initial code repo

This patch creates initial code repo.

For ceph, luminous stable release will be used for base code,
and next changes and optimization for ceph will be added to it.

For opensds, currently any changes can be upstreamed into original
opensds repo (https://github.com/opensds/opensds), and so stor4nfv
will directly clone opensds code to deploy stor4nfv environment.
And the scripts for deployment based on ceph and opensds will be
put into 'ci' directory.

Change-Id: I46a32218884c75dda2936337604ff03c554648e4
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/src/ceph/doc/dev/osd_internals/osd_overview.rst b/src/ceph/doc/dev/osd_internals/osd_overview.rst
new file mode 100644
index 0000000..192ddf8
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+===
+OSD
+===
+
+Concepts
+--------
+
+*Messenger*
+   See src/msg/Messenger.h
+
+   Handles sending and receipt of messages on behalf of the OSD.  The OSD uses
+   two messengers: 
+
+     1. cluster_messenger - handles traffic to other OSDs, monitors
+     2. client_messenger - handles client traffic
+
+	 This division allows the OSD to be configured with different interfaces for
+	 client and cluster traffic.
+
+*Dispatcher*
+   See src/msg/Dispatcher.h
+
+	 OSD implements the Dispatcher interface.  Of particular note is ms_dispatch,
+	 which serves as the entry point for messages received via either the client
+	 or cluster messenger.  Because there are two messengers, ms_dispatch may be
+	 called from at least two threads.  The osd_lock is always held during
+	 ms_dispatch.
+
+*WorkQueue*
+  See src/common/WorkQueue.h
+
+  The WorkQueue class abstracts the process of queueing independent tasks
+  for asynchronous execution.  Each OSD process contains workqueues for
+  distinct tasks:
+
+    1. OpWQ: handles ops (from clients) and subops (from other OSDs).
+       Runs in the op_tp threadpool.
+    2. PeeringWQ: handles peering tasks and pg map advancement
+       Runs in the op_tp threadpool.
+       See Peering
+    3. CommandWQ: handles commands (pg query, etc)
+       Runs in the command_tp threadpool.
+    4. RecoveryWQ: handles recovery tasks.
+       Runs in the recovery_tp threadpool.
+    5. SnapTrimWQ: handles snap trimming
+       Runs in the disk_tp threadpool.
+       See SnapTrimmer
+    6. ScrubWQ: handles primary scrub path
+       Runs in the disk_tp threadpool.
+       See Scrub
+    7. ScrubFinalizeWQ: handles primary scrub finalize
+       Runs in the disk_tp threadpool.
+       See Scrub
+    8. RepScrubWQ: handles replica scrub path
+       Runs in the disk_tp threadpool
+       See Scrub
+    9. RemoveWQ: Asynchronously removes old pg directories
+       Runs in the disk_tp threadpool
+       See PGRemoval
+
+*ThreadPool*
+  See src/common/WorkQueue.h
+  See also above.
+
+  There are 4 OSD threadpools:
+
+    1. op_tp: handles ops and subops
+    2. recovery_tp: handles recovery tasks
+    3. disk_tp: handles disk intensive tasks
+    4. command_tp: handles commands
+
+*OSDMap*
+  See src/osd/OSDMap.h
+
+  The crush algorithm takes two inputs: a picture of the cluster
+  with status information about which nodes are up/down and in/out, 
+  and the pgid to place.  The former is encapsulated by the OSDMap.
+  Maps are numbered by *epoch* (epoch_t).  These maps are passed around
+  within the OSD as std::tr1::shared_ptr<const OSDMap>.
+
+  See MapHandling
+
+*PG*
+  See src/osd/PG.* src/osd/PrimaryLogPG.*
+
+  Objects in rados are hashed into *PGs* and *PGs* are placed via crush onto
+  OSDs.  The PG structure is responsible for handling requests pertaining to
+  a particular *PG* as well as for maintaining relevant metadata and controlling
+  recovery.
+
+*OSDService*
+  See src/osd/OSD.cc OSDService
+
+  The OSDService acts as a broker between PG threads and OSD state which allows
+  PGs to perform actions using OSD services such as workqueues and messengers.
+  This is still a work in progress.  Future cleanups will focus on moving such
+  state entirely from the OSD into the OSDService.
+
+Overview
+--------
+  See src/ceph_osd.cc
+
+  The OSD process represents one leaf device in the crush hierarchy.  There
+  might be one OSD process per physical machine, or more than one if, for
+  example, the user configures one OSD instance per disk.
+