metadisp: new translator for data and metadata separation

Summary:

feature/metadisp is an xlator for performing "metadata dispersal" across
multiple children. it does this by flattening the complex
POSIX paths into /$GFID style paths, then forwarding the
metadata operations to its first child and forwarding the
data operations to its second child.

The purpose of this xlator is to allow separation of data and metadata,
in cases where metadata might be stored in another format (embedded kv?),
on another disk (ssd), on another host (dht2).

Change-Id: I392c8bd0c867a3237d144aea327323f700a2728d
Updates: #816
Signed-Off-By: Sheena Artrip <sheenobu@fb.com>
Tested-By: Amar Tumballi <amar@kadalu.io>

1 files changed, 51 insertions, 0 deletions

diff --git a/xlators/features/metadisp/src/metadisp-fops.h b/xlators/features/metadisp/src/metadisp-fops.h
new file mode 100644
index 00000000000..56dd427cf34
--- /dev/null
+++ b/xlators/features/metadisp/src/metadisp-fops.h
@@ -0,0 +1,51 @@
+#ifndef GF_METADISP_FOPS_H_
+#define GF_METADISP_FOPS_H_
+
+#include <glusterfs/xlator.h>
+#include <glusterfs/dict.h>
+#include <glusterfs/glusterfs.h>
+
+#include <sys/types.h>
+
+/* fops in here are defined in their own file. Every other fop is just defined
+ * inline of fops.c */
+
+int
+metadisp_readdir(call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
+                 off_t off, dict_t *xdata);
+
+int
+metadisp_readdirp(call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
+                  off_t off, dict_t *dict);
+
+int
+metadisp_lookup(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata);
+
+int
+metadisp_create(call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
+                mode_t mode, mode_t umask, fd_t *fd, dict_t *xdata);
+
+int
+metadisp_open(call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
+              fd_t *fd, dict_t *xdata);
+
+int
+metadisp_stat(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata);
+
+int
+metadisp_inodelk(call_frame_t *frame, xlator_t *this, const char *volume,
+                 loc_t *loc, int32_t cmd, struct gf_flock *lock, dict_t *xdata);
+
+int
+metadisp_fsync(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t flags,
+               dict_t *xdata);
+
+int
+metadisp_unlink(call_frame_t *frame, xlator_t *this, loc_t *loc, int xflag,
+                dict_t *xdata);
+
+int
+metadisp_setattr(call_frame_t *frame, xlator_t *this, loc_t *loc,
+                 struct iatt *stbuf, int32_t valid, dict_t *xdata);
+
+#endif