rados.cc: fix pool alignment check

Only check pool alignment if io_ctx is initialized.

Introduced in 304b08a23a3db57010078046955a786fe3589ef8
Fixes: #8652
Signed-off-by: Samuel Just <sam.just@inktank.com>
Merge pull request #2020 from ceph/wip-fix-rados-tool

rados.cc: fix pool alignment check

Reviewed-by: Sage Weil <sage@inktank.com>
doc: RPM instructions correction

Signed-off-by: John Spray <john.spray@inktank.com>
mds: add 'enabled' flag to MDSMap

When 'enabled' is false, the MDSMap is effectively
null.  This allows Ceph clusters with no filesystem
or filesystem data/metadata pools.

Signed-off-by: John Spray <john.spray@inktank.com>
mds: no initial filesystem

Because not everyone uses CephFS, we would
like to avoid initially creating any data/metadata
pools for CephFS.

To avoid creating those pools, we must avoid initially
populating the MDSMap.

Signed-off-by: John Spray <john.spray@inktank.com>
osdmap: Don't create FS pools by default

Because many Ceph users don't use the filesystem,
don't create the 'data' and 'metadata' pools by
default -- they will be created by newfs if
they are needed.

Signed-off-by: John Spray <john.spray@inktank.com>
mon: don't require 'sure' flag for new fs

Only prompt for --yes-i-really-mean-it if there
is an existing FS.

Signed-off-by: John Spray <john.spray@inktank.com>
mon: warn in newfs if crash_replay_interval=0

This is the setting we would apply to data pools
created automatically, so notify the user if they're
failing to use it for data pools they have created
by hand.

Signed-off-by: John Spray <john.spray@inktank.com>
mon: enable deleting pools when FS disabled

Signed-off-by: John Spray <john.spray@inktank.com>
mon: stop MDSMonitor when FS disabled

Where 'stopped' means ignoring beacons and
not performing 'tick' activities.

Signed-off-by: John Spray <john.spray@inktank.com>
mon: hide mdsmap in 'ceph status' if not enabled

Previously we checked if the MDS map had ever been
updated (epoch > 1), now we have an explicit flag
for whether it's enabled.

Signed-off-by: John Spray <john.spray@inktank.com>
mon: add `ceph fs [new|rm|ls]`

Signed-off-by: John Spray <john.spray@inktank.com>

Conflicts:
	src/mon/MDSMonitor.cc
vstart: update for newfs/rmfs changes

Signed-off-by: John Spray <john.spray@inktank.com>
test/qa: update for MDSMonitor changes

Accomodate changes:
 * data and metadata pools no longer exist by default
 * filesystem-using tests must use `fs new` to create
   the filesystem first.

Signed-off-by: John Spray <john.spray@inktank.com>
mds: journal-related debug messages

Signed-off-by: John Spray <john.spray@redhat.com>
mds: Handle setting 'enabled' in upgrades

Previously was always defaulting to disabled,
should be enabled if MDS map epoch is >1 (i.e.
if an MDS was ever started).

Signed-off-by: John Spray <john.spray@redhat.com>
mon/MDSMonitor: s/enabled/get_enabled()/

Signed-off-by: John Spray <john.spray@redhat.com>
mon/MDSMonitor: fix incorrect comment

Signed-off-by: John Spray <john.spray@redhat.com>
mon/MDSMonitor: log warning while MDS up but no FS

Signed-off-by: John Spray <john.spray@redhat.com>
mds: Update default FS name

From 'default' to 'cephfs' so that it looks
at least vaguely meaningful.

Signed-off-by: John Spray <john.spray@redhat.com>

Conflicts:
	qa/workunits/cephtool/test.sh