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, 36 insertions, 0 deletions

diff --git a/src/ceph/doc/dev/mds_internals/data-structures.rst b/src/ceph/doc/dev/mds_internals/data-structures.rst
new file mode 100644
index 0000000..1197b62
--- /dev/null
+++ b/src/ceph/doc/dev/mds_internals/data-structures.rst
@@ -0,0 +1,36 @@
+MDS internal data structures
+==============================
+
+*CInode*
+  CInode contains the metadata of a file, there is one CInode for each file.
+  The CInode stores information like who owns the file, how big the file is.
+
+*CDentry*
+  CDentry is the glue that holds inodes and files together by relating inode to
+  file/directory names. A CDentry links to at most one CInode (it may not link
+  to any CInode). A CInode may be linked by multiple CDentries.
+
+*CDir*
+  CDir only exists for directory inode, it's used to link CDentries under the
+  directory. A CInode can have multiple CDir when the directory is fragmented.
+
+These data structures are linked together as::
+
+  CInode
+  CDir
+   |   \
+   |      \
+   |         \
+  CDentry   CDentry
+  CInode    CInode
+  CDir      CDir
+   |         |  \
+   |         |     \
+   |         |        \
+  CDentry   CDentry  CDentry
+  CInode    CInode   CInode
+
+As this doc is being written, size of CInode is about 1400 bytes, size of CDentry
+is about 400 bytes, size of CDir is about 700 bytes. These data structures are
+quite large. Please be careful if you want to add new fields to them.
+