Reimplement alternative database locations with symlinks. No changes in

user interface.

diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 802e68670153a870d49be0acd97d278704789d4f..0360b5f7bd12a198d9726fc83018ad34a2d42b3c 100644 (file)
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.63 2000/10/28 16:20:54 vadim Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/commands/dbcommands.c,v 1.64 2000/11/08 16:59:49 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,8 +17,6 @@
 
 #include <errno.h>
 #include <fcntl.h>
-#include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -37,12 +35,10 @@
 
 
 /* non-export function prototypes */
-static bool
-                       get_user_info(Oid use_sysid, bool *use_super, bool *use_createdb);
-
-static bool
-                       get_db_info(const char *name, char *dbpath, Oid *dbIdP, int4 *ownerIdP);
-
+static bool get_user_info(Oid use_sysid, bool *use_super, bool *use_createdb);
+static bool get_db_info(const char *name, char *dbpath, Oid *dbIdP, int4 *ownerIdP);
+static char * resolve_alt_dbpath(const char * dbpath, Oid dboid);
+static bool remove_dbdirs(const char * real_loc, const char * altloc);
 
 /*
  * CREATE DATABASE
@@ -52,8 +48,8 @@ void
 createdb(const char *dbname, const char *dbpath, int encoding)
 {
        char            buf[2 * MAXPGPATH + 100];
-       char       *loc;
-       char            locbuf[512];
+       char       *altloc;
+       char       *real_loc;
        int                     ret;
        bool            use_super,
                                use_createdb;
@@ -77,24 +73,6 @@ createdb(const char *dbname, const char *dbpath, int encoding)
        if (IsTransactionBlock())
                elog(ERROR, "CREATE DATABASE: may not be called in a transaction block");
 
-#ifdef OLD_FILE_NAMING
-       /* Generate directory name for the new database */
-       if (dbpath == NULL || strcmp(dbpath, dbname) == 0)
-               strcpy(locbuf, dbname);
-       else
-               snprintf(locbuf, sizeof(locbuf), "%s/%s", dbpath, dbname);
-
-       loc = ExpandDatabasePath(locbuf);
-
-       if (loc == NULL)
-               elog(ERROR,
-                        "The database path '%s' is invalid. "
-                        "This may be due to a character that is not allowed or because the chosen "
-                        "path isn't permitted for databases", dbpath);
-#else
-       locbuf[0] = 0; /* Avoid junk in strings */
-#endif
-
        /*
         * Insert a new tuple into pg_database
         */
@@ -108,13 +86,15 @@ createdb(const char *dbname, const char *dbpath, int encoding)
        dboid = newoid();
 
        /* Form tuple */
-       new_record[Anum_pg_database_datname - 1] = DirectFunctionCall1(namein,
-                                                                                                       CStringGetDatum(dbname));
+       new_record[Anum_pg_database_datname - 1] =
+               DirectFunctionCall1(namein, CStringGetDatum(dbname));
        new_record[Anum_pg_database_datdba - 1] = Int32GetDatum(GetUserId());
        new_record[Anum_pg_database_encoding - 1] = Int32GetDatum(encoding);
-       new_record[Anum_pg_database_datlastsysoid - 1] = ObjectIdGetDatum(dboid); /* Save current OID val */
-       new_record[Anum_pg_database_datpath - 1] = DirectFunctionCall1(textin,
-                                                                                                       CStringGetDatum(locbuf));
+       /* Save current OID val */
+       new_record[Anum_pg_database_datlastsysoid - 1] = ObjectIdGetDatum(dboid);
+       /* no nulls here, GetRawDatabaseInfo doesn't like them */
+       new_record[Anum_pg_database_datpath - 1] =
+               DirectFunctionCall1(textin, CStringGetDatum(dbpath ? dbpath : ""));
 
        tuple = heap_formtuple(pg_database_dsc, new_record, new_record_nulls);
 
@@ -126,9 +106,12 @@ createdb(const char *dbname, const char *dbpath, int encoding)
         */
        heap_insert(pg_database_rel, tuple);
 
-#ifndef OLD_FILE_NAMING
-       loc = GetDatabasePath(tuple->t_data->t_oid);
-#endif
+       real_loc = GetDatabasePath(tuple->t_data->t_oid);
+       altloc = resolve_alt_dbpath(dbpath, tuple->t_data->t_oid);
+
+       if (strchr(real_loc, '\'') && strchr(altloc, '\''))
+               elog(ERROR, "database path may not contain single quotes");
+       /* ... otherwise we'd be open to shell exploits below */
 
        /*
         * Update indexes (there aren't any currently)
@@ -156,41 +139,28 @@ createdb(const char *dbname, const char *dbpath, int encoding)
 
        /* Copy the template database to the new location */
 
-       if (mkdir(loc, S_IRWXU) != 0)
-               elog(ERROR, "CREATE DATABASE: unable to create database directory '%s': %s", loc, strerror(errno));
+       if (mkdir((altloc ? altloc : real_loc), S_IRWXU) != 0)
+               elog(ERROR, "CREATE DATABASE: unable to create database directory '%s': %s",
+                        (altloc ? altloc : real_loc), strerror(errno));
 
-#ifdef OLD_FILE_NAMING
-       snprintf(buf, sizeof(buf), "cp %s%cbase%ctemplate1%c* '%s'",
-                        DataDir, SEP_CHAR, SEP_CHAR, SEP_CHAR, loc);
-#else
+       if (altloc)
        {
-               char   *tmpl = GetDatabasePath(TemplateDbOid);
-
-               snprintf(buf, sizeof(buf), "cp %s%c* '%s'",
-                       tmpl, SEP_CHAR, loc);
-               pfree(tmpl);
+               if (symlink(altloc, real_loc) != 0)
+                       elog(ERROR, "CREATE DATABASE: could not link %s to %s: %s",
+                                real_loc, altloc, strerror(errno));
        }
-#endif
+
+       snprintf(buf, sizeof(buf), "cp '%s'/* '%s'",
+                        GetDatabasePath(TemplateDbOid), real_loc);
 
        ret = system(buf);
        /* Some versions of SunOS seem to return ECHILD after a system() call */
-#if defined(sun)
        if (ret != 0 && errno != ECHILD)
-#else
-       if (ret != 0)
-#endif
        {
-               /* Failed, so try to clean up the created directory ... */
-               snprintf(buf, sizeof(buf), "rm -rf '%s'", loc);
-               ret = system(buf);
-#if defined(sun)
-               if (ret == 0 || errno == ECHILD)
-#else
-               if (ret == 0)
-#endif
+               if (remove_dbdirs(real_loc, altloc))
                        elog(ERROR, "CREATE DATABASE: could not initialize database directory");
                else
-                       elog(ERROR, "CREATE DATABASE: Could not initialize database directory. Delete failed as well");
+                       elog(ERROR, "CREATE DATABASE: could not initialize database directory; delete failed as well");
        }
 
 #ifdef XLOG
@@ -210,9 +180,9 @@ dropdb(const char *dbname)
        int4            db_owner;
        bool            use_super;
        Oid                     db_id;
-       char       *path,
-                               dbpath[MAXPGPATH],
-                               buf[MAXPGPATH + 100];
+       char       *altloc;
+       char       *real_loc;
+       char        dbpath[MAXPGPATH];
        Relation        pgdbrel;
        HeapScanDesc pgdbscan;
        ScanKeyData key;
@@ -221,33 +191,25 @@ dropdb(const char *dbname)
        AssertArg(dbname);
 
        if (strcmp(dbname, "template1") == 0)
-               elog(ERROR, "DROP DATABASE: May not be executed on the template1 database");
+               elog(ERROR, "DROP DATABASE: may not be executed on the template1 database");
 
        if (strcmp(dbname, DatabaseName) == 0)
-               elog(ERROR, "DROP DATABASE: Cannot be executed on the currently open database");
+               elog(ERROR, "DROP DATABASE: cannot be executed on the currently open database");
 
        if (IsTransactionBlock())
-               elog(ERROR, "DROP DATABASE: May not be called in a transaction block");
+               elog(ERROR, "DROP DATABASE: may not be called in a transaction block");
 
        if (!get_user_info(GetUserId(), &use_super, NULL))
-               elog(ERROR, "Current user name is invalid");
+               elog(ERROR, "current user name is invalid");
 
        if (!get_db_info(dbname, dbpath, &db_id, &db_owner))
-               elog(ERROR, "DROP DATABASE: Database \"%s\" does not exist", dbname);
+               elog(ERROR, "DROP DATABASE: database \"%s\" does not exist", dbname);
 
        if (GetUserId() != db_owner && !use_super)
-               elog(ERROR, "DROP DATABASE: Permission denied");
-
-#ifdef OLD_FILE_NAMING
-       path = ExpandDatabasePath(dbpath);
-       if (path == NULL)
-               elog(ERROR,
-                        "The database path '%s' is invalid. "
-                        "This may be due to a character that is not allowed or because the chosen "
-                        "path isn't permitted for databases", path);
-#else
-       path = GetDatabasePath(db_id);
-#endif
+               elog(ERROR, "DROP DATABASE: permission denied");
+
+       real_loc = GetDatabasePath(db_id);
+       altloc = resolve_alt_dbpath(dbpath, db_id);
 
        /*
         * Obtain exclusive lock on pg_database.  We need this to ensure that
@@ -266,7 +228,7 @@ dropdb(const char *dbname)
        if (DatabaseHasActiveBackends(db_id))
        {
                heap_close(pgdbrel, AccessExclusiveLock);
-               elog(ERROR, "DROP DATABASE: Database \"%s\" is being accessed by other users", dbname);
+               elog(ERROR, "DROP DATABASE: database \"%s\" is being accessed by other users", dbname);
        }
 
        /*
@@ -320,13 +282,7 @@ dropdb(const char *dbname)
        /*
         * Remove the database's subdirectory and everything in it.
         */
-       snprintf(buf, sizeof(buf), "rm -rf '%s'", path);
-#if defined(sun)
-       if (system(buf) != 0 && errno != ECHILD)
-#else
-       if (system(buf) != 0)
-#endif
-               elog(NOTICE, "DROP DATABASE: The database directory '%s' could not be removed", path);
+       remove_dbdirs(real_loc, altloc);
 }
 
 
@@ -426,3 +382,66 @@ get_user_info(Oid use_sysid, bool *use_super, bool *use_createdb)
 
        return true;
 }
+
+
+static char *
+resolve_alt_dbpath(const char * dbpath, Oid dboid)
+{
+       char * prefix;
+       char * ret;
+       size_t len;
+
+       if (dbpath == NULL || dbpath[0] == '\0')
+               return NULL;
+
+       if (strchr(dbpath, '/'))
+       {
+#ifdef ALLOW_ABSOLUTE_DBPATHS
+               prefix = dbpath;
+#else
+               elog(ERROR, "Absolute paths are not allowed as database locations");
+#endif
+       }
+       else
+       {
+               /* must be environment variable */
+               char * var = getenv(dbpath);
+               if (!var)
+                       elog(ERROR, "environment variable %s not set", dbpath);
+               if (var[0] != '/')
+                       elog(ERROR, "environment variable %s must be absolute path", dbpath);
+               prefix = var;
+       }
+
+       len = strlen(prefix) + 6 + sizeof(Oid) * 8 + 1;
+       ret = palloc(len);
+       snprintf(ret, len, "%s/base/%u", prefix, dboid);
+
+       return ret;
+}
+
+
+static bool
+remove_dbdirs(const char * real_loc, const char * altloc)
+{
+       char buf[MAXPGPATH + 100];
+       bool success = true;
+
+       if (altloc)
+               /* remove symlink */
+               if (unlink(real_loc) != 0)
+               {
+                       elog(NOTICE, "could not remove '%s': %s", real_loc, strerror(errno));
+                       success = false;
+               }
+
+       snprintf(buf, sizeof(buf), "rm -rf '%s'", altloc ? altloc : real_loc);
+       if (system(buf) != 0 && errno != ECHILD)
+       {
+               elog(NOTICE, "database directory '%s' could not be removed",
+                        altloc ? altloc : real_loc);
+               success = false;
+       }
+
+       return success;
+}

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index a87bd2b913bdfb3add0da711662c94d337587c75..01efe5efb98cd04aa43104d06962c0b74a32b6a6 100644 (file)
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catversion.h,v 1.55 2000/11/06 15:58:46 thomas Exp $
+ * $Id: catversion.h,v 1.56 2000/11/08 16:59:50 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*                                                     yyyymmddN */
-#define CATALOG_VERSION_NO     200011060
+#define CATALOG_VERSION_NO     200011080
 
 #endif

diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index a535f5d2246d745a9c4d03c7474a976b4204e213..76127094de8743fa34771c24d27ddb74b724b00c 100644 (file)
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_database.h,v 1.13 2000/10/22 18:29:58 tgl Exp $
+ * $Id: pg_database.h,v 1.14 2000/11/08 16:59:50 petere Exp $
  *
  * NOTES
  *       the genbki.sh script reads this file and generates .bki
@@ -58,7 +58,7 @@ typedef FormData_pg_database *Form_pg_database;
 #define Anum_pg_database_datlastsysoid  4
 #define Anum_pg_database_datpath               5
 
-DATA(insert OID = 1 (  template1 PGUID ENCODING 0 template1 ));
+DATA(insert OID = 1 (  template1 PGUID ENCODING 0 "" ));
 DESCR("");
 
 #define TemplateDbOid                  1