On 12/17/24 10:58 PM, Christoph Hellwig wrote:
Use the new append writes that return the written offsets we've
talked about.
Here is why this is not a solution for SCSI devices:
* There is no Zone Append command in the relevant SCSI standard (ZBC).
* It is unlikely that a zone append command will ever be standardized
for SCSI devices. Damien explained a few months ago why. See also
https://lore.kernel.org/linux-block/4f48b57f-e8bb-4164-355a-95f5887bac36@xxxxxxxxxxxxxxxxxx/
and
https://lore.kernel.org/linux-block/6a17bdb3-af76-edf7-85a4-0991ee66d380@xxxxxxxxxxxxxxxxxx/
* For SCSI devices, to support QD > 1 per zone for zone append writes,
the write order of the emulated zone write commands has to be
preserved.
In other words, no matter whether we use regular writes or zone append
writes for SCSI devices, something like the write pipelining patch
series that I posted is needed to support QD > 1 per zone for writes to
zoned SCSI devices.
Bart.
