[Sheepdog] [PATCH v2 04/15] sheepfs: add 'cluster' entry

[Liu Yuan]

From: Liu Yuan <tailai.ly at taobao.com>

This export cluster state as collie cluster command.

You can read the those info by simply ordinary read/write. For e.g,

tailai.ly at taobao:~/sheepdog$ cat sheepfs_dir/cluster/info
Cluster status: running

Cluster created at Mon May 14 15:45:37 2012

Epoch Time           Version
2012-05-14 15:45:38      1 [127.0.0.1:7000, 127.0.0.1:7001, 127.0.0.1:7002]

Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
---
 include/net.h       |    2 +
 sheepfs/Makefile.am |    2 +-
 sheepfs/cluster.c   |   59 +++++++++++++++++++++++++++++++++++++++++++++++++++
 sheepfs/core.c      |    9 ++++++-
 sheepfs/sheepfs.h   |    6 +++++
 5 files changed, 75 insertions(+), 3 deletions(-)
 create mode 100644 sheepfs/cluster.c

diff --git a/include/net.h b/include/net.h
index 698b55e..0286ea5 100644
--- a/include/net.h
+++ b/include/net.h
@@ -4,6 +4,8 @@
 #include <sys/socket.h>
 #include <arpa/inet.h>
 
+#include "sheepdog_proto.h"
+
 #define DEFAULT_SOCKET_TIMEOUT 5 /* seconds */
 
 enum conn_state {
diff --git a/sheepfs/Makefile.am b/sheepfs/Makefile.am
index c6c6741..2dfbbe4 100644
--- a/sheepfs/Makefile.am
+++ b/sheepfs/Makefile.am
@@ -23,7 +23,7 @@ INCLUDES		= -I$(top_builddir)/include -I$(top_srcdir)/include
 
 sbin_PROGRAMS		= sheepfs
 
-sheepfs_SOURCES		= core.c
+sheepfs_SOURCES		= core.c cluster.c
 
 sheepfs_LDADD	  	= ../lib/libsheepdog.a $(fuse_LIBS) $(LIBS)
 sheepfs_DEPENDENCIES	= ../lib/libsheepdog.a
diff --git a/sheepfs/cluster.c b/sheepfs/cluster.c
new file mode 100644
index 0000000..c4a481b
--- /dev/null
+++ b/sheepfs/cluster.c
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2012 Taobao Inc.
+ *
+ * Liu Yuan <namei.unix at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <syslog.h>
+
+#include "strbuf.h"
+#include "sheepfs.h"
+#include "net.h"
+
+#define PATH_CLUSTER		"/cluster"
+#define PATH_CLUSTER_INFO	"/cluster/info"
+
+int create_cluster_layout(void)
+{
+	if (shadow_dir_create(PATH_CLUSTER) < 0)
+		return -1;
+
+	if (shadow_file_create(PATH_CLUSTER_INFO) < 0)
+		return -1;
+	if (sheepfs_set_op(PATH_CLUSTER_INFO, OP_CLUSTER_INFO) < 0)
+		return -1;
+
+	return 0;
+}
+
+int cluster_info_read(const char *path, char *buf, size_t size, off_t ignore)
+{
+	return shadow_file_read(path, buf, size, 0);
+}
+
+size_t cluster_info_get_size(const char *path)
+{
+	struct strbuf *buf = sheepfs_run_cmd("collie cluster info");
+	size_t len;
+
+	if (!buf)
+		return 0;
+
+	len = shadow_file_write(path, buf->buf, buf->len);
+	strbuf_release(buf);
+	return len;
+}
diff --git a/sheepfs/core.c b/sheepfs/core.c
index 230794d..3499862 100644
--- a/sheepfs/core.c
+++ b/sheepfs/core.c
@@ -47,7 +47,9 @@ static struct sheepfs_file_operation {
 	int (*write)(const char *path, const char *buf, size_t size, off_t);
 	size_t (*get_size)(const char *path);
 } sheepfs_file_ops[] = {
-	[OP_NULL] = { NULL, NULL, NULL },
+	[OP_NULL]	  = { NULL, NULL, NULL },
+	[OP_CLUSTER_INFO] = { cluster_info_read, NULL,
+				cluster_info_get_size },
 };
 
 int sheepfs_set_op(const char *path, unsigned opcode)
@@ -194,8 +196,11 @@ static int sheepfs_main_loop(char *mountpoint)
 	return ret;
 }
 
-static int create_sheepfs_layout(char *path)
+static int create_sheepfs_layout(void)
 {
+	if (create_cluster_layout() < 0)
+		return -1;
+
 	return 0;
 }
 
diff --git a/sheepfs/sheepfs.h b/sheepfs/sheepfs.h
index d1b2a14..128e69c 100644
--- a/sheepfs/sheepfs.h
+++ b/sheepfs/sheepfs.h
@@ -3,6 +3,7 @@
 
 enum sheepfs_opcode {
 	OP_NULL = 0,
+	OP_CLUSTER_INFO,
 };
 
 extern char sheepfs_shadow[];
@@ -10,4 +11,9 @@ extern char sheepfs_shadow[];
 extern struct strbuf *sheepfs_run_cmd(const char *command);
 extern int sheepfs_set_op(const char *path, unsigned opcode);
 
+/* cluster.c */
+extern int cluster_info_read(const char *path, char *buf, size_t size, off_t);
+extern size_t cluster_info_get_size(const char *path);
+extern int create_cluster_layout(void);
+
 #endif
-- 
1.7.8.2