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 65e46483a44bce571c01b609f76a71e610b65294..8ae13a51ec1ae32e59f2d19d55f25f73727e8563 100644 (file)
--- 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;
 }