postgresql/contrib/pg_upgrade/relfilenode.c
Bruce Momjian 7228d02989 Throw error for mismatched pg_upgrade clusters
If someone removes the 'postgres' database from the old cluster and the
new cluster has a 'postgres' database, the number of databases will not
match.  We actually could upgrade such a setup, but it would violate the
1-to-1 mapping of database counts, so we throw an error instead.

Previously they got an error during the upgrade, and not at the check
stage; PG 9.0.4 does the same.
2011-04-19 21:00:29 -04:00

257 lines
6.9 KiB
C

/*
* relfilenode.c
*
* relfilenode functions
*
* Copyright (c) 2010-2011, PostgreSQL Global Development Group
* contrib/pg_upgrade/relfilenode.c
*/
#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);
static void transfer_relfile(pageCnvCtx *pageConverter,
const char *fromfile, const char *tofile,
const char *nspname, const char *relname);
/* used by scandir(), must be global */
char scandir_file_pattern[MAXPGPATH];
/*
* transfer_all_new_dbs()
*
* Responsible for upgrading all database. invokes routines to generate mappings and then
* physically link the databases.
*/
const char *
transfer_all_new_dbs(DbInfoArr *old_db_arr,
DbInfoArr *new_db_arr, char *old_pgdata, char *new_pgdata)
{
int dbnum;
const char *msg = NULL;
prep_status("Restoring user relation files\n");
if (old_db_arr->ndbs != new_db_arr->ndbs)
pg_log(PG_FATAL, "old and new clusters have a different number of databases\n");
for (dbnum = 0; dbnum < old_db_arr->ndbs; dbnum++)
{
DbInfo *old_db = &old_db_arr->dbs[dbnum];
DbInfo *new_db = &new_db_arr->dbs[dbnum];
FileNameMap *mappings;
int n_maps;
pageCnvCtx *pageConverter = NULL;
if (strcmp(old_db->db_name, new_db->db_name) != 0)
pg_log(PG_FATAL, "old and new databases have different names: old \"%s\", new \"%s\"\n",
old_db->db_name, new_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
msg = setupPageConverter(&pageConverter);
#endif
transfer_single_new_db(pageConverter, mappings, n_maps);
pg_free(mappings);
}
}
prep_status(""); /* in case nothing printed */
check_ok();
return msg;
}
/*
* 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_dir[MAXPGPATH];
struct dirent **namelist = NULL;
int numFiles = 0;
int mapnum;
int fileno;
old_dir[0] = '\0';
for (mapnum = 0; mapnum < size; mapnum++)
{
char old_file[MAXPGPATH];
char new_file[MAXPGPATH];
/* Changed tablespaces? Need a new directory scan? */
if (strcmp(maps[mapnum].old_dir, old_dir) != 0)
{
if (numFiles > 0)
{
for (fileno = 0; fileno < numFiles; fileno++)
pg_free(namelist[fileno]);
pg_free(namelist);
}
snprintf(old_dir, sizeof(old_dir), "%s", maps[mapnum].old_dir);
numFiles = pg_scandir(old_dir, &namelist, NULL);
}
/* Copying files might take some time, so give feedback. */
snprintf(old_file, sizeof(old_file), "%s/%u", maps[mapnum].old_dir,
maps[mapnum].old_relfilenode);
snprintf(new_file, sizeof(new_file), "%s/%u", maps[mapnum].new_dir,
maps[mapnum].new_relfilenode);
pg_log(PG_REPORT, OVERWRITE_MESSAGE, old_file);
/*
* Copy/link the relation file to the new cluster
*/
unlink(new_file);
transfer_relfile(pageConverter, old_file, new_file,
maps[mapnum].nspname, maps[mapnum].relname);
/* 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
*/
snprintf(scandir_file_pattern, sizeof(scandir_file_pattern), "%u_",
maps[mapnum].old_relfilenode);
for (fileno = 0; fileno < numFiles; fileno++)
{
if (strncmp(namelist[fileno]->d_name, scandir_file_pattern,
strlen(scandir_file_pattern)) == 0)
{
snprintf(old_file, sizeof(old_file), "%s/%s", maps[mapnum].old_dir,
namelist[fileno]->d_name);
snprintf(new_file, sizeof(new_file), "%s/%u%s", maps[mapnum].new_dir,
maps[mapnum].new_relfilenode, strchr(namelist[fileno]->d_name, '_'));
unlink(new_file);
transfer_relfile(pageConverter, old_file, new_file,
maps[mapnum].nspname, maps[mapnum].relname);
}
}
}
/*
* 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, ... 'fsm' and 'vm' files use underscores so are not
* copied.
*/
snprintf(scandir_file_pattern, sizeof(scandir_file_pattern), "%u.",
maps[mapnum].old_relfilenode);
for (fileno = 0; fileno < numFiles; fileno++)
{
if (strncmp(namelist[fileno]->d_name, scandir_file_pattern,
strlen(scandir_file_pattern)) == 0)
{
snprintf(old_file, sizeof(old_file), "%s/%s", maps[mapnum].old_dir,
namelist[fileno]->d_name);
snprintf(new_file, sizeof(new_file), "%s/%u%s", maps[mapnum].new_dir,
maps[mapnum].new_relfilenode, strchr(namelist[fileno]->d_name, '.'));
unlink(new_file);
transfer_relfile(pageConverter, old_file, new_file,
maps[mapnum].nspname, maps[mapnum].relname);
}
}
}
if (numFiles > 0)
{
for (fileno = 0; fileno < numFiles; fileno++)
pg_free(namelist[fileno]);
pg_free(namelist);
}
}
/*
* transfer_relfile()
*
* Copy or link file from old cluster to new one.
*/
static void
transfer_relfile(pageCnvCtx *pageConverter, const char *old_file,
const char *new_file, const char *nspname, const char *relname)
{
const char *msg;
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_INFO, "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 %s.%s (%s to %s): %s\n",
nspname, relname, old_file, new_file, msg);
}
else
{
pg_log(PG_INFO, "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 from %s.%s (%s to %s): %s\n",
nspname, relname, old_file, new_file, msg);
}
return;
}