svn commit: r358040 - in projects/nfs-over-tls/sys: kern sys

[Rick Macklem]

Author: rmacklem
Date: Mon Feb 17 20:09:06 2020
New Revision: 358040
URL: https://svnweb.freebsd.org/changeset/base/358040

Log:
  Add two functions to kern_mbuf.c used by the RPC-over-TLS to
  copy a list of regular mbuf(s) to a list of ext_pgs ones.
  If these are not considered generic enough, they can easily
  be moved to the krpc sources and renamed.

Modified:
  projects/nfs-over-tls/sys/kern/kern_mbuf.c
  projects/nfs-over-tls/sys/sys/mbuf.h

Modified: projects/nfs-over-tls/sys/kern/kern_mbuf.c
==============================================================================
--- projects/nfs-over-tls/sys/kern/kern_mbuf.c	Mon Feb 17 20:02:14 2020	(r358039)
+++ projects/nfs-over-tls/sys/kern/kern_mbuf.c	Mon Feb 17 20:09:06 2020	(r358040)
@@ -60,6 +60,7 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_extern.h>
 #include <vm/vm_kern.h>
 #include <vm/vm_page.h>
+#include <vm/vm_pageout.h>
 #include <vm/vm_map.h>
 #include <vm/uma.h>
 #include <vm/uma_dbg.h>
@@ -1592,4 +1593,107 @@ m_snd_tag_destroy(struct m_snd_tag *mst)
 	ifp->if_snd_tag_free(mst);
 	if_rele(ifp);
 	counter_u64_add(snd_tag_count, -1);
+}
+
+/*
+ * Allocate an mbuf with anonymous external pages.
+ */
+struct mbuf *
+mb_alloc_ext_plus_pages(int len, int how, bool pkthdr, m_ext_free_t ext_free)
+{
+	struct mbuf *m;
+	vm_page_t pg;
+	int i, npgs;
+
+	m = mb_alloc_ext_pgs(how, pkthdr, ext_free);
+	if (m == NULL)
+		return (NULL);
+	m->m_ext.ext_pgs->flags |= MBUF_PEXT_FLAG_ANON;
+	npgs = howmany(len, PAGE_SIZE);
+	for (i = 0; i < npgs; i++) {
+		do {
+			pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
+			    VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP | VM_ALLOC_WIRED);
+			if (pg == NULL) {
+				if (how == M_NOWAIT) {
+					m->m_ext.ext_pgs->npgs = i;
+					m_free(m);
+					return (NULL);
+				}
+				vm_wait(NULL);
+			}
+		} while (pg == NULL);
+		m->m_ext.ext_pgs->pa[i] = VM_PAGE_TO_PHYS(pg);
+	}
+	m->m_ext.ext_pgs->npgs = npgs;
+	return (m);
+}
+
+/*
+ * Copy the data in the mbuf chain to a chain of mbufs with external pages.
+ * len is the length of data in the input mbuf chain.
+ * mlen is the maximum number of bytes put into each ext_page mbuf.
+ */
+struct mbuf *
+mb_copym_ext_pgs(struct mbuf *mp, int len, int mlen, int how, bool pkthdr,
+    m_ext_free_t ext_free, struct mbuf **mlast)
+{
+	struct mbuf *m, *mout = NULL;
+	char *pgpos = NULL, *mbpos;
+	int i = 0, mblen, mbufsiz, pglen, xfer;
+
+	if (len == 0)
+		return (NULL);
+	m = NULL;
+	pglen = mblen = 0;
+	do {
+		if (pglen == 0) {
+			if (m == NULL || ++i == m->m_ext.ext_pgs->npgs) {
+				mbufsiz = min(mlen, len);
+				if (m == NULL) {
+					m = mout = mb_alloc_ext_plus_pages(
+					    mbufsiz, how, pkthdr, ext_free);
+					if (m == NULL)
+						return (m);
+					if (pkthdr)
+						m->m_pkthdr.len = len;
+				} else {
+					m->m_ext.ext_pgs->last_pg_len =
+					    PAGE_SIZE;
+					m->m_next = mb_alloc_ext_plus_pages(
+					    mbufsiz, how, false, ext_free);
+					m = m->m_next;
+					if (m == NULL) {
+						m_freem(mout);
+						return (m);
+					}
+				}
+				i = 0;
+			}
+			pgpos = (char *)(void *)
+			    PHYS_TO_DMAP(m->m_ext.ext_pgs->pa[i]);
+			pglen = PAGE_SIZE;
+		}
+		while (mblen == 0) {
+			if (mp == NULL) {
+				m_freem(mout);
+				return (NULL);
+			}
+			mbpos = mtod(mp, char *);
+			mblen = mp->m_len;
+			mp = mp->m_next;
+		}
+		xfer = min(mblen, pglen);
+		bcopy(mbpos, pgpos, xfer);
+		pgpos += xfer;
+		mbpos += xfer;
+		pglen -= xfer;
+		mblen -= xfer;
+		len -= xfer;
+		m->m_len += xfer;
+	} while (len > 0);
+	m->m_ext.ext_pgs->last_pg_len = PAGE_SIZE - pglen;
+	if (mlast != NULL)
+		*mlast = m;
+	return (mout);
 }

Modified: projects/nfs-over-tls/sys/sys/mbuf.h
==============================================================================
--- projects/nfs-over-tls/sys/sys/mbuf.h	Mon Feb 17 20:02:14 2020	(r358039)
+++ projects/nfs-over-tls/sys/sys/mbuf.h	Mon Feb 17 20:09:06 2020	(r358040)
@@ -700,6 +700,9 @@ void		 mb_dupcl(struct mbuf *, struct mbuf *);
 void		 mb_free_ext(struct mbuf *);
 void		 mb_free_mext_pgs(struct mbuf *);
 struct mbuf	*mb_alloc_ext_pgs(int, bool, m_ext_free_t);
+struct mbuf	*mb_alloc_ext_plus_pages(int, int, bool, m_ext_free_t);
+struct mbuf	*mb_copym_ext_pgs(struct mbuf *, int, int, int, bool,
+		    m_ext_free_t, struct mbuf **);
 int		 mb_unmapped_compress(struct mbuf *m);
 struct mbuf 	*mb_unmapped_to_ext(struct mbuf *m);
 void		 mb_free_notready(struct mbuf *m, int count);