Improve handling of GUC USERLIMIT variables by reorganizing code. Also,

handle new postgresql.conf values with SIGHUP better by better enforcing
USERLIMIT settings on existing non-super-user backends.

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 26f4210ad0e035f0ed128717b08b8d2556a4fd7d..b58bba82e1b727189117814245c2f8e226cf6392 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut .
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.195 2004/04/01 21:28:45 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.196 2004/04/05 02:48:09 momjian Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -2571,8 +2571,7 @@ set_config_option(const char *name, const char *value,
 {
    struct config_generic *record;
    int         elevel;
-   bool        makeDefault;
-   bool        changeVal_orig;
+   bool        makeDefault, changeValOrig = changeVal;
 
    if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
        elevel = DEBUG2;
@@ -2694,7 +2693,6 @@ set_config_option(const char *name, const char *value,
     * to set the reset/session values even if we can't set the variable
     * itself.
     */
-   changeVal_orig = changeVal;         /* we might have to reverse this later */
    if (record->source > source)
    {
        if (changeVal && !makeDefault)
@@ -2703,11 +2701,15 @@ set_config_option(const char *name, const char *value,
                 name);
            return true;
        }
-       changeVal = false;          /* we won't change the variable itself */
+       changeVal = false;          /* this might be reset in USERLIMIT */
    }
 
    /*
-    * Evaluate value and set variable
+    * Evaluate value and set variable.
+    * USERLIMIT checks two things:  1) is the user making a change
+    * that is blocked by an administrator setting.  2) is the administrator
+    * changing a setting and doing a SIGHUP that requires us to override
+    * a user setting.
     */
    switch (record->vartype)
    {
@@ -2726,26 +2728,30 @@ set_config_option(const char *name, const char *value,
                                        name)));
                        return false;
                    }
-                   /* Limit non-superuser changes */
                    if (record->context == PGC_USERLIMIT &&
-                       source > PGC_S_UNPRIVILEGED &&
-                       newval < conf->reset_val &&
-                       !superuser())
+                       IsUnderPostmaster && !superuser())
                    {
-                       ereport(elevel,
-                               (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-                        errmsg("permission denied to set parameter \"%s\"",
-                               name),
-                                errhint("Must be superuser to change this value to false.")));
-                       return false;
+                       if (newval < conf->reset_val)
+                       {
+                           /* Limit non-superuser changes */
+                           if (source > PGC_S_UNPRIVILEGED)
+                           {
+                               ereport(elevel,
+                                       (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+                                errmsg("permission denied to set parameter \"%s\"",
+                                       name),
+                                        errhint("Must be superuser to change this value to false.")));
+                               return false;
+                           }
+                       }
+                       if (newval > *conf->variable)
+                       {
+                           /* Allow change if admin should override */
+                           if (source < PGC_S_UNPRIVILEGED &&
+                               record->source > PGC_S_UNPRIVILEGED)
+                               changeVal = changeValOrig;
+                       }
                    }
-                   /* Honor change to config file with SIGHUP */
-                   if (record->context == PGC_USERLIMIT &&
-                       source < PGC_S_UNPRIVILEGED &&
-                       record->reset_source > PGC_S_UNPRIVILEGED &&
-                       newval > conf->reset_val &&
-                       !superuser())
-                       changeVal = changeVal_orig;
                }
                else
                {
@@ -2822,27 +2828,35 @@ set_config_option(const char *name, const char *value,
                                   newval, name, conf->min, conf->max)));
                        return false;
                    }
-                   /* Limit non-superuser changes */
                    if (record->context == PGC_USERLIMIT &&
-                       source > PGC_S_UNPRIVILEGED &&
-                       conf->reset_val != 0 &&
-                       (newval > conf->reset_val || newval == 0) &&
-                       !superuser())
+                       IsUnderPostmaster && !superuser())
                    {
-                       ereport(elevel,
-                               (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-                        errmsg("permission denied to set parameter \"%s\"",
-                               name),
-                                errhint("Must be superuser to increase this value or set it to zero.")));
-                       return false;
+                       /* handle log_min_duration_statement, -1=disable */
+                       if ((newval != -1 && conf->reset_val != -1 &&
+                            newval > conf->reset_val) || /* increase duration */
+                           (newval == -1 && conf->reset_val != -1)) /* turn off */
+                       {
+                           /* Limit non-superuser changes */
+                           if (source > PGC_S_UNPRIVILEGED)
+                           {
+                               ereport(elevel,
+                                       (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+                                errmsg("permission denied to set parameter \"%s\"",
+                                       name),
+                                        errhint("Must be superuser to increase this value or turn it off.")));
+                               return false;
+                           }
+                       }
+                       /* Allow change if admin should override */
+                       if ((newval != -1 && *conf->variable != -1 &&
+                            newval < *conf->variable) || /* decrease duration */
+                           (newval != -1 && *conf->variable == -1)) /* turn on */
+                       {
+                           if (source < PGC_S_UNPRIVILEGED &&
+                               record->source > PGC_S_UNPRIVILEGED)
+                               changeVal = changeValOrig;
+                       }
                    }
-                   /* Honor change to config file with SIGHUP */
-                   if (record->context == PGC_USERLIMIT &&
-                       source < PGC_S_UNPRIVILEGED &&
-                       record->reset_source > PGC_S_UNPRIVILEGED &&
-                       newval < conf->reset_val && newval != 0 &&
-                       !superuser())
-                       changeVal = changeVal_orig;
                }
                else
                {
@@ -2919,26 +2933,25 @@ set_config_option(const char *name, const char *value,
                                   newval, name, conf->min, conf->max)));
                        return false;
                    }
-                   /* Limit non-superuser changes */
                    if (record->context == PGC_USERLIMIT &&
-                       source > PGC_S_UNPRIVILEGED &&
-                       newval > conf->reset_val &&
-                       !superuser())
+                       IsUnderPostmaster && !superuser())
+                   /* No REAL PGC_USERLIMIT */
                    {
-                       ereport(elevel,
-                               (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-                        errmsg("permission denied to set parameter \"%s\"",
-                               name),
-                                errhint("Must be superuser to increase this value.")));
-                       return false;
+                       /* Limit non-superuser changes */
+                       if (source > PGC_S_UNPRIVILEGED)
+                       {
+                           ereport(elevel,
+                                   (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+                            errmsg("permission denied to set parameter \"%s\"",
+                                   name),
+                                    errhint("Must be superuser to increase this value or turn it off.")));
+                           return false;
+                       }
+                       /* Allow change if admin should override */
+                       if (source < PGC_S_UNPRIVILEGED &&
+                           record->source > PGC_S_UNPRIVILEGED)
+                           changeVal = false;
                    }
-                   /* Honor change to config file with SIGHUP */
-                   if (record->context == PGC_USERLIMIT &&
-                       source < PGC_S_UNPRIVILEGED &&
-                       record->reset_source > PGC_S_UNPRIVILEGED &&
-                       newval < conf->reset_val &&
-                       !superuser())
-                       changeVal = changeVal_orig;
                }
                else
                {
@@ -3009,34 +3022,38 @@ set_config_option(const char *name, const char *value,
                    }
 
                    if (record->context == PGC_USERLIMIT &&
-                       *conf->variable)
+                       IsUnderPostmaster && !superuser())
                    {
                        int         old_int_value,
                                    new_int_value;
 
                        /* all USERLIMIT strings are message levels */
-                       assign_msglvl(&old_int_value, conf->reset_val,
-                                     true, source);
                        assign_msglvl(&new_int_value, newval,
                                      true, source);
-                       /* Limit non-superuser changes */
-                       if (source > PGC_S_UNPRIVILEGED &&
-                           new_int_value > old_int_value &&
-                           !superuser())
+                       assign_msglvl(&old_int_value, conf->reset_val,
+                                     true, source);
+                       if (new_int_value > old_int_value)
                        {
-                           ereport(elevel,
-                               (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+                           /* Limit non-superuser changes */
+                           if (source > PGC_S_UNPRIVILEGED)
+                           {
+                               ereport(elevel,
+                                       (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
                                 errmsg("permission denied to set parameter \"%s\"",
                                        name),
-                                errhint("Must be superuser to increase this value.")));
-                           return false;
+                                        errhint("Must be superuser to increase this value.")));
+                               return false;
+                           }
+                       }
+                           /* Allow change if admin should override */
+                       assign_msglvl(&old_int_value, *conf->variable,
+                                     true, source);
+                       if (new_int_value < old_int_value)
+                       {
+                           if (source < PGC_S_UNPRIVILEGED &&
+                               record->source > PGC_S_UNPRIVILEGED)
+                               changeVal = changeValOrig;
                        }
-                       /* Honor change to config file with SIGHUP */
-                       if (source < PGC_S_UNPRIVILEGED &&
-                           record->reset_source > PGC_S_UNPRIVILEGED &&
-                           newval < conf->reset_val &&
-                           !superuser())
-                           changeVal = changeVal_orig;
                    }
                }
                else if (conf->reset_val)