From: Greg Stark <stark@mit.edu>
Date: Sun, 14 Feb 2010 17:50:34 +0000 (+0000)
Subject: Make CREATE DATABASE safe against losing whole files by fsyncing the
X-Git-Tag: REL8_1_20~17
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7f92f7cf711833db77b2d8214c60190cbfeebf1e;p=thirdparty%2Fpostgresql.git

Make CREATE DATABASE safe against losing whole files by fsyncing the
directory and not just the individual files.

Back-patch to 8.1 -- before that we just called "cp -r" and never
fsynced anything anyways.
---

diff --git a/src/port/copydir.c b/src/port/copydir.c
index d98b71933d3..bd252691812 100644
--- a/src/port/copydir.c
+++ b/src/port/copydir.c
@@ -11,7 +11,7 @@
  *	as a service.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/port/copydir.c,v 1.16.2.1 2008/03/31 01:32:48 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/port/copydir.c,v 1.16.2.2 2010/02/14 17:50:34 stark Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,6 +50,7 @@ copydir(char *fromdir, char *todir, bool recurse)
 {
 	DIR		   *xldir;
 	struct dirent *xlde;
+	int         dirfd;
 	char		fromfile[MAXPGPATH];
 	char		tofile[MAXPGPATH];
 
@@ -91,6 +92,26 @@ copydir(char *fromdir, char *todir, bool recurse)
 	}
 
 	FreeDir(xldir);
+
+	/*
+	 * fsync the directory to make sure not just the data but also the
+	 * new directory file entries have reached the disk. While needed
+	 * by most filesystems, the window got bigger with newer ones like
+	 * ext4.
+	 */
+	dirfd = BasicOpenFile(todir,
+	                      O_RDONLY | PG_BINARY,
+	                      S_IRUSR | S_IWUSR);
+	if(dirfd == -1)
+		ereport(ERROR,
+		        (errcode_for_file_access(),
+		         errmsg("could not open directory for fsync \"%s\": %m", todir)));
+
+	if(pg_fsync(dirfd) == -1)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not fsync directory \"%s\": %m", todir)));
+	close(dirfd);
 }
 
 /*