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Commit dcd8c53f authored by OGAWA Hirofumi's avatar OGAWA Hirofumi Committed by Linus Torvalds
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fat: small optimization to __fat_readdir() 



This removes unnecessary parsing for directory entries.

If short_only, we don't need to parse longname.  And if !both and it found
the longname, we don't need shortname.

Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 98a15160

fs/fat/dir.c

+39 −32
Original line number Diff line number Diff line
@@ -481,11 +481,11 @@ static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent, 
	unsigned short opt_shortname = sbi->options.shortname;

	int isvfat = sbi->options.isvfat;

	int nocase = sbi->options.nocase;

	const char *fill_name;

	const char *fill_name = NULL;

	unsigned long inum;

	unsigned long lpos, dummy, *furrfu = &lpos;

	loff_t cpos;

	int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len;

	int chi, chl, i, i2, j, last, last_u, dotoffset = 0, fill_len = 0;

	int ret = 0;



	lock_super(sb);
@@ -516,8 +516,11 @@ get_new: 
		goto end_of_dir;

parse_record:

	nr_slots = 0;

	/* Check for long filename entry */

	if (isvfat) {

	/*

	 * Check for long filename entry, but if short_only, we don't

	 * need to parse long filename.

	 */

	if (isvfat && !short_only) {

		if (de->name[0] == DELETED_FLAG)

			goto record_end;

		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
@@ -542,6 +545,18 @@ parse_record: 
			goto parse_record;

		else if (status == PARSE_EOF)

			goto end_of_dir;



		if (nr_slots) {

			void *longname = unicode + FAT_MAX_UNI_CHARS;

			int size = PATH_MAX - FAT_MAX_UNI_SIZE;

			int len = fat_uni_to_x8(sbi, unicode, longname, size);



			fill_name = longname;

			fill_len = len;

			/* !both && !short_only, so we don't need shortname. */

			if (!both)

				goto start_filldir;

		}

	}



	if (sbi->options.dotsOK) {
@@ -608,6 +623,26 @@ parse_record: 
	i = last + dotoffset;

	j = last_u;



	if (isvfat) {

		bufuname[j] = 0x0000;

		i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));

	}

	if (nr_slots) {

		/* hack for fat_ioctl_filldir() */

		struct fat_ioctl_filldir_callback *p = dirent;



		p->longname = fill_name;

		p->long_len = fill_len;

		p->shortname = bufname;

		p->short_len = i;

		fill_name = NULL;

		fill_len = 0;

	} else {

		fill_name = bufname;

		fill_len = i;

	}



start_filldir:

	lpos = cpos - (nr_slots + 1) * sizeof(struct msdos_dir_entry);

	if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))

		inum = inode->i_ino;
@@ -623,34 +658,6 @@ parse_record: 
			inum = iunique(sb, MSDOS_ROOT_INO);

	}



	if (isvfat) {

		bufuname[j] = 0x0000;

		i = fat_uni_to_x8(sbi, bufuname, bufname, sizeof(bufname));

	}



	fill_name = bufname;

	fill_len = i;

	if (!short_only && nr_slots) {

		void *longname = unicode + FAT_MAX_UNI_CHARS;

		int long_len, size = PATH_MAX - FAT_MAX_UNI_SIZE;



		long_len = fat_uni_to_x8(sbi, unicode, longname, size);



		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, fill_name, fill_len, *furrfu, inum,

		    (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)

		goto fill_failed;