Christoph, On 6/7/17 18:07, Christoph Hellwig wrote: > On Wed, Jun 07, 2017 at 06:03:52PM +0900, Damien Le Moal wrote: >> Tejun, Hannes, >> >> Currently, in libata-scsi.c, the function ata_scsi_zbc_in_xlat >> translating ZBC REPORT ZONES into the ZAC version returns an error if >> the scsi command buffer length is not aligned on 512. This is possible >> since the ZBC version allows report zones buffer as a multiple of 64B, >> while the ZAC version of the same command requires 512B size alignment >> of the command buffer. >> >> However, SAT-4, in section 9.13.3 says: >> >> "The SATL shall send the ATA REPORT ZONES EXT command with the ATA >> RETURN PAGE COUNT field set to INT((ALLOCATION LENGTH + 511)/512)." >> >> So clearly, instead of returning an error, we need to bounce the scsi >> command buffer to a bigger 512B size aligned temporary buffer for the >> ZAC report zones. I do not see any code ready to use to do so easily, >> but I may be missing it. Is there something that can be used to do so or >> do I need to cook something ? > > Just like for TRIM we should reject any ZBC_IN/OUT command that doesn't > come from the block layer, and then we can tightly control what input > we get. Sure, that is one solution. However, not a ideal one as that would prevent ZBC/ZAC drives working with target/iscsi. There are a few problems there that I am fixing right now, but that translation error is stopping all effort. -- Damien Le Moal, Western Digital -- To unsubscribe from this list: 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
