X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/e2ccd3578c37d918be84b729422735376a7045a2..d051056f921f465c487a85f9fa29a2324332bc4b:/pipe.c

diff --git a/pipe.c b/pipe.c
index fd3487aa..84706085 100644
--- a/pipe.c
+++ b/pipe.c
@@ -24,12 +24,12 @@
 extern int am_sender;
 extern int am_server;
 extern int blocking_io;
-extern int orig_umask;
-extern int read_batch;
 extern int filesfrom_fd;
+extern mode_t orig_umask;
+extern struct chmod_mode_struct *chmod_modes;
 
 /**
- * Create a child connected to use on stdin/stdout.
+ * Create a child connected to us via its stdin/stdout.
  *
  * This is derived from CVS code
  *
@@ -94,13 +94,26 @@ pid_t piped_child(char **command, int *f_in, int *f_out)
 	return pid;
 }
 
-pid_t local_child(int argc, char **argv,int *f_in,int *f_out,
+/* This function forks a child which calls child_main().  First,
+ * however, it has to establish communication paths to and from the
+ * newborn child.  It creates two socket pairs -- one for writing to
+ * the child (from the parent) and one for reading from the child
+ * (writing to the parent).  Since that's four socket ends, each
+ * process has to close the two ends it doesn't need.  The remaining
+ * two socket ends are retained for reading and writing.  In the
+ * child, the STDIN and STDOUT file descriptors refer to these
+ * sockets.  In the parent, the function arguments f_in and f_out are
+ * set to refer to these sockets. */
+pid_t local_child(int argc, char **argv, int *f_in, int *f_out,
 		  int (*child_main)(int, char*[]))
 {
 	pid_t pid;
 	int to_child_pipe[2];
 	int from_child_pipe[2];
 
+	/* The parent process is always the sender for a local rsync. */
+	assert(am_sender);
+
 	if (fd_pair(to_child_pipe) < 0 ||
 	    fd_pair(from_child_pipe) < 0) {
 		rsyserr(FERROR, errno, "pipe");
@@ -114,11 +127,10 @@ pid_t local_child(int argc, char **argv,int *f_in,int *f_out,
 	}
 
 	if (pid == 0) {
-		am_sender = read_batch ? 0 : !am_sender;
+		am_sender = 0;
 		am_server = 1;
-
-		if (!am_sender)
-			filesfrom_fd = -1;
+		filesfrom_fd = -1;
+		chmod_modes = NULL; /* Let the sending side handle this. */
 
 		if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
 		    close(to_child_pipe[1]) < 0 ||
@@ -127,14 +139,13 @@ pid_t local_child(int argc, char **argv,int *f_in,int *f_out,
 			rsyserr(FERROR, errno, "Failed to dup/close");
 			exit_cleanup(RERR_IPC);
 		}
-		if (to_child_pipe[0] != STDIN_FILENO) close(to_child_pipe[0]);
-		if (from_child_pipe[1] != STDOUT_FILENO) close(from_child_pipe[1]);
+		if (to_child_pipe[0] != STDIN_FILENO)
+			close(to_child_pipe[0]);
+		if (from_child_pipe[1] != STDOUT_FILENO)
+			close(from_child_pipe[1]);
 		child_main(argc, argv);
 	}
 
-	if (!am_sender)
-		filesfrom_fd = -1;
-
 	if (close(from_child_pipe[1]) < 0 ||
 	    close(to_child_pipe[0]) < 0) {
 		rsyserr(FERROR, errno, "Failed to close");