svn commit: r360572 - in head/sys: kern sys

[Gleb Smirnoff]

Author: glebius
Date: Sat May  2 22:56:22 2020
New Revision: 360572
URL: https://svnweb.freebsd.org/changeset/base/360572

Log:
  Get rid of the mbuf self-pointing pointer.
  
  Reviewed by:	gallatin
  Differential Revision:	https://reviews.freebsd.org/D24598

Modified:
  head/sys/kern/uipc_ktls.c
  head/sys/sys/mbuf.h

Modified: head/sys/kern/uipc_ktls.c
==============================================================================
--- head/sys/kern/uipc_ktls.c	Sat May  2 22:49:14 2020	(r360571)
+++ head/sys/kern/uipc_ktls.c	Sat May  2 22:56:22 2020	(r360572)
@@ -1436,7 +1436,7 @@ ktls_enqueue_to_free(struct mbuf_ext_pgs *pgs)
 	bool running;
 
 	/* Mark it for freeing. */
-	pgs->mbuf = NULL;
+	pgs->flags |= EPG_FLAG_2FREE;
 	wq = &ktls_wq[pgs->tls->wq_index];
 	mtx_lock(&wq->mtx);
 	STAILQ_INSERT_TAIL(&wq->head, pgs, stailq);
@@ -1463,7 +1463,6 @@ ktls_enqueue(struct mbuf *m, struct socket *so, int pa
 	KASSERT(pgs->tls->mode == TCP_TLS_MODE_SW, ("!SW TLS mbuf"));
 
 	pgs->enc_cnt = page_count;
-	pgs->mbuf = m;
 
 	/*
 	 * Save a pointer to the socket.  The caller is responsible
@@ -1496,12 +1495,11 @@ ktls_encrypt(struct mbuf_ext_pgs *pgs)
 
 	so = pgs->so;
 	tls = pgs->tls;
-	top = pgs->mbuf;
+	top = __containerof(pgs, struct mbuf, m_ext_pgs);
 	KASSERT(tls != NULL, ("tls = NULL, top = %p, pgs = %p\n", top, pgs));
 	KASSERT(so != NULL, ("so = NULL, top = %p, pgs = %p\n", top, pgs));
 #ifdef INVARIANTS
 	pgs->so = NULL;
-	pgs->mbuf = NULL;
 #endif
 	total_pages = pgs->enc_cnt;
 	npages = 0;
@@ -1654,14 +1652,14 @@ ktls_work_thread(void *ctx)
 		mtx_unlock(&wq->mtx);
 
 		STAILQ_FOREACH_SAFE(p, &local_head, stailq, n) {
-			if (p->mbuf != NULL) {
-				ktls_encrypt(p);
-				counter_u64_add(ktls_cnt_on, -1);
-			} else {
+			if (p->flags & EPG_FLAG_2FREE) {
 				tls = p->tls;
 				ktls_free(tls);
 				m = __containerof(p, struct mbuf, m_ext_pgs);
 				uma_zfree(zone_mbuf, m);
+			} else {
+				ktls_encrypt(p);
+				counter_u64_add(ktls_cnt_on, -1);
 			}
 		}
 	}

Modified: head/sys/sys/mbuf.h
==============================================================================
--- head/sys/sys/mbuf.h	Sat May  2 22:49:14 2020	(r360571)
+++ head/sys/sys/mbuf.h	Sat May  2 22:56:22 2020	(r360572)
@@ -365,13 +365,13 @@ struct mbuf {
 					uint16_t last_pg_len;
 					uint8_t	flags;
 #define	EPG_FLAG_ANON	0x1	/* Data can be encrypted in place. */
+#define	EPG_FLAG_2FREE	0x2	/* Scheduled for free. */
 					uint8_t	record_type;
 					uint8_t	spare[2];
 					int	enc_cnt;
 					struct ktls_session *tls;
 					struct socket	*so;
 					uint64_t	seqno;
-					struct mbuf	*mbuf;
 					STAILQ_ENTRY(mbuf_ext_pgs) stailq;
 				} m_ext_pgs;
 			};