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Date:   Thu, 12 Jan 2023 16:02:04 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     David Howells <dhowells@redhat.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
        Christoph Hellwig <hch@lst.de>,
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        Logan Gunthorpe <logang@deltatee.com>,
        linux-block@vger.kernel.org, Jeff Layton <jlayton@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 8/9] iov_iter, block: Make bio structs pin pages
 rather than ref'ing if appropriate
Message-ID: <20230112150204.GA11315@lst.de>
References: <Y8AWY991ilrO5Yco@infradead.org> <Y7+6YVkhZsvdW+Hr@infradead.org> <167344725490.2425628.13771289553670112965.stgit@warthog.procyon.org.uk> <167344731521.2425628.5403113335062567245.stgit@warthog.procyon.org.uk> <15237.1673519321@warthog.procyon.org.uk> <Y8AUjB5hxkwxhnGK@infradead.org> <147887.1673535529@warthog.procyon.org.uk>
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On Thu, Jan 12, 2023 at 02:58:49PM +0000, David Howells wrote:
> That's kind of what I'm doing - though I've left out the else just in case the
> VM decides to indicate back both FOLL_GET and FOLL_PIN.  I'm not sure why it
> would but...

It really can't - they are exclusive.  Maybe we need an assert for that
somewhere, but we surely shouldn't try to deal with it.