The patch titled
Subject: mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4
has been added to the -mm tree. Its filename is
mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4.patch
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------------------------------------------------------
From: Mauricio Faria de Oliveira <mfo@xxxxxxxxxxxxx>
Subject: mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4
v4: - fixed Fixes: tag to first support, after tests on v4.5;
updated commit message/reproducer section with results.
- tested on v5.17-rc3 and v4.5.
- shorten comment line; remove inner braces in the check.
(Thanks: Christoph Hellwig <hch@xxxxxxxxxxxxx>)
- clarify comment about __remove_mapping()
(Thanks: Yu Zhao <yuzhao@xxxxxxxxxx>)
Link: https://lkml.kernel.org/r/20220209202659.183418-1-mfo@xxxxxxxxxxxxx
Fixes: 854e9ed09ded ("mm: support madvise(MADV_FREE)")
Signed-off-by: Mauricio Faria de Oliveira <mfo@xxxxxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Dan Hill <daniel.hill@xxxxxxxxxxxxx>
Cc: Dan Streetman <dan.streetman@xxxxxxxxxxxxx>
Cc: Dongdong Tao <dongdong.tao@xxxxxxxxxxxxx>
Cc: Gavin Guo <gavin.guo@xxxxxxxxxxxxx>
Cc: Gerald Yang <gerald.yang@xxxxxxxxxxxxx>
Cc: Heitor Alves de Siqueira <halves@xxxxxxxxxxxxx>
Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@xxxxxxxxxxxxx>
Cc: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
Cc: Matthew Ruffell <matthew.ruffell@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Ponnuvel Palaniyappan <ponnuvel.palaniyappan@xxxxxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/rmap.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/mm/rmap.c~mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4
+++ a/mm/rmap.c
@@ -1614,16 +1614,16 @@ static bool try_to_unmap_one(struct page
map_count = page_mapcount(page);
/*
- * Order reads for page refcount and dirty flag;
- * see __remove_mapping().
+ * Order reads for page refcount and dirty flag
+ * (see comments in __remove_mapping()).
*/
smp_rmb();
/*
- * The only page refs must be from the isolation
- * plus one or more rmap's (dropped by discard:).
+ * The only page refs must be one from isolation
+ * plus the rmap(s) (dropped by discard:).
*/
- if ((ref_count == 1 + map_count) &&
+ if (ref_count == 1 + map_count &&
!PageDirty(page)) {
/* Invalidate as we cleared the pte */
mmu_notifier_invalidate_range(mm,
_
Patches currently in -mm which might be from mfo@xxxxxxxxxxxxx are
mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read.patch
mm-fix-race-between-madv_free-reclaim-and-blkdev-direct-io-read-v4.patch
