Douglas Gilbert wrote: > Eric, > Now for a really serious issue: in sbc3r24 > TPRZ == "thin provisioning read zeros". > SBC-3 uses the shorter variant of the plural of > zero. [ACS-2 uses both zeros and zeroes :-)] > > The reason I point that out (apart from trying to > distract James B. from another dispute) is that > you are introducing a new module option called > "unmap_zeroes". I prefer the shorter form. Ok, I think i was following Martin's lead there, based on what's presented in sysfs: queue/discard_zeroes_data Believe it or not I thought about this ;) > When I tried to combine your patch on top of Martin's > I needed to do a hand merge (since I'm "gitless") onto > lk 2.6.35 . Both of you picked almost the same lines > to change. Attached is the result of my patch merge > against lk 2.6.35 . It may not be tab clean. > > With that combined patch I checked a real SSD that > does TPRZ against the scsi_debug virtual SSD and it > looked okay with my utilities. Thanks, will look over your combined patch & let you know if I see anything. -Eric > > SCSI WRITE SAME does have one interesting quirk that > Martin may like to consider. If the "number of > logical blocks" field is zero, then that implies write > to the end of the LU!! Madness when you think about it. > libata's SCSI WRITE SAME translation takes the zero > number of LBs literally and does nothing I guess > (when the UNMAP bit is given). > > Doug Gilbert > > > > On 10-08-23 03:24 PM, Eric Sandeen wrote: >> Add TPRZ support to scsi_debug; i.e. return zero for >> unmapped blocks. >> >> Rather than checking for unmapped blocks at >> read time, this just zeroes them on the backing store >> at unmap time so it behaves the same way. >> >> This also adds a module parameter to disable it, since >> some SSDs have this behavior. >> >> Signed-off-by: Eric Sandeen<sandeen@xxxxxxxxxx> > > Acked-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
