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/time.h>
15 #include <linux/slab.h>
16 #include <linux/smp_lock.h>
17 #include <linux/seq_file.h>
18 #include <linux/msdos_fs.h>
19 #include <linux/pagemap.h>
20 #include <linux/buffer_head.h>
21 #include <linux/mount.h>
22 #include <linux/vfs.h>
23 #include <linux/parser.h>
24 #include <asm/unaligned.h>
26 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
27 /* if user don't select VFAT, this is undefined. */
28 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
31 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
32 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
34 static int fat_statfs(struct super_block *sb, struct kstatfs *buf);
35 static int fat_write_inode(struct inode *inode, int wait);
38 * New FAT inode stuff. We do the following:
39 * a) i_ino is constant and has nothing with on-disk location.
40 * b) FAT manages its own cache of directory entries.
41 * c) *This* cache is indexed by on-disk location.
42 * d) inode has an associated directory entry, all right, but
44 * e) currently entries are stored within struct inode. That should
46 * f) we deal with races in the following way:
47 * 1. readdir() and lookup() do FAT-dir-cache lookup.
48 * 2. rename() unhashes the F-d-c entry and rehashes it in
50 * 3. unlink() and rmdir() unhash F-d-c entry.
51 * 4. fat_write_inode() checks whether the thing is unhashed.
52 * If it is we silently return. If it isn't we do bread(),
53 * check if the location is still valid and retry if it
54 * isn't. Otherwise we do changes.
55 * 5. Spinlock is used to protect hash/unhash/location check/lookup
56 * 6. fat_clear_inode() unhashes the F-d-c entry.
57 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
58 * and consider negative result as cache miss.
61 static void fat_hash_init(struct super_block *sb)
63 struct msdos_sb_info *sbi = MSDOS_SB(sb);
66 spin_lock_init(&sbi->inode_hash_lock);
67 for (i = 0; i < FAT_HASH_SIZE; i++)
68 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
71 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
73 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
74 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
75 return tmp & FAT_HASH_MASK;
78 void fat_attach(struct inode *inode, loff_t i_pos)
80 struct super_block *sb = inode->i_sb;
81 struct msdos_sb_info *sbi = MSDOS_SB(sb);
83 spin_lock(&sbi->inode_hash_lock);
84 MSDOS_I(inode)->i_pos = i_pos;
85 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
86 sbi->inode_hashtable + fat_hash(sb, i_pos));
87 spin_unlock(&sbi->inode_hash_lock);
90 void fat_detach(struct inode *inode)
92 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
93 spin_lock(&sbi->inode_hash_lock);
94 MSDOS_I(inode)->i_pos = 0;
95 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
96 spin_unlock(&sbi->inode_hash_lock);
99 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
101 struct msdos_sb_info *sbi = MSDOS_SB(sb);
102 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
103 struct hlist_node *_p;
104 struct msdos_inode_info *i;
105 struct inode *inode = NULL;
107 spin_lock(&sbi->inode_hash_lock);
108 hlist_for_each_entry(i, _p, head, i_fat_hash) {
109 BUG_ON(i->vfs_inode.i_sb != sb);
110 if (i->i_pos != i_pos)
112 inode = igrab(&i->vfs_inode);
116 spin_unlock(&sbi->inode_hash_lock);
120 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
122 struct inode *fat_build_inode(struct super_block *sb,
123 struct msdos_dir_entry *de, loff_t i_pos, int *res)
127 inode = fat_iget(sb, i_pos);
130 inode = new_inode(sb);
134 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
135 inode->i_version = 1;
136 *res = fat_fill_inode(inode, de);
142 fat_attach(inode, i_pos);
143 insert_inode_hash(inode);
148 static void fat_delete_inode(struct inode *inode)
150 if (!is_bad_inode(inode)) {
157 static void fat_clear_inode(struct inode *inode)
159 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
161 if (is_bad_inode(inode))
164 spin_lock(&sbi->inode_hash_lock);
165 fat_cache_inval_inode(inode);
166 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
167 spin_unlock(&sbi->inode_hash_lock);
171 static void fat_put_super(struct super_block *sb)
173 struct msdos_sb_info *sbi = MSDOS_SB(sb);
175 if (!(sb->s_flags & MS_RDONLY))
176 fat_clusters_flush(sb);
179 unload_nls(sbi->nls_disk);
180 sbi->nls_disk = NULL;
181 sbi->options.codepage = fat_default_codepage;
184 unload_nls(sbi->nls_io);
187 if (sbi->options.iocharset != fat_default_iocharset) {
188 kfree(sbi->options.iocharset);
189 sbi->options.iocharset = fat_default_iocharset;
192 sb->s_fs_info = NULL;
196 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
198 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
199 struct fat_mount_options *opts = &sbi->options;
200 int isvfat = opts->isvfat;
202 if (opts->fs_uid != 0)
203 seq_printf(m, ",uid=%u", opts->fs_uid);
204 if (opts->fs_gid != 0)
205 seq_printf(m, ",gid=%u", opts->fs_gid);
206 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
207 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
208 if (sbi->nls_disk && opts->codepage != fat_default_codepage)
209 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
212 strcmp(opts->iocharset, fat_default_iocharset))
213 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
215 switch (opts->shortname) {
216 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
217 seq_puts(m, ",shortname=win95");
219 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
220 seq_puts(m, ",shortname=winnt");
222 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
223 seq_puts(m, ",shortname=mixed");
225 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
226 /* seq_puts(m, ",shortname=lower"); */
229 seq_puts(m, ",shortname=unknown");
233 if (opts->name_check != 'n')
234 seq_printf(m, ",check=%c", opts->name_check);
236 seq_puts(m, ",quiet");
238 seq_puts(m, ",showexec");
239 if (opts->sys_immutable)
240 seq_puts(m, ",sys_immutable");
243 seq_puts(m, ",dotsOK=yes");
245 seq_puts(m, ",nocase");
248 seq_puts(m, ",utf8");
249 if (opts->unicode_xlate)
250 seq_puts(m, ",uni_xlate");
252 seq_puts(m, ",nonumtail");
259 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
260 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
261 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
262 Opt_dots, Opt_nodots,
263 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
264 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
265 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
266 Opt_obsolate, Opt_err,
269 static match_table_t fat_tokens = {
270 {Opt_check_r, "check=relaxed"},
271 {Opt_check_s, "check=strict"},
272 {Opt_check_n, "check=normal"},
273 {Opt_check_r, "check=r"},
274 {Opt_check_s, "check=s"},
275 {Opt_check_n, "check=n"},
278 {Opt_umask, "umask=%o"},
279 {Opt_dmask, "dmask=%o"},
280 {Opt_fmask, "fmask=%o"},
281 {Opt_codepage, "codepage=%u"},
282 {Opt_nocase, "nocase"},
283 {Opt_quiet, "quiet"},
284 {Opt_showexec, "showexec"},
285 {Opt_debug, "debug"},
286 {Opt_immutable, "sys_immutable"},
287 {Opt_obsolate, "conv=binary"},
288 {Opt_obsolate, "conv=text"},
289 {Opt_obsolate, "conv=auto"},
290 {Opt_obsolate, "conv=b"},
291 {Opt_obsolate, "conv=t"},
292 {Opt_obsolate, "conv=a"},
293 {Opt_obsolate, "fat=%u"},
294 {Opt_obsolate, "blocksize=%u"},
295 {Opt_obsolate, "cvf_format=%20s"},
296 {Opt_obsolate, "cvf_options=%100s"},
297 {Opt_obsolate, "posix"},
300 static match_table_t msdos_tokens = {
301 {Opt_nodots, "nodots"},
302 {Opt_nodots, "dotsOK=no"},
304 {Opt_dots, "dotsOK=yes"},
307 static match_table_t vfat_tokens = {
308 {Opt_charset, "iocharset=%s"},
309 {Opt_shortname_lower, "shortname=lower"},
310 {Opt_shortname_win95, "shortname=win95"},
311 {Opt_shortname_winnt, "shortname=winnt"},
312 {Opt_shortname_mixed, "shortname=mixed"},
313 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
314 {Opt_utf8_no, "utf8=no"},
315 {Opt_utf8_no, "utf8=false"},
316 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
317 {Opt_utf8_yes, "utf8=yes"},
318 {Opt_utf8_yes, "utf8=true"},
319 {Opt_utf8_yes, "utf8"},
320 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
321 {Opt_uni_xl_no, "uni_xlate=no"},
322 {Opt_uni_xl_no, "uni_xlate=false"},
323 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
324 {Opt_uni_xl_yes, "uni_xlate=yes"},
325 {Opt_uni_xl_yes, "uni_xlate=true"},
326 {Opt_uni_xl_yes, "uni_xlate"},
327 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
328 {Opt_nonumtail_no, "nonumtail=no"},
329 {Opt_nonumtail_no, "nonumtail=false"},
330 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
331 {Opt_nonumtail_yes, "nonumtail=yes"},
332 {Opt_nonumtail_yes, "nonumtail=true"},
333 {Opt_nonumtail_yes, "nonumtail"},
337 static int parse_options(char *options, int is_vfat, int *debug,
338 struct fat_mount_options *opts)
341 substring_t args[MAX_OPT_ARGS];
345 opts->isvfat = is_vfat;
347 opts->fs_uid = current->uid;
348 opts->fs_gid = current->gid;
349 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
350 opts->codepage = fat_default_codepage;
351 opts->iocharset = fat_default_iocharset;
353 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
356 opts->name_check = 'n';
357 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
358 opts->utf8 = opts->unicode_xlate = 0;
366 while ((p = strsep(&options, ",")) != NULL) {
371 token = match_token(p, fat_tokens, args);
372 if (token == Opt_err) {
374 token = match_token(p, vfat_tokens, args);
376 token = match_token(p, msdos_tokens, args);
380 opts->name_check = 's';
383 opts->name_check = 'r';
386 opts->name_check = 'n';
392 /* for backward compatibility */
393 opts->shortname = VFAT_SFN_DISPLAY_WIN95
394 | VFAT_SFN_CREATE_WIN95;
407 opts->sys_immutable = 1;
410 if (match_int(&args[0], &option))
412 opts->fs_uid = option;
415 if (match_int(&args[0], &option))
417 opts->fs_gid = option;
420 if (match_octal(&args[0], &option))
422 opts->fs_fmask = opts->fs_dmask = option;
425 if (match_octal(&args[0], &option))
427 opts->fs_dmask = option;
430 if (match_octal(&args[0], &option))
432 opts->fs_fmask = option;
435 if (match_int(&args[0], &option))
437 opts->codepage = option;
450 if (opts->iocharset != fat_default_iocharset)
451 kfree(opts->iocharset);
452 iocharset = match_strdup(&args[0]);
455 opts->iocharset = iocharset;
457 case Opt_shortname_lower:
458 opts->shortname = VFAT_SFN_DISPLAY_LOWER
459 | VFAT_SFN_CREATE_WIN95;
461 case Opt_shortname_win95:
462 opts->shortname = VFAT_SFN_DISPLAY_WIN95
463 | VFAT_SFN_CREATE_WIN95;
465 case Opt_shortname_winnt:
466 opts->shortname = VFAT_SFN_DISPLAY_WINNT
467 | VFAT_SFN_CREATE_WINNT;
469 case Opt_shortname_mixed:
470 opts->shortname = VFAT_SFN_DISPLAY_WINNT
471 | VFAT_SFN_CREATE_WIN95;
473 case Opt_utf8_no: /* 0 or no or false */
476 case Opt_utf8_yes: /* empty or 1 or yes or true */
479 case Opt_uni_xl_no: /* 0 or no or false */
480 opts->unicode_xlate = 0;
482 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
483 opts->unicode_xlate = 1;
485 case Opt_nonumtail_no: /* 0 or no or false */
486 opts->numtail = 1; /* negated option */
488 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
489 opts->numtail = 0; /* negated option */
492 /* obsolete mount options */
494 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
495 "not supported now\n", p);
499 printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" "
500 "or missing value\n", p);
504 /* UTF8 doesn't provide FAT semantics */
505 if (!strcmp(opts->iocharset, "utf8")) {
506 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
507 " for FAT filesystems, filesystem will be case sensitive!\n");
510 if (opts->unicode_xlate)
516 static int fat_calc_dir_size(struct inode *inode)
518 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
519 int ret, fclus, dclus;
522 if (MSDOS_I(inode)->i_start == 0)
525 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
528 inode->i_size = (fclus + 1) << sbi->cluster_bits;
533 static int fat_read_root(struct inode *inode)
535 struct super_block *sb = inode->i_sb;
536 struct msdos_sb_info *sbi = MSDOS_SB(sb);
539 MSDOS_I(inode)->i_pos = 0;
540 inode->i_uid = sbi->options.fs_uid;
541 inode->i_gid = sbi->options.fs_gid;
543 inode->i_generation = 0;
544 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
545 inode->i_op = sbi->dir_ops;
546 inode->i_fop = &fat_dir_operations;
547 if (sbi->fat_bits == 32) {
548 MSDOS_I(inode)->i_start = sbi->root_cluster;
549 error = fat_calc_dir_size(inode);
553 MSDOS_I(inode)->i_start = 0;
554 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
556 inode->i_blksize = sbi->cluster_size;
557 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
558 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
559 MSDOS_I(inode)->i_logstart = 0;
560 MSDOS_I(inode)->mmu_private = inode->i_size;
562 MSDOS_I(inode)->i_attrs = 0;
563 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
564 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
565 MSDOS_I(inode)->i_ctime_ms = 0;
566 inode->i_nlink = fat_subdirs(inode)+2;
572 * a FAT file handle with fhtype 3 is
573 * 0/ i_ino - for fast, reliable lookup if still in the cache
574 * 1/ i_generation - to see if i_ino is still valid
575 * bit 0 == 0 iff directory
576 * 2/ i_pos(8-39) - if ino has changed, but still in cache
577 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
578 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
580 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
581 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
582 * of i_logstart is used to store the directory entry offset.
585 static struct dentry *
586 fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
587 int (*acceptable)(void *context, struct dentry *de),
591 return ERR_PTR(-ESTALE);
593 return ERR_PTR(-ESTALE);
595 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
598 static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
600 struct inode *inode = NULL;
601 struct dentry *result;
604 inode = iget(sb, fh[0]);
605 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
612 int i_logstart = fh[3] & 0x0fffffff;
614 i_pos = (loff_t)fh[2] << 8;
615 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
617 /* try 2 - see if i_pos is in F-d-c
618 * require i_logstart to be the same
619 * Will fail if you truncate and then re-write
622 inode = fat_iget(sb, i_pos);
623 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
629 /* For now, do nothing
630 * What we could do is:
631 * follow the file starting at fh[4], and record
632 * the ".." entry, and the name of the fh[2] entry.
633 * The follow the ".." file finding the next step up.
634 * This way we build a path to the root of
635 * the tree. If this works, we lookup the path and so
636 * get this inode into the cache.
637 * Finally try the fat_iget lookup again
638 * If that fails, then weare totally out of luck
639 * But all that is for another day
643 return ERR_PTR(-ESTALE);
646 /* now to find a dentry.
647 * If possible, get a well-connected one
649 result = d_alloc_anon(inode);
650 if (result == NULL) {
652 return ERR_PTR(-ENOMEM);
654 result->d_op = sb->s_root->d_op;
659 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
662 struct inode *inode = de->d_inode;
663 u32 ipos_h, ipos_m, ipos_l;
666 return 255; /* no room */
668 ipos_h = MSDOS_I(inode)->i_pos >> 8;
669 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
670 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
672 fh[0] = inode->i_ino;
673 fh[1] = inode->i_generation;
675 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
676 spin_lock(&de->d_lock);
677 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
678 spin_unlock(&de->d_lock);
682 static struct dentry *fat_get_parent(struct dentry *child)
684 struct buffer_head *bh=NULL;
685 struct msdos_dir_entry *de = NULL;
686 struct dentry *parent = NULL;
692 res = fat_scan(child->d_inode, MSDOS_DOTDOT, &bh, &de, &i_pos);
696 inode = fat_build_inode(child->d_sb, de, i_pos, &res);
702 parent = d_alloc_anon(inode);
719 static kmem_cache_t *fat_inode_cachep;
721 static struct inode *fat_alloc_inode(struct super_block *sb)
723 struct msdos_inode_info *ei;
724 ei = (struct msdos_inode_info *)kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
727 return &ei->vfs_inode;
730 static void fat_destroy_inode(struct inode *inode)
732 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
735 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
737 struct msdos_inode_info *ei = (struct msdos_inode_info *) foo;
739 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
740 SLAB_CTOR_CONSTRUCTOR) {
741 spin_lock_init(&ei->cache_lru_lock);
743 ei->cache_valid_id = FAT_CACHE_VALID + 1;
744 INIT_LIST_HEAD(&ei->cache_lru);
745 INIT_HLIST_NODE(&ei->i_fat_hash);
746 inode_init_once(&ei->vfs_inode);
750 int __init fat_init_inodecache(void)
752 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
753 sizeof(struct msdos_inode_info),
754 0, SLAB_RECLAIM_ACCOUNT,
756 if (fat_inode_cachep == NULL)
761 void __exit fat_destroy_inodecache(void)
763 if (kmem_cache_destroy(fat_inode_cachep))
764 printk(KERN_INFO "fat_inode_cache: not all structures were freed\n");
767 static int fat_remount(struct super_block *sb, int *flags, char *data)
769 *flags |= MS_NODIRATIME;
773 static struct super_operations fat_sops = {
774 .alloc_inode = fat_alloc_inode,
775 .destroy_inode = fat_destroy_inode,
776 .write_inode = fat_write_inode,
777 .delete_inode = fat_delete_inode,
778 .put_super = fat_put_super,
779 .statfs = fat_statfs,
780 .clear_inode = fat_clear_inode,
781 .remount_fs = fat_remount,
783 .read_inode = make_bad_inode,
785 .show_options = fat_show_options,
788 static struct export_operations fat_export_ops = {
789 .decode_fh = fat_decode_fh,
790 .encode_fh = fat_encode_fh,
791 .get_dentry = fat_get_dentry,
792 .get_parent = fat_get_parent,
796 * Read the super block of an MS-DOS FS.
798 int fat_fill_super(struct super_block *sb, void *data, int silent,
799 struct inode_operations *fs_dir_inode_ops, int isvfat)
801 struct inode *root_inode = NULL;
802 struct buffer_head *bh;
803 struct fat_boot_sector *b;
804 struct msdos_sb_info *sbi;
805 u16 logical_sector_size;
806 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
812 sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
816 memset(sbi, 0, sizeof(struct msdos_sb_info));
818 sb->s_flags |= MS_NODIRATIME;
819 sb->s_magic = MSDOS_SUPER_MAGIC;
820 sb->s_op = &fat_sops;
821 sb->s_export_op = &fat_export_ops;
822 sbi->dir_ops = fs_dir_inode_ops;
824 error = parse_options(data, isvfat, &debug, &sbi->options);
828 /* set up enough so that it can read an inode */
830 init_MUTEX(&sbi->fat_lock);
833 sb_min_blocksize(sb, 512);
834 bh = sb_bread(sb, 0);
836 printk(KERN_ERR "FAT: unable to read boot sector\n");
840 b = (struct fat_boot_sector *) bh->b_data;
843 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
849 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
855 * Earlier we checked here that b->secs_track and b->head are nonzero,
856 * but it turns out valid FAT filesystems can have zero there.
860 if (!FAT_VALID_MEDIA(media)) {
862 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
867 logical_sector_size =
868 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
869 if (!logical_sector_size
870 || (logical_sector_size & (logical_sector_size - 1))
871 || (logical_sector_size < 512)
872 || (PAGE_CACHE_SIZE < logical_sector_size)) {
874 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
875 logical_sector_size);
879 sbi->sec_per_clus = b->sec_per_clus;
880 if (!sbi->sec_per_clus
881 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
883 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
889 if (logical_sector_size < sb->s_blocksize) {
890 printk(KERN_ERR "FAT: logical sector size too small for device"
891 " (logical sector size = %u)\n", logical_sector_size);
895 if (logical_sector_size > sb->s_blocksize) {
898 if (!sb_set_blocksize(sb, logical_sector_size)) {
899 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
900 logical_sector_size);
903 bh = sb_bread(sb, 0);
905 printk(KERN_ERR "FAT: unable to read boot sector"
906 " (logical sector size = %lu)\n",
910 b = (struct fat_boot_sector *) bh->b_data;
913 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
914 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
916 sbi->fat_bits = 0; /* Don't know yet */
917 sbi->fat_start = le16_to_cpu(b->reserved);
918 sbi->fat_length = le16_to_cpu(b->fat_length);
919 sbi->root_cluster = 0;
920 sbi->free_clusters = -1; /* Don't know yet */
923 if (!sbi->fat_length && b->fat32_length) {
924 struct fat_boot_fsinfo *fsinfo;
925 struct buffer_head *fsinfo_bh;
929 sbi->fat_length = le32_to_cpu(b->fat32_length);
930 sbi->root_cluster = le32_to_cpu(b->root_cluster);
932 sb->s_maxbytes = 0xffffffff;
934 /* MC - if info_sector is 0, don't multiply by 0 */
935 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
936 if (sbi->fsinfo_sector == 0)
937 sbi->fsinfo_sector = 1;
939 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
940 if (fsinfo_bh == NULL) {
941 printk(KERN_ERR "FAT: bread failed, FSINFO block"
942 " (sector = %lu)\n", sbi->fsinfo_sector);
947 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
948 if (!IS_FSINFO(fsinfo)) {
950 "FAT: Did not find valid FSINFO signature.\n"
951 " Found signature1 0x%08x signature2 0x%08x"
953 le32_to_cpu(fsinfo->signature1),
954 le32_to_cpu(fsinfo->signature2),
957 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
958 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
964 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
965 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
967 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
969 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
970 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
972 printk(KERN_ERR "FAT: bogus directroy-entries per block"
973 " (%u)\n", sbi->dir_entries);
978 rootdir_sectors = sbi->dir_entries
979 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
980 sbi->data_start = sbi->dir_start + rootdir_sectors;
981 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
982 if (total_sectors == 0)
983 total_sectors = le32_to_cpu(b->total_sect);
985 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
987 if (sbi->fat_bits != 32)
988 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
990 /* check that FAT table does not overflow */
991 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
992 total_clusters = min(total_clusters, fat_clusters - 2);
993 if (total_clusters > MAX_FAT(sb)) {
995 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1001 sbi->clusters = total_clusters;
1002 /* check the free_clusters, it's not necessarily correct */
1003 if (sbi->free_clusters != -1 && sbi->free_clusters > sbi->clusters)
1004 sbi->free_clusters = -1;
1009 * The low byte of FAT's first entry must have same value with
1010 * media-field. But in real world, too many devices is
1011 * writing wrong value. So, removed that validity check.
1013 * if (FAT_FIRST_ENT(sb, media) != first)
1017 sprintf(buf, "cp%d", sbi->options.codepage);
1018 sbi->nls_disk = load_nls(buf);
1019 if (!sbi->nls_disk) {
1020 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1024 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1025 if (sbi->options.isvfat) {
1026 sbi->nls_io = load_nls(sbi->options.iocharset);
1028 printk(KERN_ERR "FAT: IO charset %s not found\n",
1029 sbi->options.iocharset);
1035 root_inode = new_inode(sb);
1038 root_inode->i_ino = MSDOS_ROOT_INO;
1039 root_inode->i_version = 1;
1040 error = fat_read_root(root_inode);
1044 insert_inode_hash(root_inode);
1045 sb->s_root = d_alloc_root(root_inode);
1047 printk(KERN_ERR "FAT: get root inode failed\n");
1056 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1057 " on dev %s.\n", sb->s_id);
1063 unload_nls(sbi->nls_io);
1065 unload_nls(sbi->nls_disk);
1066 if (sbi->options.iocharset != fat_default_iocharset)
1067 kfree(sbi->options.iocharset);
1068 sb->s_fs_info = NULL;
1073 static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
1077 if (MSDOS_SB(sb)->free_clusters != -1)
1078 free = MSDOS_SB(sb)->free_clusters;
1081 if (MSDOS_SB(sb)->free_clusters != -1)
1082 free = MSDOS_SB(sb)->free_clusters;
1085 for (nr = 2; nr < MSDOS_SB(sb)->clusters + 2; nr++) {
1086 ret = fat_access(sb, nr, -1);
1090 } else if (ret == FAT_ENT_FREE)
1093 MSDOS_SB(sb)->free_clusters = free;
1098 buf->f_type = sb->s_magic;
1099 buf->f_bsize = MSDOS_SB(sb)->cluster_size;
1100 buf->f_blocks = MSDOS_SB(sb)->clusters;
1101 buf->f_bfree = free;
1102 buf->f_bavail = free;
1103 buf->f_namelen = MSDOS_SB(sb)->options.isvfat ? 260 : 12;
1108 static int is_exec(unsigned char *extension)
1110 unsigned char *exe_extensions = "EXECOMBAT", *walk;
1112 for (walk = exe_extensions; *walk; walk += 3)
1113 if (!strncmp(extension, walk, 3))
1118 static int fat_writepage(struct page *page, struct writeback_control *wbc)
1120 return block_write_full_page(page,fat_get_block, wbc);
1122 static int fat_readpage(struct file *file, struct page *page)
1124 return block_read_full_page(page,fat_get_block);
1128 fat_prepare_write(struct file *file, struct page *page,
1129 unsigned from, unsigned to)
1132 return cont_prepare_write(page,from,to,fat_get_block,
1133 &MSDOS_I(page->mapping->host)->mmu_private);
1137 fat_commit_write(struct file *file, struct page *page,
1138 unsigned from, unsigned to)
1141 return generic_commit_write(file, page, from, to);
1144 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
1146 return generic_block_bmap(mapping,block,fat_get_block);
1148 static struct address_space_operations fat_aops = {
1149 .readpage = fat_readpage,
1150 .writepage = fat_writepage,
1151 .sync_page = block_sync_page,
1152 .prepare_write = fat_prepare_write,
1153 .commit_write = fat_commit_write,
1157 /* doesn't deal with root inode */
1158 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
1160 struct super_block *sb = inode->i_sb;
1161 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1164 MSDOS_I(inode)->i_pos = 0;
1165 inode->i_uid = sbi->options.fs_uid;
1166 inode->i_gid = sbi->options.fs_gid;
1168 inode->i_generation = get_seconds();
1170 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
1171 inode->i_generation &= ~1;
1172 inode->i_mode = MSDOS_MKMODE(de->attr,
1173 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1174 inode->i_op = sbi->dir_ops;
1175 inode->i_fop = &fat_dir_operations;
1177 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
1178 if (sbi->fat_bits == 32)
1179 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
1181 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
1182 error = fat_calc_dir_size(inode);
1185 MSDOS_I(inode)->mmu_private = inode->i_size;
1187 inode->i_nlink = fat_subdirs(inode);
1188 } else { /* not a directory */
1189 inode->i_generation |= 1;
1190 inode->i_mode = MSDOS_MKMODE(de->attr,
1191 ((sbi->options.showexec &&
1193 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
1194 & ~sbi->options.fs_fmask) | S_IFREG;
1195 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
1196 if (sbi->fat_bits == 32)
1197 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
1199 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
1200 inode->i_size = le32_to_cpu(de->size);
1201 inode->i_op = &fat_file_inode_operations;
1202 inode->i_fop = &fat_file_operations;
1203 inode->i_mapping->a_ops = &fat_aops;
1204 MSDOS_I(inode)->mmu_private = inode->i_size;
1206 if(de->attr & ATTR_SYS)
1207 if (sbi->options.sys_immutable)
1208 inode->i_flags |= S_IMMUTABLE;
1209 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
1210 /* this is as close to the truth as we can get ... */
1211 inode->i_blksize = sbi->cluster_size;
1212 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1213 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1214 inode->i_mtime.tv_sec = inode->i_atime.tv_sec =
1215 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
1216 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0;
1217 inode->i_ctime.tv_sec =
1218 MSDOS_SB(sb)->options.isvfat
1219 ? date_dos2unix(le16_to_cpu(de->ctime), le16_to_cpu(de->cdate))
1220 : inode->i_mtime.tv_sec;
1221 inode->i_ctime.tv_nsec = de->ctime_ms * 1000000;
1222 MSDOS_I(inode)->i_ctime_ms = de->ctime_ms;
1227 static int fat_write_inode(struct inode *inode, int wait)
1229 struct super_block *sb = inode->i_sb;
1230 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1231 struct buffer_head *bh;
1232 struct msdos_dir_entry *raw_entry;
1236 i_pos = MSDOS_I(inode)->i_pos;
1237 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) {
1241 if (!(bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits))) {
1242 printk(KERN_ERR "FAT: unable to read inode block "
1243 "for updating (i_pos %lld)\n", i_pos);
1247 spin_lock(&sbi->inode_hash_lock);
1248 if (i_pos != MSDOS_I(inode)->i_pos) {
1249 spin_unlock(&sbi->inode_hash_lock);
1255 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
1256 [i_pos & (sbi->dir_per_block - 1)];
1257 if (S_ISDIR(inode->i_mode)) {
1258 raw_entry->attr = ATTR_DIR;
1259 raw_entry->size = 0;
1262 raw_entry->attr = ATTR_NONE;
1263 raw_entry->size = cpu_to_le32(inode->i_size);
1265 raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
1266 MSDOS_I(inode)->i_attrs;
1267 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
1268 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
1269 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
1270 if (sbi->options.isvfat) {
1271 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
1272 raw_entry->ctime_ms = MSDOS_I(inode)->i_ctime_ms; /* use i_ctime.tv_nsec? */
1274 spin_unlock(&sbi->inode_hash_lock);
1275 mark_buffer_dirty(bh);
1282 int fat_notify_change(struct dentry * dentry, struct iattr * attr)
1284 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
1285 struct inode *inode = dentry->d_inode;
1286 int mask, error = 0;
1290 /* FAT cannot truncate to a longer file */
1291 if (attr->ia_valid & ATTR_SIZE) {
1292 if (attr->ia_size > inode->i_size) {
1298 error = inode_change_ok(inode, attr);
1300 if (sbi->options.quiet)
1305 if (((attr->ia_valid & ATTR_UID) &&
1306 (attr->ia_uid != sbi->options.fs_uid)) ||
1307 ((attr->ia_valid & ATTR_GID) &&
1308 (attr->ia_gid != sbi->options.fs_gid)) ||
1309 ((attr->ia_valid & ATTR_MODE) &&
1310 (attr->ia_mode & ~MSDOS_VALID_MODE)))
1314 if (sbi->options.quiet)
1318 error = inode_setattr(inode, attr);
1322 if (S_ISDIR(inode->i_mode))
1323 mask = sbi->options.fs_dmask;
1325 mask = sbi->options.fs_fmask;
1326 inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
1331 MODULE_LICENSE("GPL");