[PATCH 5.8 049/148] f2fs: fix to check page dirty status before writeback

Greg Kroah-Hartman
2020-08-24T08:34:01Z

From: Chao Yu <yuchao0@huawei.com>

[ 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>
---
fs/f2fs/compress.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index f6fbe61b1251e..2390f7943f6c8 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1310,6 +1310,12 @@ 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;
}
--
2.25.1