svn commit: r274686 - in projects/sendfile/sys: kern sys

[Gleb Smirnoff]

Author: glebius
Date: Wed Nov 19 05:46:27 2014
New Revision: 274686
URL: https://svnweb.freebsd.org/changeset/base/274686

Log:
  Revert M_SBCUT changes, the flag isn't actually needed. If sf_iodone()
  does soisdisconnected() in case of I/O error, then PCB would be marked
  dropped and if any more I/Os are pending on this socket, they will free
  their mbufs in tcp_usr_ready().
  
  Sponsored by:	Netflix
  Sponsored by:	Nginx, Inc.

Modified:
  projects/sendfile/sys/kern/uipc_sockbuf.c
  projects/sendfile/sys/kern/uipc_syscalls.c
  projects/sendfile/sys/sys/sockbuf.h

Modified: projects/sendfile/sys/kern/uipc_sockbuf.c
==============================================================================
--- projects/sendfile/sys/kern/uipc_sockbuf.c	Wed Nov 19 05:43:31 2014	(r274685)
+++ projects/sendfile/sys/kern/uipc_sockbuf.c	Wed Nov 19 05:46:27 2014	(r274686)
@@ -77,21 +77,6 @@ sbready(struct sockbuf *sb, struct mbuf 
 	u_int blocker;
 
 	SOCKBUF_LOCK_ASSERT(sb);
-
-	if (m->m_flags & M_SBCUT) {
-		/*
-		 * Oops, something bad happened to the socket buffer while
-		 * we were working on the data.  Our mbufs are detached from
-		 * the sockbuf, and all what we can do is free them.
-		 */
-		for (int i = 0; i < count; i++) {
-			KASSERT(m->m_flags & M_SBCUT,
-			    ("%s: m %p !M_SBCUT", __func__, m));
-			m = m_free(m);
-		}
-		return (EPIPE);
-	}
-
 	KASSERT(sb->sb_fnrdy != NULL, ("%s: sb %p NULL fnrdy", __func__, sb));
 
 	blocker = (sb->sb_fnrdy == m) ? M_BLOCKED : 0;
@@ -1032,7 +1017,7 @@ sbflush(struct sockbuf *sb)
 static struct mbuf *
 sbcut_internal(struct sockbuf *sb, int len)
 {
-	struct mbuf *m, *n, *next, *mfree;
+	struct mbuf *m, *next, *mfree;
 
 	next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
 	mfree = NULL;
@@ -1058,14 +1043,20 @@ sbcut_internal(struct sockbuf *sb, int l
 		}
 		len -= m->m_len;
 		sbfree(sb, m);
-		n = m->m_next;
+		/*
+		 * Do not put M_NOTREADY buffers to the free list, they
+		 * are referenced from outside.
+		 */
 		if (m->m_flags & M_NOTREADY)
-			m->m_flags |= M_SBCUT;
+			m = m->m_next;
 		else {
+			struct mbuf *n;
+
+			n = m->m_next;
 			m->m_next = mfree;
 			mfree = m;
+			m = n;
 		}
-		m = n;
 	}
 	if (m) {
 		sb->sb_mb = m;

Modified: projects/sendfile/sys/kern/uipc_syscalls.c
==============================================================================
--- projects/sendfile/sys/kern/uipc_syscalls.c	Wed Nov 19 05:43:31 2014	(r274685)
+++ projects/sendfile/sys/kern/uipc_syscalls.c	Wed Nov 19 05:46:27 2014	(r274686)
@@ -2092,10 +2092,8 @@ sf_iodone(void *arg, vm_page_t *pg, int 
 		 * for read, so that application receives EIO on next
 		 * syscall and eventually closes the socket.
 		 */
-		SOCKBUF_LOCK(&(so)->so_snd);
-		sbflush_locked(&so->so_snd);
 		so->so_error = EIO;
-		sowakeup((so), &(so)->so_snd);
+		soisdisconnected(so);
 
 		m = sfio->m;
 		for (int i = 0; i < sfio->npages; i++)

Modified: projects/sendfile/sys/sys/sockbuf.h
==============================================================================
--- projects/sendfile/sys/sys/sockbuf.h	Wed Nov 19 05:43:31 2014	(r274685)
+++ projects/sendfile/sys/sys/sockbuf.h	Wed Nov 19 05:46:27 2014	(r274686)
@@ -128,7 +128,6 @@ struct	sockbuf {
 #define	M_NOTREADY	M_PROTO1	/* m_data not populated yet */
 #define	M_BLOCKED	M_PROTO2	/* M_NOTREADY in front of m */
 #define	M_NOTAVAIL	(M_NOTREADY | M_BLOCKED)
-#define	M_SBCUT		M_PROTO3	/* mbuf was sbcut out */
 
 void	sbappend(struct sockbuf *sb, struct mbuf *m);
 void	sbappend_locked(struct sockbuf *sb, struct mbuf *m);