Back out nfs_realign() change, it causes "pool_get: must have NOWAIT" panics.

deraadt@ OK

1 files changed, 86 insertions, 36 deletions

diff --git a/sys/nfs/nfs_socket.c b/sys/nfs/nfs_socket.c
index fb12bf9258b..2f5a353eab9 100644
--- a/sys/nfs/nfs_socket.c
+++ b/sys/nfs/nfs_socket.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_socket.c,v 1.25 2002/04/10 18:16:46 csapuntz Exp $	*/
+/*	$OpenBSD: nfs_socket.c,v 1.26 2002/04/11 18:44:24 millert Exp $	*/
 /*	$NetBSD: nfs_socket.c,v 1.27 1996/04/15 20:20:00 thorpej Exp $	*/
 
 /*
@@ -136,9 +136,7 @@ static int nfs_backoff[8] = { 2, 4, 8, 16, 32, 64, 128, 256, };
 int nfsrtton = 0;
 struct nfsrtt nfsrtt;
 
-void nfs_realign(struct mbuf **, int);
-unsigned int nfs_realign_test = 0;
-unsigned int nfs_realign_count = 0;
+void nfs_realign(struct mbuf *, int);
 
 /*
  * Initialize sockets and congestion for a new NFS connection.
@@ -532,7 +530,6 @@ tryagain:
 			}
 			if (error)
 				goto errout;
-
 			len = ntohl(len) & ~0x80000000;
 			/*
 			 * This is SERIOUS! We are out of sync with the sender
@@ -633,7 +630,7 @@ errout:
 	 * These could cause pointer alignment problems, so copy them to
 	 * well aligned mbufs.
 	 */
-	nfs_realign(mp, 5 * NFSX_UNSIGNED);
+	nfs_realign(*mp, 5 * NFSX_UNSIGNED);
 	return (error);
 }
 
@@ -1445,44 +1442,97 @@ nfs_rcvunlock(flagp)
 }
 
 /*
- *  NFS parsing code requires 32-bit alignment
+ * Check for badly aligned mbuf data areas and
+ * realign data in an mbuf list by copying the data areas up, as required.
  */
 void
-nfs_realign(struct mbuf **pm, int hsiz)
-{
+nfs_realign(m, hsiz)
 	struct mbuf *m;
-	struct mbuf *n = NULL;
-	int off = 0;
-
-	++nfs_realign_test;
-	while ((m = *pm) != NULL) {
-		if ((m->m_len & 0x3) || (mtod(m, long) & 0x3)) {
-			MGET(n, M_WAIT, MT_DATA);
-			if (m->m_len >= MINCLSIZE) {
-				MCLGET(n, M_WAIT);
-			}
-			n->m_len = 0;
-			break;
+	int hsiz;
+{
+	struct mbuf *m2;
+	int siz, mlen, olen;
+	caddr_t tcp, fcp;
+	struct mbuf *mnew;
+
+	while (m) {
+	    /*
+	     * This never happens for UDP, rarely happens for TCP
+	     * but frequently happens for iso transport.
+	     */
+	    if ((m->m_len & 0x3) || (mtod(m, long) & 0x3)) {
+		olen = m->m_len;
+		fcp = mtod(m, caddr_t);
+		if ((long)fcp & 0x3) {
+		        if (m->m_flags & M_PKTHDR)
+				m_tag_delete_chain(m, NULL);
+			m->m_flags &= ~M_PKTHDR;
+			if (m->m_flags & M_EXT)
+				m->m_data = m->m_ext.ext_buf +
+					((m->m_ext.ext_size - olen) & ~0x3);
+			else
+				m->m_data = m->m_dat;
 		}
-		pm = &m->m_next;
-	}
-	/*
-	 * If n is non-NULL, loop on m copying data, then replace the
-	 * portion of the chain that had to be realigned.
-	 */
-	if (n != NULL) {
-		++nfs_realign_count;
+		m->m_len = 0;
+		tcp = mtod(m, caddr_t);
+		mnew = m;
+		m2 = m->m_next;
+	
+		/*
+		 * If possible, only put the first invariant part
+		 * of the RPC header in the first mbuf.
+		 */
+		mlen = M_TRAILINGSPACE(m);
+		if (olen <= hsiz && mlen > hsiz)
+			mlen = hsiz;
+	
+		/* Loop through the mbuf list consolidating data. */
 		while (m) {
-			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
-			off += m->m_len;
+			while (olen > 0) {
+				if (mlen == 0) {
+				        if (m2->m_flags & M_PKTHDR)
+						m_tag_delete_chain(m2, NULL);
+					m2->m_flags &= ~M_PKTHDR;
+					if (m2->m_flags & M_EXT)
+						m2->m_data = m2->m_ext.ext_buf;
+					else
+						m2->m_data = m2->m_dat;
+					m2->m_len = 0;
+					mlen = M_TRAILINGSPACE(m2);
+					tcp = mtod(m2, caddr_t);
+					mnew = m2;
+					m2 = m2->m_next;
+				}
+				siz = min(mlen, olen);
+				if (tcp != fcp)
+					bcopy(fcp, tcp, siz);
+				mnew->m_len += siz;
+				mlen -= siz;
+				olen -= siz;
+				tcp += siz;
+				fcp += siz;
+			}
 			m = m->m_next;
+			if (m) {
+				olen = m->m_len;
+				fcp = mtod(m, caddr_t);
+			}
 		}
-		m_freem(*pm);
-		*pm = n;
+	
+		/*
+		 * Finally, set m_len == 0 for any trailing mbufs that have
+		 * been copied out of.
+		 */
+		while (m2) {
+			m2->m_len = 0;
+			m2 = m2->m_next;
+		}
+		return;
+	    }
+	    m = m->m_next;
 	}
 }
 
-
 /*
  * Parse an RPC request
  * - verify it
@@ -1837,7 +1887,7 @@ nfsrv_rcv(so, arg, waitflag)
 			error = soreceive(so, &nam, &auio, &mp,
 						(struct mbuf **)0, &flags);
 			if (mp) {
-				nfs_realign(&mp, 10 * NFSX_UNSIGNED);
+				nfs_realign(mp, 10 * NFSX_UNSIGNED);
 				if (nam) {
 					m = nam;
 					m->m_next = mp;
@@ -1981,7 +2031,7 @@ nfsrv_getstream(slp, waitflag)
 		mpp = &((*mpp)->m_next);
 	    *mpp = recm;
 	    if (slp->ns_flag & SLP_LASTFRAG) {
-		nfs_realign(&slp->ns_frag, 10 * NFSX_UNSIGNED);
+		nfs_realign(slp->ns_frag, 10 * NFSX_UNSIGNED);
 		if (slp->ns_recend)
 		    slp->ns_recend->m_nextpkt = slp->ns_frag;
 		else