diff options
| author | Mauricio Faria de Oliveira <mfo@canonical.com> | 2022-03-15 17:00:01 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2022-03-15 23:13:47 +1100 |
| commit | a6a69225b547cdeaf460910788cef7f0dee99df4 (patch) | |
| tree | 6a468a70c6c9fc4eb97d728fec2702291598dd83 | |
| parent | f4c958137ccbe3b88ab31909d6cc81f2bb823013 (diff) | |
| download | linux-a6a69225b547cdeaf460910788cef7f0dee99df4.tar.gz linux-a6a69225b547cdeaf460910788cef7f0dee99df4.tar.xz | |
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@infradead.org>)
- clarify comment about __remove_mapping()
(Thanks: Yu Zhao <yuzhao@google.com>)
Link: https://lkml.kernel.org/r/20220209202659.183418-1-mfo@canonical.com
Fixes: 854e9ed09ded ("mm: support madvise(MADV_FREE)")
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dan Hill <daniel.hill@canonical.com>
Cc: Dan Streetman <dan.streetman@canonical.com>
Cc: Dongdong Tao <dongdong.tao@canonical.com>
Cc: Gavin Guo <gavin.guo@canonical.com>
Cc: Gerald Yang <gerald.yang@canonical.com>
Cc: Heitor Alves de Siqueira <halves@canonical.com>
Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Cc: Jay Vosburgh <jay.vosburgh@canonical.com>
Cc: Matthew Ruffell <matthew.ruffell@canonical.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ponnuvel Palaniyappan <ponnuvel.palaniyappan@canonical.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
| -rw-r--r-- | mm/rmap.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index c729171b9520..70375c331083 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1645,16 +1645,16 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, map_count = folio_mapcount(folio); /* - * 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 && !folio_test_dirty(folio)) { /* Invalidate as we cleared the pte */ mmu_notifier_invalidate_range(mm, |