From 9faf31b68f049ca6432a1ef086a76344ff2a2357 Mon Sep 17 00:00:00 2001 From: Michael Tokarev Date: Mon, 16 Jan 2012 18:37:44 +0400 Subject: [PATCH] do not chdir(/) in qemu-nbd before opening all files 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 Signed-off-by: Paolo Bonzini --- qemu-nbd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/qemu-nbd.c b/qemu-nbd.c index eb61c33acd..e189cf86f4 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -429,7 +429,7 @@ int main(int argc, char **argv) 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); @@ -527,6 +527,12 @@ int main(int argc, char **argv) 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));