Christoph, >> Not sure what to do about the storage tag. For Linux that would >> probably be owned by the filesystem (as opposed to the application). >> But I guess one could envision a userland application acting as a >> storage target and in that case the tag would need to be passed to >> the kernel. > > Right now the series only supports PI on the block device. In that > case the userspace application can clearly make use of it. If we > want to support PI on file systems (which I'd really like to do for > XFS) both ownership models might make sense depending on the file > system, although I think just giving it to the application is going > to be the only thing we'll see for a while. Maybe we need a way > to query if the application can use the app tag? tag_size currently indicates the size of the app tag available to the application. I.e. if ATO=1, tag_size is 2. And if ATO=0, tag_size is 0. To properly support the NVMe extensions I guess we'll have to have fields indicating the actual size of the reference and storage tags. -- Martin K. Petersen Oracle Linux Engineering
