From 5b0f9d72d49053d246463b7bb024f21f1c24d983 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Fri, 3 Mar 2017 13:52:31 +0000

Subject: [PATCH] rescue: Implement -m and -i options.

`virt-rescue -a disk -i' does the right thing.

`-m' was previously an alternate form of `--memsize'.  By sniffing the

parameter we can make `-m MB' continue to work, while also allowing

`-m' to be used as a short form for the `--mount' option.

This also removes most of the description of `--suggest' from the man

page, since it is no longer needed.

(cherry picked from commit 33d2ae796119ae5dd38e2afcbf1ba4216bd99846)

---

 appliance/init         | 12 +++++--

 rescue/Makefile.am     |  3 +-

 rescue/rescue.c        | 87 +++++++++++++++++++++++++++++++++++++-------------

 rescue/virt-rescue.pod | 80 ++++++++++++++++++++++++++++------------------

 4 files changed, 126 insertions(+), 56 deletions(-)

diff --git a/appliance/init b/appliance/init

index ea763c2d3..4133de434 100755

--- a/appliance/init

+++ b/appliance/init

@@ -181,6 +181,10 @@ else

     # We need a daemon, even in virt-rescue.

     $cmd &

+    # XXX This gives a bit of time for virt-rescue to connect to the

+    # daemon and mount any filesystems.

+    sleep 2

+

     # Get name of the serial port, from console= passed by libguestfs.

     # XXX Consider using /proc/consoles

     guestfs_serial=$(grep -Eo 'console=[^[:space:]]+' /proc/cmdline |

@@ -210,8 +214,12 @@ else

     echo "Welcome to virt-rescue, the libguestfs rescue shell."

     echo

     echo "Note: The contents of / (root) are the rescue appliance."

-    echo "You have to mount the guest's partitions under /sysroot"

-    echo "before you can examine them."

+    if ! test -d "/sysroot/dev"; then

+        echo "You have to mount the guest's partitions under /sysroot"

+        echo "before you can examine them."

+    else

+        echo "Use 'cd /sysroot' or 'chroot /sysroot' to see guest filesystems."

+    fi

     echo

     run_bash_with_ctty

     echo

diff --git a/rescue/Makefile.am b/rescue/Makefile.am

index 99d4b79ae..c83c43458 100644

--- a/rescue/Makefile.am

+++ b/rescue/Makefile.am

@@ -35,7 +35,7 @@ virt_rescue_CPPFLAGS = \

 	-I$(top_srcdir)/common/utils -I$(top_builddir)/common/utils \

 	-I$(top_srcdir)/lib -I$(top_builddir)/lib \

 	-I$(top_srcdir)/common/options -I$(top_builddir)/common/options \

-	-I$(top_srcdir)/fish \

+	-I$(top_srcdir)/common/windows -I$(top_builddir)/common/windows \

 	-I$(srcdir)/../gnulib/lib -I../gnulib/lib

 virt_rescue_CFLAGS = \

@@ -43,6 +43,7 @@ virt_rescue_CFLAGS = \

 	$(LIBXML2_CFLAGS)

 virt_rescue_LDADD = \

+	$(top_builddir)/common/windows/libwindows.la \

 	$(top_builddir)/common/options/liboptions.la \

 	$(top_builddir)/common/utils/libutils.la \

 	$(top_builddir)/lib/libguestfs.la \

diff --git a/rescue/rescue.c b/rescue/rescue.c

index b145dcd40..2b461378d 100644

--- a/rescue/rescue.c

+++ b/rescue/rescue.c

@@ -23,7 +23,6 @@

 #include <string.h>

 #include <inttypes.h>

 #include <unistd.h>

-#include <fcntl.h>

 #include <getopt.h>

 #include <errno.h>

 #include <error.h>

@@ -37,9 +36,11 @@

 #include "full-write.h"

 #include "getprogname.h"

 #include "ignore-value.h"

+#include "nonblocking.h"

 #include "xvasprintf.h"

 #include "guestfs.h"

+#include "windows.h"

 #include "options.h"

 #include "display-options.h"

@@ -87,7 +88,9 @@ usage (int status)

               "  -d|--domain guest    Add disks from libvirt guest\n"

               "  --format[=raw|..]    Force disk format for -a option\n"

               "  --help               Display brief help\n"

-              "  -m|--memsize MB      Set memory size in megabytes\n"

+              "  -i|--inspector       Automatically mount filesystems\n"

+              "  -m|--mount dev[:mnt[:opts[:fstype]] Mount dev on mnt (if omitted, /)\n"

+              "  --memsize MB         Set memory size in megabytes\n"

               "  --network            Enable network\n"

               "  -r|--ro              Access read-only\n"

               "  --scratch[=N]        Add scratch disk(s)\n"

@@ -116,7 +119,7 @@ main (int argc, char *argv[])

   enum { HELP_OPTION = CHAR_MAX + 1 };

-  static const char options[] = "a:c:d:m:rvVwx";

+  static const char options[] = "a:c:d:im:rvVwx";

   static const struct option long_options[] = {

     { "add", 1, 0, 'a' },

     { "append", 1, 0, 0 },

@@ -124,8 +127,10 @@ main (int argc, char *argv[])

     { "domain", 1, 0, 'd' },

     { "format", 2, 0, 0 },

     { "help", 0, 0, HELP_OPTION },

+    { "inspector", 0, 0, 'i' },

     { "long-options", 0, 0, 0 },

-    { "memsize", 1, 0, 'm' },

+    { "mount", 1, 0, 'm' },

+    { "memsize", 1, 0, 0 },

     { "network", 0, 0, 0 },

     { "ro", 0, 0, 'r' },

     { "rw", 0, 0, 'w' },

@@ -140,13 +145,16 @@ main (int argc, char *argv[])

   };

   struct drv *drvs = NULL;

   struct drv *drv;

+  struct mp *mps = NULL;

+  struct mp *mp;

+  char *p;

   const char *format = NULL;

   bool format_consumed = true;

   int c;

   int option_index;

   int network = 0;

   const char *append = NULL;

-  int memsize = 0;

+  int memsize = 0, m;

   int smp = 0;

   int suggest = 0;

   char *append_full;

@@ -196,6 +204,10 @@ main (int argc, char *argv[])

                    _("--scratch parameter '%s' should be >= 1"), optarg);

           add_scratch_disks (n, &drvs);

         }

+      } else if (STREQ (long_options[option_index].name, "memsize")) {

+        if (sscanf (optarg, "%d", &memsize) != 1)

+          error (EXIT_FAILURE, 0,

+                 _("could not parse memory size '%s'"), optarg);

       } else

         error (EXIT_FAILURE, 0,

                _("unknown long option: %s (%d)"),

@@ -214,10 +226,19 @@ main (int argc, char *argv[])

       OPTION_d;

       break;

+    case 'i':

+      OPTION_i;

+      break;

+

     case 'm':

-      if (sscanf (optarg, "%d", &memsize) != 1)

-        error (EXIT_FAILURE, 0,

-               _("could not parse memory size '%s'"), optarg);

+      /* For backwards compatibility with virt-rescue <= 1.36, we

+       * must handle -m <number> as a synonym for --memsize.

+       */

+      if (sscanf (optarg, "%d", &m) == 1)

+        memsize = m;

+      else {

+        OPTION_m;

+      }

       break;

     case 'r':

@@ -288,7 +309,6 @@ main (int argc, char *argv[])

    * options parsing code.  Assert here that they have known-good

    * values.

    */

-  assert (inspector == 0);

   assert (keys_from_stdin == 0);

   assert (echo_keys == 0);

   assert (live == 0);

@@ -332,12 +352,6 @@ main (int argc, char *argv[])

     exit (EXIT_FAILURE);

   free (append_full);

-  /* Add drives. */

-  add_drives (drvs);

-

-  /* Free up data structures, no longer needed after this point. */

-  free_drives (drvs);

-

   /* Add an event handler to print "log messages".  These will be the

    * output of the appliance console during launch and shutdown.

    * After launch, we will read the console messages directly from the

@@ -347,21 +361,50 @@ main (int argc, char *argv[])

                                   GUESTFS_EVENT_APPLIANCE, 0, NULL) == -1)

     exit (EXIT_FAILURE);

-  /* Run the appliance. */

+  /* Do the guest drives and mountpoints. */

+  add_drives (drvs);

   if (guestfs_launch (g) == -1)

     exit (EXIT_FAILURE);

+  if (inspector)

+    inspect_mount ();

+  mount_mps (mps);

+

+  free_drives (drvs);

+  free_mps (mps);

+

+  /* Also bind-mount /dev etc under /sysroot, if -i was given. */

+  if (inspector) {

+    CLEANUP_FREE_STRING_LIST char **roots;

+    int windows;

+

+    roots = guestfs_inspect_get_roots (g);

+    windows = roots && roots[0] && is_windows (g, roots[0]);

+    if (!windows) {

+      const char *cmd[5] = { "mount", "--rbind", NULL, NULL, NULL };

+      char *r;

+

+      cmd[2] = "/dev"; cmd[3] = "/sysroot/dev";

+      r = guestfs_debug (g, "sh", (char **) cmd);

+      free (r);

+

+      cmd[2] = "/proc"; cmd[3] = "/sysroot/proc";

+      r = guestfs_debug (g, "sh", (char **) cmd);

+      free (r);

+

+      cmd[2] = "/sys"; cmd[3] = "/sysroot/sys";

+      r = guestfs_debug (g, "sh", (char **) cmd);

+      free (r);

+    }

+  }

   sock = guestfs_internal_get_console_socket (g);

   if (sock == -1)

     exit (EXIT_FAILURE);

   /* Try to set all sockets to non-blocking. */

-  if (fcntl (STDIN_FILENO, F_SETFL, O_NONBLOCK) == -1)

-    perror ("could not set stdin to non-blocking");

-  if (fcntl (STDOUT_FILENO, F_SETFL, O_NONBLOCK) == -1)

-    perror ("could not set stdout to non-blocking");

-  if (fcntl (sock, F_SETFL, O_NONBLOCK) == -1)

-    perror ("could not set console socket to non-blocking");

+  ignore_value (set_nonblocking_flag (STDIN_FILENO, 1));

+  ignore_value (set_nonblocking_flag (STDOUT_FILENO, 1));

+  ignore_value (set_nonblocking_flag (sock, 1));

   /* Save the initial state of the tty so we always have the original

    * state to go back to.

diff --git a/rescue/virt-rescue.pod b/rescue/virt-rescue.pod

index b8aa32637..b651f84e7 100644

--- a/rescue/virt-rescue.pod

+++ b/rescue/virt-rescue.pod

@@ -6,9 +6,7 @@ virt-rescue - Run a rescue shell on a virtual machine

  virt-rescue [--options] -d domname

- virt-rescue [--options] -a disk.img [-a disk.img ...]

-

- virt-rescue --suggest (-d domname | -a disk.img ...)

+ virt-rescue [--options] -a disk.img [-a disk.img ...] [-i]

 Old style:

@@ -26,13 +24,13 @@ machine or disk image.

 You can run virt-rescue on any virtual machine known to libvirt, or

 directly on disk image(s):

- virt-rescue -d GuestName

+ virt-rescue -d GuestName -i

- virt-rescue --ro -a /path/to/disk.img

+ virt-rescue --ro -a /path/to/disk.img -i

  virt-rescue -a /dev/sdc

-For live VMs you I<must> use the --ro option.

+For live VMs you I<must> use the I<--ro> option.

 When you run virt-rescue on a virtual machine or disk image, you are

 placed in an interactive bash shell where you can use many ordinary

@@ -41,26 +39,10 @@ rescue appliance.  You must mount the virtual machine's filesystems by

 hand.  There is an empty directory called F</sysroot> where you can

 mount filesystems.

-You can get virt-rescue to suggest mount commands for you by using the

-I<--suggest> option (in another terminal):

-

- $ virt-rescue --suggest -d Fedora15

- Inspecting the virtual machine or disk image ...

- 

- This disk contains one or more operating systems.  You can use these

- mount commands in virt-rescue (at the ><rescue> prompt) to mount the

- filesystems.

- 

- # /dev/vg_f15x32/lv_root is the root of a linux operating system

- # type: linux, distro: fedora, version: 15.0

- # Fedora release 15 (Lovelock)

- 

- mount /dev/vg_f15x32/lv_root /sysroot/

- mount /dev/vda1 /sysroot/boot

- mount --bind /dev /sysroot/dev

- mount --bind /dev/pts /sysroot/dev/pts

- mount --bind /proc /sysroot/proc

- mount --bind /sys /sysroot/sys

+To automatically mount the virtual machine's filesystems under

+F</sysroot> use the I<-i> option.  This uses libguestfs inspection to

+find the filesystems and mount them in the right place.  You can also

+mount filesystems individually using the I<-m> option.

 Another way is to list the logical volumes (with L<lvs(8)>) and

 partitions (with L<parted(8)>) and mount them by hand:

@@ -170,7 +152,15 @@ If you have untrusted raw-format guest disk images, you should use

 this option to specify the disk format.  This avoids a possible

 security problem with malicious guests (CVE-2010-3851).

-=item B<-m> MB

+=item B<-i>

+

+=item B<--inspector>

+

+Using L<virt-inspector(1)> code, inspect the disks looking for

+an operating system and mount filesystems as they would be

+mounted on the real virtual machine.

+

+The filesystems are mounted on F</sysroot> in the rescue environment.

 =item B<--memsize> MB

@@ -179,6 +169,33 @@ default is set by libguestfs and is small but adequate for running

 system tools.  The occasional program might need more memory.  The

 parameter is specified in megabytes.

+=item B<-m> dev[:mountpoint[:options[:fstype]]]

+

+=item B<--mount> dev[:mountpoint[:options[:fstype]]]

+

+Mount the named partition or logical volume on the given mountpoint

+B<in the guest> (this has nothing to do with mountpoints in the host).

+

+If the mountpoint is omitted, it defaults to F.  You have to mount

+something on F.

+

+The filesystems are mounted under F</sysroot> in the rescue environment.

+

+The third (and rarely used) part of the mount parameter is the list of

+mount options used to mount the underlying filesystem.  If this is not

+given, then the mount options are either the empty string or C<ro>

+(the latter if the I<--ro> flag is used).  By specifying the mount

+options, you override this default choice.  Probably the only time you

+would use this is to enable ACLs and/or extended attributes if the

+filesystem can support them:

+

+ -m /dev/sda1:/:acl,user_xattr

+

+The fourth part of the parameter is the filesystem driver to use, such

+as C<ext3> or C<ntfs>. This is rarely needed, but can be useful if

+multiple drivers are valid for a filesystem (eg: C<ext2> and C<ext3>),

+or if libguestfs misidentifies a filesystem.

+

 =item B<--network>

 Enable QEMU user networking in the guest.  See L</NETWORK>.

@@ -217,9 +234,10 @@ Enable N E<ge> 2 virtual CPUs in the rescue appliance.

 =item B<--suggest>

-Inspect the disk image and suggest what mount commands should be used

-to mount the disks.  You should use the I<--suggest> option in a

-second terminal, then paste the commands into another virt-rescue.

+This option was used in older versions of virt-rescue to suggest what

+commands you could use to mount filesystems under F</sysroot>.  For

+the current version of virt-rescue, it is easier to use the I<-i>

+option instead.

 This option implies I<--ro> and is safe to use even if the guest is up

 or if another virt-rescue is running.

@@ -240,7 +258,7 @@ Display version number and exit.

 =item B<--rw>

-This changes the I<-a> and I<-d> options so that disks are

+This changes the I<-a>, I<-d> and I<-m> options so that disks are

 added and mounts are done read-write.

 See L<guestfish(1)/OPENING DISKS FOR READ AND WRITE>.

-- 

2.14.3