From 752f66a75abad2ae40b4570b3c77b422389cffcf Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@suse.de>
Date: Mon, 8 Oct 2018 20:41:09 +0800
Subject: [PATCH] bcache: use REQ_PRIO to indicate bio for metadata
Git-commit: 752f66a75abad2ae40b4570b3c77b422389cffcf
Patch-mainline: v4.20-rc1
References: bsc#1130972

In cached_dev_cache_miss() and check_should_bypass(), REQ_META is used
to check whether a bio is for metadata request. REQ_META is used for
blktrace, the correct REQ_ flag should be REQ_PRIO. This flag means the
bio should be prior to other bio, and frequently be used to indicate
metadata io in file system code.

This patch replaces REQ_META with correct flag REQ_PRIO.

CC Adam Manzanares because he explains to me what REQ_PRIO is for.

Signed-off-by: Coly Li <colyli@suse.de>
Cc: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

---
 drivers/md/bcache/request.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 4946d486f734..ee15fb039fd0 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -395,7 +395,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
 	 * unless the read-ahead request is for metadata (eg, for gfs2).
 	 */
 	if (bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) &&
-	    !(bio->bi_opf & REQ_META))
+	    !(bio->bi_opf & REQ_PRIO))
 		goto skip;
 
 	if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) ||
@@ -877,7 +877,7 @@ static int cached_dev_cache_miss(struct btree *b, struct search *s,
 	}
 
 	if (!(bio->bi_opf & REQ_RAHEAD) &&
-	    !(bio->bi_opf & REQ_META) &&
+	    !(bio->bi_opf & REQ_PRIO) &&
 	    s->iop.c->gc_stats.in_use < CUTOFF_CACHE_READA)
 		reada = min_t(sector_t, dc->readahead >> 9,
 			      get_capacity(bio->bi_disk) - bio_end_sector(bio));
-- 
2.16.4