On 03/18/2009 04:09 PM, James Bottomley wrote: > On Wed, 2009-03-18 at 12:12 -0700, Chandra Seetharaman wrote: >> On Wed, 2009-03-18 at 18:47 +0000, James Bottomley wrote: >>> On Tue, 2009-03-17 at 18:36 -0700, Chandra Seetharaman wrote: >>>> From: Peter Jones <pjones@xxxxxxxxxx> >>>> >>>> This patch allows the use of modaliases on scsi targets to correctly >>>> load scsi device handler modules when the devices are found. >>>> >>>> Signed-off-by: Peter Jones <pjones@xxxxxxxxxx> >>>> Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx> >>> I have to say this is a bit icky. >>> >>> overloading the modalias type like this produces several nasty effects: >>> >>> 1. You don't actually care about type for any of the scsi_dh >>> handlers, so they all have it as a useless extra field >>> 2. TYPE_ANY is a bogus (non SAM) definition ... I suppose it's >>> unlikely ever to clash, but you never know Yeah, I wasn't really enthusiastic about this hack when I wrote it, either. More on that below. >> >From (1) and (2) are you suggesting _not_ to use the TYPE field for >> scsi_dh handlers ? > > Well, you don't ever set it to anything other than TYPE_ANY, do you? so > it's completely superfluous as far as you're concerned. That's why > overloading the SCSI ULD modalias looks rather contrived. To be honest, I only used that particular modalias because it seemed like the most natural place for it; so TYPE_ANY is really only there because it already was. Though I could imagine somebody writing a device handler for e.g. a tape robot. Or we could make the structure have another field that says how to treat the type field, but that seems sloppy. If there's a /different/ object on which you think the modalias for the scsi target itself should go, that'd be fine by me, I just didn't see anywhere that looked better. [...] >> BTW, dm-multipath currently have code to insert appropriate modules if >> needed (if they are not already made available). > > So all of this is just to keep the initrd boot quiet? Well, really it's so that we don't have to add /extra/ code in userland to decide which device handlers to load and to load them. Especially since that's what modaliases are *for*. -- Peter -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
