Bug #18690 - Falsche Anzeige bzgl. loop-Mount

http://lists.xensource.com/archives/html/xen-devel/2007-07/msg00084.html
Index: xen-3.4/xen-3.4.3/tools/hotplug/Linux/block
===================================================================
--- xen-3.4.orig/xen-3.4.3/tools/hotplug/Linux/block	2010-06-17 16:16:22.000000000 +0200
+++ xen-3.4/xen-3.4.3/tools/hotplug/Linux/block	2010-06-17 16:20:21.000000000 +0200
@@ -230,6 +230,7 @@
         file=$(readlink -f "$p") || fatal "$p does not exist."
         test -f "$file" || fatal "$file does not exist."
         mode=$(canonicalise_mode "$mode")
+        major_minor=$(stat -c [%D]:%i "$file")
 
         claim_lock "block"
 
@@ -241,31 +242,20 @@
 mount it read-write in a guest domain."
         fi
 
-        loopdev=''
-        for dev in /dev/loop*
-        do
-          if [ ! -b "$dev" ]
-          then
-            continue
-          fi
-
-          f=$(losetup "$dev" 2>/dev/null) || f=''
-
-          if [ "$f" ]
-          then
-            # $dev is in use.  Check sharing.
-            if [ "x$mode" = 'x!' ]
+        if [ "x$mode" != 'x!' ]
+        then
+          while IFS=$'\t' read dev lmajor_minor f
+          do
+            if [ "$major_minor" != "$lmajor_minor" ]
             then
               continue
             fi
 
-            f=$(echo "$f" | sed -e 's/.*(\(.*\)).*/\1/g')
-
             # $f is the filename, as read from losetup, but the loopback
             # driver truncates filenames at 64 characters, so we need to go
             # trawling through the store if it's longer than that.  Truncation
             # is indicated by an asterisk at the end of the filename.
-            if expr index "$f" '*' >/dev/null
+            if [ "${f:62}" = "*" ]
             then
               found=""
               for dom in $(xenstore-list "$XENBUS_BASE_PATH")
@@ -318,18 +308,10 @@
             then
               check_file_sharing "$file" "$dev" "$mode"
             fi
-          else
-            # $dev is not in use, so we'll remember it for use later; we want
-            # to finish the sharing check first.
-
-            if [ "$loopdev" = '' ]
-            then
-              loopdev="$dev"
-            fi
-          fi
-        done
+          done < <(losetup -a | sed -e 's,\(/dev/.*\): \(\[[0-9a-f]\+\]:[0-9]\+\) (\(.*\))$,\1\t\2\t\3,')
+        fi
 
-        if [ "$loopdev" = '' ]
+        if ! loopdev=$(losetup -f)
         then
           release_lock "block"
           fatal 'Failed to find an unused loop device'