On 2022-06-17 08:56, Damien Le Moal wrote: >> >> So we call this function device_not_matches_zone_sectors() from >> validate_hardware_zoned_model() for each target and we let the validate >> succeed even if the target's zone size is different from the underlying >> device zone size if this feature flag is set. Let me know if I am >> missing something and how this can be moved to >> validate_hardware_zoned_model(). > > Your change does not match the function name > device_not_matches_zone_sectors(), at all. So I think this is wrong. > > The fact is that zone support in DM has been built under the following > assumptions: > 1) A zoned device can be used to create a *zoned* target (e.g. dm-linear, > dm-flakey, dm-crypt). For this case, the target *must* use the same zone > size as the underlying devices and all devices used for the target must > have the same zone size. > 2) A zoned device can be used to create a *regular* device target (e.g. > dm-zoned). All zoned devices used for the target must have the same zone size. > > This new target driver completely breaks (1) and does not fit with (2). I > suspect this is why you are seeing problems with dm_revalidate_zones() as > that one uses the underlying device instead of the target report zones. > > Based on this analysis, validate_hardware_zoned_model() definitely needs > to be changed. But device_not_matches_zone_sectors() is to check the > assumptions (1) and (2) so changing it for your new case is wrong in my > opinion. You need another set of assumptions (3) (define that well please) > and modify validate_hardware_zoned_model() so that the defined constraints > are checked. Using a target flag to indicate the type of zoned target is > fine by me. > Got it. Thanks for the explanation. Renaming device_not_matches_zone_sectors() function to something meaningful with my changes should address what you have pointed out to accommodate all three types. I see that something similar was done to dm_table_supports_zoned_model() to accommodate type 2(dm-zoned) with different underlying zoned models even though the initial impl. supported only type 1. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
