4 * directory handling functions for fat-based filesystems
6 * Written 1992,1993 by Werner Almesberger
8 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
10 * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
11 * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
12 * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
13 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/time.h>
19 #include <linux/buffer_head.h>
20 #include <linux/compat.h>
21 #include <asm/uaccess.h>
22 #include <linux/kernel.h>
26 * Maximum buffer size of short name.
27 * [(MSDOS_NAME + '.') * max one char + nul]
28 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
30 #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
32 * Maximum buffer size of unicode chars from slots.
33 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
35 #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
36 #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
38 static inline unsigned char fat_tolower(unsigned char c)
40 return ((c >= 'A') && (c <= 'Z')) ? c+32 : c;
43 static inline loff_t fat_make_i_pos(struct super_block *sb,
44 struct buffer_head *bh,
45 struct msdos_dir_entry *de)
47 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
48 | (de - (struct msdos_dir_entry *)bh->b_data);
51 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
54 struct super_block *sb = dir->i_sb;
55 struct msdos_sb_info *sbi = MSDOS_SB(sb);
56 struct buffer_head *bh;
59 /* This is not a first sector of cluster, or sec_per_clus == 1 */
60 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
62 /* root dir of FAT12/FAT16 */
63 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
66 bh = sb_find_get_block(sb, phys);
67 if (bh == NULL || !buffer_uptodate(bh)) {
68 for (sec = 0; sec < sbi->sec_per_clus; sec++)
69 sb_breadahead(sb, phys + sec);
74 /* Returns the inode number of the directory entry at offset pos. If bh is
75 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
77 AV. Most often we do it item-by-item. Makes sense to optimize.
78 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
79 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
80 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
81 AV. Additionally, when we return -1 (i.e. reached the end of directory)
84 static int fat__get_entry(struct inode *dir, loff_t *pos,
85 struct buffer_head **bh, struct msdos_dir_entry **de)
87 struct super_block *sb = dir->i_sb;
88 sector_t phys, iblock;
89 unsigned long mapped_blocks;
97 iblock = *pos >> sb->s_blocksize_bits;
98 err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
100 return -1; /* beyond EOF or error */
102 fat_dir_readahead(dir, iblock, phys);
104 *bh = sb_bread(sb, phys);
106 fat_msg_ratelimit(sb, KERN_ERR,
107 "Directory bread(block %llu) failed", (llu)phys);
108 /* skip this block */
109 *pos = (iblock + 1) << sb->s_blocksize_bits;
113 offset = *pos & (sb->s_blocksize - 1);
114 *pos += sizeof(struct msdos_dir_entry);
115 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
120 static inline int fat_get_entry(struct inode *dir, loff_t *pos,
121 struct buffer_head **bh,
122 struct msdos_dir_entry **de)
124 /* Fast stuff first */
126 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
127 *pos += sizeof(struct msdos_dir_entry);
131 return fat__get_entry(dir, pos, bh, de);
135 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
136 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
137 * colon as an escape character since it is normally invalid on the vfat
138 * filesystem. The following four characters are the hexadecimal digits
139 * of Unicode value. This lets us do a full dump and restore of Unicode
140 * filenames. We could get into some trouble with long Unicode names,
141 * but ignore that right now.
142 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
144 static int uni16_to_x8(struct super_block *sb, unsigned char *ascii,
145 const wchar_t *uni, int len, struct nls_table *nls)
147 int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
156 while (*ip && ((len - NLS_MAX_CHARSET_SIZE) > 0)) {
158 if ((charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
162 if (uni_xlate == 1) {
164 op = hex_byte_pack(op, ec >> 8);
165 op = hex_byte_pack(op, ec);
175 fat_msg(sb, KERN_WARNING, "filename was truncated while "
183 static inline int fat_uni_to_x8(struct super_block *sb, const wchar_t *uni,
184 unsigned char *buf, int size)
186 struct msdos_sb_info *sbi = MSDOS_SB(sb);
187 if (sbi->options.utf8)
188 return utf16s_to_utf8s(uni, FAT_MAX_UNI_CHARS,
189 UTF16_HOST_ENDIAN, buf, size);
191 return uni16_to_x8(sb, buf, uni, size, sbi->nls_io);
195 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
199 charlen = t->char2uni(c, clen, uni);
201 *uni = 0x003f; /* a question mark */
208 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
213 charlen = t->char2uni(c, clen, &wc);
215 *uni = 0x003f; /* a question mark */
217 } else if (charlen <= 1) {
218 unsigned char nc = t->charset2lower[*c];
223 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
224 *uni = 0x003f; /* a question mark */
234 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
235 wchar_t *uni_buf, unsigned short opt, int lower)
239 if (opt & VFAT_SFN_DISPLAY_LOWER)
240 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
241 else if (opt & VFAT_SFN_DISPLAY_WIN95)
242 len = fat_short2uni(nls, buf, buf_size, uni_buf);
243 else if (opt & VFAT_SFN_DISPLAY_WINNT) {
245 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
247 len = fat_short2uni(nls, buf, buf_size, uni_buf);
249 len = fat_short2uni(nls, buf, buf_size, uni_buf);
254 static inline int fat_name_match(struct msdos_sb_info *sbi,
255 const unsigned char *a, int a_len,
256 const unsigned char *b, int b_len)
261 if (sbi->options.name_check != 's')
262 return !nls_strnicmp(sbi->nls_io, a, b, a_len);
264 return !memcmp(a, b, a_len);
267 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
270 * fat_parse_long - Parse extended directory entry.
272 * This function returns zero on success, negative value on error, or one of
275 * %PARSE_INVALID - Directory entry is invalid.
276 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
277 * %PARSE_EOF - Directory has no more entries.
279 static int fat_parse_long(struct inode *dir, loff_t *pos,
280 struct buffer_head **bh, struct msdos_dir_entry **de,
281 wchar_t **unicode, unsigned char *nr_slots)
283 struct msdos_dir_slot *ds;
284 unsigned char id, slot, slots, alias_checksum;
287 *unicode = __getname();
295 ds = (struct msdos_dir_slot *)*de;
298 return PARSE_INVALID;
300 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
301 return PARSE_INVALID;
303 alias_checksum = ds->alias_checksum;
311 fat16_towchar(*unicode + offset, ds->name0_4, 5);
312 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
313 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
316 (*unicode)[offset + 13] = 0;
317 if (fat_get_entry(dir, pos, bh, de) < 0)
321 ds = (struct msdos_dir_slot *)*de;
322 if (ds->attr != ATTR_EXT)
323 return PARSE_NOT_LONGNAME;
324 if ((ds->id & ~0x40) != slot)
326 if (ds->alias_checksum != alias_checksum)
329 if ((*de)->name[0] == DELETED_FLAG)
330 return PARSE_INVALID;
331 if ((*de)->attr == ATTR_EXT)
333 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
334 return PARSE_INVALID;
335 if (fat_checksum((*de)->name) != alias_checksum)
342 * fat_parse_short - Parse MS-DOS (short) directory entry.
344 * @de: directory entry to parse
345 * @name: FAT_MAX_SHORT_SIZE array in which to place extracted name
346 * @dot_hidden: Nonzero == prepend '.' to names with ATTR_HIDDEN
348 * Returns the number of characters extracted into 'name'.
350 static int fat_parse_short(struct super_block *sb,
351 const struct msdos_dir_entry *de,
352 unsigned char *name, int dot_hidden)
354 const struct msdos_sb_info *sbi = MSDOS_SB(sb);
355 int isvfat = sbi->options.isvfat;
356 int nocase = sbi->options.nocase;
357 unsigned short opt_shortname = sbi->options.shortname;
358 struct nls_table *nls_disk = sbi->nls_disk;
359 wchar_t uni_name[14];
360 unsigned char c, work[MSDOS_NAME];
361 unsigned char *ptname = name;
362 int chi, chl, i, j, k;
364 int name_len = 0, uni_len = 0;
366 if (!isvfat && dot_hidden && (de->attr & ATTR_HIDDEN)) {
371 memcpy(work, de->name, sizeof(work));
372 /* see namei.c, msdos_format_name */
377 for (i = 0, j = 0; i < 8;) {
381 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
382 &uni_name[j++], opt_shortname,
383 de->lcase & CASE_LOWER_BASE);
386 ptname[i] = nocase ? c : fat_tolower(c);
397 for (chi = 0; chi < chl && i < 8; chi++, i++)
407 fat_short2uni(nls_disk, ".", 1, &uni_name[j++]);
413 for (k = 8; k < MSDOS_NAME;) {
417 chl = fat_shortname2uni(nls_disk, &work[k], MSDOS_NAME - k,
418 &uni_name[j++], opt_shortname,
419 de->lcase & CASE_LOWER_EXT);
423 ptname[i] = nocase ? c : fat_tolower(c);
432 int offset = min(chl, MSDOS_NAME-k);
436 for (chi = 0; chi < chl && k < MSDOS_NAME;
447 name_len += dotoffset;
449 if (sbi->options.isvfat) {
450 uni_name[uni_len] = 0x0000;
451 name_len = fat_uni_to_x8(sb, uni_name, name,
460 * Return values: negative -> error, 0 -> not found, positive -> found,
461 * value is the total amount of slots, including the shortname entry.
463 int fat_search_long(struct inode *inode, const unsigned char *name,
464 int name_len, struct fat_slot_info *sinfo)
466 struct super_block *sb = inode->i_sb;
467 struct msdos_sb_info *sbi = MSDOS_SB(sb);
468 struct buffer_head *bh = NULL;
469 struct msdos_dir_entry *de;
470 unsigned char nr_slots;
471 wchar_t *unicode = NULL;
472 unsigned char bufname[FAT_MAX_SHORT_SIZE];
478 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
482 if (de->name[0] == DELETED_FLAG)
484 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
486 if (de->attr != ATTR_EXT && IS_FREE(de->name))
488 if (de->attr == ATTR_EXT) {
489 int status = fat_parse_long(inode, &cpos, &bh, &de,
490 &unicode, &nr_slots);
494 } else if (status == PARSE_INVALID)
496 else if (status == PARSE_NOT_LONGNAME)
498 else if (status == PARSE_EOF)
502 /* Never prepend '.' to hidden files here.
503 * That is done only for msdos mounts (and only when
504 * 'dotsOK=yes'); if we are executing here, it is in the
505 * context of a vfat mount.
507 len = fat_parse_short(sb, de, bufname, 0);
511 /* Compare shortname */
512 if (fat_name_match(sbi, name, name_len, bufname, len))
516 void *longname = unicode + FAT_MAX_UNI_CHARS;
517 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
519 /* Compare longname */
520 len = fat_uni_to_x8(sb, unicode, longname, size);
521 if (fat_name_match(sbi, name, name_len, longname, len))
527 nr_slots++; /* include the de */
528 sinfo->slot_off = cpos - nr_slots * sizeof(*de);
529 sinfo->nr_slots = nr_slots;
532 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
540 EXPORT_SYMBOL_GPL(fat_search_long);
542 struct fat_ioctl_filldir_callback {
546 const char *longname;
548 const char *shortname;
552 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
553 filldir_t filldir, int short_only, int both)
555 struct super_block *sb = inode->i_sb;
556 struct msdos_sb_info *sbi = MSDOS_SB(sb);
557 struct buffer_head *bh;
558 struct msdos_dir_entry *de;
559 unsigned char nr_slots;
560 wchar_t *unicode = NULL;
561 unsigned char bufname[FAT_MAX_SHORT_SIZE];
562 int isvfat = sbi->options.isvfat;
563 const char *fill_name = NULL;
565 unsigned long lpos, dummy, *furrfu = &lpos;
567 int short_len = 0, fill_len = 0;
573 /* Fake . and .. for the root directory. */
574 if (inode->i_ino == MSDOS_ROOT_INO) {
576 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
587 if (cpos & (sizeof(struct msdos_dir_entry) - 1)) {
594 if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
599 * Check for long filename entry, but if short_only, we don't
600 * need to parse long filename.
602 if (isvfat && !short_only) {
603 if (de->name[0] == DELETED_FLAG)
605 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
607 if (de->attr != ATTR_EXT && IS_FREE(de->name))
610 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
614 if (isvfat && de->attr == ATTR_EXT) {
615 int status = fat_parse_long(inode, &cpos, &bh, &de,
616 &unicode, &nr_slots);
621 } else if (status == PARSE_INVALID)
623 else if (status == PARSE_NOT_LONGNAME)
625 else if (status == PARSE_EOF)
629 void *longname = unicode + FAT_MAX_UNI_CHARS;
630 int size = PATH_MAX - FAT_MAX_UNI_SIZE;
631 int len = fat_uni_to_x8(sb, unicode, longname, size);
633 fill_name = longname;
635 /* !both && !short_only, so we don't need shortname. */
641 short_len = fat_parse_short(sb, de, bufname, sbi->options.dotsOK);
646 /* hack for fat_ioctl_filldir() */
647 struct fat_ioctl_filldir_callback *p = dirent;
649 p->longname = fill_name;
650 p->long_len = fill_len;
651 p->shortname = bufname;
652 p->short_len = short_len;
657 fill_len = short_len;
661 lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);
662 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
664 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
665 inum = parent_ino(filp->f_path.dentry);
667 loff_t i_pos = fat_make_i_pos(sb, bh, de);
668 struct inode *tmp = fat_iget(sb, i_pos);
673 inum = iunique(sb, MSDOS_ROOT_INO);
676 if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
677 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
695 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
697 struct inode *inode = filp->f_path.dentry->d_inode;
698 return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
701 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
702 static int func(void *__buf, const char *name, int name_len, \
703 loff_t offset, u64 ino, unsigned int d_type) \
705 struct fat_ioctl_filldir_callback *buf = __buf; \
706 struct dirent_type __user *d1 = buf->dirent; \
707 struct dirent_type __user *d2 = d1 + 1; \
713 if (name != NULL) { \
714 /* dirent has only short name */ \
715 if (name_len >= sizeof(d1->d_name)) \
716 name_len = sizeof(d1->d_name) - 1; \
718 if (put_user(0, d2->d_name) || \
719 put_user(0, &d2->d_reclen) || \
720 copy_to_user(d1->d_name, name, name_len) || \
721 put_user(0, d1->d_name + name_len) || \
722 put_user(name_len, &d1->d_reclen)) \
725 /* dirent has short and long name */ \
726 const char *longname = buf->longname; \
727 int long_len = buf->long_len; \
728 const char *shortname = buf->shortname; \
729 int short_len = buf->short_len; \
731 if (long_len >= sizeof(d1->d_name)) \
732 long_len = sizeof(d1->d_name) - 1; \
733 if (short_len >= sizeof(d1->d_name)) \
734 short_len = sizeof(d1->d_name) - 1; \
736 if (copy_to_user(d2->d_name, longname, long_len) || \
737 put_user(0, d2->d_name + long_len) || \
738 put_user(long_len, &d2->d_reclen) || \
739 put_user(ino, &d2->d_ino) || \
740 put_user(offset, &d2->d_off) || \
741 copy_to_user(d1->d_name, shortname, short_len) || \
742 put_user(0, d1->d_name + short_len) || \
743 put_user(short_len, &d1->d_reclen)) \
748 buf->result = -EFAULT; \
752 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
754 static int fat_ioctl_readdir(struct inode *inode, struct file *filp,
755 void __user *dirent, filldir_t filldir,
756 int short_only, int both)
758 struct fat_ioctl_filldir_callback buf;
763 mutex_lock(&inode->i_mutex);
765 if (!IS_DEADDIR(inode)) {
766 ret = __fat_readdir(inode, filp, &buf, filldir,
769 mutex_unlock(&inode->i_mutex);
775 static long fat_dir_ioctl(struct file *filp, unsigned int cmd,
778 struct inode *inode = filp->f_path.dentry->d_inode;
779 struct __fat_dirent __user *d1 = (struct __fat_dirent __user *)arg;
780 int short_only, both;
783 case VFAT_IOCTL_READDIR_SHORT:
787 case VFAT_IOCTL_READDIR_BOTH:
792 return fat_generic_ioctl(filp, cmd, arg);
795 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct __fat_dirent[2])))
798 * Yes, we don't need this put_user() absolutely. However old
799 * code didn't return the right value. So, app use this value,
800 * in order to check whether it is EOF.
802 if (put_user(0, &d1->d_reclen))
805 return fat_ioctl_readdir(inode, filp, d1, fat_ioctl_filldir,
810 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
811 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
813 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir, compat_dirent)
815 static long fat_compat_dir_ioctl(struct file *filp, unsigned cmd,
818 struct inode *inode = filp->f_path.dentry->d_inode;
819 struct compat_dirent __user *d1 = compat_ptr(arg);
820 int short_only, both;
823 case VFAT_IOCTL_READDIR_SHORT32:
827 case VFAT_IOCTL_READDIR_BOTH32:
832 return fat_generic_ioctl(filp, cmd, (unsigned long)arg);
835 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct compat_dirent[2])))
838 * Yes, we don't need this put_user() absolutely. However old
839 * code didn't return the right value. So, app use this value,
840 * in order to check whether it is EOF.
842 if (put_user(0, &d1->d_reclen))
845 return fat_ioctl_readdir(inode, filp, d1, fat_compat_ioctl_filldir,
848 #endif /* CONFIG_COMPAT */
850 const struct file_operations fat_dir_operations = {
851 .llseek = generic_file_llseek,
852 .read = generic_read_dir,
853 .readdir = fat_readdir,
854 .unlocked_ioctl = fat_dir_ioctl,
856 .compat_ioctl = fat_compat_dir_ioctl,
858 .fsync = fat_file_fsync,
861 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
862 struct buffer_head **bh,
863 struct msdos_dir_entry **de)
865 while (fat_get_entry(dir, pos, bh, de) >= 0) {
866 /* free entry or long name entry or volume label */
867 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
874 * The ".." entry can not provide the "struct fat_slot_info" information
875 * for inode, nor a usable i_pos. So, this function provides some information
878 * Since this function walks through the on-disk inodes within a directory,
879 * callers are responsible for taking any locks necessary to prevent the
880 * directory from changing.
882 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
883 struct msdos_dir_entry **de)
888 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
889 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME))
894 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
896 /* See if directory is empty */
897 int fat_dir_empty(struct inode *dir)
899 struct buffer_head *bh;
900 struct msdos_dir_entry *de;
906 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
907 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
908 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
916 EXPORT_SYMBOL_GPL(fat_dir_empty);
919 * fat_subdirs counts the number of sub-directories of dir. It can be run
920 * on directories being created.
922 int fat_subdirs(struct inode *dir)
924 struct buffer_head *bh;
925 struct msdos_dir_entry *de;
931 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
932 if (de->attr & ATTR_DIR)
940 * Scans a directory for a given file (name points to its formatted name).
941 * Returns an error code or zero.
943 int fat_scan(struct inode *dir, const unsigned char *name,
944 struct fat_slot_info *sinfo)
946 struct super_block *sb = dir->i_sb;
950 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
952 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
953 sinfo->slot_off -= sizeof(*sinfo->de);
955 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
961 EXPORT_SYMBOL_GPL(fat_scan);
963 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
965 struct super_block *sb = dir->i_sb;
966 struct buffer_head *bh;
967 struct msdos_dir_entry *de, *endp;
968 int err = 0, orig_slots;
972 if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
977 orig_slots = nr_slots;
978 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
979 while (nr_slots && de < endp) {
980 de->name[0] = DELETED_FLAG;
984 mark_buffer_dirty_inode(bh, dir);
986 err = sync_dirty_buffer(bh);
991 /* pos is *next* de's position, so this does `- sizeof(de)' */
992 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
998 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
1000 struct super_block *sb = dir->i_sb;
1001 struct msdos_dir_entry *de;
1002 struct buffer_head *bh;
1003 int err = 0, nr_slots;
1006 * First stage: Remove the shortname. By this, the directory
1009 nr_slots = sinfo->nr_slots;
1014 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
1015 de->name[0] = DELETED_FLAG;
1019 mark_buffer_dirty_inode(bh, dir);
1020 if (IS_DIRSYNC(dir))
1021 err = sync_dirty_buffer(bh);
1029 * Second stage: remove the remaining longname slots.
1030 * (This directory entry is already removed, and so return
1033 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
1035 fat_msg(sb, KERN_WARNING,
1036 "Couldn't remove the long name slots");
1040 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
1041 if (IS_DIRSYNC(dir))
1042 (void)fat_sync_inode(dir);
1044 mark_inode_dirty(dir);
1048 EXPORT_SYMBOL_GPL(fat_remove_entries);
1050 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
1051 struct buffer_head **bhs, int nr_bhs)
1053 struct super_block *sb = dir->i_sb;
1054 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
1057 /* Zeroing the unused blocks on this cluster */
1060 while (blknr < last_blknr) {
1061 bhs[n] = sb_getblk(sb, blknr);
1066 memset(bhs[n]->b_data, 0, sb->s_blocksize);
1067 set_buffer_uptodate(bhs[n]);
1068 mark_buffer_dirty_inode(bhs[n], dir);
1073 if (IS_DIRSYNC(dir)) {
1074 err = fat_sync_bhs(bhs, n);
1078 for (i = 0; i < n; i++)
1083 if (IS_DIRSYNC(dir)) {
1084 err = fat_sync_bhs(bhs, n);
1088 for (i = 0; i < n; i++)
1094 for (i = 0; i < n; i++)
1099 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1101 struct super_block *sb = dir->i_sb;
1102 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1103 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1104 struct msdos_dir_entry *de;
1110 err = fat_alloc_clusters(dir, &cluster, 1);
1114 blknr = fat_clus_to_blknr(sbi, cluster);
1115 bhs[0] = sb_getblk(sb, blknr);
1121 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
1123 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1124 /* filling the new directory slots ("." and ".." entries) */
1125 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
1126 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
1127 de->attr = de[1].attr = ATTR_DIR;
1128 de[0].lcase = de[1].lcase = 0;
1129 de[0].time = de[1].time = time;
1130 de[0].date = de[1].date = date;
1131 if (sbi->options.isvfat) {
1132 /* extra timestamps */
1133 de[0].ctime = de[1].ctime = time;
1134 de[0].ctime_cs = de[1].ctime_cs = time_cs;
1135 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
1137 de[0].ctime = de[1].ctime = 0;
1138 de[0].ctime_cs = de[1].ctime_cs = 0;
1139 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
1141 fat_set_start(&de[0], cluster);
1142 fat_set_start(&de[1], MSDOS_I(dir)->i_logstart);
1143 de[0].size = de[1].size = 0;
1144 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
1145 set_buffer_uptodate(bhs[0]);
1146 mark_buffer_dirty_inode(bhs[0], dir);
1148 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
1155 fat_free_clusters(dir, cluster);
1159 EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
1161 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
1162 int *nr_cluster, struct msdos_dir_entry **de,
1163 struct buffer_head **bh, loff_t *i_pos)
1165 struct super_block *sb = dir->i_sb;
1166 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1167 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
1168 sector_t blknr, start_blknr, last_blknr;
1169 unsigned long size, copy;
1170 int err, i, n, offset, cluster[2];
1173 * The minimum cluster size is 512bytes, and maximum entry
1174 * size is 32*slots (672bytes). So, iff the cluster size is
1175 * 512bytes, we may need two clusters.
1177 size = nr_slots * sizeof(struct msdos_dir_entry);
1178 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
1179 BUG_ON(*nr_cluster > 2);
1181 err = fat_alloc_clusters(dir, cluster, *nr_cluster);
1186 * First stage: Fill the directory entry. NOTE: This cluster
1187 * is not referenced from any inode yet, so updates order is
1192 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
1193 last_blknr = start_blknr + sbi->sec_per_clus;
1194 while (blknr < last_blknr) {
1195 bhs[n] = sb_getblk(sb, blknr);
1201 /* fill the directory entry */
1202 copy = min(size, sb->s_blocksize);
1203 memcpy(bhs[n]->b_data, slots, copy);
1206 set_buffer_uptodate(bhs[n]);
1207 mark_buffer_dirty_inode(bhs[n], dir);
1213 } while (++i < *nr_cluster);
1215 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
1216 offset = copy - sizeof(struct msdos_dir_entry);
1219 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
1220 *i_pos = fat_make_i_pos(sb, *bh, *de);
1222 /* Second stage: clear the rest of cluster, and write outs */
1223 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
1234 for (i = 0; i < n; i++)
1236 fat_free_clusters(dir, cluster[0]);
1241 int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
1242 struct fat_slot_info *sinfo)
1244 struct super_block *sb = dir->i_sb;
1245 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1246 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
1247 struct msdos_dir_entry *uninitialized_var(de);
1248 int err, free_slots, i, nr_bhs;
1251 sinfo->nr_slots = nr_slots;
1253 /* First stage: search free direcotry entries */
1254 free_slots = nr_bhs = 0;
1258 while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
1259 /* check the maximum size of directory */
1260 if (pos >= FAT_MAX_DIR_SIZE)
1263 if (IS_FREE(de->name)) {
1266 bhs[nr_bhs] = prev = bh;
1270 if (free_slots == nr_slots)
1273 for (i = 0; i < nr_bhs; i++)
1276 free_slots = nr_bhs = 0;
1279 if (dir->i_ino == MSDOS_ROOT_INO) {
1280 if (sbi->fat_bits != 32)
1282 } else if (MSDOS_I(dir)->i_start == 0) {
1283 fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",
1284 MSDOS_I(dir)->i_pos);
1291 pos -= free_slots * sizeof(*de);
1292 nr_slots -= free_slots;
1295 * Second stage: filling the free entries with new entries.
1296 * NOTE: If this slots has shortname, first, we write
1297 * the long name slots, then write the short name.
1299 int size = free_slots * sizeof(*de);
1300 int offset = pos & (sb->s_blocksize - 1);
1301 int long_bhs = nr_bhs - (nr_slots == 0);
1303 /* Fill the long name slots. */
1304 for (i = 0; i < long_bhs; i++) {
1305 int copy = min_t(int, sb->s_blocksize - offset, size);
1306 memcpy(bhs[i]->b_data + offset, slots, copy);
1307 mark_buffer_dirty_inode(bhs[i], dir);
1312 if (long_bhs && IS_DIRSYNC(dir))
1313 err = fat_sync_bhs(bhs, long_bhs);
1314 if (!err && i < nr_bhs) {
1315 /* Fill the short name slot. */
1316 int copy = min_t(int, sb->s_blocksize - offset, size);
1317 memcpy(bhs[i]->b_data + offset, slots, copy);
1318 mark_buffer_dirty_inode(bhs[i], dir);
1319 if (IS_DIRSYNC(dir))
1320 err = sync_dirty_buffer(bhs[i]);
1322 for (i = 0; i < nr_bhs; i++)
1329 int cluster, nr_cluster;
1332 * Third stage: allocate the cluster for new entries.
1333 * And initialize the cluster with new entries, then
1334 * add the cluster to dir.
1336 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
1342 err = fat_chain_add(dir, cluster, nr_cluster);
1344 fat_free_clusters(dir, cluster);
1347 if (dir->i_size & (sbi->cluster_size - 1)) {
1348 fat_fs_error(sb, "Odd directory size");
1349 dir->i_size = (dir->i_size + sbi->cluster_size - 1)
1350 & ~((loff_t)sbi->cluster_size - 1);
1352 dir->i_size += nr_cluster << sbi->cluster_bits;
1353 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
1355 sinfo->slot_off = pos;
1358 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
1364 for (i = 0; i < nr_bhs; i++)
1371 __fat_remove_entries(dir, pos, free_slots);
1374 EXPORT_SYMBOL_GPL(fat_add_entries);