On 11/22/24 21:30, Keith Busch wrote: > On Fri, Nov 22, 2024 at 01:08:28PM +0100, Christoph Hellwig wrote: >> On Fri, Nov 22, 2024 at 02:20:36PM +0530, Nilay Shroff wrote: >>> The nvme_execute_identify_ns_nvm function uses ZERO_PAGE >>> for copying SG list with all zeros. As ZERO_PAGE would not >>> necessarily return the virtual-address of the zero page, we >>> need to first convert the page address to kernel virtual- >>> address and then use it as source address for copying the >>> data to SG list with all zeros. >>> >>> Using return address of ZERO_PAGE(0) as source address for >>> copying data to SG list would fill the target buffer with >>> random value and causes the undesired side effect. This patch >>> implements the fix ensuring that we use virtual-address of the >>> zero page for copying all zeros to the SG list buffers. >> >> I wonder if using ZERO_PAGE() is simply a little too smart for it's >> own sake and it should just use kzalloc like a bunch of other identify >> implementation.. > > Sure. That'll make it easier to report non-zero values if we decide to > implement a non-stubbed version of this identification later. Ok, so if we prefer using kzalloc instead of ZERO_PAGE() in nvme_execute_identify_ns_nvm function, as we're using kzalloc at other identify call sites, then I would update the patch and send v2 where we would replace ZERO_PAGE() with kzalloc. Thanks, --Nilay
