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Date:   Sat, 26 Feb 2022 18:22:47 -0800 (PST)
From:   Hugh Dickins <hughd@google.com>
To:     Matthew Wilcox <willy@infradead.org>
cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH next] mm/thp: fix collapse_file()'s try_to_unmap(folio,)
Message-ID: <3f187b6c-e5e8-e66d-e0c0-7455ca6abb4c@google.com>
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Precedence: bulk

The foliation of THP collapse_file()'s call to try_to_unmap() is
currently wrong, crashing on a test in rmap_walk() when xas_next()
delivered a value (after which page has been loaded independently).

Fixes: c3b522d9a698 ("mm/rmap: Convert try_to_unmap() to take a folio")
Signed-off-by: Hugh Dickins <hughd@google.com>
---
Please just fold in if you agree.

 mm/khugepaged.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- mmotm/mm/khugepaged.c
+++ linux/mm/khugepaged.c
@@ -1824,7 +1824,8 @@ static void collapse_file(struct mm_stru
 		}
 
 		if (page_mapped(page))
-			try_to_unmap(folio, TTU_IGNORE_MLOCK | TTU_BATCH_FLUSH);
+			try_to_unmap(page_folio(page),
+				     TTU_IGNORE_MLOCK | TTU_BATCH_FLUSH);
 
 		xas_lock_irq(&xas);
 		xas_set(&xas, index);