When qemu-nbd becomes a daemon it calls daemon(3) with
nochdir=0, so daemon(3) changes current directory to /.
But at this time, qemu-nbd did not open any user-specified
files yet, so by changing current directory, all non-absolute
paths becomes wrong. The solution is to pass nochdir=1 to
daemon(3) function, and to chdir("/") after all init has
been performed, before entering the main loop, -- just like
a good daemon should do.
This patch is applicable for -stable.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
pid = fork();
if (pid == 0) {
close(stderr_fd[0]);
- ret = qemu_daemon(0, 0);
+ ret = qemu_daemon(1, 0);
/* Temporarily redirect stderr to the parent's pipe... */
dup2(stderr_fd[1], STDERR_FILENO);
qemu_set_fd_handler2(fd, nbd_can_accept, nbd_accept, NULL,
(void *)(uintptr_t)fd);
+ /* now when the initialization is (almost) complete, chdir("/")
+ * to free any busy filesystems */
+ if (chdir("/") < 0) {
+ err(EXIT_FAILURE, "Could not chdir to root directory");
+ }
+
do {
main_loop_wait(false);
} while (!sigterm_reported && (persistent || !nbd_started || nb_fds > 0));