On Mon, Mar 06, 2023 at 12:54:51PM +0100, David Hildenbrand wrote:
On 05.03.23 04:22, Sasha Levin wrote:This is a note to let you know that I've just added the patch titled RDMA/siw: remove FOLL_FORCE usage to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-siw-remove-foll_force-usage.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dba305c6ba7aebc95f1023375438ad7d70353453 Author: David Hildenbrand <david@xxxxxxxxxx> Date: Wed Nov 16 11:26:51 2022 +0100 RDMA/siw: remove FOLL_FORCE usage [ Upstream commit 129e636fe9837fcfea68bfd368a07548d9880726 ] GUP now supports reliable R/O long-term pinning in COW mappings, such that we break COW early. MAP_SHARED VMAs only use the shared zeropage so far in one corner case (DAXFS file with holes), which can be ignored because GUP does not support long-term pinning in fsdax (see check_vma_flags()). Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop using FOLL_FORCE, which is really only for ptrace access. Link: https://lkml.kernel.org/r/20221116102659.70287-13-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Cc: Bernard Metzler <bmt@xxxxxxxxxxxxxx> Cc: Leon Romanovsky <leon@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Stable-dep-of: 65a8fc30fb67 ("RDMA/siw: Fix user page pinning accounting") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>Unless backporting 84209e87c696 ("mm/gup: reliable R/O long-term pinning in COW mappings") [which requires a lot of backports as well], backporting this only is wrong.
Ack, I've dropped it, thanks! -- Thanks, Sasha
