Re: [RFC PATCH v2 04/11] mm: khugepaged: add shmem mTHP collapse support

[Lance Yang]

On Wed, Jun 10, 2026 at 06:29:12PM +0800, Baolin Wang wrote:
[...]
>@@ -2808,7 +2875,7 @@ static enum scan_result collapse_single_pmd(unsigned long addr,
> 	mmap_read_unlock(mm);
> 	*lock_dropped = true;
> retry:
>-	result = collapse_scan_file(mm, addr, file, pgoff, cc);
>+	result = collapse_scan_file(mm, vma, addr, file, pgoff, cc);

Looks unsafe to pass "vma" down here, since we have already dropped
mmap_read_unlock(mm) ...

A racing munmap() could leave it stale before collapse_scan_file() use
it, no?

Cheers, Lance