Messages in this thread | | | Date | Fri, 10 Feb 2006 15:13:09 +0000 | From | Alasdair G Kergon <> | Subject | Re: [PATCH] Support HDIO_GETGEO on device-mapper volumes |
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On Fri, Feb 10, 2006 at 02:53:48PM +0000, Alasdair G Kergon wrote: > I disagree - either dm should work out the *correct* geometry to > return for those mappings where a geometry is known and it's sensible > to return one (e.g. linear mapping to the start of certain scsi > devices), or else it should leave it to userspace to decide how to > handle the situation. (And there's nothing currently stopping > userspace seeing that a dm device is constructed out of a scsi device > and choosing to use the geometry of that underlying device.)
s/scsi/hd/ in those examples for slightly more sense
What would the 'geometry' of a dm 'error' target mean? Or of a snapshot?
In any patch, consider that we've already identified a need (e.g. for multipath) to add a framework to device-mapper to pass certain ioctls along to the underlying devices. I'd prefer to see that approach here: for tables with a single entry, pass the ioctl into the target. Linear and multipath would then pass it along to the underlying device; other targets would return zeros. Alasdair -- agk@redhat.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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