From: Namjae Jeon <namjae.jeon@samsung.com>
Date: Thu, 7 Feb 2013 01:27:53 +0000 (+1100)
Subject: fat: eliminate iterations in fat_search_long and __fat_readdir in case of EOD
X-Git-Tag: next-20130218~1^2~184
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8846bf15a202a4b1e4e3ae7776f0700e2f9fccf3;p=karo-tx-linux.git

fat: eliminate iterations in fat_search_long and __fat_readdir in case of EOD

When doing lookups via fat_search_long(), we can stop checking for further
entries if we detect End of Directory, i.e.  if (de->name[0] == 0x00).The
current code traverses the cluster chain of a directory until a hit is
found or till the last cluster for that directory, ignoring the EOD mark.
Fix this.

Likewise,when readdir(3) is called, we can stop checking for further
entries in __fat_readdir() when we hit EOD.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ravishankar N <ravi.n1@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 58bf744dbf39..78dabf00f46f 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -484,10 +484,10 @@ parse_record:
 		nr_slots = 0;
 		if (de->name[0] == DELETED_FLAG)
 			continue;
+		if (!de->name[0])
+			goto end_of_dir;
 		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 			continue;
-		if (de->attr != ATTR_EXT && IS_FREE(de->name))
-			continue;
 		if (de->attr == ATTR_EXT) {
 			int status = fat_parse_long(inode, &cpos, &bh, &de,
 						    &unicode, &nr_slots);
@@ -608,8 +608,8 @@ parse_record:
 			goto record_end;
 		if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
 			goto record_end;
-		if (de->attr != ATTR_EXT && IS_FREE(de->name))
-			goto record_end;
+		if (!de->name[0])
+			goto end_of_dir;
 	} else {
 		if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
 			goto record_end;