[389-devel] Please review: [389 Project] #391: Slapd crashes when deleting backends while operations are still in progress

[Noriko Hosoi]

https://fedorahosted.org/389/ticket/391

https://fedorahosted.org/389/attachment/ticket/391/0001-Trac-Ticket-391-Slapd-crashes-when-deleting-backends.patch

  Bug Description: Deleting backend code ldbm_instance_delete_instance_
  entry_callback had no checking for the ordinary operations accessing
  the backend instance.  Even if some operations are still in progress,
  the backend instance could be deleted and it crashes the server.

  Fix Description: Backend struct ldbm_instance had a member inst_ref_
  count, which was not used.  This patch converts the type PRInt32 to
  Slapi_Counter and increments it when the backend instance is in use.
  The delete code checks the counter and if it is greater than 0, it
  returns SLAPI_DSE_CALLBACK_ERROR.