[PATCH v4 2/4] blk-iocost: charge zone appends as writes

[Tao Cui <cui.tao@linux.dev>]

From: Tao Cui <cuitao@kylinos.cn>

Zone append is a primary write operation for zoned devices; zoned xfs
and btrfs use it for data writes.  It is priced at zero, so the zone
append portion of zoned workloads runs outside the controller: a
1%-weight cgroup issued 16000 appends at zero cost on a zoned null_blk.

Treat REQ_OP_ZONE_APPEND the same as REQ_OP_WRITE so it goes through
the existing seq/rand classification and charging.

Fixes: 0512a75b98f8 ("block: Introduce REQ_OP_ZONE_APPEND")
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Acked-by: Tejun Heo <tj@kernel.org>
---
 block/blk-iocost.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 546458246cf9..6b262ccb6b32 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2557,6 +2557,7 @@ static void calc_vtime_cost_builtin(struct bio *bio, struct ioc_gq *iocg,
 		coef_randio	= ioc->params.lcoefs[LCOEF_RRANDIO];
 		coef_page	= ioc->params.lcoefs[LCOEF_RPAGE];
 		break;
+	case REQ_OP_ZONE_APPEND:
 	case REQ_OP_WRITE:
 		coef_seqio	= ioc->params.lcoefs[LCOEF_WSEQIO];
 		coef_randio	= ioc->params.lcoefs[LCOEF_WRANDIO];
-- 
2.43.0