doc: restructure developer docs to new layout

The developer oriented information is scattered in source
and its very difficult to identify which are those.
With this patch subdirs are created under developer-guide
which will be the parent for developer notes. The changes
suggested in http://review.gluster.org/#/c/8827/ are also
included in this patch.

Change-Id: I4c8510d52c49f4066225f72cac8f97f087d6c70c
BUG: 1206539
Signed-off-by: Humble Devassy Chirammal <hchiramm@redhat.com>
Reviewed-on: http://review.gluster.org/10038
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Lalatendu Mohanty <lmohanty@redhat.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/doc/developer-guide/posix.md b/doc/developer-guide/posix.md
new file mode 100644
index 00000000000..84c813e55a2
--- /dev/null
+++ b/doc/developer-guide/posix.md
@@ -0,0 +1,59 @@
+storage/posix translator
+========================
+
+Notes
+-----
+
+### `SET_FS_ID`
+
+This is so that all filesystem checks are done with the user's
+uid/gid and not GlusterFS's uid/gid.
+
+### `MAKE_REAL_PATH`
+
+This macro concatenates the base directory of the posix volume
+('option directory') with the given path.
+
+### `need_xattr` in lookup
+
+If this flag is passed, lookup returns a xattr dictionary that contains
+the file's create time, the file's contents, and the version number
+of the file.
+
+This is a hack to increase small file performance. If an application
+wants to read a small file, it can finish its job with just a lookup
+call instead of a lookup followed by read.
+
+### `getdents`/`setdents`
+
+These are used by unify to set and get directory entries.
+
+### `ALIGN_BUF`
+
+Macro to align an address to a page boundary (4K).
+
+### `priv->export_statfs`
+
+In some cases, two exported volumes may reside on the same
+partition on the server. Sending statvfs info for both
+the volumes will lead to erroneous df output at the client,
+since free space on the partition will be counted twice.
+
+In such cases, user can disable exporting statvfs info
+on one of the volumes by setting this option.
+
+### `xattrop`
+
+This fop is used by replicate to set version numbers on files.
+
+### `getxattr`/`setxattr` hack to read/write files
+
+A key, `GLUSTERFS_FILE_CONTENT_STRING`, is handled in a special way by
+`getxattr`/`setxattr`. A getxattr with the key will return the entire
+content of the file as the value. A `setxattr` with the key will write
+the value as the entire content of the file.
+
+### `posix_checksum`
+
+This calculates a simple XOR checksum on all entry names in a
+directory that is used by unify to compare directory contents.