When a request complete then send ipi to original cpu which issued request.
If cpu offline during this process, send_ipi might fail.
However, there is currently no code to handle this error case.
This may cause in missing request complete.
Therefore, if send_ipi fails due to cpu offline, the request complete
has to be processed directly from the cpu where it is running.
Signed-off-by: Manjong Lee <mj0123.lee@xxxxxxxxxxx>
Signed-off-by: Changheun Lee <nanich.lee@xxxxxxxxxxx>
Signed-off-by: Junho Kim <junho89.kim@xxxxxxxxxxx>
---
block/blk-mq.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3c1e6b6d991d..f2ce79708c5e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1064,17 +1064,22 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq)
return cpu_online(rq->mq_ctx->cpu);
}
-static void blk_mq_complete_send_ipi(struct request *rq)
+static int blk_mq_complete_send_ipi(struct request *rq)
{
struct llist_head *list;
unsigned int cpu;
+ int ret = 0;
cpu = rq->mq_ctx->cpu;
list = &per_cpu(blk_cpu_done, cpu);
if (llist_add(&rq->ipi_list, list)) {
INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
- smp_call_function_single_async(cpu, &rq->csd);
+ ret = smp_call_function_single_async(cpu, &rq->csd);
+ if (ret)
+ llist_del_all(list);
}
+
+ return ret;
}
static void blk_mq_raise_softirq(struct request *rq)
@@ -1099,10 +1104,9 @@ bool blk_mq_complete_request_remote(struct request *rq)
if (rq->cmd_flags & REQ_POLLED)
return false;
- if (blk_mq_complete_need_ipi(rq)) {
- blk_mq_complete_send_ipi(rq);
- return true;
- }
+ if (blk_mq_complete_need_ipi(rq))
+ if (!blk_mq_complete_send_ipi(rq))
+ return true;
if (rq->q->nr_hw_queues == 1) {
blk_mq_raise_softirq(rq);
--
2.32.0
