Re: [PATCH 2/3] block: Add badblock management for gendisks

["Verma, Vishal L" <vishal.l.verma@intel.com>]

On Tue, 2015-11-24 at 10:34 -0500, Jeff Moyer wrote:
> Vishal Verma <vishal.l.verma@intel.com> writes:
> 
> > NVDIMM devices, which can behave more like DRAM rather than block
> > devices, may develop bad cache lines, or 'poison'. A block device
> > exposed by the pmem driver can then consume poison via a read (or
> > write), and cause a machine check. On platforms without machine
> > check recovery features, this would mean a crash.
> > 
> > The block device maintaining a runtime list of all known sectors
> > that
> > have poison can directly avoid this, and also provide a path forward
> > to enable proper handling/recovery for DAX faults on such a device.
> > 
> > Use the new badblock management interfaces to add a badblocks list
> > to
> > gendisks.
> 
> Because disk_alloc_badblocks can fail, you need to check for a NULL
> disk->bb in all of the utility functions you've defined.
> 

Thanks, Jeff - I'll fix this. I have a handful of other fixes queued up
too, will send out a v2 soon.

	-Vishal