* [PATCH 1/2] block: null_blk: Fix handling of fake timeout request
2023-03-14 4:11 [PATCH 0/2] null_blk fix and cleanup Damien Le Moal
@ 2023-03-14 4:11 ` Damien Le Moal
2023-03-15 8:54 ` Johannes Thumshirn
2023-03-14 4:11 ` [PATCH 2/2] block: null_blk: cleanup null_queue_rq() Damien Le Moal
2023-03-15 12:51 ` [PATCH 0/2] null_blk fix and cleanup Jens Axboe
2 siblings, 1 reply; 7+ messages in thread
From: Damien Le Moal @ 2023-03-14 4:11 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: Akinobu Mita
When injecting a fake timeout into the null_blk driver using
fail_io_timeout, the request timeout handler does not execute
blk_mq_complete_request(), so the complete callback is never executed
for a timedout request.
The null_blk driver also has a driver-specific fake timeout mechanism
which does not have this problem. Fix the problem with fail_io_timeout
by using the same meachanism as null_blk internal timeout feature, using
the fake_timeout field of null_blk commands.
Reported-by: Akinobu Mita <akinobu.mita@gmail.com>
Fixes: de3510e52b0a ("null_blk: fix command timeout completion handling")
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
drivers/block/null_blk/main.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 4c601ca9552a..7d95ad203c97 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1413,8 +1413,7 @@ static inline void nullb_complete_cmd(struct nullb_cmd *cmd)
case NULL_IRQ_SOFTIRQ:
switch (cmd->nq->dev->queue_mode) {
case NULL_Q_MQ:
- if (likely(!blk_should_fake_timeout(cmd->rq->q)))
- blk_mq_complete_request(cmd->rq);
+ blk_mq_complete_request(cmd->rq);
break;
case NULL_Q_BIO:
/*
@@ -1675,7 +1674,8 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
cmd->rq = bd->rq;
cmd->error = BLK_STS_OK;
cmd->nq = nq;
- cmd->fake_timeout = should_timeout_request(bd->rq);
+ cmd->fake_timeout = should_timeout_request(bd->rq) ||
+ blk_should_fake_timeout(bd->rq->q);
blk_mq_start_request(bd->rq);
--
2.39.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/2] block: null_blk: cleanup null_queue_rq()
2023-03-14 4:11 [PATCH 0/2] null_blk fix and cleanup Damien Le Moal
2023-03-14 4:11 ` [PATCH 1/2] block: null_blk: Fix handling of fake timeout request Damien Le Moal
@ 2023-03-14 4:11 ` Damien Le Moal
2023-03-14 9:51 ` Pankaj Raghav
2023-03-15 8:53 ` Johannes Thumshirn
2023-03-15 12:51 ` [PATCH 0/2] null_blk fix and cleanup Jens Axboe
2 siblings, 2 replies; 7+ messages in thread
From: Damien Le Moal @ 2023-03-14 4:11 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: Akinobu Mita
Use a local struct request pointer variable to avoid having to
dereference struct blk_mq_queue_data multiple times. While at it, also
fix the function argument indentation and remove a useless "else" after
a return.
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
drivers/block/null_blk/main.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 7d95ad203c97..9e6b032c8ecc 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1657,12 +1657,13 @@ static enum blk_eh_timer_return null_timeout_rq(struct request *rq)
}
static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
- const struct blk_mq_queue_data *bd)
+ const struct blk_mq_queue_data *bd)
{
- struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
+ struct request *rq = bd->rq;
+ struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
struct nullb_queue *nq = hctx->driver_data;
- sector_t nr_sectors = blk_rq_sectors(bd->rq);
- sector_t sector = blk_rq_pos(bd->rq);
+ sector_t nr_sectors = blk_rq_sectors(rq);
+ sector_t sector = blk_rq_pos(rq);
const bool is_poll = hctx->type == HCTX_TYPE_POLL;
might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
@@ -1671,15 +1672,15 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
cmd->timer.function = null_cmd_timer_expired;
}
- cmd->rq = bd->rq;
+ cmd->rq = rq;
cmd->error = BLK_STS_OK;
cmd->nq = nq;
- cmd->fake_timeout = should_timeout_request(bd->rq) ||
- blk_should_fake_timeout(bd->rq->q);
+ cmd->fake_timeout = should_timeout_request(rq) ||
+ blk_should_fake_timeout(rq->q);
- blk_mq_start_request(bd->rq);
+ blk_mq_start_request(rq);
- if (should_requeue_request(bd->rq)) {
+ if (should_requeue_request(rq)) {
/*
* Alternate between hitting the core BUSY path, and the
* driver driven requeue path
@@ -1687,22 +1688,20 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
nq->requeue_selection++;
if (nq->requeue_selection & 1)
return BLK_STS_RESOURCE;
- else {
- blk_mq_requeue_request(bd->rq, true);
- return BLK_STS_OK;
- }
+ blk_mq_requeue_request(rq, true);
+ return BLK_STS_OK;
}
if (is_poll) {
spin_lock(&nq->poll_lock);
- list_add_tail(&bd->rq->queuelist, &nq->poll_list);
+ list_add_tail(&rq->queuelist, &nq->poll_list);
spin_unlock(&nq->poll_lock);
return BLK_STS_OK;
}
if (cmd->fake_timeout)
return BLK_STS_OK;
- return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq));
+ return null_handle_cmd(cmd, sector, nr_sectors, req_op(rq));
}
static void cleanup_queue(struct nullb_queue *nq)
--
2.39.2
^ permalink raw reply related [flat|nested] 7+ messages in thread