gfapi: glfs_set_volfile_server() now entertains multiple calls

Previous API:

glfs_set_volfile_server (..., const char *host, ...) - single call

New API's:

glfs_set_volfile_server (..., const char *host1, ...)
glfs_set_volfile_server (..., const char *host2, ...)

Multiple calls to this function with different volfile servers,
port or transport-type would create a list of volfile servers
which would be polled during `volfile_fetch_attempts()`

glfs_unset_volfile_server (..., const char *host, ...) to remove
a server from the list (this is provided for future usage)

Change-Id: I313efbd3efbd0214e2a71465f33195788df406cc
BUG: 986429
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/7317
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: Anand Avati <avati@redhat.com>

6 files changed, 192 insertions, 55 deletions

diff --git a/api/examples/getvolfile.py b/api/examples/getvolfile.py
index 82d9db05510..184586c632d 100755
--- a/api/examples/getvolfile.py
+++ b/api/examples/getvolfile.py
@@ -5,8 +5,8 @@ import ctypes.util
 
 api = ctypes.CDLL(ctypes.util.find_library("gfapi"))
 api.glfs_get_volfile.argtypes = [ctypes.c_void_p,
-							     ctypes.c_void_p,
-								 ctypes.c_ulong]
+                                 ctypes.c_void_p,
+                                 ctypes.c_ulong]
 api.glfs_get_volfile.restype = ctypes.c_long;
 
 def get_volfile (host, volume):
diff --git a/api/src/glfs-mem-types.h b/api/src/glfs-mem-types.h
index 3301b3da537..76f4fc774cc 100644
--- a/api/src/glfs-mem-types.h
+++ b/api/src/glfs-mem-types.h
@@ -23,10 +23,10 @@ enum glfs_mem_types_ {
 	glfs_mt_glfs_io_t,
 	glfs_mt_volfile_t,
 	glfs_mt_xlator_cmdline_option_t,
+        glfs_mt_server_cmdline_t,
 	glfs_mt_glfs_object_t,
 	glfs_mt_readdirbuf_t,
 	glfs_mt_end
 
 };
 #endif
-
diff --git a/api/src/glfs-mgmt.c b/api/src/glfs-mgmt.c
index 7f62fa259af..e2a52c32468 100644
--- a/api/src/glfs-mgmt.c
+++ b/api/src/glfs-mgmt.c
@@ -425,36 +425,85 @@ mgmt_rpc_notify (struct rpc_clnt *rpc, void *mydata, rpc_clnt_event_t event,
 		 void *data)
 {
 	xlator_t	*this = NULL;
-	cmd_args_t	*cmd_args = NULL;
 	glusterfs_ctx_t *ctx = NULL;
+        server_cmdline_t *server = NULL;
+        rpc_transport_t  *rpc_trans = NULL;
 	struct glfs	 *fs = NULL;
 	int		 ret = 0;
 
 	this = mydata;
-	ctx = this->ctx;
+        rpc_trans = rpc->conn.trans;
 
+	ctx = this->ctx;
 	if (!ctx)
 		goto out;
 
 	fs = ((xlator_t *)ctx->master)->private;
-	cmd_args = &ctx->cmd_args;
 
 	switch (event) {
 	case RPC_CLNT_DISCONNECT:
 		if (!ctx->active) {
-			cmd_args->max_connect_attempts--;
-			gf_log ("glfs-mgmt", GF_LOG_ERROR,
-				"failed to connect with remote-host: %s",
-				strerror (errno));
-			gf_log ("glfs-mgmt", GF_LOG_INFO,
-				"%d connect attempts left",
-				cmd_args->max_connect_attempts);
-			if (0 >= cmd_args->max_connect_attempts) {
-				errno = ENOTCONN;
-				glfs_init_done (fs, -1);
-			}
-		}
-		break;
+                        gf_log ("glfs-mgmt", GF_LOG_ERROR,
+                                "failed to connect with remote-host: %s (%s)",
+                                ctx->cmd_args.volfile_server,
+                                strerror (errno));
+                        server = ctx->cmd_args.curr_server;
+                        if (server->list.next == &ctx->cmd_args.volfile_servers) {
+                                errno = ENOTCONN;
+                                gf_log("glfs-mgmt", GF_LOG_INFO,
+                                       "Exhausted all volfile servers");
+                                glfs_init_done (fs, -1);
+                                break;
+                        }
+                        server = list_entry (server->list.next, typeof(*server),
+                                             list);
+                        ctx->cmd_args.curr_server = server;
+                        ctx->cmd_args.volfile_server_port = server->port;
+                        ctx->cmd_args.volfile_server = server->volfile_server;
+                        ctx->cmd_args.volfile_server_transport = server->transport;
+
+                        ret = dict_set_int32 (rpc_trans->options,
+                                              "remote-port",
+                                              server->port);
+                        if (ret != 0) {
+                                gf_log ("glfs-mgmt", GF_LOG_ERROR,
+                                        "failed to set remote-port: %d",
+                                        server->port);
+                                errno = ENOTCONN;
+                                glfs_init_done (fs, -1);
+                                break;
+                        }
+
+                        ret = dict_set_str (rpc_trans->options,
+                                            "remote-host",
+                                            server->volfile_server);
+                        if (ret != 0) {
+                                gf_log ("glfs-mgmt", GF_LOG_ERROR,
+                                        "failed to set remote-host: %s",
+                                        server->volfile_server);
+                                errno = ENOTCONN;
+                                glfs_init_done (fs, -1);
+                                break;
+                        }
+
+                        ret = dict_set_str (rpc_trans->options,
+                                            "transport-type",
+                                            server->transport);
+                        if (ret != 0) {
+                                gf_log ("glfs-mgmt", GF_LOG_ERROR,
+                                        "failed to set transport-type: %s",
+                                        server->transport);
+                                errno = ENOTCONN;
+                                glfs_init_done (fs, -1);
+                                break;
+                        }
+                        gf_log ("glfs-mgmt", GF_LOG_INFO,
+                                "connecting to next volfile server %s"
+                                " at port %d with transport: %s",
+                                server->volfile_server, server->port,
+                                server->transport);
+                }
+                break;
 	case RPC_CLNT_CONNECT:
 		rpc_clnt_set_connected (&((struct rpc_clnt*)ctx->mgmt)->conn);
 
@@ -556,4 +605,3 @@ glfs_mgmt_init (struct glfs *fs)
 out:
 	return ret;
 }
-
diff --git a/api/src/glfs.c b/api/src/glfs.c
index d09c737f6d6..64c37abfa65 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -131,6 +131,8 @@ glusterfs_ctx_defaults_init (glusterfs_ctx_t *ctx)
 
 	INIT_LIST_HEAD (&pool->all_frames);
 	INIT_LIST_HEAD (&ctx->cmd_args.xlator_options);
+        INIT_LIST_HEAD (&ctx->cmd_args.volfile_servers);
+
 	LOCK_INIT (&pool->lock);
 	ctx->pool = pool;
 
@@ -312,6 +314,108 @@ enomem:
 	return -1;
 }
 
+int
+glfs_unset_volfile_server (struct glfs *fs, const char *transport,
+                           const char *host, const int port)
+{
+        cmd_args_t       *cmd_args = NULL;
+        server_cmdline_t *server = NULL;
+        int               ret = -1;
+
+        if (!transport || !host || !port) {
+                errno = EINVAL;
+                return ret;
+        }
+
+        cmd_args = &fs->ctx->cmd_args;
+        list_for_each_entry(server, &cmd_args->curr_server->list, list) {
+                if ((!strcmp(server->volfile_server, host) &&
+                     !strcmp(server->transport, transport) &&
+                     (server->port == port))) {
+                        list_del (&server->list);
+                        ret = 0;
+                        goto out;
+                }
+        }
+
+out:
+        return ret;
+}
+
+int
+glfs_set_volfile_server (struct glfs *fs, const char *transport,
+                         const char *host, int port)
+{
+        cmd_args_t            *cmd_args = NULL;
+        server_cmdline_t      *server = NULL;
+        server_cmdline_t      *tmp = NULL;
+        int                    ret = -1;
+
+        if (!transport || !host || !port) {
+                errno = EINVAL;
+                return ret;
+        }
+
+        cmd_args = &fs->ctx->cmd_args;
+
+        cmd_args->max_connect_attempts = 1;
+
+        server = GF_CALLOC (1, sizeof (server_cmdline_t),
+                            glfs_mt_server_cmdline_t);
+
+        if (!server) {
+                errno = ENOMEM;
+                goto out;
+        }
+
+        INIT_LIST_HEAD (&server->list);
+
+        server->volfile_server = gf_strdup (host);
+        if (!server->volfile_server) {
+                errno = ENOMEM;
+                goto out;
+        }
+
+        server->transport = gf_strdup (transport);
+        if (!server->transport) {
+                errno = ENOMEM;
+                goto out;
+        }
+
+        server->port = port;
+
+        if (!cmd_args->volfile_server) {
+                cmd_args->volfile_server = server->volfile_server;
+                cmd_args->volfile_server_transport = server->transport;
+                cmd_args->volfile_server_port = server->port;
+                cmd_args->curr_server = server;
+        }
+
+        list_for_each_entry(tmp, &cmd_args->volfile_servers, list) {
+                if ((!strcmp(tmp->volfile_server, host) &&
+                     !strcmp(tmp->transport, transport) &&
+                     (tmp->port == port))) {
+                        errno = EEXIST;
+                        ret = -1;
+                        goto out;
+                }
+        }
+
+        list_add_tail (&server->list, &cmd_args->volfile_servers);
+
+        ret = 0;
+out:
+        if (ret == -1) {
+                if (server) {
+                        GF_FREE (server->volfile_server);
+                        GF_FREE (server->transport);
+                        GF_FREE (server);
+                }
+        }
+
+        return ret;
+}
+
 int glfs_setfsuid (uid_t fsuid)
 {
 	return syncopctx_setfsuid (&fsuid);
@@ -464,26 +568,6 @@ glfs_set_volfile (struct glfs *fs, const char *volfile)
 
 
 int
-glfs_set_volfile_server (struct glfs *fs, const char *transport,
-			 const char *host, int port)
-{
-	cmd_args_t  *cmd_args = NULL;
-
-	cmd_args = &fs->ctx->cmd_args;
-
-	if (vol_assigned (cmd_args))
-		return -1;
-
-	cmd_args->volfile_server = gf_strdup (host);
-	cmd_args->volfile_server_transport = gf_strdup (transport);
-	cmd_args->volfile_server_port = port;
-	cmd_args->max_connect_attempts = 2;
-
-	return 0;
-}
-
-
-int
 glfs_set_logging (struct glfs *fs, const char *logfile, int loglevel)
 {
         int  ret = 0;
diff --git a/api/src/glfs.h b/api/src/glfs.h
index af6b4899037..4344df24dc7 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -115,12 +115,12 @@ int glfs_set_volfile (glfs_t *fs, const char *volfile);
 /*
   SYNOPSIS
 
-  glfs_set_volfile_server: Specify the address of management server.
+  glfs_set_volfile_server: Specify the list of addresses for management server.
 
   DESCRIPTION
 
-  This function specifies the address of the management server (glusterd)
-  to connect, and establish the volume configuration. The @volname
+  This function specifies the list of addresses for the management server
+  (glusterd) to connect, and establish the volume configuration. The @volname
   parameter passed to glfs_new() is the volume which will be virtually
   mounted as the glfs_t object. All operations performed by the CLI at
   the management server will automatically be reflected in the 'virtual
@@ -136,19 +136,22 @@ int glfs_set_volfile (glfs_t *fs, const char *volfile);
 
   @transport: String specifying the transport used to connect to the
               management daemon. Specifying NULL will result in the usage
-	      of the default (tcp) transport type. Permitted values
-	      are those what you specify as transport-type in a volume
-	      specification file (e.g "tcp", "rdma", "unix".)
+              of the default (tcp) transport type. Permitted values
+              are those what you specify as transport-type in a volume
+              specification file (e.g "tcp", "rdma" etc.)
 
-  @host: String specifying the address of where to find the management
-         daemon. Depending on the transport type this would either be
-	 an FQDN (e.g: "storage01.company.com"), ASCII encoded IP
-	 address "192.168.22.1", or a UNIX domain socket path (e.g
-	 "/tmp/glusterd.socket".)
+  @host:      String specifying the address where to find the management daemon.
+              This would either be
+              - FQDN (e.g: "storage01.company.com") or
+              - ASCII (e.g: "192.168.22.1")
+
+  NOTE: This API is special, multiple calls to this function with different
+        volfile servers, port or transport-type would create a list of volfile
+        servers which would be polled during `volfile_fetch_attempts()`
 
   @port: The TCP port number where gluster management daemon is listening.
          Specifying 0 uses the default port number GF_DEFAULT_BASE_PORT.
-	 This parameter is unused if you are using a UNIX domain socket.
+         This parameter is unused if you are using a UNIX domain socket.
 
   RETURN VALUES
 
@@ -158,9 +161,9 @@ int glfs_set_volfile (glfs_t *fs, const char *volfile);
 */
 
 int glfs_set_volfile_server (glfs_t *fs, const char *transport,
-			     const char *host, int port) __THROW;
-
-
+                             const char *host, int port) __THROW;
+int glfs_unset_volfile_server (glfs_t *fs, const char *transport,
+                               const char *host, int port) __THROW;
 /*
   SYNOPSIS
 
diff --git a/libglusterfs/src/glusterfs.h b/libglusterfs/src/glusterfs.h
index 852d686c13c..5dd26b45103 100644
--- a/libglusterfs/src/glusterfs.h
+++ b/libglusterfs/src/glusterfs.h
@@ -325,6 +325,8 @@ typedef struct _xlator_cmdline_option xlator_cmdline_option_t;
 struct _server_cmdline {
         struct list_head  list;
         char              *volfile_server;
+        char              *transport;
+        int               port;
 };
 typedef struct _server_cmdline server_cmdline_t;