0001-Delay-fsyncing-files-during-copying-in-CREATE-DATABA.patch

From bd80748883d1328a71607a447677b0bfb1f54ab0 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Mon, 28 Dec 2009 23:43:57 +0100
Subject: [PATCH] Delay fsyncing files during copying in CREATE DATABASE - this
 dramatically speeds up CREATE DATABASE on non battery backed
 rotational storage.
 Additionally fsync() the directory to ensure all metadata reaches
 storage.

---
 src/port/copydir.c |   58 +++++++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/src/port/copydir.c b/src/port/copydir.c
index a70477e..cde3dc7 100644
*** a/src/port/copydir.c
--- b/src/port/copydir.c
***************
*** 37,42 ****
--- 37,43 ----
  
  
  static void copy_file(char *fromfile, char *tofile);
+ static void fsync_fname(char *fname);
  
  
  /*
*************** copydir(char *fromdir, char *todir, bool
*** 64,69 ****
--- 65,73 ----
  				(errcode_for_file_access(),
  				 errmsg("could not open directory \"%s\": %m", fromdir)));
  
+ 	/*
+ 	 * Copy all the files
+ 	 */
  	while ((xlde = ReadDir(xldir, fromdir)) != NULL)
  	{
  		struct stat fst;
*************** copydir(char *fromdir, char *todir, bool
*** 89,96 ****
  		else if (S_ISREG(fst.st_mode))
  			copy_file(fromfile, tofile);
  	}
- 
  	FreeDir(xldir);
  }
  
  /*
--- 93,120 ----
  		else if (S_ISREG(fst.st_mode))
  			copy_file(fromfile, tofile);
  	}
  	FreeDir(xldir);
+ 
+ 	/*
+ 	 * Be paranoid here and fsync all files to ensure we catch problems.
+ 	 */
+ 	xldir = AllocateDir(fromdir);
+ 	if (xldir == NULL)
+ 		ereport(ERROR,
+ 				(errcode_for_file_access(),
+ 				 errmsg("could not open directory \"%s\": %m", fromdir)));
+ 
+ 	while ((xlde = ReadDir(xldir, fromdir)) != NULL)
+ 	{
+ 		struct stat fst;
+ 
+ 		if (strcmp(xlde->d_name, ".") == 0 ||
+ 			strcmp(xlde->d_name, "..") == 0)
+ 			continue;
+ 
+ 		snprintf(tofile, MAXPGPATH, "%s/%s", todir, xlde->d_name);
+ 		fsync_fname(tofile);
+ 	}
  }
  
  /*
*************** copy_file(char *fromfile, char *tofile)
*** 150,162 ****
  	}
  
  	/*
! 	 * 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(),
--- 174,185 ----
  	}
  
  	/*
! 	 * We tell the kernel here to write the data back in order to make
! 	 * the later fsync cheaper.
  	 */
! #if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
! 	posix_fadvise(dstfd, 0, 0, POSIX_FADV_DONTNEED);
! #endif
  	if (close(dstfd))
  		ereport(ERROR,
  				(errcode_for_file_access(),
*************** copy_file(char *fromfile, char *tofile)
*** 166,168 ****
--- 189,212 ----
  
  	pfree(buffer);
  }
+ 
+ /*
+  * fsync a file
+  */
+ static void
+ fsync_fname(char *fname)
+ {
+ 	int	fd = BasicOpenFile(fname, O_RDWR| PG_BINARY,
+ 						  S_IRUSR | S_IWUSR);
+ 
+ 	if (fd < 0)
+ 		ereport(ERROR,
+ 				(errcode_for_file_access(),
+ 				 errmsg("could not create file \"%s\": %m", fname)));
+ 
+ 	if (pg_fsync(fd) != 0)
+ 		ereport(ERROR,
+ 				(errcode_for_file_access(),
+ 				 errmsg("could not fsync file \"%s\": %m", fname)));
+ 	close(fd);
+ }
-- 
1.6.5.12.gd65df24