From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 3/4] scsi_dh_rdac: Adding the match function for rdac device handler Date: Wed, 02 Nov 2011 08:20:31 +0100 Message-ID: <4EB0EF3F.1010300@suse.de> References: <47D23AD8469A2B448F33C24BD7A39BD9105DB4D8@RTPMVEXC1-PRD.hq.netapp.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <47D23AD8469A2B448F33C24BD7A39BD9105DB4D8@RTPMVEXC1-PRD.hq.netapp.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: dm-devel@redhat.com List-Id: dm-devel.ids On 11/01/2011 06:19 PM, Moger, Babu wrote: > This patch introduces the match function for rdac device handler. Without= this, > sometimes handler attach fails during the device_add. The match function= was > introduced by this patch > http://www.spinics.net/lists/linux-scsi/msg54284.html > > Signed-off-by: Babu Moger > --- > > --- linux/drivers/scsi/device_handler/scsi_dh_rdac.c.orig 2011-10-31 11:2= 5:44.000000000 -0500 > +++ linux/drivers/scsi/device_handler/scsi_dh_rdac.c 2011-10-31 11:31:34.= 000000000 -0500 > @@ -819,6 +819,21 @@ static const struct scsi_dh_devlist rdac > {NULL, NULL}, > }; > > +static bool rdac_match(struct scsi_device *sdev) > +{ > + int i; > + > + for (i =3D 0; rdac_dev_list[i].vendor; i++) { > + if (!strncmp(sdev->vendor, rdac_dev_list[i].vendor, > + strlen(rdac_dev_list[i].vendor))&& > + !strncmp(sdev->model, rdac_dev_list[i].model, > + strlen(rdac_dev_list[i].model))) { > + return true; > + } > + } > + return false; > +} > + > static int rdac_bus_attach(struct scsi_device *sdev); > static void rdac_bus_detach(struct scsi_device *sdev); > > @@ -831,6 +846,7 @@ static struct scsi_device_handler rdac_d > .attach =3D rdac_bus_attach, > .detach =3D rdac_bus_detach, > .activate =3D rdac_activate, > + .match =3D rdac_match, > }; > > static int rdac_bus_attach(struct scsi_device *sdev) > As stated in the other mail, I guess we would need to have a check = if the LUN is in ALUA mode. And, btw, the _original_ intention was to allow vendor-specific = device_handler to do some better probing, eg querying some = vendor-specific VPD pages. Especially for RDAC it would make far more sense to query the = existence and format of one of the RDAC-specific VPD pages (eg 0xC2, = 0xC4, or 0xC8) and use that for matching. Then you could do away with the vendor/model array altogether here = and we wouldn't need to update the rdac handler every time a new = array comes out or has been rebranded by some OEM. Cheers, Hannes -- = Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg)