libxl, hotplug/Linux: default to phy backend for raw format file, take 2

This patch resurrects 11a63a166. The previous patch had a bug that
wrong "physical-device" was written to xenstore causing block script
execution fail. This patch fixes that problem.

Following configurations have been tested:

1. Raw file and PV
2. Raw file and HVM
3. Block device and PV
4. Block device and HVM

Creation / destruction / local migration all worked.

Original commit message from 11a63a166:

Modify libxl and hotplug script to allow raw format file to use phy
backend.

The block script now tests the path and determine the actual type of
file (block device or regular file) then use the actual type to
determine which branch to run.

With these changes, plus the current ordering of backend preference (phy
> qdisk > tap), we will use phy backend for raw format file by default.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/tools/hotplug/Linux/block b/tools/hotplug/Linux/block
index da26e221dc83f7a380d894dea41225a7aedf854d..8d2ee9d213c58c90f4ff42b96897d3138b1c20ce 100644 (file)
--- a/tools/hotplug/Linux/block
+++ b/tools/hotplug/Linux/block
@@ -206,6 +206,13 @@ and so cannot be mounted ${m2}${when}."
 
 
 t=$(xenstore_read_default "$XENBUS_PATH/type" 'MISSING')
+p=$(xenstore_read "$XENBUS_PATH/params")
+mode=$(xenstore_read "$XENBUS_PATH/mode")
+if [ -b "$p" ]; then
+    truetype="phy"
+elif [ -f "$p" ]; then
+    truetype="file"
+fi
 
 case "$command" in
   add)
@@ -217,16 +224,11 @@ case "$command" in
       exit 0
     fi
 
-    if [ -n "$t" ]
-    then
-      p=$(xenstore_read "$XENBUS_PATH/params")
-      mode=$(xenstore_read "$XENBUS_PATH/mode")
-    fi
     FRONTEND_ID=$(xenstore_read "$XENBUS_PATH/frontend-id")
     FRONTEND_UUID=$(xenstore_read_default \
             "/local/domain/$FRONTEND_ID/vm" 'unknown')
 
-    case $t in 
+    case $truetype in
       phy)
         dev=$(expand_dev $p)
 
@@ -319,7 +321,7 @@ mount it read-write in a guest domain."
     ;;
 
   remove)
-    case $t in 
+    case $truetype in
       phy)
        exit 0
        ;;

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 372dd3b4c9376b11aa77efee6a81a2473e48bd6b..11cf0e126d5f542a429c20516f10368f66ce80a8 100644 (file)
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -2416,9 +2416,9 @@ static void device_disk_add(libxl__egc *egc, uint32_t domid,
                 if (!disk->script &&
                     disk->backend_domid == LIBXL_TOOLSTACK_DOMID) {
                     int major, minor;
-                    libxl__device_physdisk_major_minor(dev, &major, &minor);
-                    flexarray_append_pair(back, "physical-device",
-                            libxl__sprintf(gc, "%x:%x", major, minor));
+                    if (!libxl__device_physdisk_major_minor(dev, &major, &minor))
+                        flexarray_append_pair(back, "physical-device",
+                                              libxl__sprintf(gc, "%x:%x", major, minor));
                 }
 
                 assert(device->backend_kind == LIBXL__DEVICE_KIND_VBD);

diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index 4b51ded82041c0ccf478b0bb0683a75f59090219..0f50d0475d2e3604f2c9e960d315e19ac9cbfde7 100644 (file)
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -332,6 +332,8 @@ int libxl__device_physdisk_major_minor(const char *physpath, int *major, int *mi
     struct stat buf;
     if (stat(physpath, &buf) < 0)
         return -1;
+    if (!S_ISBLK(buf.st_mode))
+        return -1;
     *major = major(buf.st_rdev);
     *minor = minor(buf.st_rdev);
     return 0;

diff --git a/tools/libxl/libxl_linux.c b/tools/libxl/libxl_linux.c
index ea5d8c16782b81fd093805c6f3d1c1fa0b580559..b51930c065b779e7d08f27855604808a2a76b992 100644 (file)
--- a/tools/libxl/libxl_linux.c
+++ b/tools/libxl/libxl_linux.c
@@ -19,11 +19,11 @@
  
 int libxl__try_phy_backend(mode_t st_mode)
 {
-    if (!S_ISBLK(st_mode)) {
-        return 0;
+    if (S_ISBLK(st_mode) || S_ISREG(st_mode)) {
+        return 1;
     }
 
-    return 1;
+    return 0;
 }
 
 #define EXT_SHIFT 28