An rbtree is lighter weight, particularly given we will generally have
very few in-flight statfs requests.
Signed-off-by: NSage Weil <sage@newdream.net>

The rbtree is a more appropriate data structure than a radix_tree.  It
avoids extra memory usage and simplifies the code.

It also fixes a bug where the debugfs 'mdsc' file wasn't including the
most recent mds request.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

Set bdi congestion bit when amount of write data in flight exceeds adjustable
threshold.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

We may first learn our fsid from any of the mon, osd, or mds maps
(whichever the monitor sends first).  Consolidate checks in a single
helper.  Initialize the client debugfs entry then, since we need the
fsid (and global_id) for the directory name.

Also remove dead mount code.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

Basic state information is available via /sys/kernel/debug/ceph,
including instances of the client, fsids, current monitor, mds and osd
maps, outstanding server requests, and hooks to adjust debug levels.
Signed-off-by: NSage Weil <sage@newdream.net>