4 * Written 1992,1993 by Werner Almesberger
5 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
6 * Rewritten for the constant inumbers support by Al Viro
10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/time.h>
16 #include <linux/slab.h>
17 #include <linux/smp_lock.h>
18 #include <linux/seq_file.h>
19 #include <linux/msdos_fs.h>
20 #include <linux/pagemap.h>
21 #include <linux/buffer_head.h>
22 #include <linux/mount.h>
23 #include <linux/vfs.h>
24 #include <linux/parser.h>
25 #include <asm/unaligned.h>
27 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
28 /* if user don't select VFAT, this is undefined. */
29 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
32 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
33 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
36 static int fat_add_cluster(struct inode *inode)
40 err = fat_alloc_clusters(inode, &cluster, 1);
43 /* FIXME: this cluster should be added after data of this
44 * cluster is writed */
45 err = fat_chain_add(inode, cluster, 1);
47 fat_free_clusters(inode, cluster);
51 static int fat_get_block(struct inode *inode, sector_t iblock,
52 struct buffer_head *bh_result, int create)
54 struct super_block *sb = inode->i_sb;
58 err = fat_bmap(inode, iblock, &phys);
62 map_bh(bh_result, sb, phys);
67 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
68 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
69 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
72 if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) {
73 err = fat_add_cluster(inode);
77 MSDOS_I(inode)->mmu_private += sb->s_blocksize;
78 err = fat_bmap(inode, iblock, &phys);
83 set_buffer_new(bh_result);
84 map_bh(bh_result, sb, phys);
88 static int fat_writepage(struct page *page, struct writeback_control *wbc)
90 return block_write_full_page(page, fat_get_block, wbc);
93 static int fat_readpage(struct file *file, struct page *page)
95 return block_read_full_page(page, fat_get_block);
98 static int fat_prepare_write(struct file *file, struct page *page,
99 unsigned from, unsigned to)
101 return cont_prepare_write(page, from, to, fat_get_block,
102 &MSDOS_I(page->mapping->host)->mmu_private);
105 static int fat_commit_write(struct file *file, struct page *page,
106 unsigned from, unsigned to)
108 struct inode *inode = page->mapping->host;
109 int err = generic_commit_write(file, page, from, to);
110 if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
111 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
112 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
113 mark_inode_dirty(inode);
118 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
120 return generic_block_bmap(mapping, block, fat_get_block);
123 static struct address_space_operations fat_aops = {
124 .readpage = fat_readpage,
125 .writepage = fat_writepage,
126 .sync_page = block_sync_page,
127 .prepare_write = fat_prepare_write,
128 .commit_write = fat_commit_write,
133 * New FAT inode stuff. We do the following:
134 * a) i_ino is constant and has nothing with on-disk location.
135 * b) FAT manages its own cache of directory entries.
136 * c) *This* cache is indexed by on-disk location.
137 * d) inode has an associated directory entry, all right, but
138 * it may be unhashed.
139 * e) currently entries are stored within struct inode. That should
141 * f) we deal with races in the following way:
142 * 1. readdir() and lookup() do FAT-dir-cache lookup.
143 * 2. rename() unhashes the F-d-c entry and rehashes it in
145 * 3. unlink() and rmdir() unhash F-d-c entry.
146 * 4. fat_write_inode() checks whether the thing is unhashed.
147 * If it is we silently return. If it isn't we do bread(),
148 * check if the location is still valid and retry if it
149 * isn't. Otherwise we do changes.
150 * 5. Spinlock is used to protect hash/unhash/location check/lookup
151 * 6. fat_clear_inode() unhashes the F-d-c entry.
152 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
153 * and consider negative result as cache miss.
156 static void fat_hash_init(struct super_block *sb)
158 struct msdos_sb_info *sbi = MSDOS_SB(sb);
161 spin_lock_init(&sbi->inode_hash_lock);
162 for (i = 0; i < FAT_HASH_SIZE; i++)
163 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
166 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
168 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
169 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
170 return tmp & FAT_HASH_MASK;
173 void fat_attach(struct inode *inode, loff_t i_pos)
175 struct super_block *sb = inode->i_sb;
176 struct msdos_sb_info *sbi = MSDOS_SB(sb);
178 spin_lock(&sbi->inode_hash_lock);
179 MSDOS_I(inode)->i_pos = i_pos;
180 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
181 sbi->inode_hashtable + fat_hash(sb, i_pos));
182 spin_unlock(&sbi->inode_hash_lock);
185 EXPORT_SYMBOL(fat_attach);
187 void fat_detach(struct inode *inode)
189 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
190 spin_lock(&sbi->inode_hash_lock);
191 MSDOS_I(inode)->i_pos = 0;
192 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
193 spin_unlock(&sbi->inode_hash_lock);
196 EXPORT_SYMBOL(fat_detach);
198 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
200 struct msdos_sb_info *sbi = MSDOS_SB(sb);
201 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
202 struct hlist_node *_p;
203 struct msdos_inode_info *i;
204 struct inode *inode = NULL;
206 spin_lock(&sbi->inode_hash_lock);
207 hlist_for_each_entry(i, _p, head, i_fat_hash) {
208 BUG_ON(i->vfs_inode.i_sb != sb);
209 if (i->i_pos != i_pos)
211 inode = igrab(&i->vfs_inode);
215 spin_unlock(&sbi->inode_hash_lock);
219 static int is_exec(unsigned char *extension)
221 unsigned char *exe_extensions = "EXECOMBAT", *walk;
223 for (walk = exe_extensions; *walk; walk += 3)
224 if (!strncmp(extension, walk, 3))
229 static int fat_calc_dir_size(struct inode *inode)
231 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
232 int ret, fclus, dclus;
235 if (MSDOS_I(inode)->i_start == 0)
238 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
241 inode->i_size = (fclus + 1) << sbi->cluster_bits;
246 /* doesn't deal with root inode */
247 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
249 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
252 MSDOS_I(inode)->i_pos = 0;
253 inode->i_uid = sbi->options.fs_uid;
254 inode->i_gid = sbi->options.fs_gid;
256 inode->i_generation = get_seconds();
258 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
259 inode->i_generation &= ~1;
260 inode->i_mode = MSDOS_MKMODE(de->attr,
261 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
262 inode->i_op = sbi->dir_ops;
263 inode->i_fop = &fat_dir_operations;
265 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
266 if (sbi->fat_bits == 32)
267 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
269 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
270 error = fat_calc_dir_size(inode);
273 MSDOS_I(inode)->mmu_private = inode->i_size;
275 inode->i_nlink = fat_subdirs(inode);
276 } else { /* not a directory */
277 inode->i_generation |= 1;
278 inode->i_mode = MSDOS_MKMODE(de->attr,
279 ((sbi->options.showexec &&
281 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
282 & ~sbi->options.fs_fmask) | S_IFREG;
283 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
284 if (sbi->fat_bits == 32)
285 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
287 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
288 inode->i_size = le32_to_cpu(de->size);
289 inode->i_op = &fat_file_inode_operations;
290 inode->i_fop = &fat_file_operations;
291 inode->i_mapping->a_ops = &fat_aops;
292 MSDOS_I(inode)->mmu_private = inode->i_size;
294 if (de->attr & ATTR_SYS) {
295 if (sbi->options.sys_immutable)
296 inode->i_flags |= S_IMMUTABLE;
298 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
299 /* this is as close to the truth as we can get ... */
300 inode->i_blksize = sbi->cluster_size;
301 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
302 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
303 inode->i_mtime.tv_sec = inode->i_atime.tv_sec =
304 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
305 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0;
306 if (sbi->options.isvfat) {
307 int secs = de->ctime_cs / 100;
308 int csecs = de->ctime_cs % 100;
309 inode->i_ctime.tv_sec =
310 date_dos2unix(le16_to_cpu(de->ctime),
311 le16_to_cpu(de->cdate)) + secs;
312 inode->i_ctime.tv_nsec = csecs * 10000000;
314 inode->i_ctime = inode->i_mtime;
319 struct inode *fat_build_inode(struct super_block *sb,
320 struct msdos_dir_entry *de, loff_t i_pos)
325 inode = fat_iget(sb, i_pos);
328 inode = new_inode(sb);
330 inode = ERR_PTR(-ENOMEM);
333 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
334 inode->i_version = 1;
335 err = fat_fill_inode(inode, de);
338 inode = ERR_PTR(err);
341 fat_attach(inode, i_pos);
342 insert_inode_hash(inode);
347 EXPORT_SYMBOL(fat_build_inode);
349 static void fat_delete_inode(struct inode *inode)
351 truncate_inode_pages(&inode->i_data, 0);
353 if (!is_bad_inode(inode)) {
360 static void fat_clear_inode(struct inode *inode)
362 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
364 if (is_bad_inode(inode))
367 spin_lock(&sbi->inode_hash_lock);
368 fat_cache_inval_inode(inode);
369 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
370 spin_unlock(&sbi->inode_hash_lock);
374 static void fat_put_super(struct super_block *sb)
376 struct msdos_sb_info *sbi = MSDOS_SB(sb);
378 if (!(sb->s_flags & MS_RDONLY))
379 fat_clusters_flush(sb);
382 unload_nls(sbi->nls_disk);
383 sbi->nls_disk = NULL;
384 sbi->options.codepage = fat_default_codepage;
387 unload_nls(sbi->nls_io);
390 if (sbi->options.iocharset != fat_default_iocharset) {
391 kfree(sbi->options.iocharset);
392 sbi->options.iocharset = fat_default_iocharset;
395 sb->s_fs_info = NULL;
399 static kmem_cache_t *fat_inode_cachep;
401 static struct inode *fat_alloc_inode(struct super_block *sb)
403 struct msdos_inode_info *ei;
404 ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
407 return &ei->vfs_inode;
410 static void fat_destroy_inode(struct inode *inode)
412 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
415 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
417 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
419 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
420 SLAB_CTOR_CONSTRUCTOR) {
421 spin_lock_init(&ei->cache_lru_lock);
423 ei->cache_valid_id = FAT_CACHE_VALID + 1;
424 INIT_LIST_HEAD(&ei->cache_lru);
425 INIT_HLIST_NODE(&ei->i_fat_hash);
426 inode_init_once(&ei->vfs_inode);
430 static int __init fat_init_inodecache(void)
432 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
433 sizeof(struct msdos_inode_info),
434 0, SLAB_RECLAIM_ACCOUNT,
436 if (fat_inode_cachep == NULL)
441 static void __exit fat_destroy_inodecache(void)
443 if (kmem_cache_destroy(fat_inode_cachep))
444 printk(KERN_INFO "fat_inode_cache: not all structures were freed\n");
447 static int fat_remount(struct super_block *sb, int *flags, char *data)
449 struct msdos_sb_info *sbi = MSDOS_SB(sb);
450 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
454 static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
456 struct msdos_sb_info *sbi = MSDOS_SB(sb);
458 /* If the count of free cluster is still unknown, counts it here. */
459 if (sbi->free_clusters == -1) {
460 int err = fat_count_free_clusters(sb);
465 buf->f_type = sb->s_magic;
466 buf->f_bsize = sbi->cluster_size;
467 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
468 buf->f_bfree = sbi->free_clusters;
469 buf->f_bavail = sbi->free_clusters;
470 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
475 static int fat_write_inode(struct inode *inode, int wait)
477 struct super_block *sb = inode->i_sb;
478 struct msdos_sb_info *sbi = MSDOS_SB(sb);
479 struct buffer_head *bh;
480 struct msdos_dir_entry *raw_entry;
485 i_pos = MSDOS_I(inode)->i_pos;
486 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
490 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
492 printk(KERN_ERR "FAT: unable to read inode block "
493 "for updating (i_pos %lld)\n", i_pos);
497 spin_lock(&sbi->inode_hash_lock);
498 if (i_pos != MSDOS_I(inode)->i_pos) {
499 spin_unlock(&sbi->inode_hash_lock);
505 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
506 [i_pos & (sbi->dir_per_block - 1)];
507 if (S_ISDIR(inode->i_mode))
510 raw_entry->size = cpu_to_le32(inode->i_size);
511 raw_entry->attr = fat_attr(inode);
512 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
513 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
514 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
515 if (sbi->options.isvfat) {
516 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
517 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
518 inode->i_ctime.tv_nsec / 10000000;
520 spin_unlock(&sbi->inode_hash_lock);
521 mark_buffer_dirty(bh);
523 err = sync_dirty_buffer(bh);
530 int fat_sync_inode(struct inode *inode)
532 return fat_write_inode(inode, 1);
535 EXPORT_SYMBOL(fat_sync_inode);
537 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
538 static struct super_operations fat_sops = {
539 .alloc_inode = fat_alloc_inode,
540 .destroy_inode = fat_destroy_inode,
541 .write_inode = fat_write_inode,
542 .delete_inode = fat_delete_inode,
543 .put_super = fat_put_super,
544 .statfs = fat_statfs,
545 .clear_inode = fat_clear_inode,
546 .remount_fs = fat_remount,
548 .read_inode = make_bad_inode,
550 .show_options = fat_show_options,
554 * a FAT file handle with fhtype 3 is
555 * 0/ i_ino - for fast, reliable lookup if still in the cache
556 * 1/ i_generation - to see if i_ino is still valid
557 * bit 0 == 0 iff directory
558 * 2/ i_pos(8-39) - if ino has changed, but still in cache
559 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
560 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
562 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
563 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
564 * of i_logstart is used to store the directory entry offset.
567 static struct dentry *
568 fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
569 int (*acceptable)(void *context, struct dentry *de),
573 return ERR_PTR(-ESTALE);
575 return ERR_PTR(-ESTALE);
577 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
580 static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
582 struct inode *inode = NULL;
583 struct dentry *result;
586 inode = iget(sb, fh[0]);
587 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
594 int i_logstart = fh[3] & 0x0fffffff;
596 i_pos = (loff_t)fh[2] << 8;
597 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
599 /* try 2 - see if i_pos is in F-d-c
600 * require i_logstart to be the same
601 * Will fail if you truncate and then re-write
604 inode = fat_iget(sb, i_pos);
605 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
611 /* For now, do nothing
612 * What we could do is:
613 * follow the file starting at fh[4], and record
614 * the ".." entry, and the name of the fh[2] entry.
615 * The follow the ".." file finding the next step up.
616 * This way we build a path to the root of
617 * the tree. If this works, we lookup the path and so
618 * get this inode into the cache.
619 * Finally try the fat_iget lookup again
620 * If that fails, then weare totally out of luck
621 * But all that is for another day
625 return ERR_PTR(-ESTALE);
628 /* now to find a dentry.
629 * If possible, get a well-connected one
631 result = d_alloc_anon(inode);
632 if (result == NULL) {
634 return ERR_PTR(-ENOMEM);
636 result->d_op = sb->s_root->d_op;
641 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
644 struct inode *inode = de->d_inode;
645 u32 ipos_h, ipos_m, ipos_l;
648 return 255; /* no room */
650 ipos_h = MSDOS_I(inode)->i_pos >> 8;
651 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
652 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
654 fh[0] = inode->i_ino;
655 fh[1] = inode->i_generation;
657 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
658 spin_lock(&de->d_lock);
659 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
660 spin_unlock(&de->d_lock);
664 static struct dentry *fat_get_parent(struct dentry *child)
666 struct buffer_head *bh;
667 struct msdos_dir_entry *de;
669 struct dentry *parent;
675 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
677 parent = ERR_PTR(err);
680 inode = fat_build_inode(child->d_sb, de, i_pos);
683 parent = ERR_PTR(PTR_ERR(inode));
686 parent = d_alloc_anon(inode);
689 parent = ERR_PTR(-ENOMEM);
697 static struct export_operations fat_export_ops = {
698 .decode_fh = fat_decode_fh,
699 .encode_fh = fat_encode_fh,
700 .get_dentry = fat_get_dentry,
701 .get_parent = fat_get_parent,
704 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
706 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
707 struct fat_mount_options *opts = &sbi->options;
708 int isvfat = opts->isvfat;
710 if (opts->fs_uid != 0)
711 seq_printf(m, ",uid=%u", opts->fs_uid);
712 if (opts->fs_gid != 0)
713 seq_printf(m, ",gid=%u", opts->fs_gid);
714 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
715 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
717 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
720 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
722 switch (opts->shortname) {
723 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
724 seq_puts(m, ",shortname=win95");
726 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
727 seq_puts(m, ",shortname=winnt");
729 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
730 seq_puts(m, ",shortname=mixed");
732 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
733 /* seq_puts(m, ",shortname=lower"); */
736 seq_puts(m, ",shortname=unknown");
740 if (opts->name_check != 'n')
741 seq_printf(m, ",check=%c", opts->name_check);
743 seq_puts(m, ",quiet");
745 seq_puts(m, ",showexec");
746 if (opts->sys_immutable)
747 seq_puts(m, ",sys_immutable");
750 seq_puts(m, ",dotsOK=yes");
752 seq_puts(m, ",nocase");
755 seq_puts(m, ",utf8");
756 if (opts->unicode_xlate)
757 seq_puts(m, ",uni_xlate");
759 seq_puts(m, ",nonumtail");
766 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
767 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
768 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
769 Opt_dots, Opt_nodots,
770 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
771 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
772 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
773 Opt_obsolate, Opt_err,
776 static match_table_t fat_tokens = {
777 {Opt_check_r, "check=relaxed"},
778 {Opt_check_s, "check=strict"},
779 {Opt_check_n, "check=normal"},
780 {Opt_check_r, "check=r"},
781 {Opt_check_s, "check=s"},
782 {Opt_check_n, "check=n"},
785 {Opt_umask, "umask=%o"},
786 {Opt_dmask, "dmask=%o"},
787 {Opt_fmask, "fmask=%o"},
788 {Opt_codepage, "codepage=%u"},
789 {Opt_nocase, "nocase"},
790 {Opt_quiet, "quiet"},
791 {Opt_showexec, "showexec"},
792 {Opt_debug, "debug"},
793 {Opt_immutable, "sys_immutable"},
794 {Opt_obsolate, "conv=binary"},
795 {Opt_obsolate, "conv=text"},
796 {Opt_obsolate, "conv=auto"},
797 {Opt_obsolate, "conv=b"},
798 {Opt_obsolate, "conv=t"},
799 {Opt_obsolate, "conv=a"},
800 {Opt_obsolate, "fat=%u"},
801 {Opt_obsolate, "blocksize=%u"},
802 {Opt_obsolate, "cvf_format=%20s"},
803 {Opt_obsolate, "cvf_options=%100s"},
804 {Opt_obsolate, "posix"},
807 static match_table_t msdos_tokens = {
808 {Opt_nodots, "nodots"},
809 {Opt_nodots, "dotsOK=no"},
811 {Opt_dots, "dotsOK=yes"},
814 static match_table_t vfat_tokens = {
815 {Opt_charset, "iocharset=%s"},
816 {Opt_shortname_lower, "shortname=lower"},
817 {Opt_shortname_win95, "shortname=win95"},
818 {Opt_shortname_winnt, "shortname=winnt"},
819 {Opt_shortname_mixed, "shortname=mixed"},
820 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
821 {Opt_utf8_no, "utf8=no"},
822 {Opt_utf8_no, "utf8=false"},
823 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
824 {Opt_utf8_yes, "utf8=yes"},
825 {Opt_utf8_yes, "utf8=true"},
826 {Opt_utf8_yes, "utf8"},
827 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
828 {Opt_uni_xl_no, "uni_xlate=no"},
829 {Opt_uni_xl_no, "uni_xlate=false"},
830 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
831 {Opt_uni_xl_yes, "uni_xlate=yes"},
832 {Opt_uni_xl_yes, "uni_xlate=true"},
833 {Opt_uni_xl_yes, "uni_xlate"},
834 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
835 {Opt_nonumtail_no, "nonumtail=no"},
836 {Opt_nonumtail_no, "nonumtail=false"},
837 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
838 {Opt_nonumtail_yes, "nonumtail=yes"},
839 {Opt_nonumtail_yes, "nonumtail=true"},
840 {Opt_nonumtail_yes, "nonumtail"},
844 static int parse_options(char *options, int is_vfat, int *debug,
845 struct fat_mount_options *opts)
848 substring_t args[MAX_OPT_ARGS];
852 opts->isvfat = is_vfat;
854 opts->fs_uid = current->uid;
855 opts->fs_gid = current->gid;
856 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
857 opts->codepage = fat_default_codepage;
858 opts->iocharset = fat_default_iocharset;
860 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
863 opts->name_check = 'n';
864 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
865 opts->utf8 = opts->unicode_xlate = 0;
873 while ((p = strsep(&options, ",")) != NULL) {
878 token = match_token(p, fat_tokens, args);
879 if (token == Opt_err) {
881 token = match_token(p, vfat_tokens, args);
883 token = match_token(p, msdos_tokens, args);
887 opts->name_check = 's';
890 opts->name_check = 'r';
893 opts->name_check = 'n';
899 /* for backward compatibility */
900 opts->shortname = VFAT_SFN_DISPLAY_WIN95
901 | VFAT_SFN_CREATE_WIN95;
914 opts->sys_immutable = 1;
917 if (match_int(&args[0], &option))
919 opts->fs_uid = option;
922 if (match_int(&args[0], &option))
924 opts->fs_gid = option;
927 if (match_octal(&args[0], &option))
929 opts->fs_fmask = opts->fs_dmask = option;
932 if (match_octal(&args[0], &option))
934 opts->fs_dmask = option;
937 if (match_octal(&args[0], &option))
939 opts->fs_fmask = option;
942 if (match_int(&args[0], &option))
944 opts->codepage = option;
957 if (opts->iocharset != fat_default_iocharset)
958 kfree(opts->iocharset);
959 iocharset = match_strdup(&args[0]);
962 opts->iocharset = iocharset;
964 case Opt_shortname_lower:
965 opts->shortname = VFAT_SFN_DISPLAY_LOWER
966 | VFAT_SFN_CREATE_WIN95;
968 case Opt_shortname_win95:
969 opts->shortname = VFAT_SFN_DISPLAY_WIN95
970 | VFAT_SFN_CREATE_WIN95;
972 case Opt_shortname_winnt:
973 opts->shortname = VFAT_SFN_DISPLAY_WINNT
974 | VFAT_SFN_CREATE_WINNT;
976 case Opt_shortname_mixed:
977 opts->shortname = VFAT_SFN_DISPLAY_WINNT
978 | VFAT_SFN_CREATE_WIN95;
980 case Opt_utf8_no: /* 0 or no or false */
983 case Opt_utf8_yes: /* empty or 1 or yes or true */
986 case Opt_uni_xl_no: /* 0 or no or false */
987 opts->unicode_xlate = 0;
989 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
990 opts->unicode_xlate = 1;
992 case Opt_nonumtail_no: /* 0 or no or false */
993 opts->numtail = 1; /* negated option */
995 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
996 opts->numtail = 0; /* negated option */
999 /* obsolete mount options */
1001 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1002 "not supported now\n", p);
1004 /* unknown option */
1006 printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" "
1007 "or missing value\n", p);
1011 /* UTF8 doesn't provide FAT semantics */
1012 if (!strcmp(opts->iocharset, "utf8")) {
1013 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1014 " for FAT filesystems, filesystem will be case sensitive!\n");
1017 if (opts->unicode_xlate)
1023 static int fat_read_root(struct inode *inode)
1025 struct super_block *sb = inode->i_sb;
1026 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1029 MSDOS_I(inode)->i_pos = 0;
1030 inode->i_uid = sbi->options.fs_uid;
1031 inode->i_gid = sbi->options.fs_gid;
1033 inode->i_generation = 0;
1034 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1035 inode->i_op = sbi->dir_ops;
1036 inode->i_fop = &fat_dir_operations;
1037 if (sbi->fat_bits == 32) {
1038 MSDOS_I(inode)->i_start = sbi->root_cluster;
1039 error = fat_calc_dir_size(inode);
1043 MSDOS_I(inode)->i_start = 0;
1044 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1046 inode->i_blksize = sbi->cluster_size;
1047 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1048 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1049 MSDOS_I(inode)->i_logstart = 0;
1050 MSDOS_I(inode)->mmu_private = inode->i_size;
1052 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1053 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1054 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1055 inode->i_nlink = fat_subdirs(inode)+2;
1061 * Read the super block of an MS-DOS FS.
1063 int fat_fill_super(struct super_block *sb, void *data, int silent,
1064 struct inode_operations *fs_dir_inode_ops, int isvfat)
1066 struct inode *root_inode = NULL;
1067 struct buffer_head *bh;
1068 struct fat_boot_sector *b;
1069 struct msdos_sb_info *sbi;
1070 u16 logical_sector_size;
1071 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1077 sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1080 sb->s_fs_info = sbi;
1081 memset(sbi, 0, sizeof(struct msdos_sb_info));
1083 sb->s_flags |= MS_NODIRATIME;
1084 sb->s_magic = MSDOS_SUPER_MAGIC;
1085 sb->s_op = &fat_sops;
1086 sb->s_export_op = &fat_export_ops;
1087 sbi->dir_ops = fs_dir_inode_ops;
1089 error = parse_options(data, isvfat, &debug, &sbi->options);
1094 sb_min_blocksize(sb, 512);
1095 bh = sb_bread(sb, 0);
1097 printk(KERN_ERR "FAT: unable to read boot sector\n");
1101 b = (struct fat_boot_sector *) bh->b_data;
1104 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1110 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1116 * Earlier we checked here that b->secs_track and b->head are nonzero,
1117 * but it turns out valid FAT filesystems can have zero there.
1121 if (!FAT_VALID_MEDIA(media)) {
1123 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1128 logical_sector_size =
1129 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
1130 if (!logical_sector_size
1131 || (logical_sector_size & (logical_sector_size - 1))
1132 || (logical_sector_size < 512)
1133 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1135 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1136 logical_sector_size);
1140 sbi->sec_per_clus = b->sec_per_clus;
1141 if (!sbi->sec_per_clus
1142 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
1144 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1150 if (logical_sector_size < sb->s_blocksize) {
1151 printk(KERN_ERR "FAT: logical sector size too small for device"
1152 " (logical sector size = %u)\n", logical_sector_size);
1156 if (logical_sector_size > sb->s_blocksize) {
1159 if (!sb_set_blocksize(sb, logical_sector_size)) {
1160 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1161 logical_sector_size);
1164 bh = sb_bread(sb, 0);
1166 printk(KERN_ERR "FAT: unable to read boot sector"
1167 " (logical sector size = %lu)\n",
1171 b = (struct fat_boot_sector *) bh->b_data;
1174 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1175 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1176 sbi->fats = b->fats;
1177 sbi->fat_bits = 0; /* Don't know yet */
1178 sbi->fat_start = le16_to_cpu(b->reserved);
1179 sbi->fat_length = le16_to_cpu(b->fat_length);
1180 sbi->root_cluster = 0;
1181 sbi->free_clusters = -1; /* Don't know yet */
1182 sbi->prev_free = FAT_START_ENT;
1184 if (!sbi->fat_length && b->fat32_length) {
1185 struct fat_boot_fsinfo *fsinfo;
1186 struct buffer_head *fsinfo_bh;
1190 sbi->fat_length = le32_to_cpu(b->fat32_length);
1191 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1193 sb->s_maxbytes = 0xffffffff;
1195 /* MC - if info_sector is 0, don't multiply by 0 */
1196 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1197 if (sbi->fsinfo_sector == 0)
1198 sbi->fsinfo_sector = 1;
1200 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1201 if (fsinfo_bh == NULL) {
1202 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1203 " (sector = %lu)\n", sbi->fsinfo_sector);
1208 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1209 if (!IS_FSINFO(fsinfo)) {
1211 "FAT: Did not find valid FSINFO signature.\n"
1212 " Found signature1 0x%08x signature2 0x%08x"
1213 " (sector = %lu)\n",
1214 le32_to_cpu(fsinfo->signature1),
1215 le32_to_cpu(fsinfo->signature2),
1216 sbi->fsinfo_sector);
1218 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1219 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1225 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1226 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1228 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1230 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1231 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1233 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1234 " (%u)\n", sbi->dir_entries);
1239 rootdir_sectors = sbi->dir_entries
1240 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1241 sbi->data_start = sbi->dir_start + rootdir_sectors;
1242 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1243 if (total_sectors == 0)
1244 total_sectors = le32_to_cpu(b->total_sect);
1246 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1248 if (sbi->fat_bits != 32)
1249 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1251 /* check that FAT table does not overflow */
1252 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1253 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1254 if (total_clusters > MAX_FAT(sb)) {
1256 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1262 sbi->max_cluster = total_clusters + FAT_START_ENT;
1263 /* check the free_clusters, it's not necessarily correct */
1264 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1265 sbi->free_clusters = -1;
1266 /* check the prev_free, it's not necessarily correct */
1267 sbi->prev_free %= sbi->max_cluster;
1268 if (sbi->prev_free < FAT_START_ENT)
1269 sbi->prev_free = FAT_START_ENT;
1273 /* set up enough so that it can read an inode */
1275 fat_ent_access_init(sb);
1278 * The low byte of FAT's first entry must have same value with
1279 * media-field. But in real world, too many devices is
1280 * writing wrong value. So, removed that validity check.
1282 * if (FAT_FIRST_ENT(sb, media) != first)
1286 sprintf(buf, "cp%d", sbi->options.codepage);
1287 sbi->nls_disk = load_nls(buf);
1288 if (!sbi->nls_disk) {
1289 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1293 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1294 if (sbi->options.isvfat) {
1295 sbi->nls_io = load_nls(sbi->options.iocharset);
1297 printk(KERN_ERR "FAT: IO charset %s not found\n",
1298 sbi->options.iocharset);
1304 root_inode = new_inode(sb);
1307 root_inode->i_ino = MSDOS_ROOT_INO;
1308 root_inode->i_version = 1;
1309 error = fat_read_root(root_inode);
1313 insert_inode_hash(root_inode);
1314 sb->s_root = d_alloc_root(root_inode);
1316 printk(KERN_ERR "FAT: get root inode failed\n");
1325 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1326 " on dev %s.\n", sb->s_id);
1332 unload_nls(sbi->nls_io);
1334 unload_nls(sbi->nls_disk);
1335 if (sbi->options.iocharset != fat_default_iocharset)
1336 kfree(sbi->options.iocharset);
1337 sb->s_fs_info = NULL;
1342 EXPORT_SYMBOL(fat_fill_super);
1344 int __init fat_cache_init(void);
1345 void fat_cache_destroy(void);
1347 static int __init init_fat_fs(void)
1351 err = fat_cache_init();
1355 err = fat_init_inodecache();
1362 fat_cache_destroy();
1366 static void __exit exit_fat_fs(void)
1368 fat_cache_destroy();
1369 fat_destroy_inodecache();
1372 module_init(init_fat_fs)
1373 module_exit(exit_fat_fs)
1375 MODULE_LICENSE("GPL");