Index: bpf.c
===================================================================
RCS file: /cvs/src/sys/net/bpf.c,v
retrieving revision 1.202
diff -u -p -r1.202 bpf.c
--- bpf.c	17 Jan 2021 02:27:29 -0000	1.202
+++ bpf.c	19 Jan 2021 00:10:22 -0000
@@ -379,7 +379,6 @@ bpfopen(dev_t dev, int flag, int mode, s
 	sigio_init(&bd->bd_sigio);
 
 	bd->bd_rtout = 0;	/* no timeout by default */
-	bd->bd_rnonblock = ISSET(flag, FNONBLOCK);
 
 	bpf_get(bd);
 	LIST_INSERT_HEAD(&bpf_d_list, bd, bd_list);
@@ -497,7 +496,7 @@ bpfread(dev_t dev, struct uio *uio, int 
 			ROTATE_BUFFERS(d);
 			break;
 		}
-		if (d->bd_rnonblock) {
+		if (ISSET(ioflag, IO_NDELAY)) {
 			/* User requested non-blocking I/O */
 			error = EWOULDBLOCK;
 		} else if (d->bd_rtout == 0) {
@@ -982,10 +981,7 @@ bpfioctl(dev_t dev, u_long cmd, caddr_t 
 		break;
 
 	case FIONBIO:		/* Non-blocking I/O */
-		if (*(int *)addr)
-			d->bd_rnonblock = 1;
-		else
-			d->bd_rnonblock = 0;
+		/* let vfs to keep track of this */
 		break;
 
 	case FIOASYNC:		/* Send signal on receive packets */
Index: bpfdesc.h
===================================================================
RCS file: /cvs/src/sys/net/bpfdesc.h,v
retrieving revision 1.44
diff -u -p -r1.44 bpfdesc.h
--- bpfdesc.h	2 Jan 2021 02:46:06 -0000	1.44
+++ bpfdesc.h	19 Jan 2021 00:10:22 -0000
@@ -80,7 +80,6 @@ struct bpf_d {
 	struct bpf_if  *bd_bif;		/* interface descriptor */
 	uint64_t	bd_rtout;	/* [m] Read timeout in nanoseconds */
 	u_long		bd_nreaders;	/* [m] # threads asleep in bpfread() */
-	int		bd_rnonblock;	/* true if nonblocking reads are set */
 	struct bpf_program_smr
 		       *bd_rfilter;	/* read filter code */
 	struct bpf_program_smr