From 3b7fb4319f050f4e10593138d6b352cc09c5aad5 Mon Sep 17 00:00:00 2001

From: Noriko Hosoi <nhosoi@redhat.com>

Date: Thu, 4 Jun 2015 16:27:05 -0700

Subject: [PATCH 332/333] Ticket #48192 - Individual abandoned simple paged

 results request has no chance to be cleaned up

Description: When allocating a slot in simple paged results array stashed

in a connection in pagedresults_parse_control_value, a new code is added

to scan the array if the existing slot is timed out or not.  If it is, the

slot is released and a search results is released if it is attached.

Also, if a request is abandoned, instead of returning a valid cookie, it

changed to return an empty cookie to inform the client the request was not

successfully completed.

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

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

(cherry picked from commit 9035617b50cec984a8ccfea5a0f37d4d0b11f9cd)

---

 ldap/servers/slapd/opshared.c     |  41 +++++++-------

 ldap/servers/slapd/pagedresults.c | 110 ++++++++++++++++++++++++--------------

 2 files changed, 89 insertions(+), 62 deletions(-)

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

index d446f50..7b160dd 100644

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

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

@@ -510,8 +510,7 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

           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) ||

-              (LDAP_CANCELLED == rc) || (0 == pagesize)) {

+          if ((LDAP_SUCCESS == rc) || (LDAP_CANCELLED == rc) || (0 == pagesize)) {

               unsigned int opnote = SLAPI_OP_NOTE_SIMPLEPAGED;

               op_set_pagedresults(operation);

               pr_be = pagedresults_get_current_be(pb->pb_conn, pr_idx);

@@ -538,9 +537,8 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

               }

               slapi_pblock_set( pb, SLAPI_OPERATION_NOTES, &opnote );

               if ((LDAP_CANCELLED == rc) || (0 == pagesize)) {

-                  /* paged-results-request was abandoned */

-                  pagedresults_set_response_control(pb, 0, estimate, 

-                                                    curr_search_count, pr_idx);

+                  /* paged-results-request was abandoned; making an empty cookie. */

+                  pagedresults_set_response_control(pb, 0, estimate, -1, pr_idx);

                   send_ldap_result(pb, 0, NULL,

                                    "Simple Paged Results Search abandoned",

                                    0, NULL);

@@ -567,10 +565,21 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

       /* adjust time and size limits */

       compute_limits (pb);

-    

-      /* call the pre-search plugins. if they succeed, call the backend 

-     search function. then call the post-search plugins. */

+      /* set the timelimit to clean up the too-long-lived-paged results requests */

+      if (op_is_pagedresults(operation)) {

+        time_t optime, time_up;

+        int tlimit;

+        slapi_pblock_get( pb, SLAPI_SEARCH_TIMELIMIT, &tlimit );

+        slapi_pblock_get( pb, SLAPI_OPINITIATED_TIME, &optime );

+        time_up = (tlimit==-1 ? -1 : optime + tlimit); /* -1: no time limit */

+        pagedresults_set_timelimit(pb->pb_conn, pb->pb_op, time_up, pr_idx);

+      }

+    

+      /*

+       * call the pre-search plugins. if they succeed, call the backend 

+       * search function. then call the post-search plugins.

+       */

       /* ONREPL - should regular plugin be called for internal searches ? */

       if (plugin_call_plugins(pb, SLAPI_PLUGIN_PRE_SEARCH_FN) == 0)

       {

@@ -635,16 +644,6 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

     }

   }

-  /* set the timelimit to clean up the too-long-lived-paged results requests */

-  if (op_is_pagedresults(operation)) {

-    time_t optime, time_up;

-    int tlimit;

-    slapi_pblock_get( pb, SLAPI_SEARCH_TIMELIMIT, &tlimit );

-    slapi_pblock_get( pb, SLAPI_OPINITIATED_TIME, &optime );

-    time_up = (tlimit==-1 ? -1 : optime + tlimit); /* -1: no time limit */

-    pagedresults_set_timelimit(pb->pb_conn, pb->pb_op, time_up, pr_idx);

-  }

-

   /* PAR: now filters have been rewritten, we can assign plugins to work on them */

   index_subsys_assign_filter_decoders(pb);

@@ -873,10 +872,7 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

             slapi_pblock_get(pb, SLAPI_SEARCH_RESULT_SET, &sr);

             if (PAGEDRESULTS_SEARCH_END == pr_stat) {

               if (sr) { /* in case a left over sr is found, clean it up */

-                PR_Lock(pb->pb_conn->c_mutex);

-                pagedresults_set_search_result(pb->pb_conn, operation, NULL, 1, pr_idx);

-                be->be_search_results_release(&sr);

-                PR_Unlock(pb->pb_conn->c_mutex);

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

               }

               if (NULL == next_be) {

                 /* no more entries && no more backends */

@@ -1299,7 +1295,6 @@ iterate(Slapi_PBlock *pb, Slapi_Backend *be, int send_result,

                 operation_out_of_disk_space();

             }

             pr_stat = PAGEDRESULTS_SEARCH_END;

-            pagedresults_set_timelimit(pb->pb_conn, pb->pb_op, 0, pr_idx);

             rval = -1;

             done = 1;

             continue;

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

index 327da54..402dd10 100644

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

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

@@ -41,6 +41,27 @@

 #include "slap.h"

+/* helper function to clean up one prp slot */

+static void

+_pr_cleanup_one_slot(PagedResults *prp)

+{

+    PRLock *prmutex = NULL;

+    if (!prp) {

+        return;

+    }

+    if (prp->pr_current_be && prp->pr_current_be->be_search_results_release) {

+        /* sr is left; release it. */

+        prp->pr_current_be->be_search_results_release(&(prp->pr_search_result_set));

+    }

+    /* clean up the slot */

+    if (prp->pr_mutex) {

+        /* pr_mutex is reused; back it up and reset it. */

+        prmutex = prp->pr_mutex;

+    }

+    memset(prp, '\0', sizeof(PagedResults));

+    prp->pr_mutex = prmutex;

+}

+

 /*

  * Parse the value from an LDAPv3 "Simple Paged Results" control.  They look

  * like this:

@@ -65,6 +86,7 @@ pagedresults_parse_control_value( Slapi_PBlock *pb,

     Connection *conn = pb->pb_conn;

     Operation *op = pb->pb_op;

     BerElement *ber = NULL;

+    PagedResults *prp = NULL;

     LDAPDebug0Args(LDAP_DEBUG_TRACE, "--> pagedresults_parse_control_value\n");

     if ( NULL == conn || NULL == op || NULL == pagesize || NULL == index ) {

@@ -117,13 +139,31 @@ pagedresults_parse_control_value( Slapi_PBlock *pb,

             }

             *index = maxlen; /* the first position in the new area */

         } 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;

+            time_t ctime = current_time();

+            prp = conn->c_pagedresults.prl_list;

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

+                if (!prp->pr_current_be) { /* unused slot; take it */

+                    prp->pr_current_be = be;

+                    *index = i;

+                    break;

+                } else if (((prp->pr_timelimit > 0) && (ctime < prp->pr_timelimit)) || /* timelimit exceeded */

+                           (prp->pr_flags & CONN_FLAG_PAGEDRESULTS_ABANDONED) /* abandoned */) {

+                    _pr_cleanup_one_slot(prp);

+                    conn->c_pagedresults.prl_count--;

+                    prp->pr_current_be = be;

                     *index = i;

                     break;

                 }

             }

+            /* cleaning up the rest of the timedout if any */

+            for (++i; i < conn->c_pagedresults.prl_maxlen; i++, prp++) {

+                if (prp->pr_current_be &&

+                    (((prp->pr_timelimit > 0) && (ctime < prp->pr_timelimit)) || /* timelimit exceeded */

+                    (prp->pr_flags & CONN_FLAG_PAGEDRESULTS_ABANDONED)) /* abandoned */) {

+                    _pr_cleanup_one_slot(prp);

+                    conn->c_pagedresults.prl_count--;

+                }

+            }

         }

         if ((*index > -1) && (*index < conn->c_pagedresults.prl_maxlen) &&

             !conn->c_pagedresults.prl_list[*index].pr_mutex) {

@@ -131,7 +171,6 @@ pagedresults_parse_control_value( Slapi_PBlock *pb,

         }

         conn->c_pagedresults.prl_count++;

     } else {

-        PagedResults *prp = NULL;

         /* Repeated paged results request.

          * PagedResults is already allocated. */

         char *ptr = slapi_ch_malloc(cookie.bv_len + 1);

@@ -156,8 +195,10 @@ pagedresults_parse_control_value( Slapi_PBlock *pb,

     slapi_ch_free((void **)&cookie.bv_val);

     if ((*index > -1) && (*index < conn->c_pagedresults.prl_maxlen)) {

-        if (conn->c_pagedresults.prl_list[*index].pr_flags &

-            CONN_FLAG_PAGEDRESULTS_ABANDONED) {

+        if (conn->c_pagedresults.prl_list[*index].pr_flags & CONN_FLAG_PAGEDRESULTS_ABANDONED) {

+            /* repeated case? */

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

+            _pr_cleanup_one_slot(prp);

             rc = LDAP_CANCELLED;

         } else {

             /* Need to keep the latest msgid to prepare for the abandon. */

@@ -273,20 +314,8 @@ pagedresults_free_one( Connection *conn, Operation *op, int index )

                            "conn=%d paged requests list count is %d\n",

                            conn->c_connid, conn->c_pagedresults.prl_count);

         } else if (index < conn->c_pagedresults.prl_maxlen) {

-            PRLock *prmutex = NULL;

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

-            if (prp && prp->pr_current_be &&

-                prp->pr_current_be->be_search_results_release &&

-                prp->pr_search_result_set) {

-                prp->pr_current_be->be_search_results_release(&(prp->pr_search_result_set));

-            }

-            prp->pr_current_be = NULL;

-            if (prp->pr_mutex) {

-                /* pr_mutex is reused; back it up and reset it. */

-                prmutex = prp->pr_mutex;

-            }

-            memset(prp, '\0', sizeof(PagedResults));

-            prp->pr_mutex = prmutex;

+            _pr_cleanup_one_slot(prp);

             conn->c_pagedresults.prl_count--;

             rc = 0;

         }

@@ -309,7 +338,7 @@ pagedresults_free_one_msgid_nolock( Connection *conn, ber_int_t msgid )

             ; /* Not a paged result. */

         } else {

             LDAPDebug1Arg(LDAP_DEBUG_TRACE,

-                          "--> pagedresults_free_one: msgid=%d\n", msgid);

+                          "--> pagedresults_free_one_msgid_nolock: msgid=%d\n", msgid);

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

                 if (conn->c_pagedresults.prl_list[i].pr_msgid == msgid) {

                     PagedResults *prp = conn->c_pagedresults.prl_list + i;

@@ -318,16 +347,14 @@ pagedresults_free_one_msgid_nolock( Connection *conn, ber_int_t msgid )

                         prp->pr_search_result_set) {

                         prp->pr_current_be->be_search_results_release(&(prp->pr_search_result_set));

                     }

-                    prp->pr_current_be = NULL;

                     prp->pr_flags |= CONN_FLAG_PAGEDRESULTS_ABANDONED;

                     prp->pr_flags &= ~CONN_FLAG_PAGEDRESULTS_PROCESSING;

-                    conn->c_pagedresults.prl_count--;

                     rc = 0;

                     break;

                 }

             }

             LDAPDebug1Arg(LDAP_DEBUG_TRACE,

-                          "<-- pagedresults_free_one: %d\n", rc);

+                          "<-- pagedresults_free_one_msgid_nolock: %d\n", rc);

         }

     }

@@ -845,37 +872,42 @@ pagedresults_reset_processing(Connection *conn, int index)

 }

 #endif

-/* Are all the paged results requests timed out? */

+/*

+ * This timedout is mainly for an end user leaves a commandline untouched

+ * for a long time.  This should not affect a permanent connection which

+ * manages multiple simple paged results requests over the connection.

+ *

+ * [rule]

+ * If there is just one slot and it's timed out, we return it is timedout.

+ * 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).

+ */

 int

 pagedresults_is_timedout_nolock(Connection *conn)

 {

-    int i;

     PagedResults *prp = NULL;

     time_t ctime;

-    int rc = 0;

     LDAPDebug0Args(LDAP_DEBUG_TRACE, "--> pagedresults_is_timedout\n");

-    if (NULL == conn || 0 == conn->c_pagedresults.prl_count) {

-        LDAPDebug0Args(LDAP_DEBUG_TRACE, "<-- pagedresults_is_timedout: -\n");

-        return rc;

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

+        LDAPDebug0Args(LDAP_DEBUG_TRACE, "<-- pagedresults_is_timedout: false\n");

+        return 0;

     }

     ctime = current_time();

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

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

+    prp = conn->c_pagedresults.prl_list;

+    if (prp && (1 == conn->c_pagedresults.prl_maxlen)) {

         if (prp->pr_current_be && (prp->pr_timelimit > 0)) {

-            if (ctime < prp->pr_timelimit) {

-                LDAPDebug0Args(LDAP_DEBUG_TRACE,

-                               "<-- pagedresults_is_timedout: 0\n");

-                return 0; /* at least, one request is not timed out. */

-            } else {

-                rc = 1;   /* possibly timed out */

+            if (ctime > prp->pr_timelimit) {

+                LDAPDebug0Args(LDAP_DEBUG_TRACE, "<-- pagedresults_is_timedout: true\n");

+                return 1;

             }

         }

     }

-    LDAPDebug0Args(LDAP_DEBUG_TRACE, "<-- pagedresults_is_timedout: 1\n");

-    return rc; /* all requests are timed out. */

+    LDAPDebug0Args(LDAP_DEBUG_TRACE, "<-- pagedresults_is_timedout: false\n");

+    return 0;

 }

 /* reset all timeout */

-- 

1.9.3