On Wed, 2018-06-13 at 15:46 +0530, Chaitra Basappa wrote: > 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.
Hello Chaitra, The patch at the start of this e-mail thread checks whether st->smid is zero. That check could only be useful if there would be code in the mpt3sas driver that clears that field upon command completion. However, I haven't found any such code in the mpt3sas driver. Another concern is that setting ioc->shost_recovery prevents new calls of scsih_qcmd() to submit any commands. But I don't think that setting that flag prevents any scsih_qcmd() calls that had already been started to submit a new command. In other words, I don't think that checking whether or not st->smid == 0 is sufficient to fix the reported race. Bart.
