A set of device-mapper changes for 3.13.

Improve reliability of buffer allocations for dm messages with a small
number of arguments, a couple path group initialization fixes for dm
multipath, a fix for resizing a dm array, various fixes and
optimizations for dm cache, a fix for device mapper's Kconfig menu
indentation.

Features added include:
- dm crypt support for activating legacy CBC TrueCrypt containers
  (useful for forensics of these old TCRYPT containers)
- reduced dm-cache memory requirements for each block in the cache
- basic support for shrinking a dm-cache's cache (fast) device
- most notably, dm-cache support for managing cache coherency when
  deploying dm-cache with sophisticated origin volumes (that support
  hardware snapshots and/or clustering): these changes come in the form
  of a new passthrough operation mode and a cache block invalidation
  interface.
dm cache: resolve small nits and improve Documentation

Document passthrough mode, cache shrinking, and cache invalidation.
Also, use strcasecmp() and hlist_unhashed().

Reported-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
3 files changed