From 22b0f8f0de1ee208a8c06c171bc2069da0adcc87 Mon Sep 17 00:00:00 2001

From: Noriko Hosoi <nhosoi@redhat.com>

Date: Mon, 6 Jul 2015 14:06:11 -0700

Subject: [PATCH] Ticket #48192 - Individual abandoned simple paged results

 request has no chance to be cleaned up

Description: There was a small window that the search on the next page

after the previous page abandoned referred the cleaned up simple paged

object.

This patch introduces a pagedresults_is_abandoned helper function to

check the simple paged results was abandoned or not with some improvements

based upon the comments by rmeggins@redhat.com (Thank you!!):

1) adding locking when getting a simplepaged object in pagedresults_is_

   abandoned_or_notavailable as well as in pagedresults_{un}lock.

2) sending "Simple Paged Results Search abandoned" if the previous page

   with the same cookie in the same connection was abandoned.

https://fedorahosted.org/389/ticket/48192

Reviewed by rmeggins@redhat.com (Thank you, Rich!!)

(cherry picked from commit e4d83c91fc88fcf9e6c823c608c629ac10e362f8)

(cherry picked from commit b513a502250f93cfb43df000c2140b27c4ef0d39)

(cherry picked from commit 7b17c488de280f29264920b4e53dce862ed5b7e4)

---

 ldap/servers/slapd/opshared.c     | 22 ++++++++++++++++------

 ldap/servers/slapd/pagedresults.c | 24 +++++++++++++++++++++++-

 ldap/servers/slapd/proto-slap.h   |  1 +

 3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/ldap/servers/slapd/opshared.c b/ldap/servers/slapd/opshared.c

index 4be5366..1bad7ef 100644

--- a/ldap/servers/slapd/opshared.c

+++ b/ldap/servers/slapd/opshared.c

@@ -709,12 +709,20 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

        */

       pr_search_result = pagedresults_get_search_result(pb->pb_conn, operation, pr_idx);

       if (pr_search_result) {

-        slapi_pblock_set( pb, SLAPI_SEARCH_RESULT_SET, pr_search_result );

-        rc = send_results_ext (pb, 1, &pnentries, pagesize, &pr_stat);

+        if (pagedresults_is_abandoned_or_notavailable(pb->pb_conn, pr_idx)) {

+          pagedresults_unlock(pb->pb_conn, pr_idx);

+          /* Previous operation was abandoned and the simplepaged object is not in use. */

+          send_ldap_result(pb, 0, NULL, "Simple Paged Results Search abandoned", 0, NULL);

+          rc = LDAP_SUCCESS;

+          goto free_and_return;

+        } else {

+          slapi_pblock_set( pb, SLAPI_SEARCH_RESULT_SET, pr_search_result );

+          rc = send_results_ext (pb, 1, &pnentries, pagesize, &pr_stat);

-        /* search result could be reset in the backend/dse */

-        slapi_pblock_get(pb, SLAPI_SEARCH_RESULT_SET, &sr);

-        pagedresults_set_search_result(pb->pb_conn, operation, sr, 0, pr_idx);

+          /* search result could be reset in the backend/dse */

+          slapi_pblock_get(pb, SLAPI_SEARCH_RESULT_SET, &sr);

+          pagedresults_set_search_result(pb->pb_conn, operation, sr, 0, pr_idx);

+        }

       } else {

         pr_stat = PAGEDRESULTS_SEARCH_END;

       }

@@ -744,7 +752,9 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

       if (PAGEDRESULTS_SEARCH_END == pr_stat) {

         pagedresults_lock(pb->pb_conn, pr_idx);

         slapi_pblock_set(pb, SLAPI_SEARCH_RESULT_SET, NULL);

-        pagedresults_free_one(pb->pb_conn, operation, pr_idx);

+        if (!pagedresults_is_abandoned_or_notavailable(pb->pb_conn, pr_idx)) {

+          pagedresults_free_one(pb->pb_conn, operation, pr_idx);

+        }

         pagedresults_unlock(pb->pb_conn, pr_idx);

         if (next_be) {

           /* no more entries, but at least another backend */

diff --git a/ldap/servers/slapd/pagedresults.c b/ldap/servers/slapd/pagedresults.c

index a7fe2cd..010e5c1 100644

--- a/ldap/servers/slapd/pagedresults.c

+++ b/ldap/servers/slapd/pagedresults.c

@@ -890,6 +890,8 @@ pagedresults_reset_processing(Connection *conn, int index)

  * If there are multiple slots, the connection may be a permanent one.

  * Do not return timed out here.  But let the next request take care the

  * timedout slot(s).

+ *

+ * must be called within conn->c_mutex 

  */

 int

 pagedresults_is_timedout_nolock(Connection *conn)

@@ -918,7 +920,10 @@ pagedresults_is_timedout_nolock(Connection *conn)

     return 0;

 }

-/* reset all timeout */

+/* 

+ * reset all timeout

+ * must be called within conn->c_mutex 

+ */

 int

 pagedresults_reset_timedout_nolock(Connection *conn)

 {

@@ -981,7 +986,9 @@ pagedresults_lock( Connection *conn, int index )

     if (!conn || (index < 0) || (index >= conn->c_pagedresults.prl_maxlen)) {

         return;

     }

+    PR_Lock(conn->c_mutex);

     prp = conn->c_pagedresults.prl_list + index;

+    PR_Unlock(conn->c_mutex);

     if (prp->pr_mutex) {

         PR_Lock(prp->pr_mutex);

     }

@@ -995,9 +1002,24 @@ pagedresults_unlock( Connection *conn, int index )

     if (!conn || (index < 0) || (index >= conn->c_pagedresults.prl_maxlen)) {

         return;

     }

+    PR_Lock(conn->c_mutex);

     prp = conn->c_pagedresults.prl_list + index;

+    PR_Unlock(conn->c_mutex);

     if (prp->pr_mutex) {

         PR_Unlock(prp->pr_mutex);

     }

     return;

 }

+

+int

+pagedresults_is_abandoned_or_notavailable( Connection *conn, int index )

+{

+    PagedResults *prp;

+    if (!conn || (index < 0) || (index >= conn->c_pagedresults.prl_maxlen)) {

+        return 1; /* not abandoned, but do not want to proceed paged results op. */

+    }

+    PR_Lock(conn->c_mutex);

+    prp = conn->c_pagedresults.prl_list + index;

+    PR_Unlock(conn->c_mutex);

+    return prp->pr_flags & CONN_FLAG_PAGEDRESULTS_ABANDONED;

+}

diff --git a/ldap/servers/slapd/proto-slap.h b/ldap/servers/slapd/proto-slap.h

index c5c412d..4c0d1ce 100644

--- a/ldap/servers/slapd/proto-slap.h

+++ b/ldap/servers/slapd/proto-slap.h

@@ -1515,6 +1515,7 @@ int pagedresults_cleanup_all(Connection *conn, int needlock);

 void op_set_pagedresults(Operation *op);

 void pagedresults_lock(Connection *conn, int index);

 void pagedresults_unlock(Connection *conn, int index);

+int pagedresults_is_abandoned_or_notavailable(Connection *conn, int index);

 /*

  * sort.c

-- 

1.9.3