Make variable name slightly more generic, since it will (soon)
reflect either the time the request was sent OR the time it was
last determined to be still retrying.
Signed-off-by: NSage Weil <sage@newdream.net>

This simplifies the process of timing out messages. We
keep lru of current messages that are in flight. If a
timeout has passed, we reset the osd connection, so that
messages will be retransmitted.  This is a failsafe in case
we hit some sort of problem sending out message to the OSD.
Normally, we'll get notification via an updated osdmap if
there are problems.

If a request is older than the keepalive timeout, send a
keepalive to ensure we detect any breaks in the TCP connection.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Use a single ceph_msg for the osd reply, even when we are getting multiple
replies.
Signed-off-by: NSage Weil <sage@newdream.net>

Instead of removing osd connection immediately when the
requests list is empty, put the osd connection on an lru.
Only if that osd has not been used for more than a specified
time, will it be removed.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

This includes treating all the data preallocation and revokation
at the same place, not having to have a special case for
the reserved pages.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

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

When we issue an OSD read, we specify a vector of pages that the data is to
be read into.  The request may be sent multiple times, to multiple OSDs, if
the osdmap changes, which means we can get more than one reply.

Only read data into the page vector if the reply is coming from the
OSD we last sent the request to.  Keep track of which connection is using
the vector by taking a reference.  If another connection was already
using the vector before and a new reply comes in on the right connection,
revoke the pages from the other connection.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

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

When we open a monitor session, we send an initial AUTH message listing
the auth protocols we support, our entity name, and (possibly) a previously
assigned global_id.  The monitor chooses a protocol and responds with an
initial message.

Initially implement AUTH_NONE, a dummy protocol that provides no security,
but works within the new framework.  It generates 'authorizers' that are
used when connecting to (mds, osd) services that simply state our entity
name and global_id.

This is a wire protocol change.
Signed-off-by: NSage Weil <sage@newdream.net>

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

The OSD client is responsible for reading and writing data from/to the
object storage pool.  This includes determining where objects are
stored in the cluster, and ensuring that requests are retried or
redirected in the event of a node failure or data migration.

If an OSD does not respond before a timeout expires, keepalive
messages are sent across the lossless, ordered communications channel
to ensure that any break in the TCP is discovered.  If the session
does reset, a reconnection is attempted and affected requests are
resent (by the message transport layer).
Signed-off-by: NSage Weil <sage@newdream.net>