From 01748ce128ae4c29cfb63e88cd68918e7d48e946 Mon Sep 17 00:00:00 2001 From: Inaam Rana Date: Thu, 24 May 2012 12:37:03 -0400 Subject: [PATCH] Bug #14100254 65389: MVCC IS BROKEN WITH IMPLICIT LOCK rb://1088 approved by: Marko Makela This bug was introduced in early stages of plugin. We were not checking for an implicit lock on sec index rec for trx_id that is stamped on current version of the clust_index in case where the clust_index has a previous delete marked version. --- storage/innodb_plugin/row/row0vers.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/storage/innodb_plugin/row/row0vers.c b/storage/innodb_plugin/row/row0vers.c index 8a7bb842293..9aeaa2db6c0 100644 --- a/storage/innodb_plugin/row/row0vers.c +++ b/storage/innodb_plugin/row/row0vers.c @@ -208,18 +208,6 @@ row_vers_impl_x_locked_off_kernel( vers_del = rec_get_deleted_flag(prev_version, comp); prev_trx_id = row_get_rec_trx_id(prev_version, clust_index, clust_offsets); - - /* If the trx_id and prev_trx_id are different and if - the prev_version is marked deleted then the - prev_trx_id must have already committed for the trx_id - to be able to modify the row. Therefore, prev_trx_id - cannot hold any implicit lock. */ - if (vers_del && 0 != ut_dulint_cmp(trx_id, prev_trx_id)) { - - mutex_enter(&kernel_mutex); - break; - } - /* The stack of versions is locked by mtr. Thus, it is safe to fetch the prefixes for externally stored columns. */