On 11/27/24 3:18 PM, Damien Le Moal wrote:
The BIO that failed is not recovered. The user will see the failure. The error
recovery report zones is all about avoiding more failures of plugged zone append
BIOs behind that failed BIO. These can succeed with the error recovery.
So sure, we can fail all BIOs. The user will see more failures. If that is OK,
that's easy to do. But in the end, that is not a solution because we still need
to get an updated zone write pointer to be able to restart zone append
emulation. Otherwise, we are in the dark and will not know where to send the
regular writes emulating zone append. That means that we still need to issue a
zone report and that is racing with queue freeze and reception of a new BIO. We
cannot have new BIOs "wait" for the zone report as that would create a hang
situation again if a queue freeze is started between reception of the new BIO
and the zone report. Do we fail these new BIOs too ? That seems extreme.
This patch removes the disk->fops->report_zones() call from the
blk-zoned.c code:
https://lore.kernel.org/linux-block/20241119002815.600608-6-bvanassche@xxxxxxx/.
Is it really not possible to get that
approach working for SAS SMR drives? If a torn write happens, is the
residual information in the response from the drive reliable?
Thanks,
Bart.
