From: Chao Yu <yuchao0@huawei.com>
Date: Fri, 19 Jun 2020 09:14:19 +0000 (+0800)
Subject: f2fs: fix to check page dirty status before writeback
X-Git-Tag: v5.7.18~90
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a69c653ee9e029d8cd38eb3cb9850c9e90b8237a;p=thirdparty%2Fkernel%2Fstable.git

f2fs: fix to check page dirty status before writeback

[ Upstream commit eb1353cfa9c1e9415b03dc117f8399969fa02102 ]

In f2fs_write_raw_pages(), we need to check page dirty status before
writeback, because there could be a racer (e.g. reclaimer) helps
writebacking the dirty page.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 527d50edcb956..b397121dfa107 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1207,6 +1207,12 @@ retry_write:
 				congestion_wait(BLK_RW_ASYNC,
 						DEFAULT_IO_TIMEOUT);
 				lock_page(cc->rpages[i]);
+
+				if (!PageDirty(cc->rpages[i])) {
+					unlock_page(cc->rpages[i]);
+					continue;
+				}
+
 				clear_page_dirty_for_io(cc->rpages[i]);
 				goto retry_write;
 			}