[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Y8vkOk68ZFWPr9vq@infradead.org>
Date: Sat, 21 Jan 2023 05:10:18 -0800
From: Christoph Hellwig <hch@...radead.org>
To: David Howells <dhowells@...hat.com>
Cc: Al Viro <viro@...iv.linux.org.uk>,
Christoph Hellwig <hch@...radead.org>,
Matthew Wilcox <willy@...radead.org>,
Jens Axboe <axboe@...nel.dk>, Jan Kara <jack@...e.cz>,
Jeff Layton <jlayton@...nel.org>,
Logan Gunthorpe <logang@...tatee.com>,
linux-fsdevel@...r.kernel.org, linux-block@...r.kernel.org,
linux-kernel@...r.kernel.org, Christoph Hellwig <hch@....de>,
John Hubbard <jhubbard@...dia.com>, linux-mm@...ck.org
Subject: Re: [PATCH v7 2/8] iov_iter: Add a function to extract a page list
from an iterator
On Fri, Jan 20, 2023 at 05:55:50PM +0000, David Howells wrote:
> (3) Any other sort of iterator.
>
> No refs or pins are obtained on the page, the assumption is made that
> the caller will manage page retention. ITER_ALLOW_P2PDMA is not
> permitted.
The ITER_ALLOW_P2PDMA check here is fundamentally wrong and will
break things like io_uring to fixed buffers on NVMe. ITER_ALLOW_P2PDMA
should strictly increase the group of acceptable iters, it does must
not restrict anything.
Powered by blists - more mailing lists