If REQ_OP_WRITE or REQ_OP_WRITE_ZEROES operations for the same zone
originate from different cgroups that could result in different
priorities being assigned to these operations. Do not modify the I/O
priority of these write operations to prevent that these would be
executed in the wrong order when using the mq-deadline I/O
scheduler.
Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
block/blk-ioprio.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
index 4051fada01f1..09ce083a0e3a 100644
--- a/block/blk-ioprio.c
+++ b/block/blk-ioprio.c
@@ -192,6 +192,17 @@ void blkcg_set_ioprio(struct bio *bio)
if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE)
return;
+ /*
+ * If REQ_OP_WRITE or REQ_OP_WRITE_ZEROES operations for the same zone
+ * originate from different cgroups that could result in different
+ * priorities being assigned to these operations. Do not modify the I/O
+ * priority of these write operations to prevent that these would be
+ * executed in the wrong order when using the mq-deadline I/O
+ * scheduler.
+ */
+ if (bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
+ return;
+
if (blkcg->prio_policy == POLICY_PROMOTE_TO_RT ||
blkcg->prio_policy == POLICY_NONE_TO_RT) {
/*
