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>
diff --git a/drivers/infiniband/sw/siw/siw_mem.c b/drivers/infiniband/sw/siw/siw_mem.c
index 61c17db70d658..b2b33dd3b4fa1 100644
--- a/drivers/infiniband/sw/siw/siw_mem.c
+++ b/drivers/infiniband/sw/siw/siw_mem.c
@@ -368,7 +368,7 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable)
struct mm_struct *mm_s;
u64 first_page_va;
unsigned long mlock_limit;
- unsigned int foll_flags = FOLL_WRITE;
+ unsigned int foll_flags = FOLL_LONGTERM;
int num_pages, num_chunks, i, rv = 0;
if (!can_do_mlock())
@@ -391,8 +391,8 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable)
mmgrab(mm_s);
- if (!writable)
- foll_flags |= FOLL_FORCE;
+ if (writable)
+ foll_flags |= FOLL_WRITE;
mmap_read_lock(mm_s);
@@ -423,8 +423,7 @@ struct siw_umem *siw_umem_get(u64 start, u64 len, bool writable)
while (nents) {
struct page **plist = &umem->page_chunk[i].plist[got];
- rv = pin_user_pages(first_page_va, nents,
- foll_flags | FOLL_LONGTERM,
+ rv = pin_user_pages(first_page_va, nents, foll_flags,
plist, NULL);
if (rv < 0)
goto out_sem_up;
