[PATCH] scsi: core: Add a precondition check in scsi_eh_scmd_add()

From: Bart Van Assche <bvanassche@acm.org>
To: "Martin K . Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org, Bart Van Assche <bvanassche@acm.org>,
	Hannes Reinecke <hare@suse.de>,
	Damien Le Moal <damien.lemoal@opensource.wdc.com>,
	Mike Christie <michael.christie@oracle.com>,
	John Garry <john.g.garry@oracle.com>,
	Ming Lei <ming.lei@redhat.com>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>
Subject: [PATCH] scsi: core: Add a precondition check in scsi_eh_scmd_add()
Date: Wed, 15 Nov 2023 11:33:43 -0800	[thread overview]
Message-ID: <20231115193343.2262013-1-bvanassche@acm.org> (raw)

Calling scsi_eh_scmd_add() may cause the error handler never to be woken
up because this may result in shost->host_failed to become larger than
scsi_host_busy(shost). Hence complain if scsi_eh_scmd_add() is called
after SCMD_STATE_INFLIGHT has been cleared.

Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_error.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index d7f2d90719fd..0734b3f30ef5 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -290,6 +290,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
 	int ret;
 
 	WARN_ON_ONCE(!shost->ehandler);
+	WARN_ON_ONCE(!test_bit(SCMD_STATE_INFLIGHT, &scmd->state));
 
 	spin_lock_irqsave(shost->host_lock, flags);
 	if (scsi_host_set_state(shost, SHOST_RECOVERY)) {
