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| author | Minchan Kim <minchan@kernel.org> | 2017-05-03 14:52:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-03 15:52:08 -0700 |
| commit | eb94a8784427b28479f871b5d4121c547808d0fc (patch) | |
| tree | c888f13dc71e13ea4a832598fc06cc325142373b /mm/rmap.c | |
| parent | 802a3a92ad7ac0b9be9df229dee530a1f0a8039b (diff) | |
| download | linux-eb94a8784427b28479f871b5d4121c547808d0fc.tar.gz linux-eb94a8784427b28479f871b5d4121c547808d0fc.tar.bz2 linux-eb94a8784427b28479f871b5d4121c547808d0fc.zip | |
mm: fix lazyfree BUG_ON check in try_to_unmap_one()
If a page is swapbacked, it means it should be in swapcache in
try_to_unmap_one's path.
If a page is !swapbacked, it mean it shouldn't be in swapcache in
try_to_unmap_one's path.
Check both two cases all at once and if it fails, warn and return
SWAP_FAIL. Such bug never mean we should shut down the kernel.
[minchan@kernel.org: do not use VM_WARN_ON_ONCE as if condition[
Link: http://lkml.kernel.org/r/20170309060226.GB854@bbox
Link: http://lkml.kernel.org/r/20170307055551.GC29458@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 519b7eb723d1..a19bd8b8ab0d 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1418,8 +1418,12 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * Store the swap location in the pte. * See handle_pte_fault() ... */ - VM_BUG_ON_PAGE(!PageSwapCache(page) && PageSwapBacked(page), - page); + if (unlikely(PageSwapBacked(page) != PageSwapCache(page))) { + WARN_ON_ONCE(1); + ret = SWAP_FAIL; + page_vma_mapped_walk_done(&pvmw); + break; + } /* MADV_FREE page check */ if (!PageSwapBacked(page)) { |