| Message ID | 20231115193343.2262013-1-bvanassche@acm.org |
|---|---|
| State | New |
| Headers | show |
| Series | scsi: core: Add a precondition check in scsi_eh_scmd_add() | expand |
On 15/11/2023 19:33, Bart Van Assche wrote: > 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). This is oddly worded. I think that you need to mention how calling scsi_eh_scmd_add() may lead to this scenario occurring. > Hence complain if scsi_eh_scmd_add() is called > after SCMD_STATE_INFLIGHT has been cleared. Now you hint that this mentioned scenario may occur if SCMD_STATE_INFLIGHT was cleared. Can you provide some info on when scsi_eh_scmd_add() could be called for SCMD_STATE_INFLIGHT cleared? Or is it that you don't know how (it may occur), but it is fatal if it does and we should guard against or warn about it. > > 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)); What about if SCMD_STATE_COMPLETE is set - should we also warn about that? > > spin_lock_irqsave(shost->host_lock, flags); > if (scsi_host_set_state(shost, SHOST_RECOVERY)) { Thanks, John
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)) {
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(+)