svn commit: r363001 - head/sys/fs/nfsclient

[Rick Macklem]

Author: rmacklem
Date: Wed Jul  8 02:28:08 2020
New Revision: 363001
URL: https://svnweb.freebsd.org/changeset/base/363001

Log:
  Add support for ext_pgs mbufs to nfsm_uiombuf().
  
  This patch uses a slightly different algorithm for the non-ext_pgs case,
  where a variable called "mcp" is maintained, pointing to the current
  location that mbuf data can be filled into. This avoids use of
  mtod(mp, char *) + mp->m_len to calculate the location, since this does
  not work for ext_pgs mbufs and I think it makes the algorithm more readable.
  This change should not result in semantic changes for the non-ext_pgs case.
  
  This is another in the series of commits that add support to the NFS client
  and server for building RPC messages in ext_pgs mbufs with anonymous pages.
  This is useful so that the entire mbuf list does not need to be
  copied before calling sosend() when NFS over TLS is enabled.
  
  Since ND_EXTPG is never set yet, there is no semantic change at this time.

Modified:
  head/sys/fs/nfsclient/nfs_clcomsubs.c

Modified: head/sys/fs/nfsclient/nfs_clcomsubs.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clcomsubs.c	Wed Jul  8 01:47:20 2020	(r363000)
+++ head/sys/fs/nfsclient/nfs_clcomsubs.c	Wed Jul  8 02:28:08 2020	(r363001)
@@ -62,7 +62,7 @@ nfsm_uiombuf(struct nfsrv_descript *nd, struct uio *ui
 	struct mbuf *mp, *mp2;
 	int xfer, left, mlen;
 	int uiosiz, clflg, rem;
-	char *cp, *tcp;
+	char *mcp, *tcp;
 
 	KASSERT(uiop->uio_iovcnt == 1, ("nfsm_uiotombuf: iovcnt != 1"));
 
@@ -72,41 +72,52 @@ nfsm_uiombuf(struct nfsrv_descript *nd, struct uio *ui
 		clflg = 0;
 	rem = NFSM_RNDUP(siz) - siz;
 	mp = mp2 = nd->nd_mb;
+	mcp = nd->nd_bpos;
 	while (siz > 0) {
+		KASSERT((nd->nd_flag & ND_EXTPG) != 0 || mcp ==
+		    mtod(mp, char *) + mp->m_len, ("nfsm_uiombuf: mcp wrong"));
 		left = uiop->uio_iov->iov_len;
 		uiocp = uiop->uio_iov->iov_base;
 		if (left > siz)
 			left = siz;
 		uiosiz = left;
 		while (left > 0) {
-			mlen = M_TRAILINGSPACE(mp);
-			if (mlen == 0) {
-				if (clflg)
-					NFSMCLGET(mp, M_WAITOK);
-				else
-					NFSMGET(mp);
-				mp->m_len = 0;
-				mp2->m_next = mp;
-				mp2 = mp;
+			if ((nd->nd_flag & ND_EXTPG) != 0)
+				mlen = nd->nd_bextpgsiz;
+			else
 				mlen = M_TRAILINGSPACE(mp);
+			if (mlen == 0) {
+				if ((nd->nd_flag & ND_EXTPG) != 0) {
+					mp = nfsm_add_ext_pgs(mp,
+					    nd->nd_maxextsiz, &nd->nd_bextpg);
+					mcp = (char *)(void *)PHYS_TO_DMAP(
+					  mp->m_epg_pa[nd->nd_bextpg]);
+					nd->nd_bextpgsiz = PAGE_SIZE;
+				} else {
+					if (clflg)
+						NFSMCLGET(mp, M_WAITOK);
+					else
+						NFSMGET(mp);
+					mp->m_len = 0;
+					mlen = M_TRAILINGSPACE(mp);
+					mcp = mtod(mp, char *);
+					mp2->m_next = mp;
+					mp2 = mp;
+				}
 			}
 			xfer = (left > mlen) ? mlen : left;
-#ifdef notdef
-			/* Not Yet.. */
-			if (uiop->uio_iov->iov_op != NULL)
-				(*(uiop->uio_iov->iov_op))
-				(uiocp, mtod(mp, caddr_t) + mp->m_len,
-				    xfer);
-			else
-#endif
 			if (uiop->uio_segflg == UIO_SYSSPACE)
-			    NFSBCOPY(uiocp, mtod(mp, caddr_t) + mp->m_len,
-				xfer);
+				NFSBCOPY(uiocp, mcp, xfer);
 			else
-			    copyin(uiocp, mtod(mp, caddr_t) + mp->m_len, xfer);
+				copyin(uiocp, mcp, xfer);
 			mp->m_len += xfer;
 			left -= xfer;
 			uiocp += xfer;
+			mcp += xfer;
+			if ((nd->nd_flag & ND_EXTPG) != 0) {
+				nd->nd_bextpgsiz -= xfer;
+				mp->m_epg_last_len += xfer;
+			}
 			uiop->uio_offset += xfer;
 			uiop->uio_resid -= xfer;
 		}
@@ -117,18 +128,30 @@ nfsm_uiombuf(struct nfsrv_descript *nd, struct uio *ui
 		siz -= uiosiz;
 	}
 	if (rem > 0) {
-		if (rem > M_TRAILINGSPACE(mp)) {
+		if ((nd->nd_flag & ND_EXTPG) == 0 && rem >
+		    M_TRAILINGSPACE(mp)) {
 			NFSMGET(mp);
 			mp->m_len = 0;
 			mp2->m_next = mp;
+			mcp = mtod(mp, char *);
+		} else if ((nd->nd_flag & ND_EXTPG) != 0 && rem >
+		    nd->nd_bextpgsiz) {
+			mp = nfsm_add_ext_pgs(mp, nd->nd_maxextsiz,
+			    &nd->nd_bextpg);
+			mcp = (char *)(void *)
+			    PHYS_TO_DMAP(mp->m_epg_pa[nd->nd_bextpg]);
+			nd->nd_bextpgsiz = PAGE_SIZE;
 		}
-		cp = mtod(mp, caddr_t) + mp->m_len;
 		for (left = 0; left < rem; left++)
-			*cp++ = '\0';
+			*mcp++ = '\0';
 		mp->m_len += rem;
-		nd->nd_bpos = cp;
+		nd->nd_bpos = mcp;
+		if ((nd->nd_flag & ND_EXTPG) != 0) {
+			nd->nd_bextpgsiz -= rem;
+			mp->m_epg_last_len += rem;
+		}
 	} else
-		nd->nd_bpos = mtod(mp, caddr_t) + mp->m_len;
+		nd->nd_bpos = mcp;
 	nd->nd_mb = mp;
 }