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_get_block(struct inode *inode, sector_t iblock,
37 struct buffer_head *bh_result, int create)
39 struct super_block *sb = inode->i_sb;
43 err = fat_bmap(inode, iblock, &phys);
47 map_bh(bh_result, sb, phys);
52 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
53 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
54 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
57 if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) {
60 error = fat_add_cluster(inode);
64 MSDOS_I(inode)->mmu_private += sb->s_blocksize;
65 err = fat_bmap(inode, iblock, &phys);
70 set_buffer_new(bh_result);
71 map_bh(bh_result, sb, phys);
75 static int fat_writepage(struct page *page, struct writeback_control *wbc)
77 return block_write_full_page(page, fat_get_block, wbc);
80 static int fat_readpage(struct file *file, struct page *page)
82 return block_read_full_page(page, fat_get_block);
85 static int fat_prepare_write(struct file *file, struct page *page,
86 unsigned from, unsigned to)
88 return cont_prepare_write(page, from, to, fat_get_block,
89 &MSDOS_I(page->mapping->host)->mmu_private);
92 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
94 return generic_block_bmap(mapping, block, fat_get_block);
97 static struct address_space_operations fat_aops = {
98 .readpage = fat_readpage,
99 .writepage = fat_writepage,
100 .sync_page = block_sync_page,
101 .prepare_write = fat_prepare_write,
102 .commit_write = generic_commit_write,
107 * New FAT inode stuff. We do the following:
108 * a) i_ino is constant and has nothing with on-disk location.
109 * b) FAT manages its own cache of directory entries.
110 * c) *This* cache is indexed by on-disk location.
111 * d) inode has an associated directory entry, all right, but
112 * it may be unhashed.
113 * e) currently entries are stored within struct inode. That should
115 * f) we deal with races in the following way:
116 * 1. readdir() and lookup() do FAT-dir-cache lookup.
117 * 2. rename() unhashes the F-d-c entry and rehashes it in
119 * 3. unlink() and rmdir() unhash F-d-c entry.
120 * 4. fat_write_inode() checks whether the thing is unhashed.
121 * If it is we silently return. If it isn't we do bread(),
122 * check if the location is still valid and retry if it
123 * isn't. Otherwise we do changes.
124 * 5. Spinlock is used to protect hash/unhash/location check/lookup
125 * 6. fat_clear_inode() unhashes the F-d-c entry.
126 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
127 * and consider negative result as cache miss.
130 static void fat_hash_init(struct super_block *sb)
132 struct msdos_sb_info *sbi = MSDOS_SB(sb);
135 spin_lock_init(&sbi->inode_hash_lock);
136 for (i = 0; i < FAT_HASH_SIZE; i++)
137 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
140 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
142 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
143 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
144 return tmp & FAT_HASH_MASK;
147 void fat_attach(struct inode *inode, loff_t i_pos)
149 struct super_block *sb = inode->i_sb;
150 struct msdos_sb_info *sbi = MSDOS_SB(sb);
152 spin_lock(&sbi->inode_hash_lock);
153 MSDOS_I(inode)->i_pos = i_pos;
154 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
155 sbi->inode_hashtable + fat_hash(sb, i_pos));
156 spin_unlock(&sbi->inode_hash_lock);
159 EXPORT_SYMBOL(fat_attach);
161 void fat_detach(struct inode *inode)
163 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
164 spin_lock(&sbi->inode_hash_lock);
165 MSDOS_I(inode)->i_pos = 0;
166 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
167 spin_unlock(&sbi->inode_hash_lock);
170 EXPORT_SYMBOL(fat_detach);
172 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
174 struct msdos_sb_info *sbi = MSDOS_SB(sb);
175 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
176 struct hlist_node *_p;
177 struct msdos_inode_info *i;
178 struct inode *inode = NULL;
180 spin_lock(&sbi->inode_hash_lock);
181 hlist_for_each_entry(i, _p, head, i_fat_hash) {
182 BUG_ON(i->vfs_inode.i_sb != sb);
183 if (i->i_pos != i_pos)
185 inode = igrab(&i->vfs_inode);
189 spin_unlock(&sbi->inode_hash_lock);
193 static int is_exec(unsigned char *extension)
195 unsigned char *exe_extensions = "EXECOMBAT", *walk;
197 for (walk = exe_extensions; *walk; walk += 3)
198 if (!strncmp(extension, walk, 3))
203 static int fat_calc_dir_size(struct inode *inode)
205 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
206 int ret, fclus, dclus;
209 if (MSDOS_I(inode)->i_start == 0)
212 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
215 inode->i_size = (fclus + 1) << sbi->cluster_bits;
220 /* doesn't deal with root inode */
221 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
223 struct super_block *sb = inode->i_sb;
224 struct msdos_sb_info *sbi = MSDOS_SB(sb);
227 MSDOS_I(inode)->i_pos = 0;
228 inode->i_uid = sbi->options.fs_uid;
229 inode->i_gid = sbi->options.fs_gid;
231 inode->i_generation = get_seconds();
233 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
234 inode->i_generation &= ~1;
235 inode->i_mode = MSDOS_MKMODE(de->attr,
236 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
237 inode->i_op = sbi->dir_ops;
238 inode->i_fop = &fat_dir_operations;
240 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
241 if (sbi->fat_bits == 32)
242 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
244 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
245 error = fat_calc_dir_size(inode);
248 MSDOS_I(inode)->mmu_private = inode->i_size;
250 inode->i_nlink = fat_subdirs(inode);
251 } else { /* not a directory */
252 inode->i_generation |= 1;
253 inode->i_mode = MSDOS_MKMODE(de->attr,
254 ((sbi->options.showexec &&
256 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
257 & ~sbi->options.fs_fmask) | S_IFREG;
258 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
259 if (sbi->fat_bits == 32)
260 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
262 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
263 inode->i_size = le32_to_cpu(de->size);
264 inode->i_op = &fat_file_inode_operations;
265 inode->i_fop = &fat_file_operations;
266 inode->i_mapping->a_ops = &fat_aops;
267 MSDOS_I(inode)->mmu_private = inode->i_size;
269 if(de->attr & ATTR_SYS)
270 if (sbi->options.sys_immutable)
271 inode->i_flags |= S_IMMUTABLE;
272 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
273 /* this is as close to the truth as we can get ... */
274 inode->i_blksize = sbi->cluster_size;
275 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
276 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
277 inode->i_mtime.tv_sec = inode->i_atime.tv_sec =
278 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
279 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0;
280 inode->i_ctime.tv_sec =
281 MSDOS_SB(sb)->options.isvfat
282 ? date_dos2unix(le16_to_cpu(de->ctime), le16_to_cpu(de->cdate))
283 : inode->i_mtime.tv_sec;
284 inode->i_ctime.tv_nsec = de->ctime_ms * 1000000;
285 MSDOS_I(inode)->i_ctime_ms = de->ctime_ms;
290 struct inode *fat_build_inode(struct super_block *sb,
291 struct msdos_dir_entry *de, loff_t i_pos, int *res)
295 inode = fat_iget(sb, i_pos);
298 inode = new_inode(sb);
302 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
303 inode->i_version = 1;
304 *res = fat_fill_inode(inode, de);
310 fat_attach(inode, i_pos);
311 insert_inode_hash(inode);
316 EXPORT_SYMBOL(fat_build_inode);
318 static void fat_delete_inode(struct inode *inode)
320 if (!is_bad_inode(inode)) {
327 static void fat_clear_inode(struct inode *inode)
329 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
331 if (is_bad_inode(inode))
334 spin_lock(&sbi->inode_hash_lock);
335 fat_cache_inval_inode(inode);
336 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
337 spin_unlock(&sbi->inode_hash_lock);
341 static void fat_put_super(struct super_block *sb)
343 struct msdos_sb_info *sbi = MSDOS_SB(sb);
345 if (!(sb->s_flags & MS_RDONLY))
346 fat_clusters_flush(sb);
349 unload_nls(sbi->nls_disk);
350 sbi->nls_disk = NULL;
351 sbi->options.codepage = fat_default_codepage;
354 unload_nls(sbi->nls_io);
357 if (sbi->options.iocharset != fat_default_iocharset) {
358 kfree(sbi->options.iocharset);
359 sbi->options.iocharset = fat_default_iocharset;
362 sb->s_fs_info = NULL;
366 static kmem_cache_t *fat_inode_cachep;
368 static struct inode *fat_alloc_inode(struct super_block *sb)
370 struct msdos_inode_info *ei;
371 ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
374 return &ei->vfs_inode;
377 static void fat_destroy_inode(struct inode *inode)
379 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
382 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
384 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
386 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
387 SLAB_CTOR_CONSTRUCTOR) {
388 spin_lock_init(&ei->cache_lru_lock);
390 ei->cache_valid_id = FAT_CACHE_VALID + 1;
391 INIT_LIST_HEAD(&ei->cache_lru);
392 INIT_HLIST_NODE(&ei->i_fat_hash);
393 inode_init_once(&ei->vfs_inode);
397 static int __init fat_init_inodecache(void)
399 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
400 sizeof(struct msdos_inode_info),
401 0, SLAB_RECLAIM_ACCOUNT,
403 if (fat_inode_cachep == NULL)
408 static void __exit fat_destroy_inodecache(void)
410 if (kmem_cache_destroy(fat_inode_cachep))
411 printk(KERN_INFO "fat_inode_cache: not all structures were freed\n");
414 static int fat_remount(struct super_block *sb, int *flags, char *data)
416 *flags |= MS_NODIRATIME;
420 static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
422 struct msdos_sb_info *sbi = MSDOS_SB(sb);
425 if (sbi->free_clusters != -1)
426 free = sbi->free_clusters;
429 if (sbi->free_clusters != -1)
430 free = sbi->free_clusters;
433 for (nr = FAT_START_ENT; nr < sbi->max_cluster; nr++) {
434 ret = fat_access(sb, nr, -1);
438 } else if (ret == FAT_ENT_FREE)
441 sbi->free_clusters = free;
446 buf->f_type = sb->s_magic;
447 buf->f_bsize = sbi->cluster_size;
448 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
450 buf->f_bavail = free;
451 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
456 static int fat_write_inode(struct inode *inode, int wait)
458 struct super_block *sb = inode->i_sb;
459 struct msdos_sb_info *sbi = MSDOS_SB(sb);
460 struct buffer_head *bh;
461 struct msdos_dir_entry *raw_entry;
465 i_pos = MSDOS_I(inode)->i_pos;
466 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) {
470 if (!(bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits))) {
471 printk(KERN_ERR "FAT: unable to read inode block "
472 "for updating (i_pos %lld)\n", i_pos);
476 spin_lock(&sbi->inode_hash_lock);
477 if (i_pos != MSDOS_I(inode)->i_pos) {
478 spin_unlock(&sbi->inode_hash_lock);
484 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
485 [i_pos & (sbi->dir_per_block - 1)];
486 if (S_ISDIR(inode->i_mode)) {
487 raw_entry->attr = ATTR_DIR;
491 raw_entry->attr = ATTR_NONE;
492 raw_entry->size = cpu_to_le32(inode->i_size);
494 raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
495 MSDOS_I(inode)->i_attrs;
496 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
497 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
498 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
499 if (sbi->options.isvfat) {
500 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
501 raw_entry->ctime_ms = MSDOS_I(inode)->i_ctime_ms; /* use i_ctime.tv_nsec? */
503 spin_unlock(&sbi->inode_hash_lock);
504 mark_buffer_dirty(bh);
510 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
511 static struct super_operations fat_sops = {
512 .alloc_inode = fat_alloc_inode,
513 .destroy_inode = fat_destroy_inode,
514 .write_inode = fat_write_inode,
515 .delete_inode = fat_delete_inode,
516 .put_super = fat_put_super,
517 .statfs = fat_statfs,
518 .clear_inode = fat_clear_inode,
519 .remount_fs = fat_remount,
521 .read_inode = make_bad_inode,
523 .show_options = fat_show_options,
527 * a FAT file handle with fhtype 3 is
528 * 0/ i_ino - for fast, reliable lookup if still in the cache
529 * 1/ i_generation - to see if i_ino is still valid
530 * bit 0 == 0 iff directory
531 * 2/ i_pos(8-39) - if ino has changed, but still in cache
532 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
533 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
535 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
536 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
537 * of i_logstart is used to store the directory entry offset.
540 static struct dentry *
541 fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
542 int (*acceptable)(void *context, struct dentry *de),
546 return ERR_PTR(-ESTALE);
548 return ERR_PTR(-ESTALE);
550 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
553 static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
555 struct inode *inode = NULL;
556 struct dentry *result;
559 inode = iget(sb, fh[0]);
560 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
567 int i_logstart = fh[3] & 0x0fffffff;
569 i_pos = (loff_t)fh[2] << 8;
570 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
572 /* try 2 - see if i_pos is in F-d-c
573 * require i_logstart to be the same
574 * Will fail if you truncate and then re-write
577 inode = fat_iget(sb, i_pos);
578 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
584 /* For now, do nothing
585 * What we could do is:
586 * follow the file starting at fh[4], and record
587 * the ".." entry, and the name of the fh[2] entry.
588 * The follow the ".." file finding the next step up.
589 * This way we build a path to the root of
590 * the tree. If this works, we lookup the path and so
591 * get this inode into the cache.
592 * Finally try the fat_iget lookup again
593 * If that fails, then weare totally out of luck
594 * But all that is for another day
598 return ERR_PTR(-ESTALE);
601 /* now to find a dentry.
602 * If possible, get a well-connected one
604 result = d_alloc_anon(inode);
605 if (result == NULL) {
607 return ERR_PTR(-ENOMEM);
609 result->d_op = sb->s_root->d_op;
614 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
617 struct inode *inode = de->d_inode;
618 u32 ipos_h, ipos_m, ipos_l;
621 return 255; /* no room */
623 ipos_h = MSDOS_I(inode)->i_pos >> 8;
624 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
625 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
627 fh[0] = inode->i_ino;
628 fh[1] = inode->i_generation;
630 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
631 spin_lock(&de->d_lock);
632 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
633 spin_unlock(&de->d_lock);
637 static struct dentry *fat_get_parent(struct dentry *child)
639 struct buffer_head *bh=NULL;
640 struct msdos_dir_entry *de = NULL;
641 struct dentry *parent = NULL;
647 res = fat_scan(child->d_inode, MSDOS_DOTDOT, &bh, &de, &i_pos);
651 inode = fat_build_inode(child->d_sb, de, i_pos, &res);
657 parent = d_alloc_anon(inode);
674 static struct export_operations fat_export_ops = {
675 .decode_fh = fat_decode_fh,
676 .encode_fh = fat_encode_fh,
677 .get_dentry = fat_get_dentry,
678 .get_parent = fat_get_parent,
681 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
683 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
684 struct fat_mount_options *opts = &sbi->options;
685 int isvfat = opts->isvfat;
687 if (opts->fs_uid != 0)
688 seq_printf(m, ",uid=%u", opts->fs_uid);
689 if (opts->fs_gid != 0)
690 seq_printf(m, ",gid=%u", opts->fs_gid);
691 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
692 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
694 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
697 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
699 switch (opts->shortname) {
700 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
701 seq_puts(m, ",shortname=win95");
703 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
704 seq_puts(m, ",shortname=winnt");
706 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
707 seq_puts(m, ",shortname=mixed");
709 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
710 /* seq_puts(m, ",shortname=lower"); */
713 seq_puts(m, ",shortname=unknown");
717 if (opts->name_check != 'n')
718 seq_printf(m, ",check=%c", opts->name_check);
720 seq_puts(m, ",quiet");
722 seq_puts(m, ",showexec");
723 if (opts->sys_immutable)
724 seq_puts(m, ",sys_immutable");
727 seq_puts(m, ",dotsOK=yes");
729 seq_puts(m, ",nocase");
732 seq_puts(m, ",utf8");
733 if (opts->unicode_xlate)
734 seq_puts(m, ",uni_xlate");
736 seq_puts(m, ",nonumtail");
743 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
744 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
745 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
746 Opt_dots, Opt_nodots,
747 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
748 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
749 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
750 Opt_obsolate, Opt_err,
753 static match_table_t fat_tokens = {
754 {Opt_check_r, "check=relaxed"},
755 {Opt_check_s, "check=strict"},
756 {Opt_check_n, "check=normal"},
757 {Opt_check_r, "check=r"},
758 {Opt_check_s, "check=s"},
759 {Opt_check_n, "check=n"},
762 {Opt_umask, "umask=%o"},
763 {Opt_dmask, "dmask=%o"},
764 {Opt_fmask, "fmask=%o"},
765 {Opt_codepage, "codepage=%u"},
766 {Opt_nocase, "nocase"},
767 {Opt_quiet, "quiet"},
768 {Opt_showexec, "showexec"},
769 {Opt_debug, "debug"},
770 {Opt_immutable, "sys_immutable"},
771 {Opt_obsolate, "conv=binary"},
772 {Opt_obsolate, "conv=text"},
773 {Opt_obsolate, "conv=auto"},
774 {Opt_obsolate, "conv=b"},
775 {Opt_obsolate, "conv=t"},
776 {Opt_obsolate, "conv=a"},
777 {Opt_obsolate, "fat=%u"},
778 {Opt_obsolate, "blocksize=%u"},
779 {Opt_obsolate, "cvf_format=%20s"},
780 {Opt_obsolate, "cvf_options=%100s"},
781 {Opt_obsolate, "posix"},
784 static match_table_t msdos_tokens = {
785 {Opt_nodots, "nodots"},
786 {Opt_nodots, "dotsOK=no"},
788 {Opt_dots, "dotsOK=yes"},
791 static match_table_t vfat_tokens = {
792 {Opt_charset, "iocharset=%s"},
793 {Opt_shortname_lower, "shortname=lower"},
794 {Opt_shortname_win95, "shortname=win95"},
795 {Opt_shortname_winnt, "shortname=winnt"},
796 {Opt_shortname_mixed, "shortname=mixed"},
797 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
798 {Opt_utf8_no, "utf8=no"},
799 {Opt_utf8_no, "utf8=false"},
800 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
801 {Opt_utf8_yes, "utf8=yes"},
802 {Opt_utf8_yes, "utf8=true"},
803 {Opt_utf8_yes, "utf8"},
804 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
805 {Opt_uni_xl_no, "uni_xlate=no"},
806 {Opt_uni_xl_no, "uni_xlate=false"},
807 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
808 {Opt_uni_xl_yes, "uni_xlate=yes"},
809 {Opt_uni_xl_yes, "uni_xlate=true"},
810 {Opt_uni_xl_yes, "uni_xlate"},
811 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
812 {Opt_nonumtail_no, "nonumtail=no"},
813 {Opt_nonumtail_no, "nonumtail=false"},
814 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
815 {Opt_nonumtail_yes, "nonumtail=yes"},
816 {Opt_nonumtail_yes, "nonumtail=true"},
817 {Opt_nonumtail_yes, "nonumtail"},
821 static int parse_options(char *options, int is_vfat, int *debug,
822 struct fat_mount_options *opts)
825 substring_t args[MAX_OPT_ARGS];
829 opts->isvfat = is_vfat;
831 opts->fs_uid = current->uid;
832 opts->fs_gid = current->gid;
833 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
834 opts->codepage = fat_default_codepage;
835 opts->iocharset = fat_default_iocharset;
837 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
840 opts->name_check = 'n';
841 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
842 opts->utf8 = opts->unicode_xlate = 0;
850 while ((p = strsep(&options, ",")) != NULL) {
855 token = match_token(p, fat_tokens, args);
856 if (token == Opt_err) {
858 token = match_token(p, vfat_tokens, args);
860 token = match_token(p, msdos_tokens, args);
864 opts->name_check = 's';
867 opts->name_check = 'r';
870 opts->name_check = 'n';
876 /* for backward compatibility */
877 opts->shortname = VFAT_SFN_DISPLAY_WIN95
878 | VFAT_SFN_CREATE_WIN95;
891 opts->sys_immutable = 1;
894 if (match_int(&args[0], &option))
896 opts->fs_uid = option;
899 if (match_int(&args[0], &option))
901 opts->fs_gid = option;
904 if (match_octal(&args[0], &option))
906 opts->fs_fmask = opts->fs_dmask = option;
909 if (match_octal(&args[0], &option))
911 opts->fs_dmask = option;
914 if (match_octal(&args[0], &option))
916 opts->fs_fmask = option;
919 if (match_int(&args[0], &option))
921 opts->codepage = option;
934 if (opts->iocharset != fat_default_iocharset)
935 kfree(opts->iocharset);
936 iocharset = match_strdup(&args[0]);
939 opts->iocharset = iocharset;
941 case Opt_shortname_lower:
942 opts->shortname = VFAT_SFN_DISPLAY_LOWER
943 | VFAT_SFN_CREATE_WIN95;
945 case Opt_shortname_win95:
946 opts->shortname = VFAT_SFN_DISPLAY_WIN95
947 | VFAT_SFN_CREATE_WIN95;
949 case Opt_shortname_winnt:
950 opts->shortname = VFAT_SFN_DISPLAY_WINNT
951 | VFAT_SFN_CREATE_WINNT;
953 case Opt_shortname_mixed:
954 opts->shortname = VFAT_SFN_DISPLAY_WINNT
955 | VFAT_SFN_CREATE_WIN95;
957 case Opt_utf8_no: /* 0 or no or false */
960 case Opt_utf8_yes: /* empty or 1 or yes or true */
963 case Opt_uni_xl_no: /* 0 or no or false */
964 opts->unicode_xlate = 0;
966 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
967 opts->unicode_xlate = 1;
969 case Opt_nonumtail_no: /* 0 or no or false */
970 opts->numtail = 1; /* negated option */
972 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
973 opts->numtail = 0; /* negated option */
976 /* obsolete mount options */
978 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
979 "not supported now\n", p);
983 printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" "
984 "or missing value\n", p);
988 /* UTF8 doesn't provide FAT semantics */
989 if (!strcmp(opts->iocharset, "utf8")) {
990 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
991 " for FAT filesystems, filesystem will be case sensitive!\n");
994 if (opts->unicode_xlate)
1000 static int fat_read_root(struct inode *inode)
1002 struct super_block *sb = inode->i_sb;
1003 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1006 MSDOS_I(inode)->i_pos = 0;
1007 inode->i_uid = sbi->options.fs_uid;
1008 inode->i_gid = sbi->options.fs_gid;
1010 inode->i_generation = 0;
1011 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1012 inode->i_op = sbi->dir_ops;
1013 inode->i_fop = &fat_dir_operations;
1014 if (sbi->fat_bits == 32) {
1015 MSDOS_I(inode)->i_start = sbi->root_cluster;
1016 error = fat_calc_dir_size(inode);
1020 MSDOS_I(inode)->i_start = 0;
1021 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1023 inode->i_blksize = sbi->cluster_size;
1024 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1025 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1026 MSDOS_I(inode)->i_logstart = 0;
1027 MSDOS_I(inode)->mmu_private = inode->i_size;
1029 MSDOS_I(inode)->i_attrs = 0;
1030 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1031 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1032 MSDOS_I(inode)->i_ctime_ms = 0;
1033 inode->i_nlink = fat_subdirs(inode)+2;
1039 * Read the super block of an MS-DOS FS.
1041 int fat_fill_super(struct super_block *sb, void *data, int silent,
1042 struct inode_operations *fs_dir_inode_ops, int isvfat)
1044 struct inode *root_inode = NULL;
1045 struct buffer_head *bh;
1046 struct fat_boot_sector *b;
1047 struct msdos_sb_info *sbi;
1048 u16 logical_sector_size;
1049 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1055 sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1058 sb->s_fs_info = sbi;
1059 memset(sbi, 0, sizeof(struct msdos_sb_info));
1061 sb->s_flags |= MS_NODIRATIME;
1062 sb->s_magic = MSDOS_SUPER_MAGIC;
1063 sb->s_op = &fat_sops;
1064 sb->s_export_op = &fat_export_ops;
1065 sbi->dir_ops = fs_dir_inode_ops;
1067 error = parse_options(data, isvfat, &debug, &sbi->options);
1071 /* set up enough so that it can read an inode */
1073 init_MUTEX(&sbi->fat_lock);
1076 sb_min_blocksize(sb, 512);
1077 bh = sb_bread(sb, 0);
1079 printk(KERN_ERR "FAT: unable to read boot sector\n");
1083 b = (struct fat_boot_sector *) bh->b_data;
1086 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1092 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1098 * Earlier we checked here that b->secs_track and b->head are nonzero,
1099 * but it turns out valid FAT filesystems can have zero there.
1103 if (!FAT_VALID_MEDIA(media)) {
1105 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1110 logical_sector_size =
1111 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
1112 if (!logical_sector_size
1113 || (logical_sector_size & (logical_sector_size - 1))
1114 || (logical_sector_size < 512)
1115 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1117 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1118 logical_sector_size);
1122 sbi->sec_per_clus = b->sec_per_clus;
1123 if (!sbi->sec_per_clus
1124 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
1126 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1132 if (logical_sector_size < sb->s_blocksize) {
1133 printk(KERN_ERR "FAT: logical sector size too small for device"
1134 " (logical sector size = %u)\n", logical_sector_size);
1138 if (logical_sector_size > sb->s_blocksize) {
1141 if (!sb_set_blocksize(sb, logical_sector_size)) {
1142 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1143 logical_sector_size);
1146 bh = sb_bread(sb, 0);
1148 printk(KERN_ERR "FAT: unable to read boot sector"
1149 " (logical sector size = %lu)\n",
1153 b = (struct fat_boot_sector *) bh->b_data;
1156 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1157 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1158 sbi->fats = b->fats;
1159 sbi->fat_bits = 0; /* Don't know yet */
1160 sbi->fat_start = le16_to_cpu(b->reserved);
1161 sbi->fat_length = le16_to_cpu(b->fat_length);
1162 sbi->root_cluster = 0;
1163 sbi->free_clusters = -1; /* Don't know yet */
1164 sbi->prev_free = -1;
1166 if (!sbi->fat_length && b->fat32_length) {
1167 struct fat_boot_fsinfo *fsinfo;
1168 struct buffer_head *fsinfo_bh;
1172 sbi->fat_length = le32_to_cpu(b->fat32_length);
1173 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1175 sb->s_maxbytes = 0xffffffff;
1177 /* MC - if info_sector is 0, don't multiply by 0 */
1178 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1179 if (sbi->fsinfo_sector == 0)
1180 sbi->fsinfo_sector = 1;
1182 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1183 if (fsinfo_bh == NULL) {
1184 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1185 " (sector = %lu)\n", sbi->fsinfo_sector);
1190 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1191 if (!IS_FSINFO(fsinfo)) {
1193 "FAT: Did not find valid FSINFO signature.\n"
1194 " Found signature1 0x%08x signature2 0x%08x"
1195 " (sector = %lu)\n",
1196 le32_to_cpu(fsinfo->signature1),
1197 le32_to_cpu(fsinfo->signature2),
1198 sbi->fsinfo_sector);
1200 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1201 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1207 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1208 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1210 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1212 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1213 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1215 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1216 " (%u)\n", sbi->dir_entries);
1221 rootdir_sectors = sbi->dir_entries
1222 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1223 sbi->data_start = sbi->dir_start + rootdir_sectors;
1224 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1225 if (total_sectors == 0)
1226 total_sectors = le32_to_cpu(b->total_sect);
1228 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1230 if (sbi->fat_bits != 32)
1231 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1233 /* check that FAT table does not overflow */
1234 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1235 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1236 if (total_clusters > MAX_FAT(sb)) {
1238 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1244 sbi->max_cluster = total_clusters + FAT_START_ENT;
1245 /* check the free_clusters, it's not necessarily correct */
1246 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1247 sbi->free_clusters = -1;
1252 * The low byte of FAT's first entry must have same value with
1253 * media-field. But in real world, too many devices is
1254 * writing wrong value. So, removed that validity check.
1256 * if (FAT_FIRST_ENT(sb, media) != first)
1260 sprintf(buf, "cp%d", sbi->options.codepage);
1261 sbi->nls_disk = load_nls(buf);
1262 if (!sbi->nls_disk) {
1263 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1267 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1268 if (sbi->options.isvfat) {
1269 sbi->nls_io = load_nls(sbi->options.iocharset);
1271 printk(KERN_ERR "FAT: IO charset %s not found\n",
1272 sbi->options.iocharset);
1278 root_inode = new_inode(sb);
1281 root_inode->i_ino = MSDOS_ROOT_INO;
1282 root_inode->i_version = 1;
1283 error = fat_read_root(root_inode);
1287 insert_inode_hash(root_inode);
1288 sb->s_root = d_alloc_root(root_inode);
1290 printk(KERN_ERR "FAT: get root inode failed\n");
1299 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1300 " on dev %s.\n", sb->s_id);
1306 unload_nls(sbi->nls_io);
1308 unload_nls(sbi->nls_disk);
1309 if (sbi->options.iocharset != fat_default_iocharset)
1310 kfree(sbi->options.iocharset);
1311 sb->s_fs_info = NULL;
1316 EXPORT_SYMBOL(fat_fill_super);
1318 int __init fat_cache_init(void);
1319 void __exit fat_cache_destroy(void);
1321 static int __init init_fat_fs(void)
1325 ret = fat_cache_init();
1328 return fat_init_inodecache();
1331 static void __exit exit_fat_fs(void)
1333 fat_cache_destroy();
1334 fat_destroy_inodecache();
1337 module_init(init_fat_fs)
1338 module_exit(exit_fat_fs)
1340 MODULE_LICENSE("GPL");