Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: >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. Yes, WARN_ON means something is fundamentally wrong here. But IMO it's not really a big problem when bio is full. We should not simply rely on this WARN_ON and we can handle this gracefully. Thanks.