On 5/28/24 22:04, Christoph Hellwig wrote:
The soft max_sectors limit is normally capped by the hardware limits and
an arbitrary upper limit enforced by the kernel, but can be modified by
the user. A few drivers want to increase this limit (nbd, rbd) or
adjust it up or down based on hardware capabilities (sd).
Change blk_validate_limits to default max_sectors to the optimal I/O
size, or upgrade it to the preferred minimal I/O size if that is
larger than the kernel default if no optimal I/O size is provided based
on the logic in the SD driver.
This keeps the existing kernel default for drivers that do not provide
an io_opt or very big io_min value, but picks a much more useful
default for those who provide these hints, and allows to remove the
hacks to set the user max_sectors limit in nbd, rbd and sd.
Note that rd picks a different value for the optimal I/O size vs the
^^
rbd?
user max_sectors value, so this is a bit of a behavior change that
could use careful review from people familiar with rbd.
Anyway:
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
