Five stable fixes:

- Two DM btree bufio buffer leak fixes that resolve reported BUG_ONs
  during DM thinp metadata close's dm_bufio_client_destroy().

- A DM thinp range discard fix to handle discarding a partially mapped
  range.

- A DM thinp metadata snapshot fix to make sure the btree roots saved in
  the metadata snapshot are the most current.

- A DM space map metadata refcounting fix that improves both DM thinp
  and DM cache metadata.
dm btree: fix bufio buffer leaks in dm_btree_del() error path

If dm_btree_del()'s call to push_frame() fails, e.g. due to
btree_node_validator finding invalid metadata, the dm_btree_del() error
path must unlock all frames (which have active dm-bufio buffers) that
were pushed onto the del_stack.

Otherwise, dm_bufio_client_destroy() will BUG_ON() because dm-bufio
buffers have leaked, e.g.:
  device-mapper: bufio: leaked buffer 3, hold count 1, list 0

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
1 file changed