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 26f4210..b58bba8 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * 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)