ipvs: Fix possible deadlock in sync code

Commit 998e7a76804b7a273a0460c2cdd5a51fa9856717 ("ipvs: Use kthread_run()
instead of doing a double-fork via kernel_thread()") introduced a possible
deadlock in the sync code. We need to use the _bh versions for the lock, as the
lock is also accessed from a bottom half.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Acked-by: Simon Horman <horms@verge.net.au>

diff --git a/net/ipv4/ipvs/ip_vs_sync.c b/net/ipv4/ipvs/ip_vs_sync.c
index 45e9bd96c286fd4bb11148c0c69522e36d5fbcd3..a652da2c3200c55e0c30e5d5c99315e95361db5f 100644 (file)
--- a/net/ipv4/ipvs/ip_vs_sync.c
+++ b/net/ipv4/ipvs/ip_vs_sync.c
@@ -904,9 +904,9 @@ int stop_sync_thread(int state)
                 * progress of stopping the master sync daemon.
                 */
 
-               spin_lock(&ip_vs_sync_lock);
+               spin_lock_bh(&ip_vs_sync_lock);
                ip_vs_sync_state &= ~IP_VS_STATE_MASTER;
-               spin_unlock(&ip_vs_sync_lock);
+               spin_unlock_bh(&ip_vs_sync_lock);
                kthread_stop(sync_master_thread);
                sync_master_thread = NULL;
        } else if (state == IP_VS_STATE_BACKUP) {