From 2e4ae938f101362c59bc06413c0a759063adb79c Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Wed, 31 May 2017 09:44:33 +0200
Subject: [PATCH] md: Make flush bios explicitely sync
Commit 8eecb540590c "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.
CC: linux-raid@vger.kernel.org
CC: Shaohua Li <shli@kernel.org>
Fixes: 8eecb540590c70d97c0366ea02a6a436c87fa8ef
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Shaohua Li <shli@fb.com>
---
drivers/md/md.c | 2 +-
drivers/md/raid5-cache.c | 4 ++--
drivers/md/raid5-ppl.c | 4 ++--
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 10367ffe92e3e..212a6777ff317 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -765,7 +765,7 @@ void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
test_bit(FailFast, &rdev->flags) &&
!test_bit(LastDev, &rdev->flags))
ff = MD_FAILFAST;
- bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_FUA | ff;
+ bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH | REQ_FUA | ff;
atomic_inc(&mddev->pending_writes);
submit_bio(bio);
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 4c00bc248287e..0a7af8b0a80a0 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -1782,7 +1782,7 @@ static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
mb, PAGE_SIZE));
if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
- REQ_FUA, false)) {
+ REQ_SYNC | REQ_FUA, false)) {
__free_page(page);
return -EIO;
}
@@ -2388,7 +2388,7 @@ r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
mb, PAGE_SIZE));
sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
- REQ_OP_WRITE, REQ_FUA, false);
+ REQ_OP_WRITE, REQ_SYNC | REQ_FUA, false);
sh->log_start = ctx->pos;
list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
atomic_inc(&log->stripe_in_journal_count);
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 5d25bebf3328e..ccce92e68d7fa 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -907,8 +907,8 @@ static int ppl_write_empty_header(struct ppl_log *log)
pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PAGE_SIZE));
if (!sync_page_io(rdev, rdev->ppl.sector - rdev->data_offset,
- PPL_HEADER_SIZE, page, REQ_OP_WRITE | REQ_FUA, 0,
- false)) {
+ PPL_HEADER_SIZE, page, REQ_OP_WRITE | REQ_SYNC |
+ REQ_FUA, 0, false)) {
md_error(rdev->mddev, rdev);
ret = -EIO;
}
--
2.39.5