Revert "floppy: refactor open() flags handling"

This reverts commit 09954bad.

drivers/block/floppy.c

@@ -3663,11 +3663,6 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 
 	opened_bdev[drive] = bdev;
 
-	if (!(mode & (FMODE_READ|FMODE_WRITE))) {
-		res = -EINVAL;
-		goto out;
-	}
-
 	res = -ENXIO;
 
 	if (!floppy_track_buffer) {
@@ -3711,6 +3706,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 	if (UFDCS->rawcmd == 1)
 		UFDCS->rawcmd = 2;
 
+	if (!(mode & FMODE_NDELAY)) {
+		if (mode & (FMODE_READ|FMODE_WRITE)) {
 			UDRS->last_checked = 0;
 			clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
 			check_disk_change(bdev);
@@ -3718,13 +3715,12 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 				goto out;
 			if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags))
 				goto out;
-
+		}
 		res = -EROFS;
-
 		if ((mode & FMODE_WRITE) &&
 		    !test_bit(FD_DISK_WRITABLE_BIT, &UDRS->flags))
 			goto out;
-
+	}
 	mutex_unlock(&open_lock);
 	mutex_unlock(&floppy_mutex);
 	return 0;