Anuj, > +struct uio_meta { > + meta_flags_t flags; > + u16 app_tag; > + u32 seed; > + struct iov_iter iter; > +}; Glad to see the seed added. In NVMe it can be a 64-bit value so we should bump the size of that field in the user API. 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. -- Martin K. Petersen Oracle Linux Engineering