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 #define FAT_HASH_BITS 8
62 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
63 #define FAT_HASH_MASK (FAT_HASH_SIZE-1)
64 static struct list_head fat_inode_hashtable[FAT_HASH_SIZE];
65 static spinlock_t fat_inode_lock = SPIN_LOCK_UNLOCKED;
67 void fat_hash_init(void)
70 for(i = 0; i < FAT_HASH_SIZE; i++) {
71 INIT_LIST_HEAD(&fat_inode_hashtable[i]);
75 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
77 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
78 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
79 return tmp & FAT_HASH_MASK;
82 void fat_attach(struct inode *inode, loff_t i_pos)
84 spin_lock(&fat_inode_lock);
85 MSDOS_I(inode)->i_pos = i_pos;
86 list_add(&MSDOS_I(inode)->i_fat_hash,
87 fat_inode_hashtable + fat_hash(inode->i_sb, i_pos));
88 spin_unlock(&fat_inode_lock);
91 void fat_detach(struct inode *inode)
93 spin_lock(&fat_inode_lock);
94 MSDOS_I(inode)->i_pos = 0;
95 list_del_init(&MSDOS_I(inode)->i_fat_hash);
96 spin_unlock(&fat_inode_lock);
99 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
101 struct list_head *p = fat_inode_hashtable + fat_hash(sb, i_pos);
102 struct list_head *walk;
103 struct msdos_inode_info *i;
104 struct inode *inode = NULL;
106 spin_lock(&fat_inode_lock);
107 list_for_each(walk, p) {
108 i = list_entry(walk, struct msdos_inode_info, i_fat_hash);
109 if (i->vfs_inode.i_sb != sb)
111 if (i->i_pos != i_pos)
113 inode = igrab(&i->vfs_inode);
117 spin_unlock(&fat_inode_lock);
121 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
123 struct inode *fat_build_inode(struct super_block *sb,
124 struct msdos_dir_entry *de, loff_t i_pos, int *res)
128 inode = fat_iget(sb, i_pos);
131 inode = new_inode(sb);
135 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
136 inode->i_version = 1;
137 *res = fat_fill_inode(inode, de);
143 fat_attach(inode, i_pos);
144 insert_inode_hash(inode);
149 static void fat_delete_inode(struct inode *inode)
151 if (!is_bad_inode(inode)) {
158 static void fat_clear_inode(struct inode *inode)
160 if (is_bad_inode(inode))
163 spin_lock(&fat_inode_lock);
164 fat_cache_inval_inode(inode);
165 list_del_init(&MSDOS_I(inode)->i_fat_hash);
166 spin_unlock(&fat_inode_lock);
170 static void fat_put_super(struct super_block *sb)
172 struct msdos_sb_info *sbi = MSDOS_SB(sb);
174 if (!(sb->s_flags & MS_RDONLY))
175 fat_clusters_flush(sb);
178 unload_nls(sbi->nls_disk);
179 sbi->nls_disk = NULL;
180 sbi->options.codepage = fat_default_codepage;
183 unload_nls(sbi->nls_io);
186 if (sbi->options.iocharset != fat_default_iocharset) {
187 kfree(sbi->options.iocharset);
188 sbi->options.iocharset = fat_default_iocharset;
191 sb->s_fs_info = NULL;
195 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
197 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
198 struct fat_mount_options *opts = &sbi->options;
199 int isvfat = opts->isvfat;
201 if (opts->fs_uid != 0)
202 seq_printf(m, ",uid=%u", opts->fs_uid);
203 if (opts->fs_gid != 0)
204 seq_printf(m, ",gid=%u", opts->fs_gid);
205 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
206 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
207 if (sbi->nls_disk && opts->codepage != fat_default_codepage)
208 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
211 strcmp(opts->iocharset, fat_default_iocharset))
212 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
214 switch (opts->shortname) {
215 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
216 seq_puts(m, ",shortname=win95");
218 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
219 seq_puts(m, ",shortname=winnt");
221 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
222 seq_puts(m, ",shortname=mixed");
224 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
225 /* seq_puts(m, ",shortname=lower"); */
228 seq_puts(m, ",shortname=unknown");
232 if (opts->name_check != 'n')
233 seq_printf(m, ",check=%c", opts->name_check);
235 seq_puts(m, ",quiet");
237 seq_puts(m, ",showexec");
238 if (opts->sys_immutable)
239 seq_puts(m, ",sys_immutable");
242 seq_puts(m, ",dotsOK=yes");
244 seq_puts(m, ",nocase");
247 seq_puts(m, ",utf8");
248 if (opts->unicode_xlate)
249 seq_puts(m, ",uni_xlate");
251 seq_puts(m, ",nonumtail");
258 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
259 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
260 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
261 Opt_dots, Opt_nodots,
262 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
263 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
264 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
265 Opt_obsolate, Opt_err,
268 static match_table_t fat_tokens = {
269 {Opt_check_r, "check=relaxed"},
270 {Opt_check_s, "check=strict"},
271 {Opt_check_n, "check=normal"},
272 {Opt_check_r, "check=r"},
273 {Opt_check_s, "check=s"},
274 {Opt_check_n, "check=n"},
277 {Opt_umask, "umask=%o"},
278 {Opt_dmask, "dmask=%o"},
279 {Opt_fmask, "fmask=%o"},
280 {Opt_codepage, "codepage=%u"},
281 {Opt_nocase, "nocase"},
282 {Opt_quiet, "quiet"},
283 {Opt_showexec, "showexec"},
284 {Opt_debug, "debug"},
285 {Opt_immutable, "sys_immutable"},
286 {Opt_obsolate, "conv=binary"},
287 {Opt_obsolate, "conv=text"},
288 {Opt_obsolate, "conv=auto"},
289 {Opt_obsolate, "conv=b"},
290 {Opt_obsolate, "conv=t"},
291 {Opt_obsolate, "conv=a"},
292 {Opt_obsolate, "fat=%u"},
293 {Opt_obsolate, "blocksize=%u"},
294 {Opt_obsolate, "cvf_format=%20s"},
295 {Opt_obsolate, "cvf_options=%100s"},
296 {Opt_obsolate, "posix"},
299 static match_table_t msdos_tokens = {
300 {Opt_nodots, "nodots"},
301 {Opt_nodots, "dotsOK=no"},
303 {Opt_dots, "dotsOK=yes"},
306 static match_table_t vfat_tokens = {
307 {Opt_charset, "iocharset=%s"},
308 {Opt_shortname_lower, "shortname=lower"},
309 {Opt_shortname_win95, "shortname=win95"},
310 {Opt_shortname_winnt, "shortname=winnt"},
311 {Opt_shortname_mixed, "shortname=mixed"},
312 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
313 {Opt_utf8_no, "utf8=no"},
314 {Opt_utf8_no, "utf8=false"},
315 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
316 {Opt_utf8_yes, "utf8=yes"},
317 {Opt_utf8_yes, "utf8=true"},
318 {Opt_utf8_yes, "utf8"},
319 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
320 {Opt_uni_xl_no, "uni_xlate=no"},
321 {Opt_uni_xl_no, "uni_xlate=false"},
322 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
323 {Opt_uni_xl_yes, "uni_xlate=yes"},
324 {Opt_uni_xl_yes, "uni_xlate=true"},
325 {Opt_uni_xl_yes, "uni_xlate"},
326 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
327 {Opt_nonumtail_no, "nonumtail=no"},
328 {Opt_nonumtail_no, "nonumtail=false"},
329 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
330 {Opt_nonumtail_yes, "nonumtail=yes"},
331 {Opt_nonumtail_yes, "nonumtail=true"},
332 {Opt_nonumtail_yes, "nonumtail"},
336 static int parse_options(char *options, int is_vfat, int *debug,
337 struct fat_mount_options *opts)
340 substring_t args[MAX_OPT_ARGS];
344 opts->isvfat = is_vfat;
346 opts->fs_uid = current->uid;
347 opts->fs_gid = current->gid;
348 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
349 opts->codepage = fat_default_codepage;
350 opts->iocharset = fat_default_iocharset;
352 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
355 opts->name_check = 'n';
356 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
357 opts->utf8 = opts->unicode_xlate = 0;
365 while ((p = strsep(&options, ",")) != NULL) {
370 token = match_token(p, fat_tokens, args);
371 if (token == Opt_err) {
373 token = match_token(p, vfat_tokens, args);
375 token = match_token(p, msdos_tokens, args);
379 opts->name_check = 's';
382 opts->name_check = 'r';
385 opts->name_check = 'n';
391 /* for backward compatibility */
392 opts->shortname = VFAT_SFN_DISPLAY_WIN95
393 | VFAT_SFN_CREATE_WIN95;
406 opts->sys_immutable = 1;
409 if (match_int(&args[0], &option))
411 opts->fs_uid = option;
414 if (match_int(&args[0], &option))
416 opts->fs_gid = option;
419 if (match_octal(&args[0], &option))
421 opts->fs_fmask = opts->fs_dmask = option;
424 if (match_octal(&args[0], &option))
426 opts->fs_dmask = option;
429 if (match_octal(&args[0], &option))
431 opts->fs_fmask = option;
434 if (match_int(&args[0], &option))
436 opts->codepage = option;
449 if (opts->iocharset != fat_default_iocharset)
450 kfree(opts->iocharset);
451 iocharset = match_strdup(&args[0]);
454 opts->iocharset = iocharset;
456 case Opt_shortname_lower:
457 opts->shortname = VFAT_SFN_DISPLAY_LOWER
458 | VFAT_SFN_CREATE_WIN95;
460 case Opt_shortname_win95:
461 opts->shortname = VFAT_SFN_DISPLAY_WIN95
462 | VFAT_SFN_CREATE_WIN95;
464 case Opt_shortname_winnt:
465 opts->shortname = VFAT_SFN_DISPLAY_WINNT
466 | VFAT_SFN_CREATE_WINNT;
468 case Opt_shortname_mixed:
469 opts->shortname = VFAT_SFN_DISPLAY_WINNT
470 | VFAT_SFN_CREATE_WIN95;
472 case Opt_utf8_no: /* 0 or no or false */
475 case Opt_utf8_yes: /* empty or 1 or yes or true */
478 case Opt_uni_xl_no: /* 0 or no or false */
479 opts->unicode_xlate = 0;
481 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
482 opts->unicode_xlate = 1;
484 case Opt_nonumtail_no: /* 0 or no or false */
485 opts->numtail = 1; /* negated option */
487 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
488 opts->numtail = 0; /* negated option */
491 /* obsolete mount options */
493 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
494 "not supported now\n", p);
498 printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" "
499 "or missing value\n", p);
503 /* UTF8 doesn't provide FAT semantics */
504 if (!strcmp(opts->iocharset, "utf8")) {
505 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
506 " for FAT filesystems, filesystem will be case sensitive!\n");
509 if (opts->unicode_xlate)
515 static int fat_calc_dir_size(struct inode *inode)
517 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
518 int ret, fclus, dclus;
521 if (MSDOS_I(inode)->i_start == 0)
524 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
527 inode->i_size = (fclus + 1) << sbi->cluster_bits;
532 static int fat_read_root(struct inode *inode)
534 struct super_block *sb = inode->i_sb;
535 struct msdos_sb_info *sbi = MSDOS_SB(sb);
538 MSDOS_I(inode)->file_cluster = MSDOS_I(inode)->disk_cluster = 0;
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 INIT_LIST_HEAD(&ei->i_fat_hash);
742 inode_init_once(&ei->vfs_inode);
746 int __init fat_init_inodecache(void)
748 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
749 sizeof(struct msdos_inode_info),
750 0, SLAB_RECLAIM_ACCOUNT,
752 if (fat_inode_cachep == NULL)
757 void __exit fat_destroy_inodecache(void)
759 if (kmem_cache_destroy(fat_inode_cachep))
760 printk(KERN_INFO "fat_inode_cache: not all structures were freed\n");
763 static int fat_remount(struct super_block *sb, int *flags, char *data)
765 *flags |= MS_NODIRATIME;
769 static struct super_operations fat_sops = {
770 .alloc_inode = fat_alloc_inode,
771 .destroy_inode = fat_destroy_inode,
772 .write_inode = fat_write_inode,
773 .delete_inode = fat_delete_inode,
774 .put_super = fat_put_super,
775 .statfs = fat_statfs,
776 .clear_inode = fat_clear_inode,
777 .remount_fs = fat_remount,
779 .read_inode = make_bad_inode,
781 .show_options = fat_show_options,
784 static struct export_operations fat_export_ops = {
785 .decode_fh = fat_decode_fh,
786 .encode_fh = fat_encode_fh,
787 .get_dentry = fat_get_dentry,
788 .get_parent = fat_get_parent,
792 * Read the super block of an MS-DOS FS.
794 int fat_fill_super(struct super_block *sb, void *data, int silent,
795 struct inode_operations *fs_dir_inode_ops, int isvfat)
797 struct inode *root_inode = NULL;
798 struct buffer_head *bh;
799 struct fat_boot_sector *b;
800 struct msdos_sb_info *sbi;
801 u16 logical_sector_size;
802 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
808 sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
812 memset(sbi, 0, sizeof(struct msdos_sb_info));
814 sb->s_flags |= MS_NODIRATIME;
815 sb->s_magic = MSDOS_SUPER_MAGIC;
816 sb->s_op = &fat_sops;
817 sb->s_export_op = &fat_export_ops;
818 sbi->dir_ops = fs_dir_inode_ops;
820 error = parse_options(data, isvfat, &debug, &sbi->options);
825 /* set up enough so that it can read an inode */
826 init_MUTEX(&sbi->fat_lock);
829 sb_min_blocksize(sb, 512);
830 bh = sb_bread(sb, 0);
832 printk(KERN_ERR "FAT: unable to read boot sector\n");
836 b = (struct fat_boot_sector *) bh->b_data;
839 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
845 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
851 * Earlier we checked here that b->secs_track and b->head are nonzero,
852 * but it turns out valid FAT filesystems can have zero there.
856 if (!FAT_VALID_MEDIA(media)) {
858 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
863 logical_sector_size = CF_LE_W(get_unaligned((__le16 *)&b->sector_size));
864 if (!logical_sector_size
865 || (logical_sector_size & (logical_sector_size - 1))
866 || (logical_sector_size < 512)
867 || (PAGE_CACHE_SIZE < logical_sector_size)) {
869 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
870 logical_sector_size);
874 sbi->sec_per_clus = b->sec_per_clus;
875 if (!sbi->sec_per_clus
876 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
878 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
884 if (logical_sector_size < sb->s_blocksize) {
885 printk(KERN_ERR "FAT: logical sector size too small for device"
886 " (logical sector size = %u)\n", logical_sector_size);
890 if (logical_sector_size > sb->s_blocksize) {
893 if (!sb_set_blocksize(sb, logical_sector_size)) {
894 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
895 logical_sector_size);
898 bh = sb_bread(sb, 0);
900 printk(KERN_ERR "FAT: unable to read boot sector"
901 " (logical sector size = %lu)\n",
905 b = (struct fat_boot_sector *) bh->b_data;
908 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
909 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
911 sbi->fat_bits = 0; /* Don't know yet */
912 sbi->fat_start = CF_LE_W(b->reserved);
913 sbi->fat_length = CF_LE_W(b->fat_length);
914 sbi->root_cluster = 0;
915 sbi->free_clusters = -1; /* Don't know yet */
918 if (!sbi->fat_length && b->fat32_length) {
919 struct fat_boot_fsinfo *fsinfo;
920 struct buffer_head *fsinfo_bh;
924 sbi->fat_length = CF_LE_L(b->fat32_length);
925 sbi->root_cluster = CF_LE_L(b->root_cluster);
927 sb->s_maxbytes = 0xffffffff;
929 /* MC - if info_sector is 0, don't multiply by 0 */
930 sbi->fsinfo_sector = CF_LE_W(b->info_sector);
931 if (sbi->fsinfo_sector == 0)
932 sbi->fsinfo_sector = 1;
934 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
935 if (fsinfo_bh == NULL) {
936 printk(KERN_ERR "FAT: bread failed, FSINFO block"
937 " (sector = %lu)\n", sbi->fsinfo_sector);
942 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
943 if (!IS_FSINFO(fsinfo)) {
945 "FAT: Did not find valid FSINFO signature.\n"
946 " Found signature1 0x%08x signature2 0x%08x"
948 CF_LE_L(fsinfo->signature1),
949 CF_LE_L(fsinfo->signature2),
952 sbi->free_clusters = CF_LE_L(fsinfo->free_clusters);
953 sbi->prev_free = CF_LE_L(fsinfo->next_cluster);
959 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
960 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
962 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
963 sbi->dir_entries = CF_LE_W(get_unaligned((__le16 *)&b->dir_entries));
964 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
966 printk(KERN_ERR "FAT: bogus directroy-entries per block"
967 " (%u)\n", sbi->dir_entries);
972 rootdir_sectors = sbi->dir_entries
973 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
974 sbi->data_start = sbi->dir_start + rootdir_sectors;
975 total_sectors = CF_LE_W(get_unaligned((__le16 *)&b->sectors));
976 if (total_sectors == 0)
977 total_sectors = CF_LE_L(b->total_sect);
979 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
981 if (sbi->fat_bits != 32)
982 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
984 /* check that FAT table does not overflow */
985 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
986 total_clusters = min(total_clusters, fat_clusters - 2);
987 if (total_clusters > MAX_FAT(sb)) {
989 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
995 sbi->clusters = total_clusters;
999 /* validity check of FAT */
1000 first = __fat_access(sb, 0, -1);
1005 if (FAT_FIRST_ENT(sb, media) == first) {
1006 /* all is as it should be */
1007 } else if (media == 0xf8 && FAT_FIRST_ENT(sb, 0xfe) == first) {
1008 /* bad, reported on pc9800 */
1009 } else if (media == 0xf8 && FAT_FIRST_ENT(sb, 0xff) == first) {
1010 /* bad, reported on Nokia phone with USB storage */
1011 } else if (media == 0xf0 && FAT_FIRST_ENT(sb, 0xf8) == first) {
1012 /* bad, reported with a MO disk on win95/me */
1013 } else if (first == 0) {
1014 /* bad, reported with a SmartMedia card */
1017 printk(KERN_ERR "FAT: invalid first entry of FAT "
1019 FAT_FIRST_ENT(sb, media), first);
1024 sprintf(buf, "cp%d", sbi->options.codepage);
1025 sbi->nls_disk = load_nls(buf);
1026 if (!sbi->nls_disk) {
1027 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1031 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1032 if (sbi->options.isvfat) {
1033 sbi->nls_io = load_nls(sbi->options.iocharset);
1035 printk(KERN_ERR "FAT: IO charset %s not found\n",
1036 sbi->options.iocharset);
1042 root_inode = new_inode(sb);
1045 root_inode->i_ino = MSDOS_ROOT_INO;
1046 root_inode->i_version = 1;
1047 error = fat_read_root(root_inode);
1051 insert_inode_hash(root_inode);
1052 sb->s_root = d_alloc_root(root_inode);
1054 printk(KERN_ERR "FAT: get root inode failed\n");
1063 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1064 " on dev %s.\n", sb->s_id);
1070 unload_nls(sbi->nls_io);
1072 unload_nls(sbi->nls_disk);
1073 if (sbi->options.iocharset != fat_default_iocharset)
1074 kfree(sbi->options.iocharset);
1075 sb->s_fs_info = NULL;
1080 static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
1084 if (MSDOS_SB(sb)->free_clusters != -1)
1085 free = MSDOS_SB(sb)->free_clusters;
1088 if (MSDOS_SB(sb)->free_clusters != -1)
1089 free = MSDOS_SB(sb)->free_clusters;
1092 for (nr = 2; nr < MSDOS_SB(sb)->clusters + 2; nr++) {
1093 ret = fat_access(sb, nr, -1);
1097 } else if (ret == FAT_ENT_FREE)
1100 MSDOS_SB(sb)->free_clusters = free;
1105 buf->f_type = sb->s_magic;
1106 buf->f_bsize = MSDOS_SB(sb)->cluster_size;
1107 buf->f_blocks = MSDOS_SB(sb)->clusters;
1108 buf->f_bfree = free;
1109 buf->f_bavail = free;
1110 buf->f_namelen = MSDOS_SB(sb)->options.isvfat ? 260 : 12;
1115 static int is_exec(unsigned char *extension)
1117 unsigned char *exe_extensions = "EXECOMBAT", *walk;
1119 for (walk = exe_extensions; *walk; walk += 3)
1120 if (!strncmp(extension, walk, 3))
1125 static int fat_writepage(struct page *page, struct writeback_control *wbc)
1127 return block_write_full_page(page,fat_get_block, wbc);
1129 static int fat_readpage(struct file *file, struct page *page)
1131 return block_read_full_page(page,fat_get_block);
1135 fat_prepare_write(struct file *file, struct page *page,
1136 unsigned from, unsigned to)
1139 return cont_prepare_write(page,from,to,fat_get_block,
1140 &MSDOS_I(page->mapping->host)->mmu_private);
1144 fat_commit_write(struct file *file, struct page *page,
1145 unsigned from, unsigned to)
1148 return generic_commit_write(file, page, from, to);
1151 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
1153 return generic_block_bmap(mapping,block,fat_get_block);
1155 static struct address_space_operations fat_aops = {
1156 .readpage = fat_readpage,
1157 .writepage = fat_writepage,
1158 .sync_page = block_sync_page,
1159 .prepare_write = fat_prepare_write,
1160 .commit_write = fat_commit_write,
1164 /* doesn't deal with root inode */
1165 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
1167 struct super_block *sb = inode->i_sb;
1168 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1171 MSDOS_I(inode)->file_cluster = MSDOS_I(inode)->disk_cluster = 0;
1172 MSDOS_I(inode)->i_pos = 0;
1173 inode->i_uid = sbi->options.fs_uid;
1174 inode->i_gid = sbi->options.fs_gid;
1176 inode->i_generation = get_seconds();
1178 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
1179 inode->i_generation &= ~1;
1180 inode->i_mode = MSDOS_MKMODE(de->attr,
1181 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1182 inode->i_op = sbi->dir_ops;
1183 inode->i_fop = &fat_dir_operations;
1185 MSDOS_I(inode)->i_start = CF_LE_W(de->start);
1186 if (sbi->fat_bits == 32)
1187 MSDOS_I(inode)->i_start |= (CF_LE_W(de->starthi) << 16);
1189 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
1190 error = fat_calc_dir_size(inode);
1193 MSDOS_I(inode)->mmu_private = inode->i_size;
1195 inode->i_nlink = fat_subdirs(inode);
1196 } else { /* not a directory */
1197 inode->i_generation |= 1;
1198 inode->i_mode = MSDOS_MKMODE(de->attr,
1199 ((sbi->options.showexec &&
1201 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
1202 & ~sbi->options.fs_fmask) | S_IFREG;
1203 MSDOS_I(inode)->i_start = CF_LE_W(de->start);
1204 if (sbi->fat_bits == 32)
1205 MSDOS_I(inode)->i_start |= (CF_LE_W(de->starthi) << 16);
1207 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
1208 inode->i_size = CF_LE_L(de->size);
1209 inode->i_op = &fat_file_inode_operations;
1210 inode->i_fop = &fat_file_operations;
1211 inode->i_mapping->a_ops = &fat_aops;
1212 MSDOS_I(inode)->mmu_private = inode->i_size;
1214 if(de->attr & ATTR_SYS)
1215 if (sbi->options.sys_immutable)
1216 inode->i_flags |= S_IMMUTABLE;
1217 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
1218 /* this is as close to the truth as we can get ... */
1219 inode->i_blksize = sbi->cluster_size;
1220 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1221 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1222 inode->i_mtime.tv_sec = inode->i_atime.tv_sec =
1223 date_dos2unix(CF_LE_W(de->time),CF_LE_W(de->date));
1224 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0;
1225 inode->i_ctime.tv_sec =
1226 MSDOS_SB(sb)->options.isvfat
1227 ? date_dos2unix(CF_LE_W(de->ctime),CF_LE_W(de->cdate))
1228 : inode->i_mtime.tv_sec;
1229 inode->i_ctime.tv_nsec = de->ctime_ms * 1000000;
1230 MSDOS_I(inode)->i_ctime_ms = de->ctime_ms;
1235 int fat_write_inode(struct inode *inode, int wait)
1237 struct super_block *sb = inode->i_sb;
1238 struct buffer_head *bh;
1239 struct msdos_dir_entry *raw_entry;
1243 i_pos = MSDOS_I(inode)->i_pos;
1244 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) {
1248 if (!(bh = sb_bread(sb, i_pos >> MSDOS_SB(sb)->dir_per_block_bits))) {
1249 printk(KERN_ERR "FAT: unable to read inode block "
1250 "for updating (i_pos %lld)\n", i_pos);
1254 spin_lock(&fat_inode_lock);
1255 if (i_pos != MSDOS_I(inode)->i_pos) {
1256 spin_unlock(&fat_inode_lock);
1262 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
1263 [i_pos & (MSDOS_SB(sb)->dir_per_block - 1)];
1264 if (S_ISDIR(inode->i_mode)) {
1265 raw_entry->attr = ATTR_DIR;
1266 raw_entry->size = 0;
1269 raw_entry->attr = ATTR_NONE;
1270 raw_entry->size = CT_LE_L(inode->i_size);
1272 raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
1273 MSDOS_I(inode)->i_attrs;
1274 raw_entry->start = CT_LE_W(MSDOS_I(inode)->i_logstart);
1275 raw_entry->starthi = CT_LE_W(MSDOS_I(inode)->i_logstart >> 16);
1276 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
1277 if (MSDOS_SB(sb)->options.isvfat) {
1278 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
1279 raw_entry->ctime_ms = MSDOS_I(inode)->i_ctime_ms; /* use i_ctime.tv_nsec? */
1281 spin_unlock(&fat_inode_lock);
1282 mark_buffer_dirty(bh);
1289 int fat_notify_change(struct dentry * dentry, struct iattr * attr)
1291 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
1292 struct inode *inode = dentry->d_inode;
1293 int mask, error = 0;
1297 /* FAT cannot truncate to a longer file */
1298 if (attr->ia_valid & ATTR_SIZE) {
1299 if (attr->ia_size > inode->i_size) {
1305 error = inode_change_ok(inode, attr);
1307 if (sbi->options.quiet)
1312 if (((attr->ia_valid & ATTR_UID) &&
1313 (attr->ia_uid != sbi->options.fs_uid)) ||
1314 ((attr->ia_valid & ATTR_GID) &&
1315 (attr->ia_gid != sbi->options.fs_gid)) ||
1316 ((attr->ia_valid & ATTR_MODE) &&
1317 (attr->ia_mode & ~MSDOS_VALID_MODE)))
1321 if (sbi->options.quiet)
1325 error = inode_setattr(inode, attr);
1329 if (S_ISDIR(inode->i_mode))
1330 mask = sbi->options.fs_dmask;
1332 mask = sbi->options.fs_fmask;
1333 inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
1338 MODULE_LICENSE("GPL");