diff --git a/qemu-nbd.c b/qemu-nbd.c index 7c4e22def1..30eeb6f3c7 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -255,18 +255,23 @@ struct NbdClientOpts { char *device; char *srcpath; SocketAddress *saddr; + int old_stderr; bool fork_process; bool verbose; }; -static void nbd_client_release_pipe(void) +static void nbd_client_release_pipe(int old_stderr) { /* Close stderr so that the qemu-nbd process exits. */ - if (dup2(STDOUT_FILENO, STDERR_FILENO) < 0) { + if (dup2(old_stderr, STDERR_FILENO) < 0) { error_report("Could not release pipe to parent: %s", strerror(errno)); exit(EXIT_FAILURE); } + if (old_stderr != STDOUT_FILENO && close(old_stderr) < 0) { + error_report("Could not release qemu-nbd: %s", strerror(errno)); + exit(EXIT_FAILURE); + } } #if HAVE_NBD_DEVICE @@ -332,7 +337,7 @@ static void *nbd_client_thread(void *arg) fprintf(stderr, "NBD device %s is now connected to %s\n", opts->device, opts->srcpath); } else { - nbd_client_release_pipe(); + nbd_client_release_pipe(opts->old_stderr); } if (nbd_client(fd) < 0) { @@ -597,6 +602,7 @@ int main(int argc, char **argv) .device = NULL, .srcpath = NULL, .saddr = NULL, + .old_stderr = STDOUT_FILENO, }; #ifdef CONFIG_POSIX @@ -951,6 +957,16 @@ int main(int argc, char **argv) close(stderr_fd[0]); + /* Remember parent's stderr if we will be restoring it. */ + if (opts.verbose /* fork_process is set */) { + opts.old_stderr = dup(STDERR_FILENO); + if (opts.old_stderr < 0) { + error_report("Could not dup original stderr: %s", + strerror(errno)); + exit(EXIT_FAILURE); + } + } + ret = qemu_daemon(1, 0); saved_errno = errno; /* dup2 will overwrite error below */ @@ -1181,7 +1197,7 @@ int main(int argc, char **argv) } if (opts.fork_process) { - nbd_client_release_pipe(); + nbd_client_release_pipe(opts.old_stderr); } state = RUNNING;