[merged mm-hotfixes-stable] mm-do-not-reclaim-private-data-from-pinned-page.patch removed from -mm tree
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2023-05-05 22:43:10
Also in:
mm-commits
The quilt patch titled
Subject: mm: do not reclaim private data from pinned page
has been removed from the -mm tree. Its filename was
mm-do-not-reclaim-private-data-from-pinned-page.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Jan Kara <jack@suse.cz>
Subject: mm: do not reclaim private data from pinned page
Date: Fri, 28 Apr 2023 14:41:40 +0200
If the page is pinned, there's no point in trying to reclaim it.
Furthermore if the page is from the page cache we don't want to reclaim
fs-private data from the page because the pinning process may be writing
to the page at any time and reclaiming fs private info on a dirty page can
upset the filesystem (see link below).
Link: https://lore.kernel.org/linux-mm/20180103100430.GE4911@quack2.suse.cz (local)
Link: https://lkml.kernel.org/r/20230428124140.30166-1-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Lorenzo Stoakes <redacted>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <redacted>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/vmscan.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/mm/vmscan.c~mm-do-not-reclaim-private-data-from-pinned-page
+++ a/mm/vmscan.c@@ -1967,6 +1967,16 @@ retry: } } + /* + * Folio is unmapped now so it cannot be newly pinned anymore. + * No point in trying to reclaim folio if it is pinned. + * Furthermore we don't want to reclaim underlying fs metadata + * if the folio is pinned and thus potentially modified by the + * pinning process as that may upset the filesystem. + */ + if (folio_maybe_dma_pinned(folio)) + goto activate_locked; + mapping = folio_mapping(folio); if (folio_test_dirty(folio)) { /*
_ Patches currently in -mm which might be from jack@suse.cz are