meta: (re-)Implement Meta translator

The meta translator exposes details about glusterfs itself
in the form of a virtual namespace.

Loading the translator on the client side creates the
meta virtual view under $mntpoint/.meta by default. The
directory is not listed (even with ls -a) and can be
accessed by doing a "cd /mnt/.meta"

Change-Id: I5ffdf39203841a9562a8280a1f79dc76d4dded5d
BUG: 1089216
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/7509
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Harshavardhana <harsha@harshavardhana.net>

1 files changed, 76 insertions, 0 deletions

diff --git a/xlators/meta/src/plugins/options-dir.c b/xlators/meta/src/plugins/options-dir.c
new file mode 100644
index 00000000000..229d365a9c7
--- /dev/null
+++ b/xlators/meta/src/plugins/options-dir.c
@@ -0,0 +1,76 @@
+/*
+   Copyright (c) 2014 Red Hat, Inc. <http://www.redhat.com>
+   This file is part of GlusterFS.
+
+   This file is licensed to you under your choice of the GNU Lesser
+   General Public License, version 3 or any later version (LGPLv3 or
+   later), or the GNU General Public License, version 2 (GPLv2), in all
+   cases as published by the Free Software Foundation.
+*/
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "xlator.h"
+#include "defaults.h"
+
+#include "meta-mem-types.h"
+#include "meta.h"
+#include "meta-hooks.h"
+
+
+static int
+dict_key_add (dict_t *dict, char *key, data_t *value, void *data)
+{
+	struct meta_dirent **direntp = data;
+
+	(*direntp)->name = gf_strdup (key);
+	(*direntp)->type = IA_IFREG;
+	(*direntp)->hook = meta_option_file_hook;
+
+	(*direntp)++;
+	return 0;
+}
+
+
+static int
+options_dir_fill (xlator_t *this, inode_t *inode, struct meta_dirent **dp)
+{
+	struct meta_dirent *dirent = NULL;
+	struct meta_dirent *direntp = NULL;
+	xlator_t *xl = NULL;
+
+	xl = meta_ctx_get (inode, this);
+
+	dirent = GF_CALLOC (sizeof (*dirent), xl->options->count,
+			    gf_meta_mt_dirents_t);
+	if (!dirent)
+		return -1;
+
+	direntp = dirent;
+
+	dict_foreach (xl->options, dict_key_add, &direntp);
+
+	*dp = dirent;
+
+	return xl->options->count;
+}
+
+
+static struct meta_ops options_dir_ops = {
+	.dir_fill = options_dir_fill
+};
+
+
+int
+meta_options_dir_hook (call_frame_t *frame, xlator_t *this, loc_t *loc,
+		       dict_t *xdata)
+{
+	meta_ctx_set (loc->inode, this, meta_ctx_get (loc->parent, this));
+
+	meta_ops_set (loc->inode, this, &options_dir_ops);
+
+	return 0;
+}