Pipe: rename keepalive->send_keepalive

Signed-off-by: Greg Farnum <greg@inktank.com>
msgr: add KEEPALIVE2 feature

This is similar to KEEPALIVE, except a timestamp is also exchanged.  It is
sent with the KEEPALIVE, and then returned with the ACK.  The last
received stamp is stored in the Connection so that it can be queried for
liveness.  Since all of the users of keepalive are already regularly
triggering a keepalive, they can check the liveness at the same time.

See #7888.

Signed-off-by: Sage Weil <sage@inktank.com>
mon/MonClient: use keepalive2 to verify the mon session is live

Verify that the mon is responding by checking the keepalive2 reply
timestamp.  We cannot rely solely on TCP timing out and returning an
error.

Fixes: #7888
Signed-off-by: Sage Weil <sage@inktank.com>
fuse: implement 'access' low level function

Add an empty 'access' function to fuse low level functions. This
allow us to use ceph-fuse with fuse_default_permissions = false.
'fuse_default_permissions = false' can significantly improve the
speed of create/removing large number of files.

When fuse_default_permissions is true, the fuse kernel module sends
a getattr request whenever the kernel needs to check a directory's
permission. getattr (STAT_CAP_INODE_ALL) can be very slow if the
directory was just modified.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
mon/PGMap: clear pool sum when last pg is deleted

Use the x.0 pg as a sentinel for the existence of the pool.  Note that we
have to clean in up two paths: apply_incrmenetal (which is actually
deprecated) and the normal PGMonitor refresh.

Fixes: #7912
Signed-off-by: Sage Weil <sage@inktank.com>
Add ceph-client-debug and jerasure shared objects to RPM spec file.
Merge pull request #1566 from ceph/wip-fuse-access

fuse: implement 'access' low level function

Reviewed-by: Sage Weil <sage@inktank.com>
Merge pull request #1556 from ceph/wip-7888

msgr: add new ping/ping reply to use in place of keepalive

Reviewed-by: Greg Farnum <greg@inktank.com>
Merge pull request #1573 from ceph/wip-7912

mon/PGMap: clear pool sum when last pg is deleted

Reviewed-by: Greg Farnum <greg@inktank.com>
Merge pull request #1574 from mikenel/master

Add ceph-client-debug and jerasure shared objects to RPM spec file.

Reviewed-by: Sage Weil <sage@inktank.com>
osd/PG: debug cached_removed_snaps changes

See #7915.

Signed-off-by: Sage Weil <sage@inktank.com>