Re: [PATCH] block: Fix potential page reference leak in __bio_iov_iter_get_pages()

From: Christoph Hellwig
Date: Tue Sep 01 2020 - 12:09:18 EST


On Tue, Sep 01, 2020 at 08:00:06AM -0400, Miaohe Lin wrote:
> When bio is full, __bio_iov_iter_get_pages() would return error directly
> while left page reference still held in pages. Release these references.
> Also advance the iov_iter according to what we have done successfully.
>
> Fixes: 576ed9135489 ("block: use bio_add_page in bio_iov_iter_get_pages")
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>

The WARN_ON means something is fundamentally wrong here. I think a few
leaked pages are the least of our problems in this case.