1.1 --- a/tools/examples/block	Fri Dec 02 22:27:04 2005 +0000
     1.2 +++ b/tools/examples/block	Sat Dec 03 00:51:36 2005 +0000
     1.3 @@ -250,7 +250,7 @@ case "$command" in
     1.4        file)
     1.5          # Canonicalise the file, for sharing check comparison, and the mode
     1.6          # for ease of use here.
     1.7 -        file=$(readlink -f "$p")
     1.8 +        file=$(readlink -f "$p") || fatal "$p does not exist."
     1.9          mode=$(canonicalise_mode "$mode")
    1.10  
    1.11          claim_lock "block"
    1.12 @@ -271,8 +271,7 @@ mount it read-write in a guest domain."
    1.13              continue
    1.14            fi
    1.15  
    1.16 -          f=$(losetup "$dev" 2>/dev/null) || f='()'
    1.17 -          f=$(echo "$f" | sed -e 's/.*(\(.*\)).*/\1/g')
    1.18 +          f=$(losetup "$dev" 2>/dev/null) || f=''
    1.19  
    1.20            if [ "$f" ]
    1.21            then
    1.22 @@ -282,6 +281,38 @@ mount it read-write in a guest domain."
    1.23                continue
    1.24              fi
    1.25  
    1.26 +            f=$(echo "$f" | sed -e 's/.*(\(.*\)).*/\1/g')
    1.27 +
    1.28 +            # $f is the filename, as read from losetup, but the loopback
    1.29 +            # driver truncates filenames at 64 characters, so we need to go
    1.30 +            # trawling through the store if it's longer than that.  Truncation
    1.31 +            # is indicated by an asterisk at the end of the filename.
    1.32 +            if expr index "$f" '*' >/dev/null
    1.33 +            then
    1.34 +              found=""
    1.35 +              for dom in $(xenstore-list "$XENBUS_BASE_PATH")
    1.36 +              do
    1.37 +                for domdev in $(xenstore-list "$XENBUS_BASE_PATH/$dom")
    1.38 +                do
    1.39 +                  d=$(xenstore_read_default \
    1.40 +                        "$XENBUS_BASE_PATH/$dom/$domdev/node" "")
    1.41 +                  if [ "$d" == "$dev" ]
    1.42 +                  then
    1.43 +                    f=$(xenstore_read "$XENBUS_BASE_PATH/$dom/$domdev/params")
    1.44 +                    found=1
    1.45 +                    break 2
    1.46 +                  fi
    1.47 +                done
    1.48 +              done
    1.49 +
    1.50 +              if [ ! "$found" ]
    1.51 +              then
    1.52 +                # This loopback device is in use by someone else, so skip it.
    1.53 +                log debug "Loopback sharing check skips device $dev."
    1.54 +                continue
    1.55 +              fi
    1.56 +            fi
    1.57 +
    1.58              f=$(readlink -f "$f")
    1.59  
    1.60              if [ "$f" == "$file" ]