smb3: do not attempt cifs operation in smb3 query info error path

BugLink: https://bugs.launchpad.net/bugs/1810947

commit 1e77a8c2 upstream.

If backupuid mount option is sent, we can incorrectly retry
(on access denied on query info) with a cifs (FindFirst) operation
on an smb3 mount which causes the server to force the session close.

We set backup intent on open so no need for this fallback.

See kernel bugzilla 201435
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/cifs/inode.c

@@ -756,7 +756,15 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
 	} else if (rc == -EREMOTE) {
 		cifs_create_dfs_fattr(&fattr, sb);
 		rc = 0;
-	} else if (rc == -EACCES && backup_cred(cifs_sb)) {
+	} else if ((rc == -EACCES) && backup_cred(cifs_sb) &&
+		   (strcmp(server->vals->version_string, SMB1_VERSION_STRING)
+		      == 0)) {
+			/*
+			 * For SMB2 and later the backup intent flag is already
+			 * sent if needed on open and there is no path based
+			 * FindFirst operation to use to retry with
+			 */
+
 			srchinf = kzalloc(sizeof(struct cifs_search_info),
 						GFP_KERNEL);
 			if (srchinf == NULL) {