From: Hugh Dickins hughd@google.com
[ Upstream commit 2f33a706027c94cd4f70fcd3e3f4a17c1ce4ea4b ]
When collapse_file() calls try_to_release_page(), it has already isolated the page: so if releasing buffers happens to fail (as it sometimes does), remember to putback_lru_page(): otherwise that page is left unreclaimable and unfreeable, and the file extent uncollapsible.
Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: Hugh Dickins hughd@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Acked-by: Song Liu songliubraving@fb.com Acked-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Acked-by: Johannes Weiner hannes@cmpxchg.org Cc: Rik van Riel riel@surriel.com Cc: stable@vger.kernel.org [5.4+] Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2005231837500.1766@eggly.anvils Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/khugepaged.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a8a57bebb5fa..f765475be359 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1655,6 +1655,7 @@ static void collapse_file(struct mm_struct *mm, if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) { result = SCAN_PAGE_HAS_PRIVATE; + putback_lru_page(page); goto out_unlock; }