From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Christie Subject: Re: [PATCH RFC 0/4] use scatter lists for all block pc requests and simplify hw handlers Date: Tue, 7 Jun 2005 10:26:16 -0500 Message-ID: <1118157976.42a5bc98d6f75@webmail.cs.wisc.edu> References: <1117847972.23638.62.camel@mina> <1117901234.5005.9.camel@mulgrave> <1117955727.4961.8.camel@mina> <20050606190205.GA6817@us.ibm.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20050606190205.GA6817@us.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Patrick Mansfield Cc: James Bottomley , device-mapper development , Jens Axboe , linux-scsi List-Id: linux-scsi@vger.kernel.org Quoting Patrick Mansfield : > On Sun, Jun 05, 2005 at 12:15:27AM -0700, Mike Christie wrote: > > On Sat, 2005-06-04 at 09:07, James Bottomley wrote: >=20 > > > Here's the proof of concept for this one. It converts scsi_wait_re= q to > > > do correct REQ_BLOCK_PC submission (and works nicely in my setup). >=20 > That is nice ... I didn't realize Mike's change allowed that. >=20 > > > There's some loss of functionality to this: retries are no longer > > > controllable (except by setting REQ_FASTFAIL) and the wait_req API = needs > > > to be altered, but it looks very nice. >=20 > Mike your patch did not replace the retries. >=20 > Why can't the retries be passed down via a new blk req->retries? >=20 Is that all that is needed for dm-multipath? I thought this would be a go= od time to add some code to allow the finer grained control of retries that could= also be used by dm and md. For example do you only want to retry certain failu= res X numbeer of times?