> -----Original Message----- > From: Hannes Reinecke [mailto:hare@xxxxxxx] > Sent: Wednesday, November 02, 2011 10:34 AM > To: device-mapper development > Cc: Moger, Babu; Linux SCSI Mailing list > Subject: Re: [PATCH 3/4] scsi_dh_rdac: Adding the match > function for rdac device handler > > On 11/02/2011 04:23 PM, Moger, Babu wrote: > >> -----Original Message----- > >> From: Hannes Reinecke [mailto:hare@xxxxxxx] > >> Sent: Wednesday, November 02, 2011 2:21 AM > >> To: dm-devel@xxxxxxxxxx > >> Subject: Re: [PATCH 3/4] scsi_dh_rdac: Adding the match > >> function for rdac device handler > >> > >> 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<babu.moger@xxxxxxxxxx> > >>> --- > >>> > >>> --- linux/drivers/scsi/device_handler/scsi_dh_rdac.c.orig 2011- > 10-31 > >> 11:25:44.000000000 -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 = 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 = rdac_bus_attach, > >>> .detach = rdac_bus_detach, > >>> .activate = rdac_activate, > >>> + .match = 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. > > > > OK. I will add the check for TPGS. I will send the patches tomorrow. > > For sending the VPD pages(0xC2, 0xC4 and 0xC8), I think we need be > > little careful here. > > This includes sending these commands to every possible device in the > > system. That is what we want to avoid. > > I will investigate more on that. That will be my next set of patches > > independent of this. > > > Fair enough. > As long as it's understood to be an interim solution, then we would > only need to check for the TGPS bit. > Which has the neat side-effect that we don't actually have to do any > I/O to check this, as the information is already present at that time. > > While you're at it, could you please add this check for scsi_dh_emc, > too? > The Clariion is also able to run in dual-mode, so the same check is > required there, too. Sure.. Will add the check to Clariion also.. > > Cheers, > > Hannes > -- > Dr. Hannes Reinecke zSeries & Storage > hare@xxxxxxx +49 911 74053 688 > SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg > GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
