From 513ef596d43cc35a72ae21170075136855641493 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Fri, 30 Mar 2012 11:46:08 -0500 Subject: [PATCH] dlm: prevent connections during shutdown During lowcomms shutdown, a new connection could possibly be created, and attempt to use a workqueue that's been destroyed. Similarly, during startup, a new connection could attempt to use a workqueue that's not been set up yet. Add a global variable to indicate when new connections are allowed. Based on patch by: Christine Caulfield Reported-by: dann frazier Reviewed-by: dann frazier Signed-off-by: David Teigland --- fs/dlm/lowcomms.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 133ef6dc7cb7..5c1b0e38c7a4 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -142,6 +142,7 @@ struct writequeue_entry { static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; static int dlm_local_count; +static int dlm_allow_conn; /* Work queues */ static struct workqueue_struct *recv_workqueue; @@ -710,6 +711,13 @@ static int tcp_accept_from_sock(struct connection *con) struct connection *newcon; struct connection *addcon; + mutex_lock(&connections_lock); + if (!dlm_allow_conn) { + mutex_unlock(&connections_lock); + return -1; + } + mutex_unlock(&connections_lock); + memset(&peeraddr, 0, sizeof(peeraddr)); result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, IPPROTO_TCP, &newsock); @@ -1503,6 +1511,7 @@ void dlm_lowcomms_stop(void) socket activity. */ mutex_lock(&connections_lock); + dlm_allow_conn = 0; foreach_conn(stop_conn); mutex_unlock(&connections_lock); @@ -1530,7 +1539,7 @@ int dlm_lowcomms_start(void) if (!dlm_local_count) { error = -ENOTCONN; log_print("no local IP address has been set"); - goto out; + goto fail; } error = -ENOMEM; @@ -1538,7 +1547,13 @@ int dlm_lowcomms_start(void) __alignof__(struct connection), 0, NULL); if (!con_cache) - goto out; + goto fail; + + error = work_start(); + if (error) + goto fail_destroy; + + dlm_allow_conn = 1; /* Start listening */ if (dlm_config.ci_protocol == 0) @@ -1548,20 +1563,17 @@ int dlm_lowcomms_start(void) if (error) goto fail_unlisten; - error = work_start(); - if (error) - goto fail_unlisten; - return 0; fail_unlisten: + dlm_allow_conn = 0; con = nodeid2con(0,0); if (con) { close_connection(con, false); kmem_cache_free(con_cache, con); } +fail_destroy: kmem_cache_destroy(con_cache); - -out: +fail: return error; } -- 2.39.5