From a5cdbe9f376f920af102fd0f0ecfd9952bb6bc40 Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Sat, 17 May 2025 01:09:38 +0800 Subject: mm: shmem: only remove inode from swaplist when it's swapped page count is 0 Even if we fail to allocate a swap entry, the inode might have previously allocated entry and we might take inode containing swap entry off swaplist. As a result, try_to_unuse() may enter a potential dead loop to repeatedly look for inode and clean it's swap entry. Only take inode off swaplist when it's swapped page count is 0 to fix the issue. Link: https://lkml.kernel.org/r/20250516170939.965736-5-shikemeng@huaweicloud.com Fixes: b487a2da3575 ("mm, swap: simplify folio swap allocation") Signed-off-by: Kemeng Shi Reviewed-by: Baolin Wang Reviewed-by: Kairui Song Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202505161438.9009cf47-lkp@intel.com Cc: Hugh Dickins Signed-off-by: Andrew Morton --- mm/shmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index aeeddf612baa..07b8e1400c67 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1651,8 +1651,8 @@ try_split: BUG_ON(folio_mapped(folio)); return swap_writepage(&folio->page, wbc); } - - list_del_init(&info->swaplist); + if (!info->swapped) + list_del_init(&info->swaplist); mutex_unlock(&shmem_swaplist_mutex); if (nr_pages > 1) goto try_split; -- cgit v1.2.3