linux-kernel - [PATCH v3 4/4] Revert "scsi: core: run queue if SCSI device queue isn't ready and queue is idle"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200407145906.v3.4.I630e6ca4cdcf9ab13ea899274745f9e3174eb12b@changeid>
Date:   Tue,  7 Apr 2020 15:00:05 -0700
From:   Douglas Anderson <dianders@...omium.org>
To:     axboe@...nel.dk, jejb@...ux.ibm.com, martin.petersen@...cle.com
Cc:     Ming Lei <ming.lei@...hat.com>, linux-scsi@...r.kernel.org,
        sqazi@...gle.com, Gwendal Grignou <gwendal@...omium.org>,
        groeck@...omium.org, linux-block@...r.kernel.org,
        paolo.valente@...aro.org, Douglas Anderson <dianders@...omium.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 4/4] Revert "scsi: core: run queue if SCSI device queue isn't ready and queue is idle"

This reverts commit 7e70aa789d4a0c89dbfbd2c8a974a4df717475ec.

Now that we have the patches ("blk-mq: In blk_mq_dispatch_rq_list()
"no budget" is a reason to kick") and ("blk-mq: Rerun dispatching in
the case of budget contention") we should no longer need the fix in
the SCSI code.  Revert it, resolving conflicts with other patches that
have touched this code.

With this revert (and the two new patches) I can run the script that
was in commit 7e70aa789d4a ("scsi: core: run queue if SCSI device
queue isn't ready and queue is idle") in a loop with no failure.  If I
do this revert without the two new patches I can easily get a failure.

Signed-off-by: Douglas Anderson <dianders@...omium.org>
---
I don't know for sure that we can revert this patch, but in the very
least the original test case now passes.  If there is any question
about this, we can just drop this patch.

Changes in v3:
- ("Revert "scsi: core: run queue...") new for v3.

Changes in v2: None

 drivers/scsi/scsi_lib.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 47835c4b4ee0..ea18f618dc66 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1610,12 +1610,7 @@ static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx)
 	struct request_queue *q = hctx->queue;
 	struct scsi_device *sdev = q->queuedata;
 
-	if (scsi_dev_queue_ready(q, sdev))
-		return true;
-
-	if (atomic_read(&sdev->device_busy) == 0 && !scsi_device_blocked(sdev))
-		blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
-	return false;
+	return scsi_dev_queue_ready(q, sdev);
 }
 
 static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
-- 
2.26.0.292.g33ef6b2f38-goog