flexnbd status: Add the size of the backing file, in bytes

This will be handy information if you're querying flexnbd for migration
stats, particularly.

src/status.c

@@ -9,6 +9,7 @@ struct status * status_create( struct server * serve )
 
 	status = xmalloc( sizeof( struct status ) );
 	status->pid = getpid();
+	status->size = serve->size;
 	status->has_control = serve->success;
 	status->is_mirroring = NULL != serve->mirror;
 
@@ -25,10 +26,13 @@ struct status * status_create( struct server * serve )
 	do{dprintf( fd, #var "=%s ", BOOL_S( status->var ) );}while(0)
 #define PRINT_INT( var ) \
 	do{dprintf( fd, #var "=%d ", status->var );}while(0)
+#define PRINT_UINT64( var ) \
+	do{dprintf( fd, #var "=%"PRIu64" ", status->var );}while(0)
 
 int status_write( struct status * status, int fd )
 {
 	PRINT_INT( pid );
+	PRINT_UINT64( size );
 	PRINT_BOOL( is_mirroring );
 	PRINT_BOOL( has_control );
 

src/status.h

@@ -20,6 +20,9 @@
  * pid:
  *      The current process ID.
  *
+ * size:
+ *  The size of the backing file being served, in bytes.
+ *
  * has_control:
  * 	This will be false when the server is listening for an incoming
  * 	migration.  It will switch to true when the end-of-migration
@@ -53,6 +56,7 @@
 
 struct status {
 	pid_t pid;
+	uint64_t size;
 	int has_control;
 	int is_mirroring;
 	int migration_pass;

tests/unit/check_status.c

@@ -5,12 +5,17 @@
 
 #include <check.h>
 
+void prepare_server( struct server* serve )
+{
+	serve->mirror = NULL;
+}
+
 START_TEST( test_status_create )
 {
 	struct server server;
 	struct status *status = NULL;
 
-	server.mirror = NULL;
+	prepare_server( &server );
 	status = status_create( &server );
 
 	fail_if( NULL == status, "Status wasn't allocated" );
@@ -23,7 +28,7 @@ START_TEST( test_gets_has_control )
 	struct server server;
 	struct status * status;
 
-	server.mirror = NULL;
+	prepare_server( &server );
 	server.success = 1;
 	status = status_create( &server );
 
@@ -38,7 +43,7 @@ START_TEST( test_gets_is_mirroring )
 	struct server server;
 	struct status * status;
 
-	server.mirror = NULL;
+	prepare_server( &server );
 	status = status_create( &server );
 	fail_if( status->is_mirroring, "is_mirroring was set" );
 	status_destroy( status );
@@ -55,7 +60,7 @@ START_TEST( test_gets_migration_pass )
 	struct server server;
 	struct status * status;
 
-	server.mirror = NULL;
+	prepare_server( &server );
 	status = status_create( &server );
 	fail_if( status->migration_pass != 0, "migration_pass was set" );
 	status_destroy( status );
@@ -75,7 +80,7 @@ START_TEST( test_gets_pid )
 	struct server server;
 	struct status * status;
 
-	server.mirror = NULL;
+	prepare_server( &server );
 	status = status_create( &server );
 
 	fail_unless( getpid() == status->pid, "Pid wasn't gathered" );
@@ -84,6 +89,21 @@ START_TEST( test_gets_pid )
 }
 END_TEST
 
+START_TEST( test_gets_size )
+{
+	struct server server;
+	struct status * status;
+
+	prepare_server( &server );
+	server.size = 1024;
+	status = status_create( &server );
+
+	fail_unless( 1024 == status->size, "Size wasn't gathered" );
+
+	status_destroy( status );
+}
+END_TEST
+
 
 START_TEST( test_renders_has_control )
 {
@@ -158,6 +178,23 @@ START_TEST( test_renders_pid )
 }
 END_TEST
 
+START_TEST( test_renders_size )
+{
+	struct status status;
+	int fds[2];
+	pipe(fds);
+	char buf[1024] = {0};
+
+	status.size = ( (uint64_t)1 << 33 );
+	status_write( &status, fds[1] );
+
+	fail_unless( read_until_newline( fds[0], buf, 1024 ) > 0,
+			"Couldn't read the result" );
+	char *found = strstr( buf, "size=8589934592" );
+	fail_if( NULL == found, "size=8589934592 not found" );
+}
+END_TEST
+
 START_TEST( test_renders_migration_pass )
 {
 	struct status status;
@@ -199,11 +236,13 @@ Suite *status_suite(void)
 	tcase_add_test(tc_create, test_gets_has_control);
 	tcase_add_test(tc_create, test_gets_is_mirroring);
 	tcase_add_test(tc_create, test_gets_pid);
+	tcase_add_test(tc_create, test_gets_size);
 	tcase_add_test(tc_create, test_gets_migration_pass);
 
 	tcase_add_test(tc_render, test_renders_has_control);
 	tcase_add_test(tc_render, test_renders_is_mirroring);
 	tcase_add_test(tc_render, test_renders_pid);
+	tcase_add_test(tc_render, test_renders_size);
 	tcase_add_test(tc_render, test_renders_migration_pass);
 
 	suite_add_tcase(s, tc_create);