staging: usbip: userspace: suppress a bogus error

If mkdir() of VHCI_STATE_PATH fails because the directory
already exists, that's not an error. This patch fixes
annoying "record connection" errors that would typically
come up on attach.
Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Acked-by: David Chang <dchang@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/usbip/userspace/src/usbip_attach.c

@@ -27,6 +27,7 @@
 #include <fcntl.h>
 #include <getopt.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "vhci_driver.h"
 #include "usbip_common.h"
@@ -52,8 +53,18 @@ static int record_connection(char *host, char *port, char *busid, int rhport)
 	int ret;
 
 	ret = mkdir(VHCI_STATE_PATH, 0700);
-	if (ret < 0)
-		return -1;
+	if (ret < 0) {
+		/* if VHCI_STATE_PATH exists, then it better be a directory */
+		if (errno == EEXIST) {
+			struct stat s;
+			ret = stat(VHCI_STATE_PATH, &s);
+			if (ret < 0)
+				return -1;
+			if (!(s.st_mode & S_IFDIR))
+				return -1;
+		} else
+			return -1;
+	}
 
 	snprintf(path, PATH_MAX, VHCI_STATE_PATH"/port%d", rhport);