relfilenumber.c

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/*
 *  relfilenumber.c
 *
 *  relfilenumber functions
 *
 *  Copyright (c) 2010-2023, PostgreSQL Global Development Group
 *  src/bin/pg_upgrade/relfilenumber.c
 */
 
#include "postgres_fe.h"
 
#include <sys/stat.h>
 
#include "access/transam.h"
#include "catalog/pg_class_d.h"
#include "pg_upgrade.h"
 
static void transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace);
static void transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_frozenbit);
 
 
/*
 * 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)
{
    switch (user_opts.transfer_mode)
    {
        case TRANSFER_MODE_CLONE:
            prep_status_progress("Cloning user relation files");
            break;
        case TRANSFER_MODE_COPY:
            prep_status_progress("Copying user relation files");
            break;
        case TRANSFER_MODE_LINK:
            prep_status_progress("Linking user relation files");
            break;
    }
 
    /*
     * Transferring 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();
}
 
 
/*
 * 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;
 
        /*
         * 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_fatal("old database \"%s\" not found in the new cluster",
                     old_db->db_name);
 
        mappings = gen_db_file_maps(old_db, new_db, &n_maps, old_pgdata,
                                    new_pgdata);
        if (n_maps)
        {
            transfer_single_new_db(mappings, n_maps, old_tablespace);
        }
        /* We allocate something even for n_maps == 0 */
        pg_free(mappings);
    }
}
 
/*
 * transfer_single_new_db()
 *
 * create links for mappings stored in "maps" array.
 */
static void
transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace)
{
    int         mapnum;
    bool        vm_must_add_frozenbit = false;
 
    /*
     * Do we need to rewrite visibilitymap?
     */
    if (old_cluster.controldata.cat_ver < VISIBILITY_MAP_FROZEN_BIT_CAT_VER &&
        new_cluster.controldata.cat_ver >= VISIBILITY_MAP_FROZEN_BIT_CAT_VER)
        vm_must_add_frozenbit = true;
 
    for (mapnum = 0; mapnum < size; mapnum++)
    {
        if (old_tablespace == NULL ||
            strcmp(maps[mapnum].old_tablespace, old_tablespace) == 0)
        {
            /* transfer primary file */
            transfer_relfile(&maps[mapnum], "", vm_must_add_frozenbit);
 
            /*
             * Copy/link any fsm and vm files, if they exist
             */
            transfer_relfile(&maps[mapnum], "_fsm", vm_must_add_frozenbit);
            transfer_relfile(&maps[mapnum], "_vm", vm_must_add_frozenbit);
        }
    }
}
 
 
/*
 * transfer_relfile()
 *
 * Copy or link file from old cluster to new one.  If vm_must_add_frozenbit
 * is true, visibility map forks are converted and rewritten, even in link
 * mode.
 */
static void
transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_frozenbit)
{
    char        old_file[MAXPGPATH];
    char        new_file[MAXPGPATH];
    int         segno;
    char        extent_suffix[65];
    struct stat statbuf;
 
    /*
     * 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 relfilenumber.1, relfilenumber.2, relfilenumber.3.
     */
    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->db_oid,
                 map->relfilenumber,
                 type_suffix,
                 extent_suffix);
        snprintf(new_file, sizeof(new_file), "%s%s/%u/%u%s%s",
                 map->new_tablespace,
                 map->new_tablespace_suffix,
                 map->db_oid,
                 map->relfilenumber,
                 type_suffix,
                 extent_suffix);
 
        /* Is it an extent, fsm, or vm file? */
        if (type_suffix[0] != '\0' || segno != 0)
        {
            /* Did file open fail? */
            if (stat(old_file, &statbuf) != 0)
            {
                /* File does not exist?  That's OK, just return */
                if (errno == ENOENT)
                    return;
                else
                    pg_fatal("error while checking for file existence \"%s.%s\" (\"%s\" to \"%s\"): %s",
                             map->nspname, map->relname, old_file, new_file,
                             strerror(errno));
            }
 
            /* If file is empty, just return */
            if (statbuf.st_size == 0)
                return;
        }
 
        unlink(new_file);
 
        /* Copying files might take some time, so give feedback. */
        pg_log(PG_STATUS, "%s", old_file);
 
        if (vm_must_add_frozenbit && strcmp(type_suffix, "_vm") == 0)
        {
            /* Need to rewrite visibility map format */
            pg_log(PG_VERBOSE, "rewriting \"%s\" to \"%s\"",
                   old_file, new_file);
            rewriteVisibilityMap(old_file, new_file, map->nspname, map->relname);
        }
        else
            switch (user_opts.transfer_mode)
            {
                case TRANSFER_MODE_CLONE:
                    pg_log(PG_VERBOSE, "cloning \"%s\" to \"%s\"",
                           old_file, new_file);
                    cloneFile(old_file, new_file, map->nspname, map->relname);
                    break;
                case TRANSFER_MODE_COPY:
                    pg_log(PG_VERBOSE, "copying \"%s\" to \"%s\"",
                           old_file, new_file);
                    copyFile(old_file, new_file, map->nspname, map->relname);
                    break;
                case TRANSFER_MODE_LINK:
                    pg_log(PG_VERBOSE, "linking \"%s\" to \"%s\"",
                           old_file, new_file);
                    linkFile(old_file, new_file, map->nspname, map->relname);
            }
    }
}