From f1342709d18af97b0e71449d5696b8873d1a456c Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Mon, 26 Nov 2018 09:54:29 -0700 Subject: scsi: Do not rely on blk-mq for double completions The scsi timeout error handling had been directly updating the block layer's request state to prevent a error handling and a natural completion from completing the same request twice. Fix this layering violation by having scsi control the fate of its commands with scsi owned flags rather than use blk-mq's. Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- drivers/scsi/scsi_lib.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/scsi_lib.c') diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 0df15cb738d2..0dbf25512778 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1642,8 +1642,18 @@ static blk_status_t scsi_mq_prep_fn(struct request *req) static void scsi_mq_done(struct scsi_cmnd *cmd) { + if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) + return; trace_scsi_dispatch_cmd_done(cmd); - blk_mq_complete_request(cmd->request); + + /* + * If the block layer didn't complete the request due to a timeout + * injection, scsi must clear its internal completed state so that the + * timeout handler will see it needs to escalate its own error + * recovery. + */ + if (unlikely(!blk_mq_complete_request(cmd->request))) + clear_bit(SCMD_STATE_COMPLETE, &cmd->state); } static void scsi_mq_put_budget(struct blk_mq_hw_ctx *hctx) @@ -1702,6 +1712,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, if (!scsi_host_queue_ready(q, shost, sdev)) goto out_dec_target_busy; + clear_bit(SCMD_STATE_COMPLETE, &cmd->state); if (!(req->rq_flags & RQF_DONTPREP)) { ret = scsi_mq_prep_fn(req); if (ret != BLK_STS_OK) -- cgit v1.2.3