shithub: riscv

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ref: 857f2528e0b014b6bd839535daaa6b53853703d9
parent: ea993877a96cd535199d0cd437e49f8d616615d9
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Mon Nov 7 17:05:29 EST 2016 

ip: always pass a single block to Medium.bwrite(), avoid concatblock() calls in Dev.bwrite()

the convention for Dev.bwrite() is that it accepts a *single* block,
and not a block chain. so we never have concatblock here.

to keep stuff consistent, we also guarantee thet Medium.bwrite()
will get a *single* block passed as well, as the callers are
few in number.


--- a/sys/src/9/ip/arp.c
+++ b/sys/src/9/ip/arp.c
@@ -375,7 +375,7 @@
 				}
 				rlock(ifc);
 				if(ifc->m != nil)
-					ifc->m->bwrite(ifc, bp, version, ip);
+					ifc->m->bwrite(ifc, concatblock(bp), version, ip);
 				else
 					freeblist(bp);
 				runlock(ifc);
--- a/sys/src/9/ip/devip.c
+++ b/sys/src/9/ip/devip.c
@@ -1195,9 +1195,6 @@
 		if(c->wq == nil)
 			error(Eperm);
 
-		if(bp->next)
-			bp = concatblock(bp);
-		
 		return qbwrite(c->wq, bp);
 	default:
 		return devbwrite(ch, bp, offset);
--- a/sys/src/9/ip/ethermedium.c
+++ b/sys/src/9/ip/ethermedium.c
@@ -298,8 +298,6 @@
 
 	/* make it a single block with space for the ether header */
 	bp = padblock(bp, ifc->m->hsize);
-	if(bp->next)
-		bp = concatblock(bp);
 	if(BLEN(bp) < ifc->mintu)
 		bp = adjustblock(bp, ifc->mintu);
 	eh = (Etherhdr*)bp->rp;
--- a/sys/src/9/ip/ip.c
+++ b/sys/src/9/ip/ip.c
@@ -208,7 +208,7 @@
 		eh->cksum[0] = 0;
 		eh->cksum[1] = 0;
 		hnputs(eh->cksum, ipcsum(&eh->vihl));
-		ifc->m->bwrite(ifc, bp, V4, gate);
+		ifc->m->bwrite(ifc, concatblock(bp), V4, gate);
 		runlock(ifc);
 		poperror();
 		return 0;
@@ -240,7 +240,7 @@
 		lid = incref(&ip->id4);
 
 	offset = IP4HDR;
-	while(xp != nil && offset && offset >= BLEN(xp)) {
+	while(offset && offset >= BLEN(xp)) {
 		offset -= BLEN(xp);
 		xp = xp->next;
 	}
--- a/sys/src/9/ip/ipv6.c
+++ b/sys/src/9/ip/ipv6.c
@@ -118,7 +118,7 @@
 	medialen = ifc->maxtu - ifc->m->hsize;
 	if(len <= medialen) {
 		hnputs(eh->ploadlen, len - IP6HDR);
-		ifc->m->bwrite(ifc, bp, V6, gate);
+		ifc->m->bwrite(ifc, concatblock(bp), V6, gate);
 		runlock(ifc);
 		poperror();
 		return 0;
@@ -161,7 +161,7 @@
 
 	xp = bp;
 	offset = uflen;
-	while (xp && offset && offset >= BLEN(xp)) {
+	while (offset && offset >= BLEN(xp)) {
 		offset -= BLEN(xp);
 		xp = xp->next;
 	}
--- a/sys/src/9/ip/netdevmedium.c
+++ b/sys/src/9/ip/netdevmedium.c
@@ -86,8 +86,6 @@
 {
 	Netdevrock *er = ifc->arg;
 
-	if(bp->next)
-		bp = concatblock(bp);
 	if(BLEN(bp) < ifc->mintu)
 		bp = adjustblock(bp, ifc->mintu);
 
--- a/sys/src/9/ip/pktmedium.c
+++ b/sys/src/9/ip/pktmedium.c
@@ -51,7 +51,6 @@
 pktbwrite(Ipifc *ifc, Block *bp, int, uchar*)
 {
 	/* enqueue onto the conversation's rq */
-	bp = concatblock(bp);
 	if(ifc->conv->snoopers.ref > 0)
 		qpass(ifc->conv->sq, copyblock(bp, BLEN(bp)));
 	qpass(ifc->conv->rq, bp);