libguestfs/1000-force-virtio_blk-in-old-guest-kernel.patch

From cc07a2762371abf8959a0c1ff8954dce11a4af2c Mon Sep 17 00:00:00 2001
From: Olaf Hering <olaf@aepfle.de>
Date: Mon, 3 Sep 2012 19:50:44 +0200
Subject: [PATCH] force virtio_blk in old guest kernel

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 df/output.c            | 13 +++++++++----
 fish/options.c         |  8 +++++++-
 src/guestfs-internal.h |  2 ++
 src/guestfs.c          | 16 ++++++++++++++++
 src/inspect-fs-unix.c  |  4 ++--
 src/launch-appliance.c |  3 +++
 src/launch-libvirt.c   |  7 +++++++
 test-tool/test-tool.c  | 16 +++++++++++++---
 8 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/df/output.c b/df/output.c
index 5729dd4..fb33ca1 100644
--- a/df/output.c
+++ b/df/output.c
@@ -42,6 +42,7 @@
 #include "virt-df.h"
 
 static void write_csv_field (const char *field);
+static int use_virtio_blk;
 
 void
 print_title (void)
@@ -82,7 +83,7 @@ print_title (void)
   }
 }
 
-static char *adjust_device_offset (const char *device, int offset);
+static char *adjust_device_offset (guestfs_h *g, const char *device, int offset);
 
 void
 print_stat (const char *name, const char *uuid_param,
@@ -110,7 +111,7 @@ print_stat (const char *name, const char *uuid_param,
     exit (EXIT_FAILURE);
   if (offset >= 0) {
     char *p = dev;
-    dev = adjust_device_offset (p, offset);
+    dev = adjust_device_offset (g, p, offset);
     free (p);
   }
 
@@ -237,8 +238,9 @@ write_csv_field (const char *field)
 static char *drive_name (int index, char *ret);
 
 static char *
-adjust_device_offset (const char *device, int offset)
+adjust_device_offset (guestfs_h *g, const char *device, int offset)
 {
+  ;
   int index;
   int part_num;
   char *whole_device;
@@ -282,7 +284,10 @@ adjust_device_offset (const char *device, int offset)
     exit (EXIT_FAILURE);
   }
 
-  strcpy (ret, "/dev/sd");
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+  use_virtio_blk = 1;
+#endif
+  strcpy (ret, use_virtio_blk ? "/dev/vd" : "/dev/sd");
   drive_name (index, &ret[7]);
   len = strlen (ret);
   if (part_num > 0)
diff --git a/fish/options.c b/fish/options.c
index 0db790e..54190bc 100644
--- a/fish/options.c
+++ b/fish/options.c
@@ -27,6 +27,8 @@
 
 #include "options.h"
 
+static int use_virtio_blk;
+
 char
 add_drives (struct drv *drv, char next_drive)
 {
@@ -40,13 +42,17 @@ add_drives (struct drv *drv, char next_drive)
     exit (EXIT_FAILURE);
   }
 
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+  use_virtio_blk = 1;
+#endif
+
   if (drv) {
     next_drive = add_drives (drv->next, next_drive);
 
     free (drv->device);
     drv->device = NULL;
 
-    if (asprintf (&drv->device, "/dev/sd%c", next_drive) == -1) {
+    if (asprintf (&drv->device, "/dev/%s%c", use_virtio_blk ? "vd" : "sd", next_drive) == -1) {
       perror ("asprintf");
       exit (EXIT_FAILURE);
     }
diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index 2cfa35b..cb0cbb9 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -331,6 +331,8 @@ struct guestfs_h
     virDomainPtr dom;           /* libvirt domain */
   } virt;
 #endif
+
+  int use_virtio_blk;
 };
 
 /* Per-filesystem data stored for inspect_os. */
diff --git a/src/guestfs.c b/src/guestfs.c
index e755ffa..7e1d242 100644
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -222,6 +222,22 @@ parse_environment (guestfs_h *g,
       return -1;
   }
 
+/*
+ * Currently virtio_scsi is forced if qemu in the host supports this
+ * feature. This test does however not take the capabilities of the started
+ * guest into account. As a result no disks will be found if the guest
+ * kernel is older than 3.4.
+ */
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+  static const char env_string[] = "GUESTFS_QEMU_NO_VIRTIO_BLK";
+  str = getenv(env_string);
+  g->use_virtio_blk = str == NULL;
+  if (str)
+    debug (g, "SuSE: %s in environment, preserving virtio-scsi setting.", env_string);
+  else
+    debug (g, "SuSE: %s not in environment, preventing virtio-scsi usage in old guest kernel.", env_string);
+#endif
+
   return 0;
 }
 
diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
index 33c5ee9..c7d5398 100644
--- a/src/inspect-fs-unix.c
+++ b/src/inspect-fs-unix.c
@@ -1412,7 +1412,7 @@ resolve_fstab_device_diskbyid (guestfs_h *g, const char *part,
     return 0;
 
   /* Make the partition name and check it exists. */
-  device = safe_asprintf (g, "/dev/sda%s", part);
+  device = safe_asprintf (g, "/dev/%sa%s", g->use_virtio_blk ? "vd" : "sd", part);
   if (!is_partition (g, device)) {
     free (device);
     return 0;
@@ -1489,7 +1489,7 @@ resolve_fstab_device (guestfs_h *g, const char *spec, Hash_table *md_map)
     if (disk_i != -1 && disk_i <= 26 &&
         slice_i > 0 && slice_i <= 1 /* > 4 .. see comment above */ &&
         part_i >= 0 && part_i < 26) {
-      device = safe_asprintf (g, "/dev/sd%c%d", disk_i + 'a', part_i + 5);
+      device = safe_asprintf (g, "/dev/%s%c%d", g->use_virtio_blk ? "vd" : "sd", disk_i + 'a', part_i + 5);
     }
   }
   else if ((part = match1 (g, spec, re_diskbyid)) != NULL) {
diff --git a/src/launch-appliance.c b/src/launch-appliance.c
index 17e90d9..902cf9a 100644
--- a/src/launch-appliance.c
+++ b/src/launch-appliance.c
@@ -875,6 +875,9 @@ qemu_supports_virtio_scsi (guestfs_h *g)
       g->app.virtio_scsi = 3;
   }
 
+  if (g->use_virtio_blk)
+     g->app.virtio_scsi = 2;
+
   return g->app.virtio_scsi == 1;
 }
 
diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index 8bdf117..63f1656 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -150,6 +150,13 @@ launch_libvirt (guestfs_h *g, const char *libvirt_uri)
     return -1;
   }
 
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+  if (g->use_virtio_blk) {
+    error (g, "Using libvirt is not possible with this binary package due to forced virtio-blk usage.");
+    return -1;
+  }
+#endif
+
   guestfs___launch_send_progress (g, 0);
   TRACE0 (launch_libvirt_start);
 
diff --git a/test-tool/test-tool.c b/test-tool/test-tool.c
index 6f26e33..754f09d 100644
--- a/test-tool/test-tool.c
+++ b/test-tool/test-tool.c
@@ -35,6 +35,7 @@
 
 #include <guestfs.h>
 
+static int use_virtio_blk;
 #define _(str) dgettext(PACKAGE, (str))
 //#define N_(str) dgettext(PACKAGE, (str))
 
@@ -103,7 +104,11 @@ main (int argc, char *argv[])
   int i;
   struct guestfs_version *vers;
   char *p;
+  char *disk_name, *partition_name;
 
+#ifdef GUESTFS_QEMU_NO_VIRTIO_BLK
+  use_virtio_blk = 1;
+#endif
   /* Everyone ignores the documentation, so ... */
   printf ("     ************************************************************\n"
           "     *                    IMPORTANT NOTICE\n"
@@ -129,6 +134,11 @@ main (int argc, char *argv[])
     exit (EXIT_FAILURE);
   }
 
+  if (asprintf(&disk_name, "/dev/%s", use_virtio_blk ? "vda" : "sda") < 0)
+    exit (EXIT_FAILURE);
+  if (asprintf(&partition_name, "%s1", disk_name) < 0)
+    exit (EXIT_FAILURE);
+
   for (;;) {
     c = getopt_long (argc, argv, options, long_options, &option_index);
     if (c == -1) break;
@@ -251,19 +261,19 @@ main (int argc, char *argv[])
   fflush (stdout);
 
   /* Create the filesystem and mount everything. */
-  if (guestfs_part_disk (g, "/dev/sda", "mbr") == -1) {
+  if (guestfs_part_disk (g, disk_name, "mbr") == -1) {
     fprintf (stderr,
              _("libguestfs-test-tool: failed to run part-disk\n"));
     exit (EXIT_FAILURE);
   }
 
-  if (guestfs_mkfs (g, "ext2", "/dev/sda1") == -1) {
+  if (guestfs_mkfs (g, "ext2", partition_name) == -1) {
     fprintf (stderr,
              _("libguestfs-test-tool: failed to mkfs.ext2\n"));
     exit (EXIT_FAILURE);
   }
 
-  if (guestfs_mount (g, "/dev/sda1", "/") == -1) {
+  if (guestfs_mount (g, partition_name, "/") == -1) {
     fprintf (stderr,
              _("libguestfs-test-tool: failed to mount /dev/sda1 on /\n"));
     exit (EXIT_FAILURE);
-- 
1.7.12.3