[dm-devel] SCSI's heuristics for enabling WRITE SAME still need work [was: dm mpath: disable WRITE SAME if it fails]

[Paolo Bonzini]

Il 21/09/2013 00:03, Martin K. Petersen ha scritto:
> 
> The major headache here of course is that WRITE SAME is inherently
> destructive. We can't just fire off one during discovery and see if it
> works. For WRITE you can issue a command with a transfer length of 0 to
> see if things work. But unfortunately for WRITE SAME a transfer length
> of zero means "wipe the entire device". Yikes!

What about WRITE SAME with an out-of-range lba?  Or lba equal to the
size of the disk and #blocks equal to zero.

Paolo