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 <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, create);
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_error(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, create);
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 void fat_write_failed(struct address_space *mapping, loff_t to)
146 struct inode *inode = mapping->host;
148 if (to > inode->i_size) {
149 truncate_pagecache(inode, to, inode->i_size);
150 fat_truncate_blocks(inode, inode->i_size);
154 static int fat_write_begin(struct file *file, struct address_space *mapping,
155 loff_t pos, unsigned len, unsigned flags,
156 struct page **pagep, void **fsdata)
161 err = cont_write_begin(file, mapping, pos, len, flags,
162 pagep, fsdata, fat_get_block,
163 &MSDOS_I(mapping->host)->mmu_private);
165 fat_write_failed(mapping, pos + len);
169 static int fat_write_end(struct file *file, struct address_space *mapping,
170 loff_t pos, unsigned len, unsigned copied,
171 struct page *pagep, void *fsdata)
173 struct inode *inode = mapping->host;
175 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
177 fat_write_failed(mapping, pos + len);
178 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
179 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
180 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
181 mark_inode_dirty(inode);
186 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
187 const struct iovec *iov,
188 loff_t offset, unsigned long nr_segs)
190 struct file *file = iocb->ki_filp;
191 struct address_space *mapping = file->f_mapping;
192 struct inode *inode = mapping->host;
197 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
198 * so we need to update the ->mmu_private to block boundary.
200 * But we must fill the remaining area or hole by nul for
201 * updating ->mmu_private.
203 * Return 0, and fallback to normal buffered write.
205 loff_t size = offset + iov_length(iov, nr_segs);
206 if (MSDOS_I(inode)->mmu_private < size)
211 * FAT need to use the DIO_LOCKING for avoiding the race
212 * condition of fat_get_block() and ->truncate().
214 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
216 if (ret < 0 && (rw & WRITE))
217 fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
222 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
226 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
227 down_read(&MSDOS_I(mapping->host)->truncate_lock);
228 blocknr = generic_block_bmap(mapping, block, fat_get_block);
229 up_read(&MSDOS_I(mapping->host)->truncate_lock);
234 static const struct address_space_operations fat_aops = {
235 .readpage = fat_readpage,
236 .readpages = fat_readpages,
237 .writepage = fat_writepage,
238 .writepages = fat_writepages,
239 .write_begin = fat_write_begin,
240 .write_end = fat_write_end,
241 .direct_IO = fat_direct_IO,
246 * New FAT inode stuff. We do the following:
247 * a) i_ino is constant and has nothing with on-disk location.
248 * b) FAT manages its own cache of directory entries.
249 * c) *This* cache is indexed by on-disk location.
250 * d) inode has an associated directory entry, all right, but
251 * it may be unhashed.
252 * e) currently entries are stored within struct inode. That should
254 * f) we deal with races in the following way:
255 * 1. readdir() and lookup() do FAT-dir-cache lookup.
256 * 2. rename() unhashes the F-d-c entry and rehashes it in
258 * 3. unlink() and rmdir() unhash F-d-c entry.
259 * 4. fat_write_inode() checks whether the thing is unhashed.
260 * If it is we silently return. If it isn't we do bread(),
261 * check if the location is still valid and retry if it
262 * isn't. Otherwise we do changes.
263 * 5. Spinlock is used to protect hash/unhash/location check/lookup
264 * 6. fat_evict_inode() unhashes the F-d-c entry.
265 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
266 * and consider negative result as cache miss.
269 static void fat_hash_init(struct super_block *sb)
271 struct msdos_sb_info *sbi = MSDOS_SB(sb);
274 spin_lock_init(&sbi->inode_hash_lock);
275 for (i = 0; i < FAT_HASH_SIZE; i++)
276 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
279 static inline unsigned long fat_hash(loff_t i_pos)
281 return hash_32(i_pos, FAT_HASH_BITS);
284 void fat_attach(struct inode *inode, loff_t i_pos)
286 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
287 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
289 spin_lock(&sbi->inode_hash_lock);
290 MSDOS_I(inode)->i_pos = i_pos;
291 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
292 spin_unlock(&sbi->inode_hash_lock);
294 EXPORT_SYMBOL_GPL(fat_attach);
296 void fat_detach(struct inode *inode)
298 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
299 spin_lock(&sbi->inode_hash_lock);
300 MSDOS_I(inode)->i_pos = 0;
301 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
302 spin_unlock(&sbi->inode_hash_lock);
304 EXPORT_SYMBOL_GPL(fat_detach);
306 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
308 struct msdos_sb_info *sbi = MSDOS_SB(sb);
309 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
310 struct hlist_node *_p;
311 struct msdos_inode_info *i;
312 struct inode *inode = NULL;
314 spin_lock(&sbi->inode_hash_lock);
315 hlist_for_each_entry(i, _p, head, i_fat_hash) {
316 BUG_ON(i->vfs_inode.i_sb != sb);
317 if (i->i_pos != i_pos)
319 inode = igrab(&i->vfs_inode);
323 spin_unlock(&sbi->inode_hash_lock);
327 static int is_exec(unsigned char *extension)
329 unsigned char *exe_extensions = "EXECOMBAT", *walk;
331 for (walk = exe_extensions; *walk; walk += 3)
332 if (!strncmp(extension, walk, 3))
337 static int fat_calc_dir_size(struct inode *inode)
339 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
340 int ret, fclus, dclus;
343 if (MSDOS_I(inode)->i_start == 0)
346 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
349 inode->i_size = (fclus + 1) << sbi->cluster_bits;
354 /* doesn't deal with root inode */
355 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
357 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
360 MSDOS_I(inode)->i_pos = 0;
361 inode->i_uid = sbi->options.fs_uid;
362 inode->i_gid = sbi->options.fs_gid;
364 inode->i_generation = get_seconds();
366 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
367 inode->i_generation &= ~1;
368 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
369 inode->i_op = sbi->dir_ops;
370 inode->i_fop = &fat_dir_operations;
372 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
373 if (sbi->fat_bits == 32)
374 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
376 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
377 error = fat_calc_dir_size(inode);
380 MSDOS_I(inode)->mmu_private = inode->i_size;
382 set_nlink(inode, fat_subdirs(inode));
383 } else { /* not a directory */
384 inode->i_generation |= 1;
385 inode->i_mode = fat_make_mode(sbi, de->attr,
386 ((sbi->options.showexec && !is_exec(de->name + 8))
387 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
388 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
389 if (sbi->fat_bits == 32)
390 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
392 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
393 inode->i_size = le32_to_cpu(de->size);
394 inode->i_op = &fat_file_inode_operations;
395 inode->i_fop = &fat_file_operations;
396 inode->i_mapping->a_ops = &fat_aops;
397 MSDOS_I(inode)->mmu_private = inode->i_size;
399 if (de->attr & ATTR_SYS) {
400 if (sbi->options.sys_immutable)
401 inode->i_flags |= S_IMMUTABLE;
403 fat_save_attrs(inode, de->attr);
405 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
406 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
408 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
409 if (sbi->options.isvfat) {
410 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
411 de->cdate, de->ctime_cs);
412 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
414 inode->i_ctime = inode->i_atime = inode->i_mtime;
419 struct inode *fat_build_inode(struct super_block *sb,
420 struct msdos_dir_entry *de, loff_t i_pos)
425 inode = fat_iget(sb, i_pos);
428 inode = new_inode(sb);
430 inode = ERR_PTR(-ENOMEM);
433 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
434 inode->i_version = 1;
435 err = fat_fill_inode(inode, de);
438 inode = ERR_PTR(err);
441 fat_attach(inode, i_pos);
442 insert_inode_hash(inode);
447 EXPORT_SYMBOL_GPL(fat_build_inode);
449 static void fat_evict_inode(struct inode *inode)
451 truncate_inode_pages(&inode->i_data, 0);
452 if (!inode->i_nlink) {
454 fat_truncate_blocks(inode, 0);
456 invalidate_inode_buffers(inode);
457 end_writeback(inode);
458 fat_cache_inval_inode(inode);
462 static void fat_write_super(struct super_block *sb)
467 if (!(sb->s_flags & MS_RDONLY))
468 fat_clusters_flush(sb);
472 static int fat_sync_fs(struct super_block *sb, int wait)
479 err = fat_clusters_flush(sb);
486 static void fat_put_super(struct super_block *sb)
488 struct msdos_sb_info *sbi = MSDOS_SB(sb);
493 iput(sbi->fat_inode);
495 unload_nls(sbi->nls_disk);
496 unload_nls(sbi->nls_io);
498 if (sbi->options.iocharset != fat_default_iocharset)
499 kfree(sbi->options.iocharset);
501 sb->s_fs_info = NULL;
505 static struct kmem_cache *fat_inode_cachep;
507 static struct inode *fat_alloc_inode(struct super_block *sb)
509 struct msdos_inode_info *ei;
510 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
514 init_rwsem(&ei->truncate_lock);
515 return &ei->vfs_inode;
518 static void fat_i_callback(struct rcu_head *head)
520 struct inode *inode = container_of(head, struct inode, i_rcu);
521 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
524 static void fat_destroy_inode(struct inode *inode)
526 call_rcu(&inode->i_rcu, fat_i_callback);
529 static void init_once(void *foo)
531 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
533 spin_lock_init(&ei->cache_lru_lock);
535 ei->cache_valid_id = FAT_CACHE_VALID + 1;
536 INIT_LIST_HEAD(&ei->cache_lru);
537 INIT_HLIST_NODE(&ei->i_fat_hash);
538 inode_init_once(&ei->vfs_inode);
541 static int __init fat_init_inodecache(void)
543 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
544 sizeof(struct msdos_inode_info),
545 0, (SLAB_RECLAIM_ACCOUNT|
548 if (fat_inode_cachep == NULL)
553 static void __exit fat_destroy_inodecache(void)
555 kmem_cache_destroy(fat_inode_cachep);
558 static int fat_remount(struct super_block *sb, int *flags, char *data)
560 struct msdos_sb_info *sbi = MSDOS_SB(sb);
561 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
565 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
567 struct super_block *sb = dentry->d_sb;
568 struct msdos_sb_info *sbi = MSDOS_SB(sb);
569 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
571 /* If the count of free cluster is still unknown, counts it here. */
572 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
573 int err = fat_count_free_clusters(dentry->d_sb);
578 buf->f_type = dentry->d_sb->s_magic;
579 buf->f_bsize = sbi->cluster_size;
580 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
581 buf->f_bfree = sbi->free_clusters;
582 buf->f_bavail = sbi->free_clusters;
583 buf->f_fsid.val[0] = (u32)id;
584 buf->f_fsid.val[1] = (u32)(id >> 32);
586 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
591 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
595 #if BITS_PER_LONG == 32
596 spin_lock(&sbi->inode_hash_lock);
598 i_pos = MSDOS_I(inode)->i_pos;
599 #if BITS_PER_LONG == 32
600 spin_unlock(&sbi->inode_hash_lock);
605 static int __fat_write_inode(struct inode *inode, int wait)
607 struct super_block *sb = inode->i_sb;
608 struct msdos_sb_info *sbi = MSDOS_SB(sb);
609 struct buffer_head *bh;
610 struct msdos_dir_entry *raw_entry;
614 if (inode->i_ino == MSDOS_ROOT_INO)
618 i_pos = fat_i_pos_read(sbi, inode);
622 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
624 fat_msg(sb, KERN_ERR, "unable to read inode block "
625 "for updating (i_pos %lld)", i_pos);
628 spin_lock(&sbi->inode_hash_lock);
629 if (i_pos != MSDOS_I(inode)->i_pos) {
630 spin_unlock(&sbi->inode_hash_lock);
635 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
636 [i_pos & (sbi->dir_per_block - 1)];
637 if (S_ISDIR(inode->i_mode))
640 raw_entry->size = cpu_to_le32(inode->i_size);
641 raw_entry->attr = fat_make_attrs(inode);
642 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
643 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
644 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
645 &raw_entry->date, NULL);
646 if (sbi->options.isvfat) {
648 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
649 &raw_entry->cdate, &raw_entry->ctime_cs);
650 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
651 &raw_entry->adate, NULL);
653 spin_unlock(&sbi->inode_hash_lock);
654 mark_buffer_dirty(bh);
657 err = sync_dirty_buffer(bh);
662 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
664 return __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
667 int fat_sync_inode(struct inode *inode)
669 return __fat_write_inode(inode, 1);
672 EXPORT_SYMBOL_GPL(fat_sync_inode);
674 static int fat_show_options(struct seq_file *m, struct dentry *root);
675 static const struct super_operations fat_sops = {
676 .alloc_inode = fat_alloc_inode,
677 .destroy_inode = fat_destroy_inode,
678 .write_inode = fat_write_inode,
679 .evict_inode = fat_evict_inode,
680 .put_super = fat_put_super,
681 .write_super = fat_write_super,
682 .sync_fs = fat_sync_fs,
683 .statfs = fat_statfs,
684 .remount_fs = fat_remount,
686 .show_options = fat_show_options,
690 * a FAT file handle with fhtype 3 is
691 * 0/ i_ino - for fast, reliable lookup if still in the cache
692 * 1/ i_generation - to see if i_ino is still valid
693 * bit 0 == 0 iff directory
694 * 2/ i_pos(8-39) - if ino has changed, but still in cache
695 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
696 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
698 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
699 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
700 * of i_logstart is used to store the directory entry offset.
703 static struct dentry *fat_fh_to_dentry(struct super_block *sb,
704 struct fid *fid, int fh_len, int fh_type)
706 struct inode *inode = NULL;
709 if (fh_len < 5 || fh_type != 3)
712 inode = ilookup(sb, fh[0]);
713 if (!inode || inode->i_generation != fh[1]) {
720 int i_logstart = fh[3] & 0x0fffffff;
722 i_pos = (loff_t)fh[2] << 8;
723 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
725 /* try 2 - see if i_pos is in F-d-c
726 * require i_logstart to be the same
727 * Will fail if you truncate and then re-write
730 inode = fat_iget(sb, i_pos);
731 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
738 * For now, do nothing if the inode is not found.
740 * What we could do is:
742 * - follow the file starting at fh[4], and record the ".." entry,
743 * and the name of the fh[2] entry.
744 * - then follow the ".." file finding the next step up.
746 * This way we build a path to the root of the tree. If this works, we
747 * lookup the path and so get this inode into the cache. Finally try
748 * the fat_iget lookup again. If that fails, then we are totally out
749 * of luck. But all that is for another day
751 return d_obtain_alias(inode);
755 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
758 struct inode *inode = de->d_inode;
759 u32 ipos_h, ipos_m, ipos_l;
763 return 255; /* no room */
766 ipos_h = MSDOS_I(inode)->i_pos >> 8;
767 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
768 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
770 fh[0] = inode->i_ino;
771 fh[1] = inode->i_generation;
773 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
774 spin_lock(&de->d_lock);
775 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
776 spin_unlock(&de->d_lock);
780 static struct dentry *fat_get_parent(struct dentry *child)
782 struct super_block *sb = child->d_sb;
783 struct buffer_head *bh;
784 struct msdos_dir_entry *de;
786 struct dentry *parent;
792 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
794 parent = ERR_PTR(err);
797 inode = fat_build_inode(sb, de, i_pos);
800 parent = d_obtain_alias(inode);
807 static const struct export_operations fat_export_ops = {
808 .encode_fh = fat_encode_fh,
809 .fh_to_dentry = fat_fh_to_dentry,
810 .get_parent = fat_get_parent,
813 static int fat_show_options(struct seq_file *m, struct dentry *root)
815 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
816 struct fat_mount_options *opts = &sbi->options;
817 int isvfat = opts->isvfat;
819 if (opts->fs_uid != 0)
820 seq_printf(m, ",uid=%u", opts->fs_uid);
821 if (opts->fs_gid != 0)
822 seq_printf(m, ",gid=%u", opts->fs_gid);
823 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
824 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
825 if (opts->allow_utime)
826 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
828 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
831 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
833 switch (opts->shortname) {
834 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
835 seq_puts(m, ",shortname=win95");
837 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
838 seq_puts(m, ",shortname=winnt");
840 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
841 seq_puts(m, ",shortname=mixed");
843 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
844 seq_puts(m, ",shortname=lower");
847 seq_puts(m, ",shortname=unknown");
851 if (opts->name_check != 'n')
852 seq_printf(m, ",check=%c", opts->name_check);
854 seq_puts(m, ",usefree");
856 seq_puts(m, ",quiet");
858 seq_puts(m, ",showexec");
859 if (opts->sys_immutable)
860 seq_puts(m, ",sys_immutable");
863 seq_puts(m, ",dotsOK=yes");
865 seq_puts(m, ",nocase");
868 seq_puts(m, ",utf8");
869 if (opts->unicode_xlate)
870 seq_puts(m, ",uni_xlate");
872 seq_puts(m, ",nonumtail");
874 seq_puts(m, ",rodir");
877 seq_puts(m, ",flush");
879 seq_puts(m, ",tz=UTC");
880 if (opts->errors == FAT_ERRORS_CONT)
881 seq_puts(m, ",errors=continue");
882 else if (opts->errors == FAT_ERRORS_PANIC)
883 seq_puts(m, ",errors=panic");
885 seq_puts(m, ",errors=remount-ro");
887 seq_puts(m, ",discard");
893 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
894 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
895 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
896 Opt_immutable, Opt_dots, Opt_nodots,
897 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
898 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
899 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
900 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
901 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
904 static const match_table_t fat_tokens = {
905 {Opt_check_r, "check=relaxed"},
906 {Opt_check_s, "check=strict"},
907 {Opt_check_n, "check=normal"},
908 {Opt_check_r, "check=r"},
909 {Opt_check_s, "check=s"},
910 {Opt_check_n, "check=n"},
913 {Opt_umask, "umask=%o"},
914 {Opt_dmask, "dmask=%o"},
915 {Opt_fmask, "fmask=%o"},
916 {Opt_allow_utime, "allow_utime=%o"},
917 {Opt_codepage, "codepage=%u"},
918 {Opt_usefree, "usefree"},
919 {Opt_nocase, "nocase"},
920 {Opt_quiet, "quiet"},
921 {Opt_showexec, "showexec"},
922 {Opt_debug, "debug"},
923 {Opt_immutable, "sys_immutable"},
924 {Opt_flush, "flush"},
925 {Opt_tz_utc, "tz=UTC"},
926 {Opt_err_cont, "errors=continue"},
927 {Opt_err_panic, "errors=panic"},
928 {Opt_err_ro, "errors=remount-ro"},
929 {Opt_discard, "discard"},
930 {Opt_obsolete, "conv=binary"},
931 {Opt_obsolete, "conv=text"},
932 {Opt_obsolete, "conv=auto"},
933 {Opt_obsolete, "conv=b"},
934 {Opt_obsolete, "conv=t"},
935 {Opt_obsolete, "conv=a"},
936 {Opt_obsolete, "fat=%u"},
937 {Opt_obsolete, "blocksize=%u"},
938 {Opt_obsolete, "cvf_format=%20s"},
939 {Opt_obsolete, "cvf_options=%100s"},
940 {Opt_obsolete, "posix"},
943 static const match_table_t msdos_tokens = {
944 {Opt_nodots, "nodots"},
945 {Opt_nodots, "dotsOK=no"},
947 {Opt_dots, "dotsOK=yes"},
950 static const match_table_t vfat_tokens = {
951 {Opt_charset, "iocharset=%s"},
952 {Opt_shortname_lower, "shortname=lower"},
953 {Opt_shortname_win95, "shortname=win95"},
954 {Opt_shortname_winnt, "shortname=winnt"},
955 {Opt_shortname_mixed, "shortname=mixed"},
956 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
957 {Opt_utf8_no, "utf8=no"},
958 {Opt_utf8_no, "utf8=false"},
959 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
960 {Opt_utf8_yes, "utf8=yes"},
961 {Opt_utf8_yes, "utf8=true"},
962 {Opt_utf8_yes, "utf8"},
963 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
964 {Opt_uni_xl_no, "uni_xlate=no"},
965 {Opt_uni_xl_no, "uni_xlate=false"},
966 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
967 {Opt_uni_xl_yes, "uni_xlate=yes"},
968 {Opt_uni_xl_yes, "uni_xlate=true"},
969 {Opt_uni_xl_yes, "uni_xlate"},
970 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
971 {Opt_nonumtail_no, "nonumtail=no"},
972 {Opt_nonumtail_no, "nonumtail=false"},
973 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
974 {Opt_nonumtail_yes, "nonumtail=yes"},
975 {Opt_nonumtail_yes, "nonumtail=true"},
976 {Opt_nonumtail_yes, "nonumtail"},
977 {Opt_rodir, "rodir"},
981 static int parse_options(struct super_block *sb, char *options, int is_vfat,
982 int silent, int *debug, struct fat_mount_options *opts)
985 substring_t args[MAX_OPT_ARGS];
989 opts->isvfat = is_vfat;
991 opts->fs_uid = current_uid();
992 opts->fs_gid = current_gid();
993 opts->fs_fmask = opts->fs_dmask = current_umask();
994 opts->allow_utime = -1;
995 opts->codepage = fat_default_codepage;
996 opts->iocharset = fat_default_iocharset;
998 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1001 opts->shortname = 0;
1004 opts->name_check = 'n';
1005 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1006 opts->utf8 = opts->unicode_xlate = 0;
1008 opts->usefree = opts->nocase = 0;
1010 opts->errors = FAT_ERRORS_RO;
1016 while ((p = strsep(&options, ",")) != NULL) {
1021 token = match_token(p, fat_tokens, args);
1022 if (token == Opt_err) {
1024 token = match_token(p, vfat_tokens, args);
1026 token = match_token(p, msdos_tokens, args);
1030 opts->name_check = 's';
1033 opts->name_check = 'r';
1036 opts->name_check = 'n';
1045 /* for backward compatibility */
1046 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1047 | VFAT_SFN_CREATE_WIN95;
1060 opts->sys_immutable = 1;
1063 if (match_int(&args[0], &option))
1065 opts->fs_uid = option;
1068 if (match_int(&args[0], &option))
1070 opts->fs_gid = option;
1073 if (match_octal(&args[0], &option))
1075 opts->fs_fmask = opts->fs_dmask = option;
1078 if (match_octal(&args[0], &option))
1080 opts->fs_dmask = option;
1083 if (match_octal(&args[0], &option))
1085 opts->fs_fmask = option;
1087 case Opt_allow_utime:
1088 if (match_octal(&args[0], &option))
1090 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1093 if (match_int(&args[0], &option))
1095 opts->codepage = option;
1104 opts->errors = FAT_ERRORS_CONT;
1107 opts->errors = FAT_ERRORS_PANIC;
1110 opts->errors = FAT_ERRORS_RO;
1113 /* msdos specific */
1123 if (opts->iocharset != fat_default_iocharset)
1124 kfree(opts->iocharset);
1125 iocharset = match_strdup(&args[0]);
1128 opts->iocharset = iocharset;
1130 case Opt_shortname_lower:
1131 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1132 | VFAT_SFN_CREATE_WIN95;
1134 case Opt_shortname_win95:
1135 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1136 | VFAT_SFN_CREATE_WIN95;
1138 case Opt_shortname_winnt:
1139 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1140 | VFAT_SFN_CREATE_WINNT;
1142 case Opt_shortname_mixed:
1143 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1144 | VFAT_SFN_CREATE_WIN95;
1146 case Opt_utf8_no: /* 0 or no or false */
1149 case Opt_utf8_yes: /* empty or 1 or yes or true */
1152 case Opt_uni_xl_no: /* 0 or no or false */
1153 opts->unicode_xlate = 0;
1155 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1156 opts->unicode_xlate = 1;
1158 case Opt_nonumtail_no: /* 0 or no or false */
1159 opts->numtail = 1; /* negated option */
1161 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1162 opts->numtail = 0; /* negated option */
1171 /* obsolete mount options */
1173 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1174 "not supported now", p);
1176 /* unknown option */
1179 fat_msg(sb, KERN_ERR,
1180 "Unrecognized mount option \"%s\" "
1181 "or missing value", p);
1188 /* UTF-8 doesn't provide FAT semantics */
1189 if (!strcmp(opts->iocharset, "utf8")) {
1190 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1191 " for FAT filesystems, filesystem will be "
1195 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1196 if (opts->allow_utime == (unsigned short)-1)
1197 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1198 if (opts->unicode_xlate)
1204 static int fat_read_root(struct inode *inode)
1206 struct super_block *sb = inode->i_sb;
1207 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1210 MSDOS_I(inode)->i_pos = 0;
1211 inode->i_uid = sbi->options.fs_uid;
1212 inode->i_gid = sbi->options.fs_gid;
1214 inode->i_generation = 0;
1215 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1216 inode->i_op = sbi->dir_ops;
1217 inode->i_fop = &fat_dir_operations;
1218 if (sbi->fat_bits == 32) {
1219 MSDOS_I(inode)->i_start = sbi->root_cluster;
1220 error = fat_calc_dir_size(inode);
1224 MSDOS_I(inode)->i_start = 0;
1225 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1227 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1228 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1229 MSDOS_I(inode)->i_logstart = 0;
1230 MSDOS_I(inode)->mmu_private = inode->i_size;
1232 fat_save_attrs(inode, ATTR_DIR);
1233 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1234 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1235 set_nlink(inode, fat_subdirs(inode)+2);
1241 * Read the super block of an MS-DOS FS.
1243 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1244 void (*setup)(struct super_block *))
1246 struct inode *root_inode = NULL, *fat_inode = NULL;
1247 struct buffer_head *bh;
1248 struct fat_boot_sector *b;
1249 struct msdos_sb_info *sbi;
1250 u16 logical_sector_size;
1251 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1258 * GFP_KERNEL is ok here, because while we do hold the
1259 * supeblock lock, memory pressure can't call back into
1260 * the filesystem, since we're only just about to mount
1261 * it and have no inodes etc active!
1263 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1266 sb->s_fs_info = sbi;
1268 sb->s_flags |= MS_NODIRATIME;
1269 sb->s_magic = MSDOS_SUPER_MAGIC;
1270 sb->s_op = &fat_sops;
1271 sb->s_export_op = &fat_export_ops;
1272 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1273 DEFAULT_RATELIMIT_BURST);
1275 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1279 setup(sb); /* flavour-specific stuff that needs options */
1282 sb_min_blocksize(sb, 512);
1283 bh = sb_bread(sb, 0);
1285 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1289 b = (struct fat_boot_sector *) bh->b_data;
1292 fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
1298 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1304 * Earlier we checked here that b->secs_track and b->head are nonzero,
1305 * but it turns out valid FAT filesystems can have zero there.
1309 if (!fat_valid_media(media)) {
1311 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1316 logical_sector_size = get_unaligned_le16(&b->sector_size);
1317 if (!is_power_of_2(logical_sector_size)
1318 || (logical_sector_size < 512)
1319 || (logical_sector_size > 4096)) {
1321 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1322 logical_sector_size);
1326 sbi->sec_per_clus = b->sec_per_clus;
1327 if (!is_power_of_2(sbi->sec_per_clus)) {
1329 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1335 if (logical_sector_size < sb->s_blocksize) {
1336 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1337 " (logical sector size = %u)", logical_sector_size);
1341 if (logical_sector_size > sb->s_blocksize) {
1344 if (!sb_set_blocksize(sb, logical_sector_size)) {
1345 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1346 logical_sector_size);
1349 bh = sb_bread(sb, 0);
1351 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1352 " (logical sector size = %lu)",
1356 b = (struct fat_boot_sector *) bh->b_data;
1359 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1360 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1361 sbi->fats = b->fats;
1362 sbi->fat_bits = 0; /* Don't know yet */
1363 sbi->fat_start = le16_to_cpu(b->reserved);
1364 sbi->fat_length = le16_to_cpu(b->fat_length);
1365 sbi->root_cluster = 0;
1366 sbi->free_clusters = -1; /* Don't know yet */
1367 sbi->free_clus_valid = 0;
1368 sbi->prev_free = FAT_START_ENT;
1369 sb->s_maxbytes = 0xffffffff;
1371 if (!sbi->fat_length && b->fat32_length) {
1372 struct fat_boot_fsinfo *fsinfo;
1373 struct buffer_head *fsinfo_bh;
1377 sbi->fat_length = le32_to_cpu(b->fat32_length);
1378 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1380 /* MC - if info_sector is 0, don't multiply by 0 */
1381 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1382 if (sbi->fsinfo_sector == 0)
1383 sbi->fsinfo_sector = 1;
1385 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1386 if (fsinfo_bh == NULL) {
1387 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1388 " (sector = %lu)", sbi->fsinfo_sector);
1393 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1394 if (!IS_FSINFO(fsinfo)) {
1395 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1396 "0x%08x, 0x%08x (sector = %lu)",
1397 le32_to_cpu(fsinfo->signature1),
1398 le32_to_cpu(fsinfo->signature2),
1399 sbi->fsinfo_sector);
1401 if (sbi->options.usefree)
1402 sbi->free_clus_valid = 1;
1403 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1404 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1410 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1411 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1413 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1414 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1415 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1417 fat_msg(sb, KERN_ERR, "bogus directroy-entries per block"
1418 " (%u)", sbi->dir_entries);
1423 rootdir_sectors = sbi->dir_entries
1424 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1425 sbi->data_start = sbi->dir_start + rootdir_sectors;
1426 total_sectors = get_unaligned_le16(&b->sectors);
1427 if (total_sectors == 0)
1428 total_sectors = le32_to_cpu(b->total_sect);
1430 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1432 if (sbi->fat_bits != 32)
1433 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1435 /* check that FAT table does not overflow */
1436 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1437 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1438 if (total_clusters > MAX_FAT(sb)) {
1440 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1446 sbi->max_cluster = total_clusters + FAT_START_ENT;
1447 /* check the free_clusters, it's not necessarily correct */
1448 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1449 sbi->free_clusters = -1;
1450 /* check the prev_free, it's not necessarily correct */
1451 sbi->prev_free %= sbi->max_cluster;
1452 if (sbi->prev_free < FAT_START_ENT)
1453 sbi->prev_free = FAT_START_ENT;
1457 /* set up enough so that it can read an inode */
1459 fat_ent_access_init(sb);
1462 * The low byte of FAT's first entry must have same value with
1463 * media-field. But in real world, too many devices is
1464 * writing wrong value. So, removed that validity check.
1466 * if (FAT_FIRST_ENT(sb, media) != first)
1470 sprintf(buf, "cp%d", sbi->options.codepage);
1471 sbi->nls_disk = load_nls(buf);
1472 if (!sbi->nls_disk) {
1473 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1477 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1478 if (sbi->options.isvfat) {
1479 sbi->nls_io = load_nls(sbi->options.iocharset);
1481 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1482 sbi->options.iocharset);
1488 fat_inode = new_inode(sb);
1491 MSDOS_I(fat_inode)->i_pos = 0;
1492 sbi->fat_inode = fat_inode;
1493 root_inode = new_inode(sb);
1496 root_inode->i_ino = MSDOS_ROOT_INO;
1497 root_inode->i_version = 1;
1498 error = fat_read_root(root_inode);
1502 insert_inode_hash(root_inode);
1503 sb->s_root = d_alloc_root(root_inode);
1505 fat_msg(sb, KERN_ERR, "get root inode failed");
1514 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1521 unload_nls(sbi->nls_io);
1522 unload_nls(sbi->nls_disk);
1523 if (sbi->options.iocharset != fat_default_iocharset)
1524 kfree(sbi->options.iocharset);
1525 sb->s_fs_info = NULL;
1530 EXPORT_SYMBOL_GPL(fat_fill_super);
1533 * helper function for fat_flush_inodes. This writes both the inode
1534 * and the file data blocks, waiting for in flight data blocks before
1535 * the start of the call. It does not wait for any io started
1538 static int writeback_inode(struct inode *inode)
1542 struct address_space *mapping = inode->i_mapping;
1543 struct writeback_control wbc = {
1544 .sync_mode = WB_SYNC_NONE,
1547 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1548 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1549 * and filemap_fdatawrite is used for the data blocks
1551 ret = sync_inode(inode, &wbc);
1553 ret = filemap_fdatawrite(mapping);
1558 * write data and metadata corresponding to i1 and i2. The io is
1559 * started but we do not wait for any of it to finish.
1561 * filemap_flush is used for the block device, so if there is a dirty
1562 * page for a block already in flight, we will not wait and start the
1565 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1568 if (!MSDOS_SB(sb)->options.flush)
1571 ret = writeback_inode(i1);
1573 ret = writeback_inode(i2);
1575 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1576 ret = filemap_flush(mapping);
1580 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1582 static int __init init_fat_fs(void)
1586 err = fat_cache_init();
1590 err = fat_init_inodecache();
1597 fat_cache_destroy();
1601 static void __exit exit_fat_fs(void)
1603 fat_cache_destroy();
1604 fat_destroy_inodecache();
1607 module_init(init_fat_fs)
1608 module_exit(exit_fat_fs)
1610 MODULE_LICENSE("GPL");