From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Becker Subject: Re: [LSF/MM TOPIC][ATTEND] protection information and userspace Date: Fri, 8 Feb 2013 01:36:01 -0800 Message-ID: <20130208093558.GA2733@localhost> References: <20130206195122.GA30652@sgi.com> <20130206202444.GA4771@blackbox.djwong.org> <20DAFDEA-0C44-478E-B406-C5B08BC67FBC@oracle.com> <20130207094012.GA28047@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Chuck Lever , "Darrick J. Wong" , Ben Myers , lsf-pc@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-scsi@vger.kernel.org To: "Martin K. Petersen" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Feb 07, 2013 at 02:12:57PM -0500, Martin K. Petersen wrote: > >>>>> "Joel" == Joel Becker writes: > > Joel> I'm happy to chat about it. Unfortunately, like Darrick says, > Joel> sys_dio() coding hasn't happened. I do think we're better off > Joel> with some kind of explicit API than some magic state on the file. > Joel> I mean, even something like: > > Joel> ssize_t write_with_pi(int fd, const void *buf, size_t count, > Joel> const void *pi, size_t pi_count); > > Joel> It's not as nice as a non-historical API (eg sys_dio), but it also > Joel> probably plays nicer with buffered I/O. > > Pretty much everyone I have talked to that are interested in explicitly > attaching PI (as opposed to relying on the kernel doing it) are using > Linux aio. > > I am not opposed to having more read()/write() like interface as > well. But I think it's important to cater to the I/O paradigm used by > the applications interested in this. It's a lot easier to tweak a few > IOCB fields than it is to rewrite how an application does I/O. You know I'm not going to argue with this. I was merely stating that I'm flexible in how we start :-) Joel > > -- > Martin K. Petersen Oracle Linux Engineering > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- "Depend on the rabbit's foot if you will, but remember, it didn't help the rabbit." - R. E. Shay http://www.jlbec.org/ jlbec@evilplan.org