X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Ffat%2Fdir.c;h=698b85bb1dd45855a709635eb6239a4c9bbef0d6;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=27ee2ec822c3ef8b6f26d2c2e724cfaa2c796741;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 27ee2ec82..698b85bb1 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -13,24 +13,108 @@
  *  Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
  */
 
+#include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/msdos_fs.h>
 #include <linux/dirent.h>
 #include <linux/smp_lock.h>
 #include <linux/buffer_head.h>
-
 #include <asm/uaccess.h>
 
-struct file_operations fat_dir_operations = {
-	.read		= generic_read_dir,
-	.readdir	= fat_readdir,
-	.ioctl		= fat_dir_ioctl,
-	.fsync		= file_fsync,
-};
+static inline loff_t fat_make_i_pos(struct super_block *sb,
+				    struct buffer_head *bh,
+				    struct msdos_dir_entry *de)
+{
+	return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
+		| (de - (struct msdos_dir_entry *)bh->b_data);
+}
+
+static inline void fat_dir_readahead(struct inode *dir, sector_t iblock,
+				     sector_t phys)
+{
+	struct super_block *sb = dir->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct buffer_head *bh;
+	int sec;
+
+	/* This is not a first sector of cluster, or sec_per_clus == 1 */
+	if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)
+		return;
+	/* root dir of FAT12/FAT16 */
+	if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))
+		return;
+
+	bh = sb_find_get_block(sb, phys);
+	if (bh == NULL || !buffer_uptodate(bh)) {
+		for (sec = 0; sec < sbi->sec_per_clus; sec++)
+			sb_breadahead(sb, phys + sec);
+	}
+	brelse(bh);
+}
+
+/* Returns the inode number of the directory entry at offset pos. If bh is
+   non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
+   returned in bh.
+   AV. Most often we do it item-by-item. Makes sense to optimize.
+   AV. OK, there we go: if both bh and de are non-NULL we assume that we just
+   AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
+   AV. It's done in fat_get_entry() (inlined), here the slow case lives.
+   AV. Additionally, when we return -1 (i.e. reached the end of directory)
+   AV. we make bh NULL.
+ */
+static int fat__get_entry(struct inode *dir, loff_t *pos,
+			  struct buffer_head **bh, struct msdos_dir_entry **de)
+{
+	struct super_block *sb = dir->i_sb;
+	sector_t phys, iblock;
+	unsigned long mapped_blocks;
+	int err, offset;
+
+next:
+	if (*bh)
+		brelse(*bh);
+
+	*bh = NULL;
+	iblock = *pos >> sb->s_blocksize_bits;
+	err = fat_bmap(dir, iblock, &phys, &mapped_blocks);
+	if (err || !phys)
+		return -1;	/* beyond EOF or error */
+
+	fat_dir_readahead(dir, iblock, phys);
+
+	*bh = sb_bread(sb, phys);
+	if (*bh == NULL) {
+		printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
+		       (unsigned long long)phys);
+		/* skip this block */
+		*pos = (iblock + 1) << sb->s_blocksize_bits;
+		goto next;
+	}
+
+	offset = *pos & (sb->s_blocksize - 1);
+	*pos += sizeof(struct msdos_dir_entry);
+	*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
+
+	return 0;
+}
+
+static inline int fat_get_entry(struct inode *dir, loff_t *pos,
+				struct buffer_head **bh,
+				struct msdos_dir_entry **de)
+{
+	/* Fast stuff first */
+	if (*bh && *de &&
+	    (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
+		*pos += sizeof(struct msdos_dir_entry);
+		(*de)++;
+		return 0;
+	}
+	return fat__get_entry(dir, pos, bh, de);
+}
 
 /*
- * Convert Unicode 16 to UTF8, translated Unicode, or ASCII.
+ * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
  * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
  * colon as an escape character since it is normally invalid on the vfat
  * filesystem. The following four characters are the hexadecimal digits
@@ -39,9 +123,8 @@ struct file_operations fat_dir_operations = {
  * but ignore that right now.
  * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
  */
-static int
-uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
-	    struct nls_table *nls)
+static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
+		       struct nls_table *nls)
 {
 	wchar_t *ip, ec;
 	unsigned char *op, nc;
@@ -79,28 +162,6 @@ uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
 	return (op - ascii);
 }
 
-#if 0
-static void dump_de(struct msdos_dir_entry *de)
-{
-	int i;
-	unsigned char *p = (unsigned char *) de;
-	printk("[");
-
-	for (i = 0; i < 32; i++, p++) {
-		printk("%02x ", *p);
-	}
-	printk("]\n");
-}
-#endif
-
-static inline unsigned char
-fat_tolower(struct nls_table *t, unsigned char c)
-{
-	unsigned char nc = t->charset2lower[c];
-
-	return nc ? nc : c;
-}
-
 static inline int
 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
 {
@@ -126,29 +187,18 @@ fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *un
 		charlen = 1;
 	} else if (charlen <= 1) {
 		unsigned char nc = t->charset2lower[*c];
-		
+
 		if (!nc)
 			nc = *c;
-		
+
 		if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
 			*uni = 0x003f;	/* a question mark */
 			charlen = 1;
 		}
 	} else
 		*uni = wc;
-	
-	return charlen;
-}
-
-static int
-fat_strnicmp(struct nls_table *t, const unsigned char *s1,
-					const unsigned char *s2, int len)
-{
-	while(len--)
-		if (fat_tolower(t, *s1++) != fat_tolower(t, *s2++))
-			return 1;
 
-	return 0;
+	return charlen;
 }
 
 static inline int
@@ -164,7 +214,7 @@ fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
 	else if (opt & VFAT_SFN_DISPLAY_WINNT) {
 		if (lower)
 			len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
-		else 
+		else
 			len = fat_short2uni(nls, buf, buf_size, uni_buf);
 	} else
 		len = fat_short2uni(nls, buf, buf_size, uni_buf);
@@ -172,33 +222,110 @@ fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
 	return len;
 }
 
+enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, };
+
+/**
+ * fat_parse_long - Parse extended directory entry.
+ *
+ * This function returns zero on success, negative value on error, or one of
+ * the following:
+ *
+ * %PARSE_INVALID - Directory entry is invalid.
+ * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
+ * %PARSE_EOF - Directory has no more entries.
+ */
+static int fat_parse_long(struct inode *dir, loff_t *pos,
+			  struct buffer_head **bh, struct msdos_dir_entry **de,
+			  wchar_t **unicode, unsigned char *nr_slots)
+{
+	struct msdos_dir_slot *ds;
+	unsigned char id, slot, slots, alias_checksum;
+
+	if (!*unicode) {
+		*unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
+		if (!*unicode) {
+			brelse(*bh);
+			return -ENOMEM;
+		}
+	}
+parse_long:
+	slots = 0;
+	ds = (struct msdos_dir_slot *)*de;
+	id = ds->id;
+	if (!(id & 0x40))
+		return PARSE_INVALID;
+	slots = id & ~0x40;
+	if (slots > 20 || !slots)	/* ceil(256 * 2 / 26) */
+		return PARSE_INVALID;
+	*nr_slots = slots;
+	alias_checksum = ds->alias_checksum;
+
+	slot = slots;
+	while (1) {
+		int offset;
+
+		slot--;
+		offset = slot * 13;
+		fat16_towchar(*unicode + offset, ds->name0_4, 5);
+		fat16_towchar(*unicode + offset + 5, ds->name5_10, 6);
+		fat16_towchar(*unicode + offset + 11, ds->name11_12, 2);
+
+		if (ds->id & 0x40)
+			(*unicode)[offset + 13] = 0;
+		if (fat_get_entry(dir, pos, bh, de) < 0)
+			return PARSE_EOF;
+		if (slot == 0)
+			break;
+		ds = (struct msdos_dir_slot *)*de;
+		if (ds->attr != ATTR_EXT)
+			return PARSE_NOT_LONGNAME;
+		if ((ds->id & ~0x40) != slot)
+			goto parse_long;
+		if (ds->alias_checksum != alias_checksum)
+			goto parse_long;
+	}
+	if ((*de)->name[0] == DELETED_FLAG)
+		return PARSE_INVALID;
+	if ((*de)->attr == ATTR_EXT)
+		goto parse_long;
+	if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME))
+		return PARSE_INVALID;
+	if (fat_checksum((*de)->name) != alias_checksum)
+		*nr_slots = 0;
+
+	return 0;
+}
+
 /*
  * Return values: negative -> error, 0 -> not found, positive -> found,
  * value is the total amount of slots, including the shortname entry.
  */
 int fat_search_long(struct inode *inode, const unsigned char *name,
-		    int name_len, int anycase, loff_t *spos, loff_t *lpos)
+		    int name_len, struct fat_slot_info *sinfo)
 {
 	struct super_block *sb = inode->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	struct buffer_head *bh = NULL;
 	struct msdos_dir_entry *de;
-	struct nls_table *nls_io = MSDOS_SB(sb)->nls_io;
-	struct nls_table *nls_disk = MSDOS_SB(sb)->nls_disk;
+	struct nls_table *nls_io = sbi->nls_io;
+	struct nls_table *nls_disk = sbi->nls_disk;
 	wchar_t bufuname[14];
-	unsigned char xlate_len, long_slots;
+	unsigned char xlate_len, nr_slots;
 	wchar_t *unicode = NULL;
 	unsigned char work[8], bufname[260];	/* 256 + 4 */
-	int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
-	int utf8 = MSDOS_SB(sb)->options.utf8;
-	unsigned short opt_shortname = MSDOS_SB(sb)->options.shortname;
-	int chl, i, j, last_u, res = 0;
-	loff_t i_pos, cpos = 0;
-
+	int uni_xlate = sbi->options.unicode_xlate;
+	int utf8 = sbi->options.utf8;
+	int anycase = (sbi->options.name_check != 's');
+	unsigned short opt_shortname = sbi->options.shortname;
+	loff_t cpos = 0;
+	int chl, i, j, last_u, err;
+
+	err = -ENOENT;
 	while(1) {
-		if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos) == -1)
+		if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 			goto EODir;
 parse_record:
-		long_slots = 0;
+		nr_slots = 0;
 		if (de->name[0] == DELETED_FLAG)
 			continue;
 		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
@@ -206,68 +333,16 @@ parse_record:
 		if (de->attr != ATTR_EXT && IS_FREE(de->name))
 			continue;
 		if (de->attr == ATTR_EXT) {
-			struct msdos_dir_slot *ds;
-			unsigned char id;
-			unsigned char slot;
-			unsigned char slots;
-			unsigned char sum;
-			unsigned char alias_checksum;
-
-			if (!unicode) {
-				unicode = (wchar_t *)
-					__get_free_page(GFP_KERNEL);
-				if (!unicode) {
-					brelse(bh);
-					return -ENOMEM;
-				}
-			}
-parse_long:
-			slots = 0;
-			ds = (struct msdos_dir_slot *) de;
-			id = ds->id;
-			if (!(id & 0x40))
-				continue;
-			slots = id & ~0x40;
-			if (slots > 20 || !slots)	/* ceil(256 * 2 / 26) */
+			int status = fat_parse_long(inode, &cpos, &bh, &de,
+						    &unicode, &nr_slots);
+			if (status < 0)
+				return status;
+			else if (status == PARSE_INVALID)
 				continue;
-			long_slots = slots;
-			alias_checksum = ds->alias_checksum;
-
-			slot = slots;
-			while (1) {
-				int offset;
-
-				slot--;
-				offset = slot * 13;
-				fat16_towchar(unicode + offset, ds->name0_4, 5);
-				fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
-				fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
-
-				if (ds->id & 0x40) {
-					unicode[offset + 13] = 0;
-				}
-				if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos)<0)
-					goto EODir;
-				if (slot == 0)
-					break;
-				ds = (struct msdos_dir_slot *) de;
-				if (ds->attr !=  ATTR_EXT)
-					goto parse_record;
-				if ((ds->id & ~0x40) != slot)
-					goto parse_long;
-				if (ds->alias_checksum != alias_checksum)
-					goto parse_long;
-			}
-			if (de->name[0] == DELETED_FLAG)
-				continue;
-			if (de->attr ==  ATTR_EXT)
-				goto parse_long;
-			if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
-				continue;
-			for (sum = 0, i = 0; i < 11; i++)
-				sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
-			if (sum != alias_checksum)
-				long_slots = 0;
+			else if (status == PARSE_NOT_LONGNAME)
+				goto parse_record;
+			else if (status == PARSE_EOF)
+				goto EODir;
 		}
 
 		memcpy(work, de->name, sizeof(de->name));
@@ -311,58 +386,76 @@ parse_long:
 			:uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
 		if (xlate_len == name_len)
 			if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
-			    (anycase && !fat_strnicmp(nls_io, name, bufname,
+			    (anycase && !nls_strnicmp(nls_io, name, bufname,
 								xlate_len)))
 				goto Found;
 
-		if (long_slots) {
+		if (nr_slots) {
 			xlate_len = utf8
 				?utf8_wcstombs(bufname, unicode, sizeof(bufname))
 				:uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
 			if (xlate_len != name_len)
 				continue;
 			if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
-			    (anycase && !fat_strnicmp(nls_io, name, bufname,
+			    (anycase && !nls_strnicmp(nls_io, name, bufname,
 								xlate_len)))
 				goto Found;
 		}
 	}
 
 Found:
-	res = long_slots + 1;
-	*spos = cpos - sizeof(struct msdos_dir_entry);
-	*lpos = cpos - res*sizeof(struct msdos_dir_entry);
+	nr_slots++;	/* include the de */
+	sinfo->slot_off = cpos - nr_slots * sizeof(*de);
+	sinfo->nr_slots = nr_slots;
+	sinfo->de = de;
+	sinfo->bh = bh;
+	sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
+	err = 0;
 EODir:
-	brelse(bh);
-	if (unicode) {
-		free_page((unsigned long) unicode);
-	}
-	return res;
+	if (unicode)
+		free_page((unsigned long)unicode);
+
+	return err;
 }
 
-static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
-			filldir_t filldir, int shortnames, int both)
+EXPORT_SYMBOL_GPL(fat_search_long);
+
+struct fat_ioctl_filldir_callback {
+	struct dirent __user *dirent;
+	int result;
+	/* for dir ioctl */
+	const char *longname;
+	int long_len;
+	const char *shortname;
+	int short_len;
+};
+
+static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent,
+			 filldir_t filldir, int short_only, int both)
 {
 	struct super_block *sb = inode->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	struct buffer_head *bh;
 	struct msdos_dir_entry *de;
-	struct nls_table *nls_io = MSDOS_SB(sb)->nls_io;
-	struct nls_table *nls_disk = MSDOS_SB(sb)->nls_disk;
-	wchar_t bufuname[14];
+	struct nls_table *nls_io = sbi->nls_io;
+	struct nls_table *nls_disk = sbi->nls_disk;
 	unsigned char long_slots;
+	const char *fill_name;
+	int fill_len;
+	wchar_t bufuname[14];
 	wchar_t *unicode = NULL;
 	unsigned char c, work[8], bufname[56], *ptname = bufname;
 	unsigned long lpos, dummy, *furrfu = &lpos;
-	int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate;
-	int isvfat = MSDOS_SB(sb)->options.isvfat;
-	int utf8 = MSDOS_SB(sb)->options.utf8;
-	int nocase = MSDOS_SB(sb)->options.nocase;
-	unsigned short opt_shortname = MSDOS_SB(sb)->options.shortname;
+	int uni_xlate = sbi->options.unicode_xlate;
+	int isvfat = sbi->options.isvfat;
+	int utf8 = sbi->options.utf8;
+	int nocase = sbi->options.nocase;
+	unsigned short opt_shortname = sbi->options.shortname;
 	unsigned long inum;
 	int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
-	loff_t i_pos, cpos;
+	loff_t cpos;
 	int ret = 0;
-	
+
 	lock_kernel();
 
 	cpos = filp->f_pos;
@@ -385,11 +478,12 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
 		goto out;
 	}
 
- 	bh = NULL;
+	bh = NULL;
 GetNew:
-	long_slots = 0;
-	if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos) == -1)
+	if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
 		goto EODir;
+parse_record:
+	long_slots = 0;
 	/* Check for long filename entry */
 	if (isvfat) {
 		if (de->name[0] == DELETED_FLAG)
@@ -404,75 +498,27 @@ GetNew:
 	}
 
 	if (isvfat && de->attr == ATTR_EXT) {
-		struct msdos_dir_slot *ds;
-		unsigned char id;
-		unsigned char slot;
-		unsigned char slots;
-		unsigned char sum;
-		unsigned char alias_checksum;
-
-		if (!unicode) {
-			unicode = (wchar_t *)
-				__get_free_page(GFP_KERNEL);
-			if (!unicode) {
-				filp->f_pos = cpos;
-				brelse(bh);
-				ret = -ENOMEM;
-				goto out;
-			}
-		}
-ParseLong:
-		slots = 0;
-		ds = (struct msdos_dir_slot *) de;
-		id = ds->id;
-		if (!(id & 0x40))
-			goto RecEnd;
-		slots = id & ~0x40;
-		if (slots > 20 || !slots)	/* ceil(256 * 2 / 26) */
-			goto RecEnd;
-		long_slots = slots;
-		alias_checksum = ds->alias_checksum;
-
-		slot = slots;
-		while (1) {
-			int offset;
-
-			slot--;
-			offset = slot * 13;
-			fat16_towchar(unicode + offset, ds->name0_4, 5);
-			fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
-			fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
-
-			if (ds->id & 0x40) {
-				unicode[offset + 13] = 0;
-			}
-			if (fat_get_entry(inode,&cpos,&bh,&de,&i_pos) == -1)
-				goto EODir;
-			if (slot == 0)
-				break;
-			ds = (struct msdos_dir_slot *) de;
-			if (ds->attr !=  ATTR_EXT)
-				goto RecEnd;	/* XXX */
-			if ((ds->id & ~0x40) != slot)
-				goto ParseLong;
-			if (ds->alias_checksum != alias_checksum)
-				goto ParseLong;
-		}
-		if (de->name[0] == DELETED_FLAG)
-			goto RecEnd;
-		if (de->attr ==  ATTR_EXT)
-			goto ParseLong;
-		if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
+		int status = fat_parse_long(inode, &cpos, &bh, &de,
+					    &unicode, &long_slots);
+		if (status < 0) {
+			filp->f_pos = cpos;
+			ret = status;
+			goto out;
+		} else if (status == PARSE_INVALID)
 			goto RecEnd;
-		for (sum = 0, i = 0; i < 11; i++)
-			sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
-		if (sum != alias_checksum)
-			long_slots = 0;
+		else if (status == PARSE_NOT_LONGNAME)
+			goto parse_record;
+		else if (status == PARSE_EOF)
+			goto EODir;
 	}
 
-	if ((de->attr & ATTR_HIDDEN) && MSDOS_SB(sb)->options.dotsOK) {
-		*ptname++ = '.';
-		dotoffset = 1;
+	if (sbi->options.dotsOK) {
+		ptname = bufname;
+		dotoffset = 0;
+		if (de->attr & ATTR_HIDDEN) {
+			*ptname++ = '.';
+			dotoffset = 1;
+		}
 	}
 
 	memcpy(work, de->name, sizeof(de->name));
@@ -529,11 +575,12 @@ ParseLong:
 	j = last_u;
 
 	lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
-	if (!memcmp(de->name,MSDOS_DOT,11))
+	if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
 		inum = inode->i_ino;
-	else if (!memcmp(de->name,MSDOS_DOTDOT,11)) {
+	else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 		inum = parent_ino(filp->f_dentry);
 	} else {
+		loff_t i_pos = fat_make_i_pos(sb, bh, de);
 		struct inode *tmp = fat_iget(sb, i_pos);
 		if (tmp) {
 			inum = tmp->i_ino;
@@ -548,26 +595,35 @@ ParseLong:
 			 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
 	}
 
-	if (!long_slots||shortnames) {
-		if (both)
-			bufname[i] = '\0';
-		if (filldir(dirent, bufname, i, *furrfu, inum,
-			    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
-			goto FillFailed;
-	} else {
-		unsigned char longname[275];
+	fill_name = bufname;
+	fill_len = i;
+	if (!short_only && long_slots) {
+		/* convert the unicode long name. 261 is maximum size
+		 * of unicode buffer. (13 * slots + nul) */
+		void *longname = unicode + 261;
+		int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
 		int long_len = utf8
-			? utf8_wcstombs(longname, unicode, sizeof(longname))
-			: uni16_to_x8(longname, unicode, uni_xlate,
-				      nls_io);
-		if (both) {
-			memcpy(&longname[long_len+1], bufname, i);
-			long_len += i;
+			? utf8_wcstombs(longname, unicode, buf_size)
+			: uni16_to_x8(longname, unicode, uni_xlate, nls_io);
+
+		if (!both) {
+			fill_name = longname;
+			fill_len = long_len;
+		} else {
+			/* hack for fat_ioctl_filldir() */
+			struct fat_ioctl_filldir_callback *p = dirent;
+
+			p->longname = longname;
+			p->long_len = long_len;
+			p->shortname = bufname;
+			p->short_len = i;
+			fill_name = NULL;
+			fill_len = 0;
 		}
-		if (filldir(dirent, longname, long_len, *furrfu, inum,
-			    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
-			goto FillFailed;
 	}
+	if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
+		    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
+		goto FillFailed;
 
 RecEnd:
 	furrfu = &lpos;
@@ -576,65 +632,62 @@ RecEnd:
 EODir:
 	filp->f_pos = cpos;
 FillFailed:
-	if (bh)
-		brelse(bh);
-	if (unicode) {
-		free_page((unsigned long) unicode);
-	}
+	brelse(bh);
+	if (unicode)
+		free_page((unsigned long)unicode);
 out:
 	unlock_kernel();
 	return ret;
 }
 
-int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
+static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
 	struct inode *inode = filp->f_dentry->d_inode;
-	return fat_readdirx(inode, filp, dirent, filldir, 0, 0);
+	return __fat_readdir(inode, filp, dirent, filldir, 0, 0);
 }
 
-struct fat_ioctl_filldir_callback {
-	struct dirent __user *dirent;
-	int result;
-};
-
-static int fat_ioctl_filldir(void *__buf, const char * name, int name_len,
+static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
 			     loff_t offset, ino_t ino, unsigned int d_type)
 {
 	struct fat_ioctl_filldir_callback *buf = __buf;
 	struct dirent __user *d1 = buf->dirent;
 	struct dirent __user *d2 = d1 + 1;
-	int len, slen;
-	int dotdir;
 
 	if (buf->result)
 		return -EINVAL;
 	buf->result++;
 
-	if ((name_len == 1 && name[0] == '.') ||
-	    (name_len == 2 && name[0] == '.' && name[1] == '.')) {
-		dotdir = 1;
-		len = name_len;
-	} else {
-		dotdir = 0;
-		len = strlen(name);
-	}
-	if (len != name_len) {
-		slen = name_len - len;
-		if (copy_to_user(d2->d_name, name, len)		||
-		    put_user(0, d2->d_name + len)		||
-		    put_user(len, &d2->d_reclen)		||
-		    put_user(ino, &d2->d_ino)			||
-		    put_user(offset, &d2->d_off)		||
-		    copy_to_user(d1->d_name, name+len+1, slen)	||
-		    put_user(0, d1->d_name+slen)		||
-		    put_user(slen, &d1->d_reclen))
-			goto efault;
-	} else {
+	if (name != NULL) {
+		/* dirent has only short name */
+		if (name_len >= sizeof(d1->d_name))
+			name_len = sizeof(d1->d_name) - 1;
+
 		if (put_user(0, d2->d_name)			||
 		    put_user(0, &d2->d_reclen)			||
-		    copy_to_user(d1->d_name, name, len)		||
-		    put_user(0, d1->d_name+len)			||
-		    put_user(len, &d1->d_reclen))
+		    copy_to_user(d1->d_name, name, name_len)	||
+		    put_user(0, d1->d_name + name_len)		||
+		    put_user(name_len, &d1->d_reclen))
+			goto efault;
+	} else {
+		/* dirent has short and long name */
+		const char *longname = buf->longname;
+		int long_len = buf->long_len;
+		const char *shortname = buf->shortname;
+		int short_len = buf->short_len;
+
+		if (long_len >= sizeof(d1->d_name))
+			long_len = sizeof(d1->d_name) - 1;
+		if (short_len >= sizeof(d1->d_name))
+			short_len = sizeof(d1->d_name) - 1;
+
+		if (copy_to_user(d2->d_name, longname, long_len)	||
+		    put_user(0, d2->d_name + long_len)			||
+		    put_user(long_len, &d2->d_reclen)			||
+		    put_user(ino, &d2->d_ino)				||
+		    put_user(offset, &d2->d_off)			||
+		    copy_to_user(d1->d_name, shortname, short_len)	||
+		    put_user(0, d1->d_name + short_len)			||
+		    put_user(short_len, &d1->d_reclen))
 			goto efault;
 	}
 	return 0;
@@ -643,24 +696,24 @@ efault:
 	return -EFAULT;
 }
 
-int fat_dir_ioctl(struct inode * inode, struct file * filp,
+static int fat_dir_ioctl(struct inode * inode, struct file * filp,
 		  unsigned int cmd, unsigned long arg)
 {
 	struct fat_ioctl_filldir_callback buf;
 	struct dirent __user *d1;
-	int ret, shortname, both;
+	int ret, short_only, both;
 
 	switch (cmd) {
 	case VFAT_IOCTL_READDIR_SHORT:
-		shortname = 1;
-		both = 1;
+		short_only = 1;
+		both = 0;
 		break;
 	case VFAT_IOCTL_READDIR_BOTH:
-		shortname = 0;
+		short_only = 0;
 		both = 1;
 		break;
 	default:
-		return -EINVAL;
+		return fat_generic_ioctl(inode, filp, cmd, arg);
 	}
 
 	d1 = (struct dirent __user *)arg;
@@ -676,117 +729,70 @@ int fat_dir_ioctl(struct inode * inode, struct file * filp,
 
 	buf.dirent = d1;
 	buf.result = 0;
-	down(&inode->i_sem);
+	mutex_lock(&inode->i_mutex);
 	ret = -ENOENT;
 	if (!IS_DEADDIR(inode)) {
-		ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,
-				   shortname, both);
+		ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir,
+				    short_only, both);
 	}
-	up(&inode->i_sem);
+	mutex_unlock(&inode->i_mutex);
 	if (ret >= 0)
 		ret = buf.result;
 	return ret;
 }
 
-/* This assumes that size of cluster is above the 32*slots */
+const struct file_operations fat_dir_operations = {
+	.read		= generic_read_dir,
+	.readdir	= fat_readdir,
+	.ioctl		= fat_dir_ioctl,
+	.fsync		= file_fsync,
+};
 
-int fat_add_entries(struct inode *dir,int slots, struct buffer_head **bh,
-		  struct msdos_dir_entry **de, loff_t *i_pos)
+static int fat_get_short_entry(struct inode *dir, loff_t *pos,
+			       struct buffer_head **bh,
+			       struct msdos_dir_entry **de)
 {
-	struct super_block *sb = dir->i_sb;
-	loff_t offset, curr;
-	int row;
-	struct buffer_head *new_bh;
-
-	offset = curr = 0;
-	*bh = NULL;
-	row = 0;
-	while (fat_get_entry(dir, &curr, bh, de, i_pos) > -1) {
-		/* check the maximum size of directory */
-		if (curr >= FAT_MAX_DIR_SIZE) {
-			brelse(*bh);
-			return -ENOSPC;
-		}
-
-		if (IS_FREE((*de)->name)) {
-			if (++row == slots)
-				return offset;
-		} else {
-			row = 0;
-			offset = curr;
-		}
+	while (fat_get_entry(dir, pos, bh, de) >= 0) {
+		/* free entry or long name entry or volume label */
+		if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
+			return 0;
 	}
-	if ((dir->i_ino == MSDOS_ROOT_INO) && (MSDOS_SB(sb)->fat_bits != 32)) 
-		return -ENOSPC;
-	new_bh = fat_extend_dir(dir);
-	if (IS_ERR(new_bh))
-		return PTR_ERR(new_bh);
-	brelse(new_bh);
-	do {
-		fat_get_entry(dir, &curr, bh, de, i_pos);
-	} while (++row < slots);
-
-	return offset;
+	return -ENOENT;
 }
 
-int fat_new_dir(struct inode *dir, struct inode *parent, int is_vfat)
+/*
+ * The ".." entry can not provide the "struct fat_slot_info" informations
+ * for inode. So, this function provide the some informations only.
+ */
+int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
+			 struct msdos_dir_entry **de, loff_t *i_pos)
 {
-	struct buffer_head *bh;
-	struct msdos_dir_entry *de;
-	__u16 date, time;
-
-	bh = fat_extend_dir(dir);
-	if (IS_ERR(bh))
-		return PTR_ERR(bh);
-
-	/* zeroed out, so... */
-	fat_date_unix2dos(dir->i_mtime.tv_sec,&time,&date);
-	de = (struct msdos_dir_entry*)&bh->b_data[0];
-	memcpy(de[0].name,MSDOS_DOT,MSDOS_NAME);
-	memcpy(de[1].name,MSDOS_DOTDOT,MSDOS_NAME);
-	de[0].attr = de[1].attr = ATTR_DIR;
-	de[0].time = de[1].time = CT_LE_W(time);
-	de[0].date = de[1].date = CT_LE_W(date);
-	if (is_vfat) {	/* extra timestamps */
-		de[0].ctime = de[1].ctime = CT_LE_W(time);
-		de[0].adate = de[0].cdate =
-			de[1].adate = de[1].cdate = CT_LE_W(date);
-	}
-	de[0].start = CT_LE_W(MSDOS_I(dir)->i_logstart);
-	de[0].starthi = CT_LE_W(MSDOS_I(dir)->i_logstart>>16);
-	de[1].start = CT_LE_W(MSDOS_I(parent)->i_logstart);
-	de[1].starthi = CT_LE_W(MSDOS_I(parent)->i_logstart>>16);
-	mark_buffer_dirty(bh);
-	brelse(bh);
-	dir->i_atime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	mark_inode_dirty(dir);
+	loff_t offset;
 
-	return 0;
-}
-
-static int fat_get_short_entry(struct inode *dir, loff_t *pos,
-			       struct buffer_head **bh,
-			       struct msdos_dir_entry **de, loff_t *i_pos)
-{
-	while (fat_get_entry(dir, pos, bh, de, i_pos) >= 0) {
-		/* free entry or long name entry or volume label */
-		if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
+	offset = 0;
+	*bh = NULL;
+	while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
+		if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
+			*i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
 			return 0;
+		}
 	}
 	return -ENOENT;
 }
 
+EXPORT_SYMBOL_GPL(fat_get_dotdot_entry);
+
 /* See if directory is empty */
 int fat_dir_empty(struct inode *dir)
 {
 	struct buffer_head *bh;
 	struct msdos_dir_entry *de;
-	loff_t cpos, i_pos;
+	loff_t cpos;
 	int result = 0;
 
 	bh = NULL;
 	cpos = 0;
-	while (fat_get_short_entry(dir, &cpos, &bh, &de, &i_pos) >= 0) {
+	while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 		if (strncmp(de->name, MSDOS_DOT   , MSDOS_NAME) &&
 		    strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
 			result = -ENOTEMPTY;
@@ -797,6 +803,8 @@ int fat_dir_empty(struct inode *dir)
 	return result;
 }
 
+EXPORT_SYMBOL_GPL(fat_dir_empty);
+
 /*
  * fat_subdirs counts the number of sub-directories of dir. It can be run
  * on directories being created.
@@ -805,12 +813,12 @@ int fat_subdirs(struct inode *dir)
 {
 	struct buffer_head *bh;
 	struct msdos_dir_entry *de;
-	loff_t cpos, i_pos;
+	loff_t cpos;
 	int count = 0;
 
 	bh = NULL;
 	cpos = 0;
-	while (fat_get_short_entry(dir, &cpos, &bh, &de, &i_pos) >= 0) {
+	while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
 		if (de->attr & ATTR_DIR)
 			count++;
 	}
@@ -823,16 +831,437 @@ int fat_subdirs(struct inode *dir)
  * Returns an error code or zero.
  */
 int fat_scan(struct inode *dir, const unsigned char *name,
-	     struct buffer_head **bh, struct msdos_dir_entry **de,
-	     loff_t *i_pos)
+	     struct fat_slot_info *sinfo)
 {
-	loff_t cpos;
+	struct super_block *sb = dir->i_sb;
 
-	*bh = NULL;
-	cpos = 0;
-	while (fat_get_short_entry(dir, &cpos, bh, de, i_pos) >= 0) {
-		if (!strncmp((*de)->name, name, MSDOS_NAME))
+	sinfo->slot_off = 0;
+	sinfo->bh = NULL;
+	while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
+				   &sinfo->de) >= 0) {
+		if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
+			sinfo->slot_off -= sizeof(*sinfo->de);
+			sinfo->nr_slots = 1;
+			sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
 			return 0;
+		}
 	}
 	return -ENOENT;
 }
+
+EXPORT_SYMBOL_GPL(fat_scan);
+
+static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *bh;
+	struct msdos_dir_entry *de, *endp;
+	int err = 0, orig_slots;
+
+	while (nr_slots) {
+		bh = NULL;
+		if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
+			err = -EIO;
+			break;
+		}
+
+		orig_slots = nr_slots;
+		endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
+		while (nr_slots && de < endp) {
+			de->name[0] = DELETED_FLAG;
+			de++;
+			nr_slots--;
+		}
+		mark_buffer_dirty(bh);
+		if (IS_DIRSYNC(dir))
+			err = sync_dirty_buffer(bh);
+		brelse(bh);
+		if (err)
+			break;
+
+		/* pos is *next* de's position, so this does `- sizeof(de)' */
+		pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
+	}
+
+	return err;
+}
+
+int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
+{
+	struct msdos_dir_entry *de;
+	struct buffer_head *bh;
+	int err = 0, nr_slots;
+
+	/*
+	 * First stage: Remove the shortname. By this, the directory
+	 * entry is removed.
+	 */
+	nr_slots = sinfo->nr_slots;
+	de = sinfo->de;
+	sinfo->de = NULL;
+	bh = sinfo->bh;
+	sinfo->bh = NULL;
+	while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
+		de->name[0] = DELETED_FLAG;
+		de--;
+		nr_slots--;
+	}
+	mark_buffer_dirty(bh);
+	if (IS_DIRSYNC(dir))
+		err = sync_dirty_buffer(bh);
+	brelse(bh);
+	if (err)
+		return err;
+	dir->i_version++;
+
+	if (nr_slots) {
+		/*
+		 * Second stage: remove the remaining longname slots.
+		 * (This directory entry is already removed, and so return
+		 * the success)
+		 */
+		err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
+		if (err) {
+			printk(KERN_WARNING
+			       "FAT: Couldn't remove the long name slots\n");
+		}
+	}
+
+	dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
+	if (IS_DIRSYNC(dir))
+		(void)fat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(fat_remove_entries);
+
+static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
+			      struct buffer_head **bhs, int nr_bhs)
+{
+	struct super_block *sb = dir->i_sb;
+	sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
+	int err, i, n;
+
+	/* Zeroing the unused blocks on this cluster */
+	blknr += nr_used;
+	n = nr_used;
+	while (blknr < last_blknr) {
+		bhs[n] = sb_getblk(sb, blknr);
+		if (!bhs[n]) {
+			err = -ENOMEM;
+			goto error;
+		}
+		memset(bhs[n]->b_data, 0, sb->s_blocksize);
+		set_buffer_uptodate(bhs[n]);
+		mark_buffer_dirty(bhs[n]);
+
+		n++;
+		blknr++;
+		if (n == nr_bhs) {
+			if (IS_DIRSYNC(dir)) {
+				err = fat_sync_bhs(bhs, n);
+				if (err)
+					goto error;
+			}
+			for (i = 0; i < n; i++)
+				brelse(bhs[i]);
+			n = 0;
+		}
+	}
+	if (IS_DIRSYNC(dir)) {
+		err = fat_sync_bhs(bhs, n);
+		if (err)
+			goto error;
+	}
+	for (i = 0; i < n; i++)
+		brelse(bhs[i]);
+
+	return 0;
+
+error:
+	for (i = 0; i < n; i++)
+		bforget(bhs[i]);
+	return err;
+}
+
+int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
+{
+	struct super_block *sb = dir->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+	struct msdos_dir_entry *de;
+	sector_t blknr;
+	__le16 date, time;
+	int err, cluster;
+
+	err = fat_alloc_clusters(dir, &cluster, 1);
+	if (err)
+		goto error;
+
+	blknr = fat_clus_to_blknr(sbi, cluster);
+	bhs[0] = sb_getblk(sb, blknr);
+	if (!bhs[0]) {
+		err = -ENOMEM;
+		goto error_free;
+	}
+
+	fat_date_unix2dos(ts->tv_sec, &time, &date);
+
+	de = (struct msdos_dir_entry *)bhs[0]->b_data;
+	/* filling the new directory slots ("." and ".." entries) */
+	memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
+	memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
+	de->attr = de[1].attr = ATTR_DIR;
+	de[0].lcase = de[1].lcase = 0;
+	de[0].time = de[1].time = time;
+	de[0].date = de[1].date = date;
+	de[0].ctime_cs = de[1].ctime_cs = 0;
+	if (sbi->options.isvfat) {
+		/* extra timestamps */
+		de[0].ctime = de[1].ctime = time;
+		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
+	} else {
+		de[0].ctime = de[1].ctime = 0;
+		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
+	}
+	de[0].start = cpu_to_le16(cluster);
+	de[0].starthi = cpu_to_le16(cluster >> 16);
+	de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
+	de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
+	de[0].size = de[1].size = 0;
+	memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
+	set_buffer_uptodate(bhs[0]);
+	mark_buffer_dirty(bhs[0]);
+
+	err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
+	if (err)
+		goto error_free;
+
+	return cluster;
+
+error_free:
+	fat_free_clusters(dir, cluster);
+error:
+	return err;
+}
+
+EXPORT_SYMBOL_GPL(fat_alloc_new_dir);
+
+static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
+			       int *nr_cluster, struct msdos_dir_entry **de,
+			       struct buffer_head **bh, loff_t *i_pos)
+{
+	struct super_block *sb = dir->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+	sector_t blknr, start_blknr, last_blknr;
+	unsigned long size, copy;
+	int err, i, n, offset, cluster[2];
+
+	/*
+	 * The minimum cluster size is 512bytes, and maximum entry
+	 * size is 32*slots (672bytes).  So, iff the cluster size is
+	 * 512bytes, we may need two clusters.
+	 */
+	size = nr_slots * sizeof(struct msdos_dir_entry);
+	*nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
+	BUG_ON(*nr_cluster > 2);
+
+	err = fat_alloc_clusters(dir, cluster, *nr_cluster);
+	if (err)
+		goto error;
+
+	/*
+	 * First stage: Fill the directory entry.  NOTE: This cluster
+	 * is not referenced from any inode yet, so updates order is
+	 * not important.
+	 */
+	i = n = copy = 0;
+	do {
+		start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
+		last_blknr = start_blknr + sbi->sec_per_clus;
+		while (blknr < last_blknr) {
+			bhs[n] = sb_getblk(sb, blknr);
+			if (!bhs[n]) {
+				err = -ENOMEM;
+				goto error_nomem;
+			}
+
+			/* fill the directory entry */
+			copy = min(size, sb->s_blocksize);
+			memcpy(bhs[n]->b_data, slots, copy);
+			slots += copy;
+			size -= copy;
+			set_buffer_uptodate(bhs[n]);
+			mark_buffer_dirty(bhs[n]);
+			if (!size)
+				break;
+			n++;
+			blknr++;
+		}
+	} while (++i < *nr_cluster);
+
+	memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
+	offset = copy - sizeof(struct msdos_dir_entry);
+	get_bh(bhs[n]);
+	*bh = bhs[n];
+	*de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
+	*i_pos = fat_make_i_pos(sb, *bh, *de);
+
+	/* Second stage: clear the rest of cluster, and write outs */
+	err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
+	if (err)
+		goto error_free;
+
+	return cluster[0];
+
+error_free:
+	brelse(*bh);
+	*bh = NULL;
+	n = 0;
+error_nomem:
+	for (i = 0; i < n; i++)
+		bforget(bhs[i]);
+	fat_free_clusters(dir, cluster[0]);
+error:
+	return err;
+}
+
+int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
+		    struct fat_slot_info *sinfo)
+{
+	struct super_block *sb = dir->i_sb;
+	struct msdos_sb_info *sbi = MSDOS_SB(sb);
+	struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
+	struct msdos_dir_entry *de;
+	int err, free_slots, i, nr_bhs;
+	loff_t pos, i_pos;
+
+	sinfo->nr_slots = nr_slots;
+
+	/* First stage: search free direcotry entries */
+	free_slots = nr_bhs = 0;
+	bh = prev = NULL;
+	pos = 0;
+	err = -ENOSPC;
+	while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
+		/* check the maximum size of directory */
+		if (pos >= FAT_MAX_DIR_SIZE)
+			goto error;
+
+		if (IS_FREE(de->name)) {
+			if (prev != bh) {
+				get_bh(bh);
+				bhs[nr_bhs] = prev = bh;
+				nr_bhs++;
+			}
+			free_slots++;
+			if (free_slots == nr_slots)
+				goto found;
+		} else {
+			for (i = 0; i < nr_bhs; i++)
+				brelse(bhs[i]);
+			prev = NULL;
+			free_slots = nr_bhs = 0;
+		}
+	}
+	if (dir->i_ino == MSDOS_ROOT_INO) {
+		if (sbi->fat_bits != 32)
+			goto error;
+	} else if (MSDOS_I(dir)->i_start == 0) {
+		printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
+		       MSDOS_I(dir)->i_pos);
+		err = -EIO;
+		goto error;
+	}
+
+found:
+	err = 0;
+	pos -= free_slots * sizeof(*de);
+	nr_slots -= free_slots;
+	if (free_slots) {
+		/*
+		 * Second stage: filling the free entries with new entries.
+		 * NOTE: If this slots has shortname, first, we write
+		 * the long name slots, then write the short name.
+		 */
+		int size = free_slots * sizeof(*de);
+		int offset = pos & (sb->s_blocksize - 1);
+		int long_bhs = nr_bhs - (nr_slots == 0);
+
+		/* Fill the long name slots. */
+		for (i = 0; i < long_bhs; i++) {
+			int copy = min_t(int, sb->s_blocksize - offset, size);
+			memcpy(bhs[i]->b_data + offset, slots, copy);
+			mark_buffer_dirty(bhs[i]);
+			offset = 0;
+			slots += copy;
+			size -= copy;
+		}
+		if (long_bhs && IS_DIRSYNC(dir))
+			err = fat_sync_bhs(bhs, long_bhs);
+		if (!err && i < nr_bhs) {
+			/* Fill the short name slot. */
+			int copy = min_t(int, sb->s_blocksize - offset, size);
+			memcpy(bhs[i]->b_data + offset, slots, copy);
+			mark_buffer_dirty(bhs[i]);
+			if (IS_DIRSYNC(dir))
+				err = sync_dirty_buffer(bhs[i]);
+		}
+		for (i = 0; i < nr_bhs; i++)
+			brelse(bhs[i]);
+		if (err)
+			goto error_remove;
+	}
+
+	if (nr_slots) {
+		int cluster, nr_cluster;
+
+		/*
+		 * Third stage: allocate the cluster for new entries.
+		 * And initialize the cluster with new entries, then
+		 * add the cluster to dir.
+		 */
+		cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
+					      &de, &bh, &i_pos);
+		if (cluster < 0) {
+			err = cluster;
+			goto error_remove;
+		}
+		err = fat_chain_add(dir, cluster, nr_cluster);
+		if (err) {
+			fat_free_clusters(dir, cluster);
+			goto error_remove;
+		}
+		if (dir->i_size & (sbi->cluster_size - 1)) {
+			fat_fs_panic(sb, "Odd directory size");
+			dir->i_size = (dir->i_size + sbi->cluster_size - 1)
+				& ~((loff_t)sbi->cluster_size - 1);
+		}
+		dir->i_size += nr_cluster << sbi->cluster_bits;
+		MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
+	}
+	sinfo->slot_off = pos;
+	sinfo->de = de;
+	sinfo->bh = bh;
+	sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
+
+	return 0;
+
+error:
+	brelse(bh);
+	for (i = 0; i < nr_bhs; i++)
+		brelse(bhs[i]);
+	return err;
+
+error_remove:
+	brelse(bh);
+	if (free_slots)
+		__fat_remove_entries(dir, pos, free_slots);
+	return err;
+}
+
+EXPORT_SYMBOL_GPL(fat_add_entries);