From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH]: create sysfs file, dh_state for SCSI devices even if they are not in the inteernal lists Date: Tue, 11 Aug 2009 10:54:12 +0200 Message-ID: <4A8131B4.6000605@suse.de> References: <1246069888.14164.53.camel@chandra-ubuntu> <4A486FF0.7040209@suse.de> <1246303830.15941.17.camel@chandra-ubuntu> <1249329099.31433.23.camel@chandra-ubuntu> 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: <1249329099.31433.23.camel@chandra-ubuntu> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: sekharan@linux.vnet.ibm.com Cc: Mario Mech , device-mapper development , linux-scsi List-Id: linux-scsi@vger.kernel.org Chandra Seetharaman wrote: > Hi Hannes, >=20 > Can you comment on this please. >=20 > If you are convinced with my justification, please send an ACK. >=20 > Thanks & Regards, >=20 > chandra > On Mon, 2009-06-29 at 12:30 -0700, Chandra Seetharaman wrote: >> On Mon, 2009-06-29 at 09:40 +0200, Hannes Reinecke wrote: >>> Chandra Seetharaman wrote: >>>> Create the sysfs file, dh_state even if the new SCSI device is not >>>> in the any of the device handler's internal lists. >>>> >>>> Signed-Off-by: Chandra Seetharaman >>>> --- >>>> drivers/scsi/device_handler/scsi_dh.c | 11 ++++------- >>>> 1 file changed, 4 insertions(+), 7 deletions(-) >>>> >>>> Index: linux-2.6.31-rc1/drivers/scsi/device_handler/scsi_dh.c >>>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>>> --- linux-2.6.31-rc1.orig/drivers/scsi/device_handler/scsi_dh.c >>>> +++ linux-2.6.31-rc1/drivers/scsi/device_handler/scsi_dh.c >>>> @@ -304,18 +304,15 @@ static int scsi_dh_notifier(struct notif >>>> sdev =3D to_scsi_device(dev); >>>> =20 >>>> if (action =3D=3D BUS_NOTIFY_ADD_DEVICE) { >>>> + err =3D device_create_file(dev, &scsi_dh_state_attr); >>>> + /* don't care about err */ >>>> devinfo =3D device_handler_match(NULL, sdev); >>>> - if (!devinfo) >>>> - goto out; >>>> - >>>> - err =3D scsi_dh_handler_attach(sdev, devinfo); >>>> - if (!err) >>>> - err =3D device_create_file(dev, &scsi_dh_state_attr); >>>> + if (devinfo) >>>> + err =3D scsi_dh_handler_attach(sdev, devinfo); >>>> } else if (action =3D=3D BUS_NOTIFY_DEL_DEVICE) { >>>> device_remove_file(dev, &scsi_dh_state_attr); >>>> scsi_dh_handler_detach(sdev, NULL); >>>> } >>>> -out: >>>> return err; >>>> } >>>> =20 >>>> >>>> >>>> -- >>>> dm-devel mailing list >>>> dm-devel@redhat.com >>>> https://www.redhat.com/mailman/listinfo/dm-devel >>> NACK. >>> >>> This will create sysfs attributes even if the attach() >>> failed for other reason like a generic error. So we'll end >>> up with device handler attributes and no device handler attached. >> we do not have to worry about if attach failed or succeeded. We will >> have "detached" if there is no device handler is attached to a device.= =20 >> >> Basically, existence of this file simply means that scsi_dh module is >> active, only the contents of this file will indicate if any device >> handler is attached or not. >> >> We are just creating the file dh_state for each SCSI device that exist= s >> and that is the only way non-in-built devices can be attached to a >> handler by the end-user. >> >> Do note that we do create this file for all the existing scsi devices >> when the scsi_dh module is inserted (see scsi_dh_init()). >> Right. So you're changing the semantics from the 'dh_state' attribute to mean 'scsi_dh' is active, not 'a scsi_dh module has been attached'. Ok, that seems reasonable. Acked-by: Hannes Reinecke Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: Markus Rex, HRB 16746 (AG N=FCrnberg)