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Commit ad2c1604 authored by Pekka Enberg's avatar Pekka Enberg Committed by Linus Torvalds
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[PATCH] fat: Remove duplicate directory scanning code 



This patch removes duplicate directory scanning code from fs/fat/dir.c.  The
two functions that share identical code are fat_readdirx() and
fat_search_long().  This patch also renames fat_readdirx to __fat_readdir().

Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9131dd42

fs/fat/dir.c

+101 −123
Original line number Diff line number Diff line
@@ -222,6 +222,80 @@ 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.
@@ -259,65 +333,16 @@ int fat_search_long(struct inode *inode, const unsigned char *name, 
		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 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))

			int status = fat_parse_long(inode, &cpos, &bh, &de,

						    &unicode, &nr_slots);

			if (status < 0)

				return status;

			else if (status == PARSE_INVALID)

				continue;

			slots = id & ~0x40;

			if (slots > 20 || !slots)	/* ceil(256 * 2 / 26) */

				continue;

			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(inode, &cpos, &bh, &de) < 0)

					goto EODir;

				if (slot == 0)

					break;

				ds = (struct msdos_dir_slot *) de;

				if (ds->attr !=  ATTR_EXT)

			else if (status == PARSE_NOT_LONGNAME)

				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;

			if (fat_checksum(de->name) != alias_checksum)

				nr_slots = 0;

			else if (status == PARSE_EOF)

				goto EODir;

		}



		memcpy(work, de->name, sizeof(de->name));
@@ -405,7 +430,7 @@ struct fat_ioctl_filldir_callback { 
	int short_len;

};



static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,

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;
@@ -455,9 +480,10 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent, 


	bh = NULL;

GetNew:

	long_slots = 0;

	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)
@@ -472,66 +498,18 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent, 
	}



	if (isvfat && de->attr == ATTR_EXT) {

		struct msdos_dir_slot *ds;

		unsigned char id;

		unsigned char slot;

		unsigned char slots;

		unsigned char alias_checksum;



		if (!unicode) {

			unicode = (wchar_t *)__get_free_page(GFP_KERNEL);

			if (!unicode) {

		int status = fat_parse_long(inode, &cpos, &bh, &de,

					    &unicode, &long_slots);

		if (status < 0) {

			filp->f_pos = cpos;

				brelse(bh);

				ret = -ENOMEM;

			ret = status;

			goto out;

			}

		}

ParseLong:

		slots = 0;

		ds = (struct msdos_dir_slot *) de;

		id = ds->id;

		if (!(id & 0x40))

		} else if (status == PARSE_INVALID)

			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) == -1)

		else if (status == PARSE_NOT_LONGNAME)

			goto parse_record;

		else if (status == PARSE_EOF)

			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))

			goto RecEnd;

		if (fat_checksum(de->name) != alias_checksum)

			long_slots = 0;

	}



	if (sbi->options.dotsOK) {
@@ -665,7 +643,7 @@ static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent, 
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);

}



static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
@@ -754,7 +732,7 @@ static int fat_dir_ioctl(struct inode * inode, struct file * filp, 
	down(&inode->i_sem);

	ret = -ENOENT;

	if (!IS_DEADDIR(inode)) {

		ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,

		ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir,

				    short_only, both);

	}

	up(&inode->i_sem);