new helpers: no_seek_end_llseek{,_size}()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/s390/char/vmur.c

@@ -782,24 +782,11 @@ static int ur_release(struct inode *inode, struct file *file)
 
 static loff_t ur_llseek(struct file *file, loff_t offset, int whence)
 {
-	loff_t newpos;
-
 	if ((file->f_flags & O_ACCMODE) != O_RDONLY)
 		return -ESPIPE; /* seek allowed only for reader */
 	if (offset % PAGE_SIZE)
 		return -ESPIPE; /* only multiples of 4K allowed */
-	switch (whence) {
-	case 0: /* SEEK_SET */
-		newpos = offset;
-		break;
-	case 1: /* SEEK_CUR */
-		newpos = file->f_pos + offset;
-		break;
-	default:
-		return -EINVAL;
-	}
-	file->f_pos = newpos;
-	return newpos;
+	return no_seek_end_llseek(file, offset, whence);
 }
 
 static const struct file_operations ur_fops = {

drivers/s390/char/zcore.c

@@ -385,18 +385,7 @@ static loff_t zcore_lseek(struct file *file, loff_t offset, int orig)
 	loff_t rc;
 
 	mutex_lock(&zcore_mutex);
-	switch (orig) {
-	case 0:
-		file->f_pos = offset;
-		rc = file->f_pos;
-		break;
-	case 1:
-		file->f_pos += offset;
-		rc = file->f_pos;
-		break;
-	default:
-		rc = -EINVAL;
-	}
+	rc = no_seek_end_llseek(file, offset, orig);
 	mutex_unlock(&zcore_mutex);
 	return rc;
 }