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To:     Bart Van Assche <bart.vanassche@gmail.com>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        David Howells <dhowells@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        Logan Gunthorpe <logang@deltatee.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Douglas Gilbert <dgilbert@interlog.com>
Subject: Re: [PATCH v5 3/9] iov_iter: Use IOCB/IOMAP_WRITE if available
 rather than iterator direction
From:   "Martin K. Petersen" <martin.petersen@oracle.com>
Organization: Oracle Corporation
Message-ID: <yq1ilh9ucg3.fsf@ca-mkp.ca.oracle.com>
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Date:   Fri, 13 Jan 2023 20:34:50 -0500
In-Reply-To: <c6f4014e-d199-d5e8-515c-5ffcd9946c80@gmail.com> (Bart Van
        Assche's message of "Thu, 12 Jan 2023 13:49:14 -0800")
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Bart,

> I'm not sure that we still need the double copy in the sg driver. It
> seems obscure to me that there is user space software that relies on
> finding "0xec" in bytes not originating from a SCSI
> device. Additionally, SCSI drivers that do not support residuals
> should be something from the past.

Yeah. I'm not aware of anything that relies on this still. But obviously
Doug has more experience in the app dependency department.

-- 
Martin K. Petersen	Oracle Linux Engineering