scsi: core: Add a precondition check in scsi_eh_scmd_add()

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>
Link: https://lore.kernel.org/r/20231115193343.2262013-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index c67cdcd..1bac12e 100644 (file)
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -301,6 +301,7 @@ 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)) {