On 01/13/2011 12:06 PM, Tejun Heo wrote:

Urgh... gees, so there actually was a user using all that cruft.
Sorry about the breakage, I'll see how multiple symlinks can be
restored.  I'm curious why this was added at all tho.  What was the
rationalization?  It's not like two subsystems can share the same
block device so marking the currently owning subsystem should have
been enough at the block layer.  There is no reason for block devices
to present information which is of no use to itself.  All that's
necessary is "this is taken by dm or md for more information, query
those".  dm and md need their own conf/representation layer anyway.

I am not sure if I understand it correctly, but multiple holders/slaves
links are very useful in userspace to present device dependences.

We just implemented lsblk command in util-linux which simple prints
tree according to these links, so dependendes of DM/MD/whatever devices
can be printed without using any system specific callbacks, just using
sysfs. See http://karelzak.blogspot.com/2010/12/lsblk8.html

Whatever changes are needed, please keep this functionality, it can be useful.

Thanks,
Milan