relfilenode.c

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/*
 *  relfilenode.c
 *
 *  relfilenode functions
 *
 *  Copyright (c) 2010-2013, PostgreSQL Global Development Group
 *  contrib/pg_upgrade/relfilenode.c
 */

#include "postgres_fe.h"

#include "pg_upgrade.h"

#include "catalog/pg_class.h"
#include "access/transam.h"


static void transfer_single_new_db(pageCnvCtx *pageConverter,
                       FileNameMap *maps, int size, char *old_tablespace);
static void transfer_relfile(pageCnvCtx *pageConverter, FileNameMap *map,
                             const char *suffix);


/*
 * transfer_all_new_tablespaces()
 *
 * Responsible for upgrading all database. invokes routines to generate mappings and then
 * physically link the databases.
 */
void
transfer_all_new_tablespaces(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
                    char *old_pgdata, char *new_pgdata)
{
    pg_log(PG_REPORT, "%s user relation files\n",
      user_opts.transfer_mode == TRANSFER_MODE_LINK ? "Linking" : "Copying");

    /*
     *  Transfering files by tablespace is tricky because a single database
     *  can use multiple tablespaces.  For non-parallel mode, we just pass a
     *  NULL tablespace path, which matches all tablespaces.  In parallel mode,
     *  we pass the default tablespace and all user-created tablespaces
     *  and let those operations happen in parallel.
     */
    if (user_opts.jobs <= 1)
        parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
                                      new_pgdata, NULL);
    else
    {
        int tblnum;

        /* transfer default tablespace */
        parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
                              new_pgdata, old_pgdata);

        for (tblnum = 0; tblnum < os_info.num_old_tablespaces; tblnum++)
            parallel_transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata,
                                  new_pgdata, os_info.old_tablespaces[tblnum]);
        /* reap all children */
        while (reap_child(true) == true)
            ;
    }

    end_progress_output();
    check_ok();

    return;
}


/*
 * transfer_all_new_dbs()
 *
 * Responsible for upgrading all database. invokes routines to generate mappings and then
 * physically link the databases.
 */
void
transfer_all_new_dbs(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr,
                    char *old_pgdata, char *new_pgdata, char *old_tablespace)
{
    int         old_dbnum,
                new_dbnum;

    /* Scan the old cluster databases and transfer their files */
    for (old_dbnum = new_dbnum = 0;
         old_dbnum < old_db_arr->ndbs;
         old_dbnum++, new_dbnum++)
    {
        DbInfo     *old_db = &old_db_arr->dbs[old_dbnum],
                   *new_db = NULL;
        FileNameMap *mappings;
        int         n_maps;
        pageCnvCtx *pageConverter = NULL;

        /*
         * Advance past any databases that exist in the new cluster but not in
         * the old, e.g. "postgres".  (The user might have removed the
         * 'postgres' database from the old cluster.)
         */
        for (; new_dbnum < new_db_arr->ndbs; new_dbnum++)
        {
            new_db = &new_db_arr->dbs[new_dbnum];
            if (strcmp(old_db->db_name, new_db->db_name) == 0)
                break;
        }

        if (new_dbnum >= new_db_arr->ndbs)
            pg_log(PG_FATAL, "old database \"%s\" not found in the new cluster\n",
                   old_db->db_name);

        n_maps = 0;
        mappings = gen_db_file_maps(old_db, new_db, &n_maps, old_pgdata,
                                    new_pgdata);

        if (n_maps)
        {
            print_maps(mappings, n_maps, new_db->db_name);

#ifdef PAGE_CONVERSION
            pageConverter = setupPageConverter();
#endif
            transfer_single_new_db(pageConverter, mappings, n_maps,
                                   old_tablespace);

            pg_free(mappings);
        }
    }

    return;
}


/*
 * get_pg_database_relfilenode()
 *
 *  Retrieves the relfilenode for a few system-catalog tables.  We need these
 *  relfilenodes later in the upgrade process.
 */
void
get_pg_database_relfilenode(ClusterInfo *cluster)
{
    PGconn     *conn = connectToServer(cluster, "template1");
    PGresult   *res;
    int         i_relfile;

    res = executeQueryOrDie(conn,
                            "SELECT c.relname, c.relfilenode "
                            "FROM   pg_catalog.pg_class c, "
                            "       pg_catalog.pg_namespace n "
                            "WHERE  c.relnamespace = n.oid AND "
                            "       n.nspname = 'pg_catalog' AND "
                            "       c.relname = 'pg_database' "
                            "ORDER BY c.relname");

    i_relfile = PQfnumber(res, "relfilenode");
    cluster->pg_database_oid = atooid(PQgetvalue(res, 0, i_relfile));

    PQclear(res);
    PQfinish(conn);
}


/*
 * transfer_single_new_db()
 *
 * create links for mappings stored in "maps" array.
 */
static void
transfer_single_new_db(pageCnvCtx *pageConverter,
                       FileNameMap *maps, int size, char *old_tablespace)
{
    int         mapnum;
    bool        vm_crashsafe_match = true;
    
    /*
     * Do the old and new cluster disagree on the crash-safetiness of the vm
     * files?  If so, do not copy them.
     */
    if (old_cluster.controldata.cat_ver < VISIBILITY_MAP_CRASHSAFE_CAT_VER &&
        new_cluster.controldata.cat_ver >= VISIBILITY_MAP_CRASHSAFE_CAT_VER)
        vm_crashsafe_match = false;

    for (mapnum = 0; mapnum < size; mapnum++)
    {
        if (old_tablespace == NULL ||
            strcmp(maps[mapnum].old_tablespace, old_tablespace) == 0)
        {
            /* transfer primary file */
            transfer_relfile(pageConverter, &maps[mapnum], "");
    
            /* fsm/vm files added in PG 8.4 */
            if (GET_MAJOR_VERSION(old_cluster.major_version) >= 804)
            {
                /*
                 * Copy/link any fsm and vm files, if they exist
                 */
                transfer_relfile(pageConverter, &maps[mapnum], "_fsm");
                if (vm_crashsafe_match)
                    transfer_relfile(pageConverter, &maps[mapnum], "_vm");
            }
        }
    }
}


/*
 * transfer_relfile()
 *
 * Copy or link file from old cluster to new one.
 */
static void
transfer_relfile(pageCnvCtx *pageConverter, FileNameMap *map,
                 const char *type_suffix)
{
    const char *msg;
    char        old_file[MAXPGPATH];
    char        new_file[MAXPGPATH];
    int         fd;
    int         segno;
    char        extent_suffix[65];
    
    /*
     * Now copy/link any related segments as well. Remember, PG breaks
     * large files into 1GB segments, the first segment has no extension,
     * subsequent segments are named relfilenode.1, relfilenode.2,
     * relfilenode.3.
     * copied.
     */
    for (segno = 0;; segno++)
    {
        if (segno == 0)
            extent_suffix[0] = '\0';
        else
            snprintf(extent_suffix, sizeof(extent_suffix), ".%d", segno);

        snprintf(old_file, sizeof(old_file), "%s%s/%u/%u%s%s", map->old_tablespace,
                 map->old_tablespace_suffix, map->old_db_oid, map->old_relfilenode,
                 type_suffix, extent_suffix);
        snprintf(new_file, sizeof(new_file), "%s%s/%u/%u%s%s", map->new_tablespace,
                 map->new_tablespace_suffix, map->new_db_oid, map->new_relfilenode,
                 type_suffix, extent_suffix);
    
        /* Is it an extent, fsm, or vm file? */
        if (type_suffix[0] != '\0' || segno != 0)
        {
            /* Did file open fail? */
            if ((fd = open(old_file, O_RDONLY, 0)) == -1)
            {
                /* File does not exist?  That's OK, just return */
                if (errno == ENOENT)
                    return;
                else
                    pg_log(PG_FATAL, "error while checking for file existance \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
                           map->nspname, map->relname, old_file, new_file,
                           getErrorText(errno));
            }
            close(fd);
        }

        unlink(new_file);
    
        /* Copying files might take some time, so give feedback. */
        pg_log(PG_STATUS, "%s", old_file);
    
        if ((user_opts.transfer_mode == TRANSFER_MODE_LINK) && (pageConverter != NULL))
            pg_log(PG_FATAL, "This upgrade requires page-by-page conversion, "
                   "you must use copy mode instead of link mode.\n");
    
        if (user_opts.transfer_mode == TRANSFER_MODE_COPY)
        {
            pg_log(PG_VERBOSE, "copying \"%s\" to \"%s\"\n", old_file, new_file);
    
            if ((msg = copyAndUpdateFile(pageConverter, old_file, new_file, true)) != NULL)
                pg_log(PG_FATAL, "error while copying relation \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
                       map->nspname, map->relname, old_file, new_file, msg);
        }
        else
        {
            pg_log(PG_VERBOSE, "linking \"%s\" to \"%s\"\n", old_file, new_file);
    
            if ((msg = linkAndUpdateFile(pageConverter, old_file, new_file)) != NULL)
                pg_log(PG_FATAL,
                       "error while creating link for relation \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
                       map->nspname, map->relname, old_file, new_file, msg);
        }
   }

    return;
}