From: Namhyung Kim <namhyung@gmail.com>
Date: Mon, 25 Oct 2010 06:01:12 +0000 (+0900)
Subject: fs/buffer.c: call __block_write_begin() if we have page
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=309f77ad9bea057d55b04580b5a711e9e3727e83;p=openwrt%2Fstaging%2Fblogic.git

fs/buffer.c: call __block_write_begin() if we have page

If we have the appropriate page already, call __block_write_begin()
directly instead of releasing and regrabbing it inside of
block_write_begin().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/buffer.c b/fs/buffer.c
index 74566c6f67b1..d895d9fd5b71 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2458,11 +2458,10 @@ int nobh_write_begin(struct address_space *mapping,
 	*fsdata = NULL;
 
 	if (page_has_buffers(page)) {
-		unlock_page(page);
-		page_cache_release(page);
-		*pagep = NULL;
-		return block_write_begin(mapping, pos, len, flags, pagep,
-					 get_block);
+		ret = __block_write_begin(page, pos, len, get_block);
+		if (unlikely(ret))
+			goto out_release;
+		return ret;
 	}
 
 	if (PageMappedToDisk(page))