linux-kernel - [PATCH 5.10 183/599] f2fs: compress: remove unneeded read when rewrite whole cluster

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Message-Id: <20220405070304.287127761@linuxfoundation.org>
Date:   Tue,  5 Apr 2022 09:27:57 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Fengnan Chang <changfengnan@...o.com>,
        Chao Yu <yuchao0@...wei.com>, Jaegeuk Kim <jaegeuk@...nel.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 183/599] f2fs: compress: remove unneeded read when rewrite whole cluster

From: Fengnan Chang <changfengnan@...o.com>

[ Upstream commit 7eab7a6968278c735b1ca6387056a408f7960265 ]

when we overwrite the whole page in cluster, we don't need read original
data before write, because after write_end(), writepages() can help to
load left data in that cluster.

Signed-off-by: Fengnan Chang <changfengnan@...o.com>
Signed-off-by: Chao Yu <yuchao0@...wei.com>
Acked-by: Chao Yu <yuchao0@...wei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 fs/f2fs/data.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d27a92a54447..04e980c58319 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3461,6 +3461,9 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 
 		*fsdata = NULL;
 
+		if (len == PAGE_SIZE)
+			goto repeat;
+
 		ret = f2fs_prepare_compress_overwrite(inode, pagep,
 							index, fsdata);
 		if (ret < 0) {
-- 
2.34.1