7:29 a.m.
daemon.c does just a chroot, without chdir. The result is that pwd does not
work correctly (it causes fs/dcache.c:prepend_unreachable() to add the
unreachable string). A workaround is to add "cd /" before each sh command.
<fs> mount /dev/sda2 /
<fs> sh "cd / ; chroot / ; /bin/pwd"
/
<fs> sh "/bin/pwd"
(unreachable)/
<fs> sh "cd / ; /bin/pwd"
/
This untested change may fix it.
===================
--- libguestfs-1.20.10.orig/daemon/guestfsd.c
+++ libguestfs-1.20.10/daemon/guestfsd.c
@@ -879,7 +879,11 @@ commandrvf (char **stdoutput, char **std
close (stdin_fd[PIPE_READ]);
close (stdin_fd[PIPE_WRITE]);
- if (chroot (sysroot) == -1) {
+ if (chdir (sysroot) == -1) {
+ perror ("chdir");
+ _exit (EXIT_FAILURE);
+ }
+ if (chroot (".") == -1) {
perror ("chroot");
_exit (EXIT_FAILURE);
}
Olaf
8:26 a.m.
On Sun, Aug 18, Olaf Hering wrote:
daemon.c does just a chroot, without chdir. The result is that pwd does not
work correctly (it causes fs/dcache.c:prepend_unreachable() to add the
unreachable string). A workaround is to add "cd /" before each sh command.
><fs> mount /dev/sda2 /
><fs> sh "cd / ; chroot / ; /bin/pwd"
/
><fs> sh "/bin/pwd"
(unreachable)/
><fs> sh "cd / ; /bin/pwd"
/
This change fixes the "pwd" output for me.
guestfish add-drive /dev/shm/olaf/vdisk-sles11sp2_full_fate310510-disk0 : launch : mount
/dev/sda2 / : sh pwd : quit
/
Olaf
---
daemon/command.c | 11 +++++++++++
1 file changed, 11 insertions(+)
Index: libguestfs-1.20.10/daemon/command.c
===================================================================
--- libguestfs-1.20.10.orig/daemon/command.c
+++ libguestfs-1.20.10/daemon/command.c
@@ -21,6 +21,9 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
#include "guestfs_protocol.h"
#include "daemon.h"
@@ -46,6 +49,7 @@ do_command (char *const *argv)
CLEANUP_FREE char *sysroot_dev = NULL, *sysroot_dev_pts = NULL,
*sysroot_proc = NULL, *sysroot_selinux = NULL, *sysroot_sys = NULL;
int dev_ok, dev_pts_ok, proc_ok, sys_ok;
+ int cwd_fd;
/* We need a root filesystem mounted to do this. */
NEED_ROOT (, return NULL);
@@ -89,8 +93,15 @@ do_command (char *const *argv)
r = command (NULL, NULL, str_mount, "--bind", "/sys", sysroot_sys,
NULL);
sys_ok = r != -1;
+ cwd_fd = open(".", O_DIRECTORY);
CHROOT_IN;
+ if (cwd_fd >= 0)
+ chdir("/");
r = commandv (&out, &err, (const char * const *) argv);
+ if (cwd_fd >= 0) {
+ fchdir(cwd_fd);
+ close(cwd_fd);
+ }
CHROOT_OUT;
if (sys_ok) umount_ignore_fail (sysroot_sys);
4:07 a.m.
On Sun, Aug 18, 2013 at 02:29:15PM +0200, Olaf Hering wrote:
daemon.c does just a chroot, without chdir. The result is that pwd does not
work correctly (it causes fs/dcache.c:prepend_unreachable() to add the
unreachable string). A workaround is to add "cd /" before each sh command.
><fs> mount /dev/sda2 /
><fs> sh "cd / ; chroot / ; /bin/pwd"
/
><fs> sh "/bin/pwd"
(unreachable)/
><fs> sh "cd / ; /bin/pwd"
/
This untested change may fix it.
===================
--- libguestfs-1.20.10.orig/daemon/guestfsd.c
+++ libguestfs-1.20.10/daemon/guestfsd.c
@@ -879,7 +879,11 @@ commandrvf (char **stdoutput, char **std
close (stdin_fd[PIPE_READ]);
close (stdin_fd[PIPE_WRITE]);
- if (chroot (sysroot) == -1) {
+ if (chdir (sysroot) == -1) {
+ perror ("chdir");
+ _exit (EXIT_FAILURE);
+ }
+ if (chroot (".") == -1) {
perror ("chroot");
_exit (EXIT_FAILURE);
}
If you look at the upstream code, this has been fixed, or at
least, the code is quite different. See:
commit 2aa731e7c441581f0d72bcd06e9431b92931466a
Author: Matthew Booth <mbooth(a)redhat.com>
Date: Thu Dec 13 15:22:39 2012 +0000
daemon: Remove redundant fork in commandrvf
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v
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3 comments
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participants (2)
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Olaf Hering -
Richard W.M. Jones