Tolerate EINVAL when calling fsync() on a directory.

Previously, we tolerated EBADF as a way for the operating system to
indicate that it doesn't support fsync() on a directory.  Tolerate
EINVAL too, for older versions of Linux CIFS.

Bug #15636.  Back-patch all the way.

Reported-by: John Klann
Discussion: https://postgr.es/m/15636-d380890dafd78fc6@postgresql.org

src/backend/storage/file/fd.c

@@ -3379,7 +3379,7 @@ fsync_fname_ext(const char *fname, bool isdir, bool ignore_perm, int elevel)
 	 * Some OSes don't allow us to fsync directories at all, so we can ignore
 	 * those errors. Anything else needs to be logged.
 	 */
-	if (returncode != 0 && !(isdir && errno == EBADF))
+	if (returncode != 0 && !(isdir && (errno == EBADF || errno == EINVAL)))
 	{
 		int			save_errno;
 

src/common/file_utils.c

@@ -299,7 +299,7 @@ fsync_fname(const char *fname, bool isdir, const char *progname)
 	 * Some OSes don't allow us to fsync directories at all, so we can ignore
 	 * those errors. Anything else needs to be reported.
 	 */
-	if (returncode != 0 && !(isdir && errno == EBADF))
+	if (returncode != 0 && !(isdir && (errno == EBADF || errno == EINVAL)))
 	{
 		fprintf(stderr, _("%s: could not fsync file \"%s\": %s\n"),
 				progname, fname, strerror(errno));