CVS commit: src/sys/fs/union

[Juergen Hannken-Illjes]

Module Name:    src
Committed By:   hannken
Date:           Mon Mar  6 10:08:49 UTC 2017

Modified Files:
        src/sys/fs/union: union_vnops.c

Log Message:
Handle v_writecount from union_open(), union_close() and union_revoke()
so lower file system vnodes get marked as open for writing.


To generate a diff of this commit:
cvs rdiff -u -r1.63 -r1.64 src/sys/fs/union/union_vnops.c

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


Modified files:

Index: src/sys/fs/union/union_vnops.c
diff -u src/sys/fs/union/union_vnops.c:1.63 src/sys/fs/union/union_vnops.c:1.64
--- src/sys/fs/union/union_vnops.c:1.63	Mon Apr 20 23:03:08 2015
+++ src/sys/fs/union/union_vnops.c	Mon Mar  6 10:08:49 2017
@@ -1,4 +1,4 @@
-/*	$NetBSD: union_vnops.c,v 1.63 2015/04/20 23:03:08 riastradh Exp $	*/
+/*	$NetBSD: union_vnops.c,v 1.64 2017/03/06 10:08:49 hannken Exp $	*/
 
 /*
  * Copyright (c) 1992, 1993, 1994, 1995
@@ -72,7 +72,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.63 2015/04/20 23:03:08 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.64 2017/03/06 10:08:49 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -616,6 +616,11 @@ union_open(void *v)
 			error = union_copyup(un, (mode&O_TRUNC) == 0, cred, l);
 			if (error == 0)
 				error = VOP_OPEN(un->un_uppervp, mode, cred);
+			if (error == 0) {
+				mutex_enter(un->un_uppervp->v_interlock);
+				un->un_uppervp->v_writecount++;
+				mutex_exit(un->un_uppervp->v_interlock);
+			}
 			return (error);
 		}
 
@@ -640,6 +645,11 @@ union_open(void *v)
 		return ENXIO;
 
 	error = VOP_OPEN(tvp, mode, cred);
+	if (error == 0 && (ap->a_mode & FWRITE)) {
+		mutex_enter(tvp->v_interlock);
+		tvp->v_writecount++;
+		mutex_exit(tvp->v_interlock);
+	}
 
 	return (error);
 }
@@ -669,6 +679,12 @@ union_close(void *v)
 
 	KASSERT(vp != NULLVP);
 	ap->a_vp = vp;
+	if ((ap->a_fflag & FWRITE)) {
+		KASSERT(vp == un->un_uppervp);
+		mutex_enter(vp->v_interlock);
+		vp->v_writecount--;
+		mutex_exit(vp->v_interlock);
+	}
 	if (do_lock)
 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 	error = VCALL(vp, VOFFSET(vop_close), ap);
@@ -1048,8 +1064,13 @@ union_revoke(void *v)
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 
-	if (UPPERVP(vp))
+	if (UPPERVP(vp)) {
+		mutex_enter(UPPERVP(vp)->v_interlock);
+		KASSERT(vp->v_interlock == UPPERVP(vp)->v_interlock);
+		UPPERVP(vp)->v_writecount -= vp->v_writecount;
+		mutex_exit(UPPERVP(vp)->v_interlock);
 		VOP_REVOKE(UPPERVP(vp), ap->a_flags);
+	}
 	if (LOWERVP(vp))
 		VOP_REVOKE(LOWERVP(vp), ap->a_flags);
 	vgone(vp);	/* XXXAD?? */