Backport "Expose fsync_fname as a public API".

Backport commit cc52d5b back to 9.1
to allow backpatching some unlogged table fixes that use fsync_fname.

Author: anarazel

src/backend/storage/file/copydir.c

@@ -38,9 +38,6 @@
 #endif
 
 
-static void fsync_fname(char *fname, bool isdir);
-
-
 /*
  * copydir: copy a directory
  *
@@ -214,59 +211,3 @@ copy_file(char *fromfile, char *tofile)
 
 	pfree(buffer);
 }
-
-
-/*
- * fsync a file
- *
- * Try to fsync directories but ignore errors that indicate the OS
- * just doesn't allow/require fsyncing directories.
- */
-static void
-fsync_fname(char *fname, bool isdir)
-{
-	int			fd;
-	int			returncode;
-
-	/*
-	 * Some OSs require directories to be opened read-only whereas other
-	 * systems don't allow us to fsync files opened read-only; so we need both
-	 * cases here
-	 */
-	if (!isdir)
-		fd = BasicOpenFile(fname,
-						   O_RDWR | PG_BINARY,
-						   S_IRUSR | S_IWUSR);
-	else
-		fd = BasicOpenFile(fname,
-						   O_RDONLY | PG_BINARY,
-						   S_IRUSR | S_IWUSR);
-
-	/*
-	 * Some OSs don't allow us to open directories at all (Windows returns
-	 * EACCES)
-	 */
-	if (fd < 0 && isdir && (errno == EISDIR || errno == EACCES))
-		return;
-
-	else if (fd < 0)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m", fname)));
-
-	returncode = pg_fsync(fd);
-
-	/* Some OSs don't allow us to fsync directories at all */
-	if (returncode != 0 && isdir && errno == EBADF)
-	{
-		close(fd);
-		return;
-	}
-
-	if (returncode != 0)
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not fsync file \"%s\": %m", fname)));
-
-	close(fd);
-}

src/backend/storage/file/fd.c

@@ -345,6 +345,62 @@ pg_flush_data(int fd, off_t offset, off_t amount)
 }
 
 
+/*
+ * fsync_fname -- fsync a file or directory, handling errors properly
+ *
+ * Try to fsync a file or directory. When doing the latter, ignore errors that
+ * indicate the OS just doesn't allow/require fsyncing directories.
+ */
+void
+fsync_fname(char *fname, bool isdir)
+{
+	int			fd;
+	int			returncode;
+
+	/*
+	 * Some OSs require directories to be opened read-only whereas other
+	 * systems don't allow us to fsync files opened read-only; so we need both
+	 * cases here
+	 */
+	if (!isdir)
+		fd = BasicOpenFile(fname,
+						   O_RDWR | PG_BINARY,
+						   S_IRUSR | S_IWUSR);
+	else
+		fd = BasicOpenFile(fname,
+						   O_RDONLY | PG_BINARY,
+						   S_IRUSR | S_IWUSR);
+
+	/*
+	 * Some OSs don't allow us to open directories at all (Windows returns
+	 * EACCES)
+	 */
+	if (fd < 0 && isdir && (errno == EISDIR || errno == EACCES))
+		return;
+
+	else if (fd < 0)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not open file \"%s\": %m", fname)));
+
+	returncode = pg_fsync(fd);
+
+	/* Some OSs don't allow us to fsync directories at all */
+	if (returncode != 0 && isdir && errno == EBADF)
+	{
+		close(fd);
+		return;
+	}
+
+	if (returncode != 0)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not fsync file \"%s\": %m", fname)));
+
+	close(fd);
+}
+
+
 /*
  * InitFileAccess --- initialize this module during backend startup
  *

src/include/storage/fd.h

@@ -99,6 +99,7 @@ extern int	pg_fsync_no_writethrough(int fd);
 extern int	pg_fsync_writethrough(int fd);
 extern int	pg_fdatasync(int fd);
 extern int	pg_flush_data(int fd, off_t offset, off_t amount);
+extern void fsync_fname(char *fname, bool isdir);
 
 /* Filename components for OpenTemporaryFile */
 #define PG_TEMP_FILES_DIR "pgsql_tmp"