debuggers.hg

changeset 21075:9300248eaad2

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hotplug: Avoid race condition when creating or destroying network bridges

I saw the following message when I created or destroyed two bridges by
using network-bridge script at same time. Of course names of the
bridges are different. But, a temporal name "tmpbridge" is used by
the script to create or destroy the bridges. I think that the message
was shown by "tmpbridge".

SIOCSIFNAME: File exists

This patch avoids race condition when creating or destroying the
bridges.

Signed-off-by: Masaki Kanno <kanno.masaki@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Mar 15 13:16:35 2010 +0000 (2010-03-15)
parents 4152a3ce90a7
children bce90bb3ce2c
files tools/hotplug/Linux/network-bridge
line diff
     1.1 --- a/tools/hotplug/Linux/network-bridge	Thu Mar 11 17:40:35 2010 +0000
     1.2 +++ b/tools/hotplug/Linux/network-bridge	Mon Mar 15 13:16:35 2010 +0000
     1.3 @@ -50,8 +50,10 @@
     1.4  
     1.5  
     1.6  dir=$(dirname "$0")
     1.7 +. "$dir/logging.sh"
     1.8  . "$dir/xen-script-common.sh"
     1.9  . "$dir/xen-network-common.sh"
    1.10 +. "$dir/locking.sh"
    1.11  
    1.12  findCommand "$@"
    1.13  evalVariables "$@"
    1.14 @@ -219,6 +221,8 @@ op_start () {
    1.15          return
    1.16      fi
    1.17  
    1.18 +    claim_lock "network-bridge"
    1.19 +
    1.20      create_bridge ${tdev}
    1.21  
    1.22      preiftransfer ${netdev}
    1.23 @@ -249,6 +253,8 @@ op_start () {
    1.24      if [ ${antispoof} = 'yes' ] ; then
    1.25  	antispoofing
    1.26      fi
    1.27 +
    1.28 +    release_lock "network-bridge"
    1.29  }
    1.30  
    1.31  op_stop () {
    1.32 @@ -259,6 +265,8 @@ op_stop () {
    1.33  	return
    1.34      fi
    1.35  
    1.36 +    claim_lock "network-bridge"
    1.37 +
    1.38      transfer_addrs ${bridge} ${pdev}
    1.39      if ! ifdown ${bridge}; then
    1.40  	get_ip_info ${bridge}
    1.41 @@ -274,6 +282,8 @@ op_stop () {
    1.42      do_ifup ${netdev}
    1.43  
    1.44      brctl delbr ${tdev}
    1.45 +
    1.46 +    release_lock "network-bridge"
    1.47  }
    1.48  
    1.49  # adds $dev to $bridge but waits for $dev to be in running state first