On Mon, 2006-05-29 at 18:08 +0900, Tejun Heo wrote: > > > > 1) Tejun's revalidate should trigger scsi_rescan_device(), as your patch > > indicates. But that's pretty much all that needs to be done. > > > > 2) Thus, a new bit (ATA_FLAG_SCSI_RESCAN) and a new workqueue are > > unnecessary. > > SCSI rescan is done by issuing commands using scsi_execute_req(). The > commands are supposed to be processed via normal SCSI command execution > path which is blocked during EH is in progress, so we need to rescan in > separate context. Thank you for giving the reason why my machine hanged when scsi_rescan_device() is invoked in SCSI EH thread :) > > * I've renamed ata_hotplug_wq to ata_scsi_wq in hotplug patches. I > think rescan can use this wq instead of creating its own. Yes, ata_scsi_wq will do the work, which can't be done in SCSI EH thread. > * When snooping for SETFEATURES in ata_scsi_qc_complete(), why check > cdb[0] for ATA_16/12? Isn't simply checking tf.command enough? Oh, checking cdb[0] for ATA_16/12 is unnecessary since the command id is unique. > * There's a race window between ATA revalidation and SCSI rescan. We > can plug this hole by deferring commands till rescan is complete. But I > doubt it would be worth the trouble. > This is really a problem. But the race condition is not so critical that we need to bother to do some sync between libata and SCSI layer, right? Thanks, Forrest - : send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
