On Fri, Dec 12, 2025 at 05:21:41PM -0800, Eric Biggers wrote:

quoted

+	memset(pages, 0, sizeof(struct page *) * nr_segs);
+	nr_allocated = alloc_pages_bulk(GFP_KERNEL, nr_segs, pages);
+	if (nr_allocated < nr_segs)
+		mempool_alloc_bulk(blk_crypto_bounce_page_pool, (void **)pages,
+				nr_segs, nr_allocated);

alloc_pages_bulk() is documented to fill in pages sequentially.  So the
"random pages in the array unallocated" part seems misleading.  This
also means that only the remaining portion needs to be passed to
mempool_alloc_bulk(), similar to blk_crypto_fallback_encrypt_endio().

I the better idea is to offset the search in mempool_alloc_bulk
based on the passed in allocated argument.  I'll prepare a patch for
that.