attr);
434 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
435 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
437 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
438 if (sbi->options.isvfat) {
439 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
440 de->cdate, de->ctime_cs);
441 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
443 inode->i_ctime = inode->i_atime = inode->i_mtime;
448 struct inode *fat_build_inode(struct super_block *sb,
449 struct msdos_dir_entry *de, loff_t i_pos)
454 inode = fat_iget(sb, i_pos);
457 inode = new_inode(sb);
459 inode = ERR_PTR(-ENOMEM);
462 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
463 inode->i_version = 1;
464 err = fat_fill_inode(inode, de);
467 inode = ERR_PTR(err);
470 fat_attach(inode, i_pos);
471 insert_inode_hash(inode);
476 EXPORT_SYMBOL_GPL(fat_build_inode);
478 static void fat_evict_inode(struct inode *inode)
480 truncate_inode_pages(&inode->i_data, 0);
481 if (!inode->i_nlink) {
483 fat_truncate_blocks(inode, 0);
485 invalidate_inode_buffers(inode);
487 fat_cache_inval_inode(inode);
491 static void fat_put_super(struct super_block *sb)
493 struct msdos_sb_info *sbi = MSDOS_SB(sb);
495 iput(sbi->fsinfo_inode);
496 iput(sbi->fat_inode);
498 unload_nls(sbi->nls_disk);
499 unload_nls(sbi->nls_io);
501 if (sbi->options.iocharset != fat_default_iocharset)
502 kfree(sbi->options.iocharset);
504 sb->s_fs_info = NULL;
508 static struct kmem_cache *fat_inode_cachep;
510 static struct inode *fat_alloc_inode(struct super_block *sb)
512 struct msdos_inode_info *ei;
513 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
517 init_rwsem(&ei->truncate_lock);
518 return &ei->vfs_inode;
521 static void fat_i_callback(struct rcu_head *head)
523 struct inode *inode = container_of(head, struct inode, i_rcu);
524 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
527 static void fat_destroy_inode(struct inode *inode)
529 call_rcu(&inode->i_rcu, fat_i_callback);
532 static void init_once(void *foo)
534 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
536 spin_lock_init(&ei->cache_lru_lock);
538 ei->cache_valid_id = FAT_CACHE_VALID + 1;
539 INIT_LIST_HEAD(&ei->cache_lru);
540 INIT_HLIST_NODE(&ei->i_fat_hash);
541 INIT_HLIST_NODE(&ei->i_dir_hash);
542 inode_init_once(&ei->vfs_inode);
545 static int __init fat_init_inodecache(void)
547 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
548 sizeof(struct msdos_inode_info),
549 0, (SLAB_RECLAIM_ACCOUNT|
552 if (fat_inode_cachep == NULL)
557 static void __exit fat_destroy_inodecache(void)
560 * Make sure all delayed rcu free inodes are flushed before we
564 kmem_cache_destroy(fat_inode_cachep);
567 static int fat_remount(struct super_block *sb, int *flags, char *data)
569 struct msdos_sb_info *sbi = MSDOS_SB(sb);
570 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
574 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
576 struct super_block *sb = dentry->d_sb;
577 struct msdos_sb_info *sbi = MSDOS_SB(sb);
578 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
580 /* If the count of free cluster is still unknown, counts it here. */
581 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
582 int err = fat_count_free_clusters(dentry->d_sb);
587 buf->f_type = dentry->d_sb->s_magic;
588 buf->f_bsize = sbi->cluster_size;
589 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
590 buf->f_bfree = sbi->free_clusters;
591 buf->f_bavail = sbi->free_clusters;
592 buf->f_fsid.val[0] = (u32)id;
593 buf->f_fsid.val[1] = (u32)(id >> 32);
595 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
600 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
604 #if BITS_PER_LONG == 32
605 spin_lock(&sbi->inode_hash_lock);
607 i_pos = MSDOS_I(inode)->i_pos;
608 #if BITS_PER_LONG == 32
609 spin_unlock(&sbi->inode_hash_lock);
614 static int __fat_write_inode(struct inode *inode, int wait)
616 struct super_block *sb = inode->i_sb;
617 struct msdos_sb_info *sbi = MSDOS_SB(sb);
618 struct buffer_head *bh;
619 struct msdos_dir_entry *raw_entry;
623 if (inode->i_ino == MSDOS_ROOT_INO)
627 i_pos = fat_i_pos_read(sbi, inode);
631 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
633 fat_msg(sb, KERN_ERR, "unable to read inode block "
634 "for updating (i_pos %lld)", i_pos);
637 spin_lock(&sbi->inode_hash_lock);
638 if (i_pos != MSDOS_I(inode)->i_pos) {
639 spin_unlock(&sbi->inode_hash_lock);
644 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
645 [i_pos & (sbi->dir_per_block - 1)];
646 if (S_ISDIR(inode->i_mode))
649 raw_entry->size = cpu_to_le32(inode->i_size);
650 raw_entry->attr = fat_make_attrs(inode);
651 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
652 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
653 &raw_entry->date, NULL);
654 if (sbi->options.isvfat) {
656 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
657 &raw_entry->cdate, &raw_entry->ctime_cs);
658 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
659 &raw_entry->adate, NULL);
661 spin_unlock(&sbi->inode_hash_lock);
662 mark_buffer_dirty(bh);
665 err = sync_dirty_buffer(bh);
670 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
674 if (inode->i_ino == MSDOS_FSINFO_INO) {
675 struct super_block *sb = inode->i_sb;
677 mutex_lock(&MSDOS_SB(sb)->s_lock);
678 err = fat_clusters_flush(sb);
679 mutex_unlock(&MSDOS_SB(sb)->s_lock);
681 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
686 int fat_sync_inode(struct inode *inode)
688 return __fat_write_inode(inode, 1);
691 EXPORT_SYMBOL_GPL(fat_sync_inode);
693 static int fat_show_options(struct seq_file *m, struct dentry *root);
694 static const struct super_operations fat_sops = {
695 .alloc_inode = fat_alloc_inode,
696 .destroy_inode = fat_destroy_inode,
697 .write_inode = fat_write_inode,
698 .evict_inode = fat_evict_inode,
699 .put_super = fat_put_super,
700 .statfs = fat_statfs,
701 .remount_fs = fat_remount,
703 .show_options = fat_show_options,
706 static const struct export_operations fat_export_ops = {
707 .fh_to_dentry = fat_fh_to_dentry,
708 .fh_to_parent = fat_fh_to_parent,
709 .get_parent = fat_get_parent,
712 static int fat_show_options(struct seq_file *m, struct dentry *root)
714 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
715 struct fat_mount_options *opts = &sbi->options;
716 int isvfat = opts->isvfat;
718 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
719 seq_printf(m, ",uid=%u",
720 from_kuid_munged(&init_user_ns, opts->fs_uid));
721 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
722 seq_printf(m, ",gid=%u",
723 from_kgid_munged(&init_user_ns, opts->fs_gid));
724 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
725 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
726 if (opts->allow_utime)
727 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
729 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
732 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
734 switch (opts->shortname) {
735 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
736 seq_puts(m, ",shortname=win95");
738 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
739 seq_puts(m, ",shortname=winnt");
741 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
742 seq_puts(m, ",shortname=mixed");
744 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
745 seq_puts(m, ",shortname=lower");
748 seq_puts(m, ",shortname=unknown");
752 if (opts->name_check != 'n')
753 seq_printf(m, ",check=%c", opts->name_check);
755 seq_puts(m, ",usefree");
757 seq_puts(m, ",quiet");
761 seq_puts(m, ",showexec");
762 if (opts->sys_immutable)
763 seq_puts(m, ",sys_immutable");
766 seq_puts(m, ",dotsOK=yes");
768 seq_puts(m, ",nocase");
771 seq_puts(m, ",utf8");
772 if (opts->unicode_xlate)
773 seq_puts(m, ",uni_xlate");
775 seq_puts(m, ",nonumtail");
777 seq_puts(m, ",rodir");
780 seq_puts(m, ",flush");
782 if (opts->time_offset)
783 seq_printf(m, ",time_offset=%d", opts->time_offset);
785 seq_puts(m, ",tz=UTC");
787 if (opts->errors == FAT_ERRORS_CONT)
788 seq_puts(m, ",errors=continue");
789 else if (opts->errors == FAT_ERRORS_PANIC)
790 seq_puts(m, ",errors=panic");
792 seq_puts(m, ",errors=remount-ro");
794 seq_puts(m, ",discard");
800 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
801 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
802 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
803 Opt_immutable, Opt_dots, Opt_nodots,
804 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
805 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
806 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
807 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
808 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
812 static const match_table_t fat_tokens = {
813 {Opt_check_r, "check=relaxed"},
814 {Opt_check_s, "check=strict"},
815 {Opt_check_n, "check=normal"},
816 {Opt_check_r, "check=r"},
817 {Opt_check_s, "check=s"},
818 {Opt_check_n, "check=n"},
821 {Opt_umask, "umask=%o"},
822 {Opt_dmask, "dmask=%o"},
823 {Opt_fmask, "fmask=%o"},
824 {Opt_allow_utime, "allow_utime=%o"},
825 {Opt_codepage, "codepage=%u"},
826 {Opt_usefree, "usefree"},
827 {Opt_nocase, "nocase"},
828 {Opt_quiet, "quiet"},
829 {Opt_showexec, "showexec"},
830 {Opt_debug, "debug"},
831 {Opt_immutable, "sys_immutable"},
832 {Opt_flush, "flush"},
833 {Opt_tz_utc, "tz=UTC"},
834 {Opt_time_offset, "time_offset=%d"},
835 {Opt_err_cont, "errors=continue"},
836 {Opt_err_panic, "errors=panic"},
837 {Opt_err_ro, "errors=remount-ro"},
838 {Opt_discard, "discard"},
840 {Opt_obsolete, "conv=binary"},
841 {Opt_obsolete, "conv=text"},
842 {Opt_obsolete, "conv=auto"},
843 {Opt_obsolete, "conv=b"},
844 {Opt_obsolete, "conv=t"},
845 {Opt_obsolete, "conv=a"},
846 {Opt_obsolete, "fat=%u"},
847 {Opt_obsolete, "blocksize=%u"},
848 {Opt_obsolete, "cvf_format=%20s"},
849 {Opt_obsolete, "cvf_options=%100s"},
850 {Opt_obsolete, "posix"},
853 static const match_table_t msdos_tokens = {
854 {Opt_nodots, "nodots"},
855 {Opt_nodots, "dotsOK=no"},
857 {Opt_dots, "dotsOK=yes"},
860 static const match_table_t vfat_tokens = {
861 {Opt_charset, "iocharset=%s"},
862 {Opt_shortname_lower, "shortname=lower"},
863 {Opt_shortname_win95, "shortname=win95"},
864 {Opt_shortname_winnt, "shortname=winnt"},
865 {Opt_shortname_mixed, "shortname=mixed"},
866 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
867 {Opt_utf8_no, "utf8=no"},
868 {Opt_utf8_no, "utf8=false"},
869 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
870 {Opt_utf8_yes, "utf8=yes"},
871 {Opt_utf8_yes, "utf8=true"},
872 {Opt_utf8_yes, "utf8"},
873 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
874 {Opt_uni_xl_no, "uni_xlate=no"},
875 {Opt_uni_xl_no, "uni_xlate=false"},
876 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
877 {Opt_uni_xl_yes, "uni_xlate=yes"},
878 {Opt_uni_xl_yes, "uni_xlate=true"},
879 {Opt_uni_xl_yes, "uni_xlate"},
880 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
881 {Opt_nonumtail_no, "nonumtail=no"},
882 {Opt_nonumtail_no, "nonumtail=false"},
883 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
884 {Opt_nonumtail_yes, "nonumtail=yes"},
885 {Opt_nonumtail_yes, "nonumtail=true"},
886 {Opt_nonumtail_yes, "nonumtail"},
887 {Opt_rodir, "rodir"},
891 static int parse_options(struct super_block *sb, char *options, int is_vfat,
892 int silent, int *debug, struct fat_mount_options *opts)
895 substring_t args[MAX_OPT_ARGS];
899 opts->isvfat = is_vfat;
901 opts->fs_uid = current_uid();
902 opts->fs_gid = current_gid();
903 opts->fs_fmask = opts->fs_dmask = current_umask();
904 opts->allow_utime = -1;
905 opts->codepage = fat_default_codepage;
906 opts->iocharset = fat_default_iocharset;
908 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
914 opts->name_check = 'n';
915 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
916 opts->utf8 = opts->unicode_xlate = 0;
918 opts->usefree = opts->nocase = 0;
921 opts->errors = FAT_ERRORS_RO;
927 while ((p = strsep(&options, ",")) != NULL) {
932 token = match_token(p, fat_tokens, args);
933 if (token == Opt_err) {
935 token = match_token(p, vfat_tokens, args);
937 token = match_token(p, msdos_tokens, args);
941 opts->name_check = 's';
944 opts->name_check = 'r';
947 opts->name_check = 'n';
956 /* for backward compatibility */
957 opts->shortname = VFAT_SFN_DISPLAY_WIN95
958 | VFAT_SFN_CREATE_WIN95;
971 opts->sys_immutable = 1;
974 if (match_int(&args[0], &option))
976 opts->fs_uid = make_kuid(current_user_ns(), option);
977 if (!uid_valid(opts->fs_uid))
981 if (match_int(&args[0], &option))
983 opts->fs_gid = make_kgid(current_user_ns(), option);
984 if (!gid_valid(opts->fs_gid))
988 if (match_octal(&args[0], &option))
990 opts->fs_fmask = opts->fs_dmask = option;
993 if (match_octal(&args[0], &option))
995 opts->fs_dmask = option;
998 if (match_octal(&args[0], &option))
1000 opts->fs_fmask = option;
1002 case Opt_allow_utime:
1003 if (match_octal(&args[0], &option))
1005 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1008 if (match_int(&args[0], &option))
1010 opts->codepage = option;
1015 case Opt_time_offset:
1016 if (match_int(&args[0], &option))
1018 if (option < -12 * 60 || option > 12 * 60)
1021 opts->time_offset = option;
1025 opts->time_offset = 0;
1028 opts->errors = FAT_ERRORS_CONT;
1031 opts->errors = FAT_ERRORS_PANIC;
1034 opts->errors = FAT_ERRORS_RO;
1037 /* msdos specific */
1047 if (opts->iocharset != fat_default_iocharset)
1048 kfree(opts->iocharset);
1049 iocharset = match_strdup(&args[0]);
1052 opts->iocharset = iocharset;
1054 case Opt_shortname_lower:
1055 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1056 | VFAT_SFN_CREATE_WIN95;
1058 case Opt_shortname_win95:
1059 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1060 | VFAT_SFN_CREATE_WIN95;
1062 case Opt_shortname_winnt:
1063 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1064 | VFAT_SFN_CREATE_WINNT;
1066 case Opt_shortname_mixed:
1067 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1068 | VFAT_SFN_CREATE_WIN95;
1070 case Opt_utf8_no: /* 0 or no or false */
1073 case Opt_utf8_yes: /* empty or 1 or yes or true */
1076 case Opt_uni_xl_no: /* 0 or no or false */
1077 opts->unicode_xlate = 0;
1079 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1080 opts->unicode_xlate = 1;
1082 case Opt_nonumtail_no: /* 0 or no or false */
1083 opts->numtail = 1; /* negated option */
1085 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1086 opts->numtail = 0; /* negated option */
1098 /* obsolete mount options */
1100 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1101 "not supported now", p);
1103 /* unknown option */
1106 fat_msg(sb, KERN_ERR,
1107 "Unrecognized mount option \"%s\" "
1108 "or missing value", p);
1115 /* UTF-8 doesn't provide FAT semantics */
1116 if (!strcmp(opts->iocharset, "utf8")) {
1117 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1118 " for FAT filesystems, filesystem will be "
1122 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1123 if (opts->allow_utime == (unsigned short)-1)
1124 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1125 if (opts->unicode_xlate)
1131 static int fat_read_root(struct inode *inode)
1133 struct super_block *sb = inode->i_sb;
1134 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1137 MSDOS_I(inode)->i_pos = 0;
1138 inode->i_uid = sbi->options.fs_uid;
1139 inode->i_gid = sbi->options.fs_gid;
1141 inode->i_generation = 0;
1142 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1143 inode->i_op = sbi->dir_ops;
1144 inode->i_fop = &fat_dir_operations;
1145 if (sbi->fat_bits == 32) {
1146 MSDOS_I(inode)->i_start = sbi->root_cluster;
1147 error = fat_calc_dir_size(inode);
1151 MSDOS_I(inode)->i_start = 0;
1152 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1154 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1155 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1156 MSDOS_I(inode)->i_logstart = 0;
1157 MSDOS_I(inode)->mmu_private = inode->i_size;
1159 fat_save_attrs(inode, ATTR_DIR);
1160 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1161 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1162 set_nlink(inode, fat_subdirs(inode)+2);
1168 * Read the super block of an MS-DOS FS.
1170 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1171 void (*setup)(struct super_block *))
1173 struct inode *root_inode = NULL, *fat_inode = NULL;
1174 struct inode *fsinfo_inode = NULL;
1175 struct buffer_head *bh;
1176 struct fat_boot_sector *b;
1177 struct msdos_sb_info *sbi;
1178 u16 logical_sector_size;
1179 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1186 * GFP_KERNEL is ok here, because while we do hold the
1187 * supeblock lock, memory pressure can't call back into
1188 * the filesystem, since we're only just about to mount
1189 * it and have no inodes etc active!
1191 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1194 sb->s_fs_info = sbi;
1196 sb->s_flags |= MS_NODIRATIME;
1197 sb->s_magic = MSDOS_SUPER_MAGIC;
1198 sb->s_op = &fat_sops;
1199 sb->s_export_op = &fat_export_ops;
1200 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1201 DEFAULT_RATELIMIT_BURST);
1203 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1207 setup(sb); /* flavour-specific stuff that needs options */
1210 sb_min_blocksize(sb, 512);
1211 bh = sb_bread(sb, 0);
1213 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1217 b = (struct fat_boot_sector *) bh->b_data;
1220 fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
1226 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1232 * Earlier we checked here that b->secs_track and b->head are nonzero,
1233 * but it turns out valid FAT filesystems can have zero there.
1237 if (!fat_valid_media(media)) {
1239 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1244 logical_sector_size = get_unaligned_le16(&b->sector_size);
1245 if (!is_power_of_2(logical_sector_size)
1246 || (logical_sector_size < 512)
1247 || (logical_sector_size > 4096)) {
1249 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1250 logical_sector_size);
1254 sbi->sec_per_clus = b->sec_per_clus;
1255 if (!is_power_of_2(sbi->sec_per_clus)) {
1257 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1263 if (logical_sector_size < sb->s_blocksize) {
1264 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1265 " (logical sector size = %u)", logical_sector_size);
1269 if (logical_sector_size > sb->s_blocksize) {
1272 if (!sb_set_blocksize(sb, logical_sector_size)) {
1273 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1274 logical_sector_size);
1277 bh = sb_bread(sb, 0);
1279 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1280 " (logical sector size = %lu)",
1284 b = (struct fat_boot_sector *) bh->b_data;
1287 mutex_init(&sbi->s_lock);
1288 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1289 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1290 sbi->fats = b->fats;
1291 sbi->fat_bits = 0; /* Don't know yet */
1292 sbi->fat_start = le16_to_cpu(b->reserved);
1293 sbi->fat_length = le16_to_cpu(b->fat_length);
1294 sbi->root_cluster = 0;
1295 sbi->free_clusters = -1; /* Don't know yet */
1296 sbi->free_clus_valid = 0;
1297 sbi->prev_free = FAT_START_ENT;
1298 sb->s_maxbytes = 0xffffffff;
1300 if (!sbi->fat_length && b->fat32_length) {
1301 struct fat_boot_fsinfo *fsinfo;
1302 struct buffer_head *fsinfo_bh;
1306 sbi->fat_length = le32_to_cpu(b->fat32_length);
1307 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1309 /* MC - if info_sector is 0, don't multiply by 0 */
1310 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1311 if (sbi->fsinfo_sector == 0)
1312 sbi->fsinfo_sector = 1;
1314 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1315 if (fsinfo_bh == NULL) {
1316 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1317 " (sector = %lu)", sbi->fsinfo_sector);
1322 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1323 if (!IS_FSINFO(fsinfo)) {
1324 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1325 "0x%08x, 0x%08x (sector = %lu)",
1326 le32_to_cpu(fsinfo->signature1),
1327 le32_to_cpu(fsinfo->signature2),
1328 sbi->fsinfo_sector);
1330 if (sbi->options.usefree)
1331 sbi->free_clus_valid = 1;
1332 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1333 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1339 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1340 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1342 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1343 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1344 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1346 fat_msg(sb, KERN_ERR, "bogus directroy-entries per block"
1347 " (%u)", sbi->dir_entries);
1352 rootdir_sectors = sbi->dir_entries
1353 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1354 sbi->data_start = sbi->dir_start + rootdir_sectors;
1355 total_sectors = get_unaligned_le16(&b->sectors);
1356 if (total_sectors == 0)
1357 total_sectors = le32_to_cpu(b->total_sect);
1359 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1361 if (sbi->fat_bits != 32)
1362 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1364 /* check that FAT table does not overflow */
1365 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1366 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1367 if (total_clusters > MAX_FAT(sb)) {
1369 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1375 sbi->max_cluster = total_clusters + FAT_START_ENT;
1376 /* check the free_clusters, it's not necessarily correct */
1377 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1378 sbi->free_clusters = -1;
1379 /* check the prev_free, it's not necessarily correct */
1380 sbi->prev_free %= sbi->max_cluster;
1381 if (sbi->prev_free < FAT_START_ENT)
1382 sbi->prev_free = FAT_START_ENT;
1386 /* set up enough so that it can read an inode */
1389 fat_ent_access_init(sb);
1392 * The low byte of FAT's first entry must have same value with
1393 * media-field. But in real world, too many devices is
1394 * writing wrong value. So, removed that validity check.
1396 * if (FAT_FIRST_ENT(sb, media) != first)
1400 sprintf(buf, "cp%d", sbi->options.codepage);
1401 sbi->nls_disk = load_nls(buf);
1402 if (!sbi->nls_disk) {
1403 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1407 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1408 if (sbi->options.isvfat) {
1409 sbi->nls_io = load_nls(sbi->options.iocharset);
1411 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1412 sbi->options.iocharset);
1418 fat_inode = new_inode(sb);
1421 MSDOS_I(fat_inode)->i_pos = 0;
1422 sbi->fat_inode = fat_inode;
1424 fsinfo_inode = new_inode(sb);
1427 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1428 sbi->fsinfo_inode = fsinfo_inode;
1429 insert_inode_hash(fsinfo_inode);
1431 root_inode = new_inode(sb);
1434 root_inode->i_ino = MSDOS_ROOT_INO;
1435 root_inode->i_version = 1;
1436 error = fat_read_root(root_inode);
1442 insert_inode_hash(root_inode);
1443 fat_attach(root_inode, 0);
1444 sb->s_root = d_make_root(root_inode);
1446 fat_msg(sb, KERN_ERR, "get root inode failed");
1450 if (sbi->options.discard) {
1451 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1452 if (!blk_queue_discard(q))
1453 fat_msg(sb, KERN_WARNING,
1454 "mounting with \"discard\" option, but "
1455 "the device does not support discard");
1463 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1470 unload_nls(sbi->nls_io);
1471 unload_nls(sbi->nls_disk);
1472 if (sbi->options.iocharset != fat_default_iocharset)
1473 kfree(sbi->options.iocharset);
1474 sb->s_fs_info = NULL;
1479 EXPORT_SYMBOL_GPL(fat_fill_super);
1482 * helper function for fat_flush_inodes. This writes both the inode
1483 * and the file data blocks, waiting for in flight data blocks before
1484 * the start of the call. It does not wait for any io started
1487 static int writeback_inode(struct inode *inode)
1492 /* if we used wait=1, sync_inode_metadata waits for the io for the
1493 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1494 * and filemap_fdatawrite is used for the data blocks
1496 ret = sync_inode_metadata(inode, 0);
1498 ret = filemap_fdatawrite(inode->i_mapping);
1503 * write data and metadata corresponding to i1 and i2. The io is
1504 * started but we do not wait for any of it to finish.
1506 * filemap_flush is used for the block device, so if there is a dirty
1507 * page for a block already in flight, we will not wait and start the
1510 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1513 if (!MSDOS_SB(sb)->options.flush)
1516 ret = writeback_inode(i1);
1518 ret = writeback_inode(i2);
1520 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1521 ret = filemap_flush(mapping);
1525 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1527 static int __init init_fat_fs(void)
1531 err = fat_cache_init();
1535 err = fat_init_inodecache();
1542 fat_cache_destroy();
1546 static void __exit exit_fat_fs(void)
1548 fat_cache_destroy();
1549 fat_destroy_inodecache();
1552 module_init(init_fat_fs)
1553 module_exit(exit_fat_fs)
1555 MODULE_LICENSE("GPL");