ovl: remove redundant IOCB_DIO_CALLER_COMP clearing

The backing_file_write_iter() function, which is called
immediately after this code, already contains identical
logic to clear the IOCB_DIO_CALLER_COMP flag along with
the same explanatory comment. There is no need to duplicate
this operation in the overlayfs code.

Signed-off-by: Seong-Gwang Heo <heo@mykernel.net>
Fixes: a6293b3 ("fs: factor out backing_file_{read,write}_iter() helpers")
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: seong-gwang-heo

fs/overlayfs/file.c

@@ -369,11 +369,6 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 	if (!ovl_should_sync(OVL_FS(inode->i_sb)))
 		ifl &= ~(IOCB_DSYNC | IOCB_SYNC);
 
-	/*
-	 * Overlayfs doesn't support deferred completions, don't copy
-	 * this property in case it is set by the issuer.
-	 */
-	ifl &= ~IOCB_DIO_CALLER_COMP;
 	ret = backing_file_write_iter(realfile, iter, iocb, ifl, &ctx);
 
 out_unlock: