svn commit: r363316 - projects/nfs-over-tls/sys/fs/nfsserver

[Rick Macklem]

Author: rmacklem
Date: Sun Jul 19 02:14:34 2020
New Revision: 363316
URL: https://svnweb.freebsd.org/changeset/base/363316

Log:
  Make sure the NFS server only generates ext_pgs mbufs when there will not
  be an m_copym() done to cache a reply.
  
  For NFSv3, the caching of a reply is based on the RPC number. For NFSv4.1
  and NFSv4.2, the Sequence operation request indicates whether or not to
  hold only a copy in the session. Normally, Read, Readdir and Getextattr
  will not need a reply copy, but this code makes sure it does not happen
  for ext_pgs mbufs.
  For NFSv4.0, it cannot use ext_pgs mbufs, since it cannot be sure that
  a cached reply copy is not created.

Modified:
  projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdport.c
  projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdserv.c

Modified: projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdport.c
==============================================================================
--- projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdport.c	Sun Jul 19 01:59:56 2020	(r363315)
+++ projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdport.c	Sun Jul 19 02:14:34 2020	(r363316)
@@ -2114,10 +2114,14 @@ again:
 	vput(vp);
 
 	/*
-	 * If the siz and cnt are larger than MCLBYTES, use ext_pgs for TLS.
+	 * If cnt > MCLBYTES and the reply will not be saved, use
+	 * ext_pgs mbufs for TLS.
+	 * For NFSv4.0, we do not know for sure if the reply will
+	 * be saved, so do not use ext_pgs mbufs for NFSv4.0.
 	 */
-	if ((nd->nd_flag & (ND_EXTPG | ND_TLS)) == ND_TLS && siz > MCLBYTES &&
-	    cnt > MCLBYTES)
+	if (cnt > MCLBYTES && siz > MCLBYTES &&
+	    (nd->nd_flag & (ND_TLS | ND_EXTPG | ND_SAVEREPLY)) == ND_TLS &&
+	    (nd->nd_flag & (ND_NFSV4 | ND_NFSV41)) != ND_NFSV4)
 		nd->nd_flag |= ND_EXTPG;
 
 	/*
@@ -2438,13 +2442,17 @@ again:
 	}
 
 	/*
-	 * If the reply is likely to exceed MCLBYTES, then use TLS.
+	 * If the reply is likely to exceed MCLBYTES and the reply will
+	 * not be saved, use ext_pgs mbufs for TLS.
 	 * It is difficult to predict how large each entry will be and
 	 * how many entries have been read, so just assume the directory
 	 * entries grow by a factor of 4 when attributes are included.
+	 * For NFSv4.0, we do not know for sure if the reply will
+	 * be saved, so do not use ext_pgs mbufs for NFSv4.0.
 	 */
-	if ((nd->nd_flag & (ND_EXTPG | ND_TLS)) == ND_TLS && cnt > MCLBYTES &&
-	    siz > MCLBYTES / 4)
+	if (cnt > MCLBYTES && siz > MCLBYTES / 4 &&
+	    (nd->nd_flag & (ND_TLS | ND_EXTPG | ND_SAVEREPLY)) == ND_TLS &&
+	    (nd->nd_flag & (ND_NFSV4 | ND_NFSV41)) != ND_NFSV4)
 		nd->nd_flag |= ND_EXTPG;
 
 	/*
@@ -6291,10 +6299,15 @@ nfsvno_getxattr(struct vnode *vp, char *name, uint32_t
 	len = siz;
 	tlen = NFSM_RNDUP(len);
 	/*
-	 * If the cnt is larger than MCLBYTES, use ext_pgs for TLS.
-	 * Always use ext_pgs if ND_EXTPG is set.
+	 * If cnt > MCLBYTES and the reply will not be saved, use
+	 * ext_pgs mbufs for TLS.
+	 * For NFSv4.0, we do not know for sure if the reply will
+	 * be saved, so do not use ext_pgs mbufs for NFSv4.0.
+	 * Always use ext_pgs mbufs if ND_EXTPG is set.
 	 */
-	if ((flag & ND_EXTPG) != 0 || ((flag & ND_TLS) != 0 && tlen > MCLBYTES))
+	if ((flag & ND_EXTPG) != 0 || (tlen > MCLBYTES &&
+	    (flag & (ND_TLS | ND_SAVEREPLY)) == ND_TLS &&
+	    (flag & (ND_NFSV4 | ND_NFSV41)) != ND_NFSV4))
 		uiop->uio_iovcnt = nfsrv_createiovec_extpgs(tlen, maxextsiz,
 		    &m, &m2, &iv);
 	else

Modified: projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdserv.c
==============================================================================
--- projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdserv.c	Sun Jul 19 01:59:56 2020	(r363315)
+++ projects/nfs-over-tls/sys/fs/nfsserver/nfs_nfsdserv.c	Sun Jul 19 02:14:34 2020	(r363316)
@@ -857,11 +857,15 @@ nfsrvd_read(struct nfsrv_descript *nd, __unused int is
 	m3 = NULL;
 	if (cnt > 0) {
 		/*
-		 * If the cnt is larger than MCLBYTES, use ext_pgs for TLS.
-		 * Always use ext_pgs if ND_EXTPG is set.
+		 * If cnt > MCLBYTES and the reply will not be saved, use
+		 * ext_pgs mbufs for TLS.
+		 * For NFSv4.0, we do not know for sure if the reply will
+		 * be saved, so do not use ext_pgs mbufs for NFSv4.0.
+		 * Always use ext_pgs mbufs if ND_EXTPG is set.
 		 */
-		if ((nd->nd_flag & ND_EXTPG) != 0 ||
-		    ((nd->nd_flag & ND_TLS) != 0 && cnt > MCLBYTES))
+		if ((nd->nd_flag & ND_EXTPG) != 0 || (cnt > MCLBYTES &&
+		    (nd->nd_flag & (ND_TLS | ND_SAVEREPLY)) == ND_TLS &&
+		    (nd->nd_flag & (ND_NFSV4 | ND_NFSV41)) != ND_NFSV4))
 			nd->nd_repstat = nfsvno_read(vp, off, cnt, nd->nd_cred,
 			    nd->nd_maxextsiz, p, &m3, &m2);
 		else