Message-ID: <7622ebe2-7405-ce4f-6bae-2d51dc8bf929@redhat.com>
Date:   Fri, 27 Jan 2023 00:45:35 +0100
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Subject: Re: [PATCH v11 1/8] iov_iter: Define flags to qualify page
 extraction.
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To:     Al Viro <viro@zeniv.linux.org.uk>,
        David Howells <dhowells@redhat.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>,
        Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Christoph Hellwig <hch@lst.de>,
        John Hubbard <jhubbard@nvidia.com>
References: <20230126141626.2809643-1-dhowells@redhat.com>
 <20230126141626.2809643-2-dhowells@redhat.com> <Y9L2iFZlC4CFwN4t@ZenIV>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <Y9L2iFZlC4CFwN4t@ZenIV>
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On 26.01.23 22:54, Al Viro wrote:
> On Thu, Jan 26, 2023 at 02:16:19PM +0000, David Howells wrote:
> 
>> +typedef unsigned int iov_iter_extraction_t;
> 
>> +/* Flags for iov_iter_get/extract_pages*() */
>> +/* Allow P2PDMA on the extracted pages */
>> +#define ITER_ALLOW_P2PDMA	((__force iov_iter_extraction_t)0x01)
> 
> That __force makes sense only if you make it a bitwise type -
> otherwise it's meaningless.  IOW, either turn the typedef into
> 
> typedef unsigned int __bitwise iov_iter_extraction_t;
> 
> or lose __force in the cast...
> 

Well spotted, iov_iter_extraction_t is missing __bitwise.

-- 
Thanks,

David / dhildenb