FAILED: patch "[PATCH] f2fs: Make flush bios explicitely sync" failed to apply to 4.10-stable tree

FAILED: patch "[PATCH] f2fs: Make flush bios explicitely sync" failed to apply to 4.10-stable tree

[gregkh]

The patch below does not apply to the 4.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 3adc5fcb7edf5f8dfe8d37dcb50ba6b30077c905 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Tue, 2 May 2017 17:03:47 +0200
Subject: [PATCH] f2fs: Make flush bios explicitely sync

Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3
Cc: stable@vger.kernel.org # 4.9+
CC: Jaegeuk Kim <jaegeuk@kernel.org>
CC: linux-f2fs-devel@lists.sourceforge.net
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 1254986dd6eb..7c0f6bdf817d 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -309,7 +309,7 @@ static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
 	if (type >= META_FLUSH) {
 		io->fio.type = META_FLUSH;
 		io->fio.op = REQ_OP_WRITE;
-		io->fio.op_flags = REQ_META | REQ_PRIO;
+		io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
 		if (!test_opt(sbi, NOBARRIER))
 			io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
 	}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6e1c8cf75749..de31030b5041 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -446,7 +446,7 @@ static int __submit_flush_wait(struct f2fs_sb_info *sbi,
 	struct bio *bio = f2fs_bio_alloc(0);
 	int ret;
 
-	bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
+	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
 	bio->bi_bdev = bdev;
 	ret = submit_bio_wait(bio);
 	bio_put(bio);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 9a14b2590337..83355ec4a92c 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1325,7 +1325,7 @@ static int __f2fs_commit_super(struct buffer_head *bh,
 	unlock_buffer(bh);
 
 	/* it's rare case, we can do fua all the time */
-	return __sync_dirty_buffer(bh, REQ_PREFLUSH | REQ_FUA);
+	return __sync_dirty_buffer(bh, REQ_SYNC | REQ_PREFLUSH | REQ_FUA);
 }
 
 static inline bool sanity_check_area_boundary(struct f2fs_sb_info *sbi,