From 62d2b0026e895448b9dff76f2565012340afdfcd Mon Sep 17 00:00:00 2001 From: Noriko Hosoi Date: Wed, 18 Nov 2015 11:44:35 -0800 Subject: [PATCH] Ticket #48338 - SimplePagedResults -- abandon could happen between the abandon check and sending results Description: commit 390b8bd9076e8976facc0858e60985d6b4fac05c introduced a self deadlock (see also bz1282607: 389-ds-base-1.2.11.15-67.el6_7 hang) First phase of the following approach: Fix design by Ludwig Krispenz and Rich Megginson (Thanks!) Investigate the connection params used in the pblock access one by one and. - for fields not used, either remove the access or just leave it as is - With a big ASSERT to flag cases if the field is ever used, and a plan to deprecate and remove the field. - for fields with atomic access, like c_isreplication_session remove the mutex - for filelds requiring copying, define them directly in the pblock and when the pblock is created, populate them from the connection, the pblock access would no longer need the c_mutex. Removing PR_Lock(c_mutex) from slapi_pblock_get(SLAPI_CONN_CLIENTNETADDR) since acquiring the lock is not necessary for the atomic reads. This change solves the self deadlock. https://fedorahosted.org/389/ticket/48338#comment:11 Reviewed by nkinder@redhat.com and mreynolds@redhat.com (Thank you, Nathan and Mark!) (cherry picked from commit 79ca67d1fc5d50d8a9ae6b686b9564f3960f8592) (cherry picked from commit 36245abd78f7abfed8219a5ac4a4cf50c1c0237c) --- ldap/servers/slapd/pblock.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/ldap/servers/slapd/pblock.c b/ldap/servers/slapd/pblock.c index bf57a33..f2017be 100644 --- a/ldap/servers/slapd/pblock.c +++ b/ldap/servers/slapd/pblock.c @@ -223,14 +223,12 @@ slapi_pblock_get( Slapi_PBlock *pblock, int arg, void *value ) memset( value, 0, sizeof( PRNetAddr )); break; } - PR_Lock( pblock->pb_conn->c_mutex ); + /* For fields with atomic access, remove the PR_Lock(c_mutex) */ if ( pblock->pb_conn->cin_addr == NULL ) { memset( value, 0, sizeof( PRNetAddr )); } else { - (*(PRNetAddr *)value) = - *(pblock->pb_conn->cin_addr); + (*(PRNetAddr *)value) = *(pblock->pb_conn->cin_addr); } - PR_Unlock( pblock->pb_conn->c_mutex ); break; case SLAPI_CONN_SERVERNETADDR: if (pblock->pb_conn == NULL) -- 2.4.3