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Date:   Tue, 13 Jun 2023 09:48:18 -0600
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Subject: Re: [PATCH v2] block: Fix dio_bio_alloc() to set BIO_PAGE_PINNED
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To:     David Howells <dhowells@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        kernel test robot <oliver.sang@intel.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        Lorenzo Stoakes <lstoakes@gmail.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-mm@kvack.org, oe-lkp@lists.linux.dev, lkp@intel.com,
        linux-kernel@vger.kernel.org
References: <545463.1686601473@warthog.procyon.org.uk>
From:   Jens Axboe <axboe@kernel.dk>
In-Reply-To: <545463.1686601473@warthog.procyon.org.uk>
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On 6/12/23 2:24 PM, David Howells wrote:
>     
> Fix dio_bio_alloc() to set BIO_PAGE_PINNED, not BIO_PAGE_REFFED, so that
> the bio code unpins the pinned pages rather than putting a ref on them.
> 
> The issue was causing:
> 
>         WARNING: CPU: 6 PID: 2220 at mm/gup.c:76 try_get_folio
> 
> This can be caused by creating a file on a loopback UDF filesystem, opening
> it O_DIRECT and making two writes to it from the same source buffer.

What is this against?

-- 
Jens Axboe