mm: shmem: remove unnecessary warning in shmem_writepage()

Although the scenario where shmem_writepage() is called with info->flags &
VM_LOCKED is unlikely to happen, it's still possible, as evidenced by
syzbot [1].  However, the warning in this case isn't necessary because the
situation is already handled correctly [2].

[2] https://lore.kernel.org/lkml/8afe1f7f-31a2-4fc0-1fbd-f9ba8a116fe3@google.com/

Link: https://lkml.kernel.org/r/20250226-20250221-warning-in-shmem_writepage-v1-1-5ad19420e17e@igalia.com
Fixes: 9a976f0c847b ("shmem: skip page split if we're not reclaiming")
Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Closes: https://lore.kernel.org/lkml/ZZ9PShXjKJkVelNm@xpf.sh.intel.com/ [1]
Suggested-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Florent Revest <revest@chromium.org>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/shmem.c b/mm/shmem.c
index cebbac97a221975de07d3614f2f7ee326079a75f..3fcd1690eedd7222169490393c66abfd7409c26e 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1548,7 +1548,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
        if (WARN_ON_ONCE(!wbc->for_reclaim))
                goto redirty;
 
-       if (WARN_ON_ONCE((info->flags & VM_LOCKED) || sbinfo->noswap))
+       if ((info->flags & VM_LOCKED) || sbinfo->noswap)
                goto redirty;
 
        if (!total_swap_pages)