CVS commit: src/sys/kern

[Juergen Hannken-Illjes]

Module Name:    src
Committed By:   hannken
Date:           Fri Oct 11 08:04:52 UTC 2019

Modified Files:
        src/sys/kern: vnode_if.sh vnode_if.src

Log Message:
As VOP_STRATEGY() usually calls itself on the file system holding "/dev"
it may deadlock on suspension of this file system.

Add fstrans type LAZY and use it for VOP_STRATEGY().

Adress PR kern/53624 (dom0 freeze on domU exit) is still there


To generate a diff of this commit:
cvs rdiff -u -r1.66 -r1.67 src/sys/kern/vnode_if.sh
cvs rdiff -u -r1.77 -r1.78 src/sys/kern/vnode_if.src

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/kern/vnode_if.sh
diff -u src/sys/kern/vnode_if.sh:1.66 src/sys/kern/vnode_if.sh:1.67
--- src/sys/kern/vnode_if.sh:1.66	Sun Jun  4 08:03:26 2017
+++ src/sys/kern/vnode_if.sh	Fri Oct 11 08:04:52 2019
@@ -29,7 +29,7 @@ copyright="\
  * SUCH DAMAGE.
  */
 "
-SCRIPT_ID='$NetBSD: vnode_if.sh,v 1.66 2017/06/04 08:03:26 hannken Exp $'
+SCRIPT_ID='$NetBSD: vnode_if.sh,v 1.67 2019/10/11 08:04:52 hannken Exp $'
 
 # Script to produce VFS front-end sugar.
 #
@@ -318,7 +318,7 @@ echo '
 
 if [ -z "${rump}" ] ; then
 	echo "
-enum fst_op { FST_NO, FST_YES, FST_TRY };
+enum fst_op { FST_NO, FST_YES, FST_LAZY, FST_TRY };
 
 static inline int
 vop_pre(vnode_t *vp, struct mount **mp, bool *mpsafe, enum fst_op op)
@@ -331,7 +331,7 @@ vop_pre(vnode_t *vp, struct mount **mp, 
 		KERNEL_LOCK(1, curlwp);
 	}
 
-	if (op == FST_YES || op == FST_TRY) {
+	if (op == FST_YES || op == FST_LAZY || op == FST_TRY) {
 		for (;;) {
 			*mp = vp->v_mount;
 			if (op == FST_TRY) {
@@ -342,6 +342,8 @@ vop_pre(vnode_t *vp, struct mount **mp, 
 					}
 					return error;
 				}
+			} else if (op == FST_LAZY) {
+				fstrans_start_lazy(*mp);
 			} else {
 				fstrans_start(*mp);
 			}
@@ -360,7 +362,7 @@ static inline void
 vop_post(vnode_t *vp, struct mount *mp, bool mpsafe, enum fst_op op)
 {
 
-	if (op == FST_YES) {
+	if (op == FST_YES || op == FST_LAZY) {
 		fstrans_done(mp);
 	}
 

Index: src/sys/kern/vnode_if.src
diff -u src/sys/kern/vnode_if.src:1.77 src/sys/kern/vnode_if.src:1.78
--- src/sys/kern/vnode_if.src:1.77	Wed Jul 12 09:31:07 2017
+++ src/sys/kern/vnode_if.src	Fri Oct 11 08:04:52 2019
@@ -1,4 +1,4 @@
-#	$NetBSD: vnode_if.src,v 1.77 2017/07/12 09:31:07 hannken Exp $
+#	$NetBSD: vnode_if.src,v 1.78 2019/10/11 08:04:52 hannken Exp $
 #
 # Copyright (c) 1992, 1993
 #	The Regents of the University of California.  All rights reserved.
@@ -436,6 +436,7 @@ vop_bmap {
 #% strategy   vp      = = =
 #
 vop_strategy {
+	FSTRANS=LAZY
 	IN struct vnode *vp;
 	IN struct buf *bp;
 };