Hi Kai, > -----Original Message----- > From: linux-scsi-ow...@vger.kernel.org [mailto:linux-scsi- > ow...@vger.kernel.org] On Behalf Of "Kai Mäkisara (Kolumbus)" > Sent: Tuesday, February 02, 2016 5:43 AM > To: Seymour, Shane M > Cc: Laurence Oberman; Emmanuel Florac; Laurence Oberman; linux- > s...@vger.kernel.org > Subject: Re: What partition should the MTMKPART argument specify? Was: > Re: st driver doesn't seem to grok LTO partitioning > > > > On 1.2.2016, at 8.31, Seymour, Shane M <shane.seym...@hpe.com> > wrote: > > > > Hi Kai, > > > > Thanks for the changes the HPE DAT72 DDS5 drive now works as expected: > > > Good. Thanks for testing. > > ... > > > > I'm asking around again one final time to see if I can lay my hands on a > > LTO5 > or greater drive so I can test LTO partitioning as well. > > > > The only other thing I can think of (I'm not sure if this is an improvement > > or > not) is if bp[pgo + PP_OFF_MAX_ADD_PARTS] + bp[pgo + > PP_OFF_NBR_ADD_PARTS] (max.parts and nbr_parts in the debug message) > is zero just return -EINVAL unless you know of any take drives that report > them both as 0 but can be partitioned? That is after this: > > > > DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n", > > psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS], > > bp[pgo + PP_OFF_NBR_ADD_PARTS]); > > > > add (and also turn off the can-partitions option): > > > > if ((bp[pgo + PP_OFF_MAX_ADD_PARTS] + bp[pgo + > PP_OFF_NBR_ADD_PARTS]) == 0) { > > DEBC_printk(STp, "Drive not partitionable - > max.parts+nbr_parts is 0\n"); > > STp->can_partitions = 0; > > return -EINVAL; > > } > > > > I'm not especially fussed if you don't want to add that though. > > > I thought about a test like this (only test maximum number) but decided not > to add it. The reason was that I did not want to change anything that has > worked before. I quite trust that the current drives return sense data instead > of crashing and the end result for the user would be the same. However, one > can argue that returning EINVAL is better than EIO but does the user notice? > If the common opinion is that a test like this should be added, I am not > against it. It can be added to the code for SCSI >=3 where it does not risk > anything for the old drives. > > IMHO, can_partitions should not be cleared based on the test. For example, > trying to partition a LTO-4 tape in a LTO-5 drive should not disable > partitioning. > (The mode page should return zero as maximum number of partitions when > a LTO-4 tape is inserted.)
No problem, I didn't think of the case where you have a non-partitionable tape in a drive that can do partitions. That case should have been obvious to me. I may be able to lay my hands on a LTO5+ drive (only a small chance). Someone in the US is checking is checking for me and will hook it up to the system I use for testing tape stuff for me. I'll only have it for about a week if I'm able to get it. Thanks Shane > > Thanks, > Kai > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the > body of a message to majord...@vger.kernel.org More majordomo info at > http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
