From: Andres Freund <andres@anarazel.de>
Date: Mon, 21 May 2018 22:43:30 +0000 (-0700)
Subject: Make FileGetRawDesc() ensure there's an associated kernel FD.
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=87a6fa9b8d478504b0a4323a3e104b353a239f1a;p=users%2Fandresfreund%2Fpostgres.git

Make FileGetRawDesc() ensure there's an associated kernel FD.

Author: Andres Freund
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:
---

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 65e46483a4..8ae13a51ec 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -2232,6 +2232,10 @@ int
 FileGetRawDesc(File file)
 {
 	Assert(FileIsValid(file));
+
+	if (FileAccess(file))
+		return -1;
+
 	return VfdCache[file].fd;
 }