Fetch backup volfile servers from glusterd2

Clients will request for a list of volfile servers from glusterd2 by
setting a (optional) flag in GETSPEC RPC call. glusterd2 will check for
the presence of this flag and accordingly return a list of glusterd2
servers in GETSPEC RPC reply. Currently, this list of servers returned
only contains servers which have bricks belonging to the volume.

See:
https://github.com/gluster/glusterd2/issues/382
https://github.com/gluster/glusterfs/issues/351

Updates #351
Change-Id: I0eee3d0bf25a87627e562380ef73063926a16b81
Signed-off-by: Prashanth Pai <ppai@redhat.com>

4 files changed, 138 insertions, 0 deletions

diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index 5345924a41d..66461e3d440 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -3577,6 +3577,136 @@ out:
 
 }
 
+/*
+ * Processes list of volfile servers.
+ * Format: <host1>:<port1> <host2>:<port2>...
+ */
+int
+gf_process_getspec_servers_list(cmd_args_t *cmd_args,
+                                const char *servers_list) {
+        char        *tmp = NULL;
+        char        *address = NULL;
+        char        *host = NULL;
+        char        *last_colon = NULL;
+        char        *save_ptr = NULL;
+        int          port = 0;
+        int          ret = -1;
+
+        tmp = gf_strdup (servers_list);
+        if (!tmp) {
+                errno = ENOMEM;
+                goto out;
+        }
+
+        address = strtok_r (tmp, " ", &save_ptr);
+        if (!address) {
+                errno = EINVAL;
+                goto out;
+        }
+
+        while (1) {
+                last_colon = strrchr (address, ':');
+                if (!last_colon) {
+                        errno = EINVAL;
+                        ret = -1;
+                        break;
+                }
+                *last_colon = '\0';
+                host = address;
+                port = atoi (last_colon + 1);
+                if (port <= 0) {
+                        errno = EINVAL;
+                        ret = -1;
+                        break;
+                }
+                ret = gf_set_volfile_server_common (
+                        cmd_args, host, GF_DEFAULT_VOLFILE_TRANSPORT, port);
+                if (ret && errno != EEXIST) {
+                        break;
+                }
+                address = strtok_r (NULL, " ", &save_ptr);
+                if (!address) {
+                        errno = 0;
+                        ret = 0;
+                        break;
+                }
+        }
+
+out:
+        if (tmp) {
+                GF_FREE (tmp);
+        }
+
+        return ret;
+}
+
+int
+gf_set_volfile_server_common (cmd_args_t *cmd_args, const char *host,
+                              const char *transport, int port)
+{
+        server_cmdline_t      *server = NULL;
+        server_cmdline_t      *tmp = NULL;
+        int                    ret = -1;
+
+        GF_VALIDATE_OR_GOTO (THIS->name, cmd_args, out);
+        GF_VALIDATE_OR_GOTO (THIS->name, host, out);
+        GF_VALIDATE_OR_GOTO (THIS->name, transport, out);
+
+        server = GF_CALLOC (1, sizeof (server_cmdline_t),
+                            gf_common_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, server->volfile_server) &&
+                     !strcmp(tmp->transport, server->transport) &&
+                     (tmp->port == server->port))) {
+                        errno = EEXIST;
+                        ret = -1;
+                        goto out;
+                }
+        }
+
+        list_add_tail (&server->list, &cmd_args->volfile_servers);
+
+        ret = 0;
+out:
+        if (-1 == ret) {
+                if (server) {
+                        GF_FREE (server->volfile_server);
+                        GF_FREE (server->transport);
+                        GF_FREE (server);
+                }
+        }
+
+        return ret;
+}
+
 /* Sets log file path from user provided arguments */
 int
 gf_set_log_file_path (cmd_args_t *cmd_args, glusterfs_ctx_t *ctx)
diff --git a/libglusterfs/src/common-utils.h b/libglusterfs/src/common-utils.h
index c7f9fd58cc8..1cf517738c4 100644
--- a/libglusterfs/src/common-utils.h
+++ b/libglusterfs/src/common-utils.h
@@ -246,6 +246,11 @@ void gf_print_trace (int32_t signal, glusterfs_ctx_t *ctx);
 int  gf_set_log_file_path (cmd_args_t *cmd_args, glusterfs_ctx_t *ctx);
 int  gf_set_log_ident (cmd_args_t *cmd_args);
 
+int gf_process_getspec_servers_list(cmd_args_t *cmd_args,
+                                    const char *servers_list);
+int gf_set_volfile_server_common (cmd_args_t *cmd_args, const char *host,
+                                  const char *transport, int port);
+
 static inline void
 BIT_SET (unsigned char *array, unsigned int index)
 {
diff --git a/libglusterfs/src/libglusterfs.sym b/libglusterfs/src/libglusterfs.sym
index 39f03cbfa44..fa1e54d3663 100644
--- a/libglusterfs/src/libglusterfs.sym
+++ b/libglusterfs/src/libglusterfs.sym
@@ -632,6 +632,7 @@ gf_proc_dump_xlator_history
 gf_proc_dump_xlator_meminfo
 gf_proc_dump_xlator_private
 gf_proc_dump_xlator_profile
+gf_process_getspec_servers_list
 gf_process_reserved_ports
 __gf_realloc
 _gf_ref_get
@@ -646,6 +647,7 @@ gf_rsync_weak_checksum
 gf_set_log_file_path
 gf_set_log_ident
 gf_set_timestamp
+gf_set_volfile_server_common
 _gf_smsg
 gf_sock_union_equal_addr
 gf_store_handle_create_on_absence
diff --git a/libglusterfs/src/mem-types.h b/libglusterfs/src/mem-types.h
index 64d0e90e1bd..85c06e9cbe5 100644
--- a/libglusterfs/src/mem-types.h
+++ b/libglusterfs/src/mem-types.h
@@ -176,6 +176,7 @@ enum gf_common_mem_types_ {
         gf_common_ping_local_t,
         gf_common_volfile_t,
         gf_common_mt_mgmt_v3_lock_timer_t,
+        gf_common_mt_server_cmdline_t,
         gf_common_mt_end
 };
 #endif