migration: merge qemu_popen_cmd with qemu_popen

There is no reason for outgoing exec migration to do popen manually
anymore (the reason used to be that we needed the FILE* to make it
non-blocking).  Use qemu_popen_cmd.

Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

include/migration/qemu-file.h

@@ -77,7 +77,6 @@ QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 QEMUFile *qemu_fopen(const char *filename, const char *mode);
 QEMUFile *qemu_fdopen(int fd, const char *mode);
 QEMUFile *qemu_fopen_socket(int fd);
-QEMUFile *qemu_popen(FILE *popen_file, const char *mode);
 QEMUFile *qemu_popen_cmd(const char *command, const char *mode);
 int qemu_get_fd(QEMUFile *f);
 int qemu_fclose(QEMUFile *f);

migration-exec.c

@@ -59,19 +59,17 @@ static int exec_close(MigrationState *s)
 
 void exec_start_outgoing_migration(MigrationState *s, const char *command, Error **errp)
 {
-    FILE *f;
-
-    f = popen(command, "w");
+    QEMUFile *f;
+    f = qemu_popen_cmd(command, "w");
     if (f == NULL) {
         error_setg_errno(errp, errno, "failed to popen the migration target");
         return;
     }
 
-    s->fd = fileno(f);
+    s->opaque = f;
+    s->fd = qemu_get_fd(f);
     assert(s->fd != -1);
 
-    s->opaque = qemu_popen(f, "w");
-
     s->close = exec_close;
     s->get_error = file_errno;
     s->write = file_write;

savevm.c

@@ -275,11 +275,17 @@ static const QEMUFileOps stdio_pipe_write_ops = {
     .close =      stdio_pclose
 };
 
-QEMUFile *qemu_popen(FILE *stdio_file, const char *mode)
+QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
 {
+    FILE *stdio_file;
     QEMUFileStdio *s;
 
-    if (stdio_file == NULL || mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
+    stdio_file = popen(command, mode);
+    if (stdio_file == NULL) {
+        return NULL;
+    }
+
+    if (mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) {
         fprintf(stderr, "qemu_popen: Argument validity check failed\n");
         return NULL;
     }
@@ -296,18 +302,6 @@ QEMUFile *qemu_popen(FILE *stdio_file, const char *mode)
     return s->file;
 }
 
-QEMUFile *qemu_popen_cmd(const char *command, const char *mode)
-{
-    FILE *popen_file;
-
-    popen_file = popen(command, mode);
-    if(popen_file == NULL) {
-        return NULL;
-    }
-
-    return qemu_popen(popen_file, mode);
-}
-
 static const QEMUFileOps stdio_file_read_ops = {
     .get_fd =     stdio_get_fd,
     .get_buffer = stdio_get_buffer,