On Tue, Sep 20, 2022 at 06:02:11AM +0100, Al Viro wrote: > nvme target: nvme read requests end up with somebody allocating and filling > sglist, followed by reading from file into it (using ITER_BVEC). Then the > pages are sent out, presumably Yes. > . I would be very surprised if it turned out > to be anything other than anon pages allocated by the driver, but I'd like > to see that confirmed by nvme folks. Probably doesn't need pinning. They are anon pages allocated by the driver using sgl_alloc(). > drivers/target/target_core_file.c:292: iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len); Same as nvme target. > The picture so far looks like we mostly need to take care of pinning when > we obtain the references from iov_iter_get_pages(). What's more, it looks > like ITER_BVEC/ITER_XARRAY/ITER_PIPE we really don't need to pin anything on > get_pages/pin_pages - they are already protected (or, in case of ITER_PIPE, > allocated by iov_iter itself and not reachable by anybody outside). That's what I've been trying to say for a while..
