From dd322d94a9449915e511b07a5bd0c342e5f72b63 Mon Sep 17 00:00:00 2001

From: Rich Megginson <rmeggins@redhat.com>

Date: Tue, 25 Jun 2013 19:48:17 -0600

Subject: [PATCH 77/99] Ticket #47409 - allow setting db deadlock rejection

 policy

https://fedorahosted.org/389/ticket/47409

Reviewed by: nhosoi (Thanks!)

Branch: 389-ds-base-1.2.11

Fix Description: Add the db config attribute nsslapd-db-deadlock-policy.  This

takes values from 1-9.  The values correspond to the deadlock detector modes

in db.h.  These are the valid values to pass to the DBENV->lock_detect

method for the atype parameter.  The default value is 9 (DB_LOCK_YOUNGEST) -

select the youngest locker and reject it.  A value of 0 (DB_LOCK_NORUN) means

to disable deadlock detection and rejection - not recommended except for

testing purposes.  Attempting to use other values will cause an error.

Platforms tested: RHEL6 x86_64

Flag Day: no

Doc impact: yes - document new config parameter

(cherry picked from commit d62cd9b69c8a4a852e7bea0345285dc8c3e1e547)

(cherry picked from commit 42a3ef2644d31355da4d82e1f11b2b2eada554a7)

(cherry picked from commit f7548908d4749db429f17e23c01624475c121def)

---

 ldap/servers/slapd/back-ldbm/dblayer.c     | 19 +++++++++++-----

 ldap/servers/slapd/back-ldbm/dblayer.h     |  1 +

 ldap/servers/slapd/back-ldbm/ldbm_config.c | 35 ++++++++++++++++++++++++++++++

 ldap/servers/slapd/back-ldbm/ldbm_config.h |  2 ++

 ldap/servers/slapd/slapi-plugin.h          |  3 +++

 5 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/ldap/servers/slapd/back-ldbm/dblayer.c b/ldap/servers/slapd/back-ldbm/dblayer.c

index 2fd2110..85e4a18 100644

--- a/ldap/servers/slapd/back-ldbm/dblayer.c

+++ b/ldap/servers/slapd/back-ldbm/dblayer.c

@@ -4206,6 +4206,7 @@ static int deadlock_threadmain(void *param)

     dblayer_private *priv = NULL;

     struct ldbminfo *li = NULL;

     PRIntervalTime    interval;   /*NSPR timeout stuffy*/

+    u_int32_t flags = 0;

     PR_ASSERT(NULL != param);

     li = (struct ldbminfo*)param;

@@ -4220,13 +4221,19 @@ static int deadlock_threadmain(void *param)

     {

         if (priv->dblayer_enable_transactions) 

         {

-            if (dblayer_db_uses_locking(priv->dblayer_env->dblayer_DB_ENV)) {

-                int aborted;

-                if ((rval = LOCK_DETECT(priv->dblayer_env->dblayer_DB_ENV,

-                                        0, DB_LOCK_YOUNGEST, &aborted)) != 0) {

+            DB_ENV *db_env = priv->dblayer_env->dblayer_DB_ENV;

+            u_int32_t deadlock_policy = priv->dblayer_deadlock_policy;

+

+            if (dblayer_db_uses_locking(db_env) && (deadlock_policy > DB_LOCK_NORUN)) {

+                int rejected = 0;

+

+                if ((rval = LOCK_DETECT(db_env, 0, deadlock_policy, &rejected)) != 0) {

                     LDAPDebug(LDAP_DEBUG_ANY,

-                      "Serious Error---Failed in deadlock detect (aborted at 0x%x), err=%d (%s)\n",

-                      aborted, rval, dblayer_strerror(rval));

+                              "Serious Error---Failed in deadlock detect (aborted at 0x%x), err=%d (%s)\n",

+                              rejected, rval, dblayer_strerror(rval));

+                } else if (rejected) {

+                    LDAPDebug1Arg(LDAP_DEBUG_TRACE, "deadlock_threadmain: found and rejected %d lock requests\n", rejected);

+

                 }

             }

         }

diff --git a/ldap/servers/slapd/back-ldbm/dblayer.h b/ldap/servers/slapd/back-ldbm/dblayer.h

index ab9a85d..7f3200c 100644

--- a/ldap/servers/slapd/back-ldbm/dblayer.h

+++ b/ldap/servers/slapd/back-ldbm/dblayer.h

@@ -178,6 +178,7 @@ struct dblayer_private

     PRCondVar *thread_count_cv;     /* condition variable for housekeeping thread shutdown */

     int dblayer_lockdown;           /* use DB_LOCKDOWN */

     int dblayer_lock_config;

+    u_int32_t dblayer_deadlock_policy;    /* i.e. the atype to DB_ENV->lock_detect in deadlock_threadmain */

 };

 #if 1000*DB_VERSION_MAJOR + 100*DB_VERSION_MINOR >= 4300

diff --git a/ldap/servers/slapd/back-ldbm/ldbm_config.c b/ldap/servers/slapd/back-ldbm/ldbm_config.c

index eeae22b..44ccf78 100644

--- a/ldap/servers/slapd/back-ldbm/ldbm_config.c

+++ b/ldap/servers/slapd/back-ldbm/ldbm_config.c

@@ -1326,6 +1326,40 @@ static int ldbm_config_db_tx_max_set(

     return retval;

 }

+static void *ldbm_config_db_deadlock_policy_get(void *arg)

+{

+    struct ldbminfo *li = (struct ldbminfo *) arg;

+

+    return (void *) ((uintptr_t)li->li_dblayer_private->dblayer_deadlock_policy);

+}

+

+static int ldbm_config_db_deadlock_policy_set(void *arg, void *value, char *errorbuf, int phase, int apply)

+{

+    struct ldbminfo *li = (struct ldbminfo *) arg;

+    int retval = LDAP_SUCCESS;

+    u_int32_t val = (u_int32_t) ((uintptr_t)value);

+

+    if ((val < DB_LOCK_NORUN) || (val > DB_LOCK_YOUNGEST)) {

+	    PR_snprintf(errorbuf, SLAPI_DSE_RETURNTEXT_SIZE,

+	                "Error: Invalid value for %s (%d). Must be between %d and %d inclusive",

+	                CONFIG_DB_DEADLOCK_POLICY, val, DB_LOCK_DEFAULT, DB_LOCK_YOUNGEST);

+	    LDAPDebug1Arg(LDAP_DEBUG_ANY, "%s\n", errorbuf);

+	    return LDAP_UNWILLING_TO_PERFORM;

+    }

+    if (val == DB_LOCK_NORUN) {

+	    PR_snprintf(errorbuf, SLAPI_DSE_RETURNTEXT_SIZE,

+	                "Warning: Setting value for %s to (%d) will disable deadlock detection",

+	                CONFIG_DB_DEADLOCK_POLICY, val);

+	    LDAPDebug1Arg(LDAP_DEBUG_ANY, "%s\n", errorbuf);

+    }

+

+    if (apply) {

+        li->li_dblayer_private->dblayer_deadlock_policy = val;

+    }

+

+    return retval;

+}

+

 /*------------------------------------------------------------------------

  * Configuration array for ldbm and dblayer variables

@@ -1385,6 +1419,7 @@ static config_info ldbm_config[] = {

     {CONFIG_PAGEDLOOKTHROUGHLIMIT, CONFIG_TYPE_INT, "0", &ldbm_config_pagedlookthroughlimit_get, &ldbm_config_pagedlookthroughlimit_set, CONFIG_FLAG_ALWAYS_SHOW|CONFIG_FLAG_ALLOW_RUNNING_CHANGE},

     {CONFIG_PAGEDIDLISTSCANLIMIT, CONFIG_TYPE_INT, "0", &ldbm_config_pagedallidsthreshold_get, &ldbm_config_pagedallidsthreshold_set, CONFIG_FLAG_ALWAYS_SHOW|CONFIG_FLAG_ALLOW_RUNNING_CHANGE},

     {CONFIG_RANGELOOKTHROUGHLIMIT, CONFIG_TYPE_INT, "5000", &ldbm_config_rangelookthroughlimit_get, &ldbm_config_rangelookthroughlimit_set, CONFIG_FLAG_ALWAYS_SHOW|CONFIG_FLAG_ALLOW_RUNNING_CHANGE},

+    {CONFIG_DB_DEADLOCK_POLICY, CONFIG_TYPE_INT, STRINGIFYDEFINE(DB_LOCK_YOUNGEST), &ldbm_config_db_deadlock_policy_get, &ldbm_config_db_deadlock_policy_set, CONFIG_FLAG_ALWAYS_SHOW|CONFIG_FLAG_ALLOW_RUNNING_CHANGE},

     {NULL, 0, NULL, NULL, NULL, 0}

 };

diff --git a/ldap/servers/slapd/back-ldbm/ldbm_config.h b/ldap/servers/slapd/back-ldbm/ldbm_config.h

index 33eb078..553d387 100644

--- a/ldap/servers/slapd/back-ldbm/ldbm_config.h

+++ b/ldap/servers/slapd/back-ldbm/ldbm_config.h

@@ -159,6 +159,8 @@ struct config_info {

 #define CONFIG_USE_LEGACY_ERRORCODE     "nsslapd-do-not-use-vlv-error"

+#define CONFIG_DB_DEADLOCK_POLICY	"nsslapd-db-deadlock-policy"

+

 #define CONFIG_LDBM_DN "cn=config,cn=ldbm database,cn=plugins,cn=config"

 #define LDBM_INSTANCE_CONFIG_DONT_WRITE 1

diff --git a/ldap/servers/slapd/slapi-plugin.h b/ldap/servers/slapd/slapi-plugin.h

index 0f69c0a..5b3e1ab 100644

--- a/ldap/servers/slapd/slapi-plugin.h

+++ b/ldap/servers/slapd/slapi-plugin.h

@@ -107,6 +107,9 @@ NSPR_API(PRUint32) PR_fprintf(struct PRFileDesc* fd, const char *fmt, ...)

 #define BERLEN_T "u"

 #endif

+#define DEFINETOSTR(xxx) #xxx

+#define STRINGIFYDEFINE(xxx) DEFINETOSTR(xxx)

+

 /* Common check on berval before accessing the contents. */

 /* bv is a struct berval *bv */

 #define BV_HAS_DATA(bv) ((bv != NULL) && (bv->bv_len > 0) && (bv->bv_val != NULL))

-- 

1.8.1.4