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skd: Avoid double completions in case of a timeout

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Avoid that normal request completion and the timeout handler can
run concurrently by calling blk_mq_complete_request() instead of
blk_mq_end_request() from skd_end_request(). Avoid that the block
layer can reuse a request while the firmware is still processing
it. Convert skd_softirq_done() to blk-mq. Pass the pointer to
skd_softirq_done() to the block layer core through
blk_mq_ops.complete instead of by calling blk_queue_softirq_done().
Pass the pointer to skd_timed_out() to the block layer core
through blk_mq_ops.timeout instead of by calling
blk_queue_timed_out(). The timeout handler has been tested as
follows:

    echo 1 > /sys/block/skd0/io-timeout-fail &&
    (cd /sys/kernel/debug/fail_io_timeout &&
      echo 100 > probability &&
      echo N > task-filter &&
      echo 1 > times)

Fixes: commit a74d5b76fa ("skd: Switch to block layer timeout mechanism")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Bart Van Assche 2017-08-23 10:56:32 -07:00 committed by Jens Axboe
parent c39c6c773d
commit f2fe445986
1 changed files with 11 additions and 11 deletions
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22
drivers/block/skd_main.c
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@ -184,6 +184,7 @@ struct skd_request_context {
struct fit_comp_error_info err_info;
blk_status_t status;
};
struct skd_special_context {
@ -596,19 +597,22 @@ static blk_status_t skd_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
return BLK_STS_OK;
}
static enum blk_eh_timer_return skd_timed_out(struct request *req)
static enum blk_eh_timer_return skd_timed_out(struct request *req,
bool reserved)
{
struct skd_device *skdev = req->q->queuedata;
dev_err(&skdev->pdev->dev, "request with tag %#x timed out\n",
blk_mq_unique_tag(req));
return BLK_EH_HANDLED;
return BLK_EH_RESET_TIMER;
}
static void skd_end_request(struct skd_device *skdev, struct request *req,
blk_status_t error)
{
struct skd_request_context *skreq = blk_mq_rq_to_pdu(req);
if (unlikely(error)) {
char *cmd = (rq_data_dir(req) == READ) ? "read" : "write";
u32 lba = (u32)blk_rq_pos(req);
@ -621,19 +625,15 @@ static void skd_end_request(struct skd_device *skdev, struct request *req,
dev_dbg(&skdev->pdev->dev, "id=0x%x error=%d\n", req->tag,
error);
blk_mq_end_request(req, error);
skreq->status = error;
blk_mq_complete_request(req);
}
/* Only called in case of a request timeout */
static void skd_softirq_done(struct request *req)
{
struct skd_device *skdev = req->q->queuedata;
struct skd_request_context *skreq = blk_mq_rq_to_pdu(req);
unsigned long flags;
spin_lock_irqsave(&skdev->lock, flags);
skd_end_request(skdev, blk_mq_rq_from_pdu(skreq), BLK_STS_TIMEOUT);
spin_unlock_irqrestore(&skdev->lock, flags);
blk_mq_end_request(req, skreq->status);
}
static bool skd_preop_sg_list(struct skd_device *skdev,
@ -2821,6 +2821,8 @@ err_out:
static const struct blk_mq_ops skd_mq_ops = {
.queue_rq = skd_mq_queue_rq,
.complete = skd_softirq_done,
.timeout = skd_timed_out,
.init_request = skd_init_request,
.exit_request = skd_exit_request,
};
@ -2884,8 +2886,6 @@ static int skd_cons_disk(struct skd_device *skdev)
queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
blk_queue_rq_timeout(q, 8 * HZ);
blk_queue_rq_timed_out(q, skd_timed_out);
blk_queue_softirq_done(q, skd_softirq_done);
spin_lock_irqsave(&skdev->lock, flags);
dev_dbg(&skdev->pdev->dev, "stopping queue\n");