From 5060d11f5039efa8534a8b65392ac6e10cbd2168 Mon Sep 17 00:00:00 2001

From: Noriko Hosoi <nhosoi@redhat.com>

Date: Fri, 1 May 2015 12:01:13 -0700

Subject: [PATCH 318/319] Ticket #48146 - async simple paged results issue;

 need to close a small window for a pr index competed among multiple threads.

Description: If multiple async simple paged results requests come in via one

connection simultaneously, the same slot in the paged results array in the

connection could be shared.  If one of them has to do paging, the search

request object stashed in the paged result array slot could be freed by the

other request if it has the shorter life cycle.

These 3 reqs use the same paged results array slot.

req0: <--------------><----x

page1           page2

req1: <----->

req2:              <------->

frees search result object of req0

(cherry picked from commit 4ae5a81d2e4d0b219cc8c19f0f7ab30c54f08ea3)

(cherry picked from commit 38efd1712dc650ccc09942efad80e52f1bc32318)

---

 ldap/servers/slapd/opshared.c     | 93 +++++++++++++++++++--------------------

 ldap/servers/slapd/pagedresults.c |  3 +-

 ldap/servers/slapd/proto-slap.h   |  2 +-

 3 files changed, 49 insertions(+), 49 deletions(-)

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

index 3e55729..15b81b6 100644

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

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

@@ -407,6 +407,51 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

    */

   operation_set_target_spec (pb->pb_op, basesdn);

+  if (be_name == NULL)

+  {

+    /* no specific backend was requested, use the mapping tree

+     */

+    err_code = slapi_mapping_tree_select_all(pb, be_list, referral_list, errorbuf);

+    if (((err_code != LDAP_SUCCESS) && (err_code != LDAP_OPERATIONS_ERROR) && (err_code != LDAP_REFERRAL))

+      || ((err_code == LDAP_OPERATIONS_ERROR) && (be_list[0] == NULL)))

+    {

+      send_ldap_result(pb, err_code, NULL, errorbuf, 0, NULL);

+      rc = -1;

+      goto free_and_return;

+    }

+    if (be_list[0] != NULL)

+    {

+      index = 0;

+      if (pr_be) { /* PAGED RESULT: be is found from the previous paging. */

+        /* move the index in the be_list which matches pr_be */

+        while (be_list[index] && be_list[index+1] && pr_be != be_list[index])

+          index++;

+      } else {

+        while (be_list[index] && be_list[index+1])

+          index++;

+      }

+      /* "be" is either pr_be or the last backend */

+      be = be_list[index];

+    }

+    else

+      be = pr_be?pr_be:NULL;

+  }

+  else

+  {

+      /* specific backend be_name was requested, use slapi_be_select_by_instance_name

+       */

+      if (pr_be) {

+        be_single = be = pr_be;

+      } else {

+        be_single = be = slapi_be_select_by_instance_name(be_name);

+      }

+      if (be_single)

+        slapi_be_Rlock(be_single);

+      be_list[0] = NULL;

+      referral_list[0] = NULL;

+      referral = NULL;

+  }

+

   /* this is time to check if mapping tree specific control

    * was used to specify that we want to parse only 

    * one backend 

@@ -471,8 +516,7 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

       if ( slapi_control_present (ctrlp, LDAP_CONTROL_PAGEDRESULTS,

                                   &ctl_value, &iscritical) )

       {

-          rc = pagedresults_parse_control_value(pb, ctl_value,

-                                                &pagesize, &pr_idx);

+          rc = pagedresults_parse_control_value(pb, ctl_value, &pagesize, &pr_idx, be);

           /* Let's set pr_idx even if it fails; in case, pr_idx == -1. */

           slapi_pblock_set(pb, SLAPI_PAGED_RESULTS_INDEX, &pr_idx);

           if ((LDAP_SUCCESS == rc) ||

@@ -513,51 +557,6 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

       }

   }

-  if (be_name == NULL)

-  {

-    /* no specific backend was requested, use the mapping tree

-     */

-    err_code = slapi_mapping_tree_select_all(pb, be_list, referral_list, errorbuf);

-    if (((err_code != LDAP_SUCCESS) && (err_code != LDAP_OPERATIONS_ERROR) && (err_code != LDAP_REFERRAL))

-      || ((err_code == LDAP_OPERATIONS_ERROR) && (be_list[0] == NULL)))

-    {

-      send_ldap_result(pb, err_code, NULL, errorbuf, 0, NULL);

-      rc = -1;

-      goto free_and_return;

-    }

-    if (be_list[0] != NULL)

-    {

-      index = 0;

-      if (pr_be) { /* PAGED RESULT: be is found from the previous paging. */

-        /* move the index in the be_list which matches pr_be */

-        while (be_list[index] && be_list[index+1] && pr_be != be_list[index])

-          index++;

-      } else {

-        while (be_list[index] && be_list[index+1])

-          index++;

-      }

-      /* "be" is either pr_be or the last backend */

-      be = be_list[index];

-    }

-    else

-      be = pr_be?pr_be:NULL;

-  }

-  else

-  {

-      /* specific backend be_name was requested, use slapi_be_select_by_instance_name

-       */

-      if (pr_be) {

-        be_single = be = pr_be;

-      } else {

-        be_single = be = slapi_be_select_by_instance_name(be_name);

-      }

-      if (be_single)

-        slapi_be_Rlock(be_single);

-      be_list[0] = NULL;

-      referral_list[0] = NULL;

-      referral = NULL;

-  }

-

   slapi_pblock_set(pb, SLAPI_BACKEND_COUNT, &index);

   if (be)

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

index e61c000..a3a5fc4 100644

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

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

@@ -58,7 +58,7 @@

 int

 pagedresults_parse_control_value( Slapi_PBlock *pb,

                                   struct berval *psbvp, ber_int_t *pagesize,

-                                  int *index )

+                                  int *index, Slapi_Backend *be )

 {

     int rc = LDAP_SUCCESS;

     struct berval cookie = {0};

@@ -119,6 +119,7 @@ pagedresults_parse_control_value( Slapi_PBlock *pb,

         } else {

             for (i = 0; i < conn->c_pagedresults.prl_maxlen; i++) {

                 if (!conn->c_pagedresults.prl_list[i].pr_current_be) {

+                    conn->c_pagedresults.prl_list[i].pr_current_be = be;

                     *index = i;

                     break;

                 }

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

index c497c14..4c3c29d 100644

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

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

@@ -1432,7 +1432,7 @@ int slapd_do_all_nss_ssl_init(int slapd_exemode, int importexport_encrypt,

  * pagedresults.c

  */

 int pagedresults_parse_control_value(Slapi_PBlock *pb, struct berval *psbvp,

-                                     ber_int_t *pagesize, int *index);

+                                     ber_int_t *pagesize, int *index, Slapi_Backend *be);

 void pagedresults_set_response_control(Slapi_PBlock *pb, int iscritical, 

                                        ber_int_t estimate,

                                        int curr_search_count, int index);

-- 

1.9.3