The quilt patch titled
Subject: userfaultfd: remove WRITE_ONCE when setting folio->index during UFFDIO_MOVE
has been removed from the -mm tree. Its filename was
userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: userfaultfd: remove WRITE_ONCE when setting folio->index during UFFDIO_MOVE
Date: Sun, 14 Apr 2024 19:08:21 -0700
When folio is moved with UFFDIO_MOVE it gets locked before the rmap and
index are modified. Due to the folio lock being already held,
WRITE_ONCE() is not needed when setting the folio index. Remove it.
Link: https://lkml.kernel.org/r/20240415020821.1152951-1-surenb@xxxxxxxxxx
Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Lokesh Gidra <lokeshgidra@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 2 +-
mm/userfaultfd.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/mm/huge_memory.c~userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move
+++ a/mm/huge_memory.c
@@ -2200,7 +2200,7 @@ int move_pages_huge_pmd(struct mm_struct
}
folio_move_anon_rmap(src_folio, dst_vma);
- WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr));
+ src_folio->index = linear_page_index(dst_vma, dst_addr);
_dst_pmd = mk_huge_pmd(&src_folio->page, dst_vma->vm_page_prot);
/* Follow mremap() behavior and treat the entry dirty after the move */
--- a/mm/userfaultfd.c~userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move
+++ a/mm/userfaultfd.c
@@ -1026,7 +1026,7 @@ static int move_present_pte(struct mm_st
}
folio_move_anon_rmap(src_folio, dst_vma);
- WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr));
+ src_folio->index = linear_page_index(dst_vma, dst_addr);
orig_dst_pte = mk_pte(&src_folio->page, dst_vma->vm_page_prot);
/* Follow mremap() behavior and treat the entry dirty after the move */
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
