On 4/10/23 00:42, Damien Le Moal wrote:
On 4/8/23 08:58, Bart Van Assche wrote:
Send zoned writes inserted by the device mapper to the I/O scheduler.
This prevents that zoned writes get reordered if a device mapper driver
has been stacked on top of a driver for a zoned block device.
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
block/blk-mq.c | 16 +++++++++++++---
block/blk.h | 19 +++++++++++++++++++
2 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index db93b1a71157..fefc9a728e0e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3008,9 +3008,19 @@ blk_status_t blk_insert_cloned_request(struct request *rq)
blk_account_io_start(rq);
/*
- * Since we have a scheduler attached on the top device,
- * bypass a potential scheduler on the bottom device for
- * insert.
+ * Send zoned writes to the I/O scheduler if an I/O scheduler has been
+ * attached.
+ */
+ if (q->elevator && blk_rq_is_seq_zoned_write(rq)) {
+ blk_mq_sched_insert_request(rq, /*at_head=*/false,
+ /*run_queue=*/true,
+ /*async=*/false);
+ return BLK_STS_OK;
+ }
Looks OK to me, but as I understand it, this function is used only for request
based device mapper, none of which currently support zoned block devices if I a
not mistaken. So is this change really necessary ?
Hi Damien,
Probably not. I will double check whether this patch can be dropped.
Thanks,
Bart.
