Clean up CREATE DATABASE processing to make it more robust and get rid

of special case for Windows port.  Put a PG_TRY around most of createdb()
to ensure that we remove copied subdirectories on failure, even if the
failure happens while creating the pg_database row.  (I think this explains
Oliver Siegmar's recent report.)  Having done that, there's no need for
the fragile assumption that copydir() mustn't ereport(ERROR), so simplify
its API.  Eliminate the old code that used system("cp ...") to copy
subdirectories, in favor of using copydir() on all platforms.  This not
only should allow much better error reporting, but allows us to fsync
the created files before trusting that the copy has succeeded.
This commit is contained in:
Tom Lane 2005-08-02 19:02:32 +00:00
parent 0001e98d54
commit 558730ac6b
6 changed files with 283 additions and 287 deletions

8
configure vendored
View File

@ -14915,14 +14915,6 @@ fi
# Win32 support
if test "$PORTNAME" = "win32"; then
case $LIBOBJS in
"copydir.$ac_objext" | \
*" copydir.$ac_objext" | \
"copydir.$ac_objext "* | \
*" copydir.$ac_objext "* ) ;;
*) LIBOBJS="$LIBOBJS copydir.$ac_objext" ;;
esac
case $LIBOBJS in
"gettimeofday.$ac_objext" | \
*" gettimeofday.$ac_objext" | \

View File

@ -1,5 +1,5 @@
dnl Process this file with autoconf to produce a configure script.
dnl $PostgreSQL: pgsql/configure.in,v 1.417 2005/07/06 21:04:13 momjian Exp $
dnl $PostgreSQL: pgsql/configure.in,v 1.418 2005/08/02 19:02:30 tgl Exp $
dnl
dnl Developers, please strive to achieve this order:
dnl
@ -913,7 +913,6 @@ fi
# Win32 support
if test "$PORTNAME" = "win32"; then
AC_LIBOBJ(copydir)
AC_LIBOBJ(gettimeofday)
AC_LIBOBJ(kill)
AC_LIBOBJ(open)

View File

@ -1,5 +1,5 @@
# -*-makefile-*-
# $PostgreSQL: pgsql/src/Makefile.global.in,v 1.218 2005/07/28 03:15:52 tgl Exp $
# $PostgreSQL: pgsql/src/Makefile.global.in,v 1.219 2005/08/02 19:02:31 tgl Exp $
#------------------------------------------------------------------------------
# All PostgreSQL makefiles include this file and use the variables it sets,
@ -388,11 +388,10 @@ endif
##########################################################################
#
# substitute implementations of C library routines
# substitute implementations of C library routines (see src/port/)
LIBOBJS = @LIBOBJS@ dirmod.o exec.o noblock.o path.o pipe.o pgsleep.o pgstrcasecmp.o sprompt.o thread.o
LIBOBJS = @LIBOBJS@ copydir.o dirmod.o exec.o noblock.o path.o pipe.o pgsleep.o pgstrcasecmp.o sprompt.o thread.o
ifneq (,$(LIBOBJS))
LIBS := -lpgport $(LIBS)
# add location of libpgport.a to LDFLAGS
ifdef PGXS
@ -400,7 +399,6 @@ override LDFLAGS := -L$(libdir) $(LDFLAGS)
else
override LDFLAGS := -L$(top_builddir)/src/port $(LDFLAGS)
endif
endif
# to make ws2_32.lib the last library, and always link with shfolder,
# so SHGetFolderName isn't picked up from shell32.dll

View File

@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.168 2005/07/31 17:19:17 tgl Exp $
* $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.169 2005/08/02 19:02:31 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -79,14 +79,14 @@ createdb(const CreatedbStmt *stmt)
TransactionId src_vacuumxid;
TransactionId src_frozenxid;
Oid src_deftablespace;
Oid dst_deftablespace;
Relation pg_database_rel;
volatile Oid dst_deftablespace;
volatile Relation pg_database_rel = NULL;
HeapTuple tuple;
TupleDesc pg_database_dsc;
Datum new_record[Natts_pg_database];
char new_record_nulls[Natts_pg_database];
Oid dboid;
Oid datdba;
volatile Oid datdba;
ListCell *option;
DefElem *dtablespacename = NULL;
DefElem *downer = NULL;
@ -96,12 +96,8 @@ createdb(const CreatedbStmt *stmt)
char *dbname = stmt->dbname;
char *dbowner = NULL;
const char *dbtemplate = NULL;
int encoding = -1;
int dbconnlimit = -1;
#ifndef WIN32
char buf[2 * MAXPGPATH + 100];
#endif
volatile int encoding = -1;
volatile int dbconnlimit = -1;
/* don't call this in a transaction block */
PreventTransactionChain((void *) stmt, "CREATE DATABASE");
@ -363,14 +359,17 @@ createdb(const CreatedbStmt *stmt)
BufferSync();
/*
* Close virtual file descriptors so the kernel has more available for
* the system() calls below.
* Once we start copying subdirectories, we need to be able to clean
* 'em up if we fail. Establish a TRY block to make sure this happens.
* (This is not a 100% solution, because of the possibility of failure
* during transaction commit after we leave this routine, but it should
* handle most scenarios.)
*/
closeAllVfds();
PG_TRY();
{
/*
* Iterate through all tablespaces of the template database, and copy
* each one to the new database.
* Iterate through all tablespaces of the template database,
* and copy each one to the new database.
*/
rel = heap_open(TableSpaceRelationId, AccessShareLock);
scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
@ -403,45 +402,12 @@ createdb(const CreatedbStmt *stmt)
dstpath = GetDatabasePath(dboid, dsttablespace);
if (stat(dstpath, &st) == 0 || errno != ENOENT)
{
remove_dbtablespaces(dboid);
ereport(ERROR,
(errmsg("could not initialize database directory"),
errdetail("Directory \"%s\" already exists.",
dstpath)));
}
#ifndef WIN32
/*
* Copy this subdirectory to the new location
*
* XXX use of cp really makes this code pretty grotty, particularly
* with respect to lack of ability to report errors well. Someday
* rewrite to do it for ourselves.
* We don't need to copy subdirectories
*/
/* We might need to use cp -R one day for portability */
snprintf(buf, sizeof(buf), "cp -r '%s' '%s'",
srcpath, dstpath);
if (system(buf) != 0)
{
remove_dbtablespaces(dboid);
ereport(ERROR,
(errmsg("could not initialize database directory"),
errdetail("Failing system command was: %s", buf),
errhint("Look in the postmaster's stderr log for more information.")));
}
#else /* WIN32 */
if (copydir(srcpath, dstpath) != 0)
{
/* copydir should already have given details of its troubles */
remove_dbtablespaces(dboid);
ereport(ERROR,
(errmsg("could not initialize database directory")));
}
#endif /* WIN32 */
copydir(srcpath, dstpath, false);
/* Record the filesystem change in XLOG */
{
@ -472,14 +438,9 @@ createdb(const CreatedbStmt *stmt)
/* Check to see if someone else created same DB name meanwhile. */
if (get_db_info(dbname, NULL, NULL, NULL,
NULL, NULL, NULL, NULL, NULL, NULL))
{
/* Don't hold lock while doing recursive remove */
heap_close(pg_database_rel, ExclusiveLock);
remove_dbtablespaces(dboid);
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_DATABASE),
errmsg("database \"%s\" already exists", dbname)));
}
/*
* Insert a new tuple into pg_database
@ -527,9 +488,6 @@ createdb(const CreatedbStmt *stmt)
/* Create pg_shdepend entries for objects within database */
copyTemplateDependencies(src_dboid, dboid);
/* Close pg_database, but keep exclusive lock till commit */
heap_close(pg_database_rel, NoLock);
/*
* We force a checkpoint before committing. This effectively means
* that committed XLOG_DBASE_CREATE operations will never need to be
@ -565,6 +523,23 @@ createdb(const CreatedbStmt *stmt)
*/
database_file_update_needed();
}
PG_CATCH();
{
/* Don't hold pg_database lock while doing recursive remove */
if (pg_database_rel != NULL)
heap_close(pg_database_rel, ExclusiveLock);
/* Throw away any successfully copied subdirectories */
remove_dbtablespaces(dboid);
PG_RE_THROW();
}
PG_END_TRY();
/* Close pg_database, but keep exclusive lock till commit */
/* This has to be outside the PG_TRY */
heap_close(pg_database_rel, NoLock);
}
/*
@ -1348,10 +1323,6 @@ dbase_redo(XLogRecPtr lsn, XLogRecord *record)
char *dst_path;
struct stat st;
#ifndef WIN32
char buf[2 * MAXPGPATH + 100];
#endif
src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
@ -1376,32 +1347,12 @@ dbase_redo(XLogRecPtr lsn, XLogRecord *record)
*/
BufferSync();
#ifndef WIN32
/*
* Copy this subdirectory to the new location
*
* XXX use of cp really makes this code pretty grotty, particularly
* with respect to lack of ability to report errors well. Someday
* rewrite to do it for ourselves.
* We don't need to copy subdirectories
*/
/* We might need to use cp -R one day for portability */
snprintf(buf, sizeof(buf), "cp -r '%s' '%s'",
src_path, dst_path);
if (system(buf) != 0)
ereport(ERROR,
(errmsg("could not initialize database directory"),
errdetail("Failing system command was: %s", buf),
errhint("Look in the postmaster's stderr log for more information.")));
#else /* WIN32 */
if (copydir(src_path, dst_path) != 0)
{
/* copydir should already have given details of its troubles */
ereport(ERROR,
(errmsg("could not initialize database directory")));
}
#endif /* WIN32 */
copydir(src_path, dst_path, false);
}
else if (info == XLOG_DBASE_DROP)
{

View File

@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/port.h,v 1.79 2005/07/06 21:40:09 momjian Exp $
* $PostgreSQL: pgsql/src/include/port.h,v 1.80 2005/08/02 19:02:32 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -206,6 +206,8 @@ extern int pgsymlink(const char *oldpath, const char *newpath);
#endif /* defined(WIN32) || defined(__CYGWIN__) */
extern void copydir(char *fromdir, char *todir, bool recurse);
extern bool rmtree(char *path, bool rmtopdir);
#if defined(WIN32) && !defined(__CYGWIN__)
@ -223,8 +225,6 @@ extern int win32_open(const char *, int,...);
#define pclose(a) _pclose(a)
#endif
extern int copydir(char *fromdir, char *todir);
/* Missing rand functions */
extern long lrand48(void);
extern void srand48(long seed);

View File

@ -11,84 +11,140 @@
* as a service.
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/port/copydir.c,v 1.11 2005/03/24 02:11:20 tgl Exp $
* $PostgreSQL: pgsql/src/port/copydir.c,v 1.12 2005/08/02 19:02:32 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include "storage/fd.h"
#undef mkdir /* no reason to use that macro because we
* ignore the 2nd arg */
static void copy_file(char *fromfile, char *tofile);
/*
* copydir: copy a directory (we only need to go one level deep)
* copydir: copy a directory
*
* Return 0 on success, nonzero on failure.
*
* NB: do not elog(ERROR) on failure. Return to caller so it can try to
* clean up.
* If recurse is false, subdirectories are ignored. Anything that's not
* a directory or a regular file is ignored.
*/
int
copydir(char *fromdir, char *todir)
void
copydir(char *fromdir, char *todir, bool recurse)
{
DIR *xldir;
struct dirent *xlde;
char fromfl[MAXPGPATH];
char tofl[MAXPGPATH];
char fromfile[MAXPGPATH];
char tofile[MAXPGPATH];
if (mkdir(todir) != 0)
{
ereport(WARNING,
if (mkdir(todir, S_IRUSR | S_IWUSR | S_IXUSR) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create directory \"%s\": %m", todir)));
return -1;
}
xldir = AllocateDir(fromdir);
if (xldir == NULL)
{
ereport(WARNING,
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open directory \"%s\": %m", fromdir)));
return -1;
while ((xlde = ReadDir(xldir, fromdir)) != NULL)
{
struct stat fst;
if (strcmp(xlde->d_name, ".") == 0 ||
strcmp(xlde->d_name, "..") == 0)
continue;
snprintf(fromfile, MAXPGPATH, "%s/%s", fromdir, xlde->d_name);
snprintf(tofile, MAXPGPATH, "%s/%s", todir, xlde->d_name);
if (stat(fromfile, &fst) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat \"%s\": %m", fromfile)));
if (fst.st_mode & S_IFDIR)
{
/* recurse to handle subdirectories */
if (recurse)
copydir(fromfile, tofile, true);
}
else if (fst.st_mode & S_IFREG)
copy_file(fromfile, tofile);
}
errno = 0;
while ((xlde = readdir(xldir)) != NULL)
{
snprintf(fromfl, MAXPGPATH, "%s/%s", fromdir, xlde->d_name);
snprintf(tofl, MAXPGPATH, "%s/%s", todir, xlde->d_name);
if (CopyFile(fromfl, tofl, TRUE) < 0)
{
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not copy file \"%s\": %m", fromfl)));
FreeDir(xldir);
return -1;
}
errno = 0;
}
#ifdef WIN32
/*
* This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
* not in released version
* copy one file
*/
if (GetLastError() == ERROR_NO_MORE_FILES)
errno = 0;
#endif
if (errno)
static void
copy_file(char *fromfile, char *tofile)
{
ereport(WARNING,
char buffer[8 * BLCKSZ];
int srcfd;
int dstfd;
int nbytes;
/*
* Open the files
*/
srcfd = BasicOpenFile(fromfile, O_RDONLY | PG_BINARY, 0);
if (srcfd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read directory \"%s\": %m", fromdir)));
FreeDir(xldir);
return -1;
errmsg("could not open file \"%s\": %m", fromfile)));
dstfd = BasicOpenFile(tofile, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
S_IRUSR | S_IWUSR);
if (dstfd < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create file \"%s\": %m", tofile)));
/*
* Do the data copying.
*/
for (;;)
{
nbytes = read(srcfd, buffer, sizeof(buffer));
if (nbytes < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read file \"%s\": %m", fromfile)));
if (nbytes == 0)
break;
errno = 0;
if ((int) write(dstfd, buffer, nbytes) != nbytes)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
errno = ENOSPC;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write to file \"%s\": %m", tofile)));
}
}
FreeDir(xldir);
return 0;
/*
* Be paranoid here to ensure we catch problems.
*/
if (pg_fsync(dstfd) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m", tofile)));
if (close(dstfd))
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not close file \"%s\": %m", tofile)));
close(srcfd);
}