diff options
| author |   Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-06-19 10:37:32 -0400 |
|---|---|---|
| committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-06-23 12:21:44 -0400 |
| commit | b653db77350c7307a513b81856fe53e94cf42446 (patch) | |
| tree | cb4f733ccff7026b5cd4eaa3220e282bcd90a07a /mm/migrate.c | |
| parent | filemap: Handle sibling entries in filemap_get_read_batch() (diff) | |
| download | wireguard-linux-b653db77350c7307a513b81856fe53e94cf42446.tar.xz wireguard-linux-b653db77350c7307a513b81856fe53e94cf42446.zip | |
mm: Clear page->private when splitting or migrating a page
In our efforts to remove uses of PG_private, we have found folios with
the private flag clear and folio->private not-NULL. That is the root
cause behind 642d51fb0775 ("ceph: check folio PG_private bit instead
of folio->private"). It can also affect a few other filesystems that
haven't yet reported a problem.
compaction_alloc() can return a page with uninitialised page->private,
and rather than checking all the callers of migrate_pages(), just zero
page->private after calling get_new_page(). Similarly, the tail pages
from split_huge_page() may also have an uninitialised page->private.
Reported-by: Xiubo Li <xiubli@redhat.com>
Tested-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/migrate.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index e51588e95f57..6c1ea61f39d8 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1106,6 +1106,7 @@ static int unmap_and_move(new_page_t get_new_page, if (!newpage) return -ENOMEM; + newpage->private = 0; rc = __unmap_and_move(page, newpage, force, mode); if (rc == MIGRATEPAGE_SUCCESS) set_page_owner_migrate_reason(newpage, reason); |