Bart, When host reset is issued from application, through ioctl reset handler _ctl_do_reset() -> mpt3sas_base_hard_reset_handler() sets “ioc->shost_recovery” flag. If “ioc->shost_recovery” flag is set then driver will return all the incoming SCSI cmds with “SCSI_MLQUEUE_HOST_BUSY” in the scsih_qcmd(). And hence no new request gets processed by the driver until the reset completes, which guarantees that the smid won't change.
Thanks, Chaitra -----Original Message----- From: Bart Van Assche [mailto:bart.vanass...@wdc.com] Sent: Tuesday, June 12, 2018 8:54 PM To: chaitra.basa...@broadcom.com; linux-scsi@vger.kernel.org Cc: sathya.prak...@broadcom.com; suganath-prabu.subram...@broadcom.com; sreekanth.re...@broadcom.com Subject: Re: [PATCH] mpt3sas: Fix calltrace observed while running IO & host reset On Tue, 2018-06-12 at 09:17 -0400, Chaitra P B wrote: > diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c > b/drivers/scsi/mpt3sas/mpt3sas_scsih.c > index 23902ad..96e523a 100644 > --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c > +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c > @@ -1489,7 +1489,7 @@ struct scsi_cmnd * > scmd = scsi_host_find_tag(ioc->shost, unique_tag); > if (scmd) { > st = scsi_cmd_priv(scmd); > - if (st->cb_idx == 0xFF) > + if (st->cb_idx == 0xFF || st->smid == 0) > scmd = NULL; > } > } What guarantees that st->smid won't change after it has been checked and before scmd is used? Thanks, Bart.
