X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/blobdiff_plain/6f83ced90ea75526068ff4fbb95caabc32a7a3d8..3bf6fec386b09ee8846e7093b18975148d9da2cc:/sys/vfs/nfs/nfs_socket.c

diff --git a/sys/vfs/nfs/nfs_socket.c b/sys/vfs/nfs/nfs_socket.c
index 294f627419..c241c3cead 100644
--- a/sys/vfs/nfs/nfs_socket.c
+++ b/sys/vfs/nfs/nfs_socket.c
@@ -1240,7 +1240,7 @@ nfs_request_try(struct nfsreq *rep)
 	 * action possible is for r_mrep to be set (once we enqueue it).
 	 */
 	if (rep->r_flags == 0xdeadc0de) {
-		print_backtrace();
+		print_backtrace(-1);
 		panic("flags nbad\n");
 	}
 	KKASSERT((rep->r_flags & (R_LOCKED | R_ONREQQ)) == 0);
@@ -2153,49 +2153,48 @@ nfs_rcvunlock(struct nfsmount *nmp)
 }
 
 /*
- *	nfs_realign:
+ * nfs_realign:
  *
- *	Check for badly aligned mbuf data and realign by copying the unaligned
- *	portion of the data into a new mbuf chain and freeing the portions
- *	of the old chain that were replaced.
+ * Check for badly aligned mbuf data and realign by copying the unaligned
+ * portion of the data into a new mbuf chain and freeing the portions
+ * of the old chain that were replaced.
  *
- *	We cannot simply realign the data within the existing mbuf chain
- *	because the underlying buffers may contain other rpc commands and
- *	we cannot afford to overwrite them.
+ * We cannot simply realign the data within the existing mbuf chain
+ * because the underlying buffers may contain other rpc commands and
+ * we cannot afford to overwrite them.
  *
- *	We would prefer to avoid this situation entirely.  The situation does
- *	not occur with NFS/UDP and is supposed to only occassionally occur
- *	with TCP.  Use vfs.nfs.realign_count and realign_test to check this.
+ * We would prefer to avoid this situation entirely.  The situation does
+ * not occur with NFS/UDP and is supposed to only occassionally occur
+ * with TCP.  Use vfs.nfs.realign_count and realign_test to check this.
+ *
+ * NOTE!  MB_DONTWAIT cannot be used here.  The mbufs must be acquired
+ *	  because the rpc request OR reply cannot be thrown away.  TCP NFS
+ *	  mounts do not retry their RPCs unless the TCP connection itself
+ *	  is dropped so throwing away a RPC will basically cause the NFS
+ *	  operation to lockup indefinitely.
  */
 static void
 nfs_realign(struct mbuf **pm, int hsiz)
 {
 	struct mbuf *m;
 	struct mbuf *n = NULL;
-	int off = 0;
 
+	/*
+	 * Check for misalignemnt
+	 */
 	++nfs_realign_test;
-
 	while ((m = *pm) != NULL) {
-		if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
-			n = m_getl(m->m_len, MB_WAIT, MT_DATA, 0, NULL);
-			n->m_len = 0;
+		if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3))
 			break;
-		}
 		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 misalignment found make a completely new copy.
 	 */
-	if (n != NULL) {
+	if (m) {
 		++nfs_realign_count;
-		while (m) {
-			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
-			off += m->m_len;
-			m = m->m_next;
-		}
+		n = m_dup_data(m, MB_WAIT);
 		m_freem(*pm);
 		*pm = n;
 	}