[dm-devel] 2.6.9-rc2-udm2

[Alasdair G Kergon]

ftp://sources.redhat.com/pub/dm/patches/2.6-unstable/2.6.9-rc2/2.6.9-rc2-udm2.tar.bz2
 
A new patchset for multipath.
This contains the final set of features I want us to work 
on making stable and tidying up before the first submission 
upstream.


Main changes:
  Removed the experimental path initialisation code for now:
  will reinstate in a more generic way after the current set of 
  features is ready for mainstream inclusion.

  Device refs by major/minor numbers so userspace tools can be more
  efficient e.g. dmsetup info -j 253 -m 1
  Take device-mapper tools from CVS to take advantage of this.
  [Userspace changes not thoroughly tested yet; a few 
   commands require kernel changes for complete support.]

  Reinstatement of failed paths directly - no need to reload the
  whole table. e.g. 'dmsetup message mp1 2000 reinstate 253:4'

  Path selector 'select' function returns how many times to use
  path before being asked again; also enables crude
  load-balancing.
  e.g. 'multipath 1 round-robin 2 1 253:4 1000 253:3 2000'
    (send 1000 I/O to first; 2000 to second)
  0 means continue using a path till it fails.
  It's still optional: 'round-robin 2 0 253:4 253:3'

  Auto-loading of unknown path selectors.


I've done some basic testing on this, but not much yet.
In particular, I've not checked any module code, not reviewed
all the uses of locks for correctness and not reviewed 
what 'status' returns.

The i386 kgdb patch (taken from -mm) is included for convenience.


Alasdair
-- 
agk at redhat.com