Framework for generating automatic test code for locking discipline

in DIAGNOSTIC mode.

Added documentation to vfs_subr.c on locking needs of a couple calls.

Improvements to the vinvalbuf patch. We need to start over after we
let our pants down.

4 files changed, 51 insertions, 24 deletions

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index a268067c23c..2e012441016 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_subr.c,v 1.26 1998/12/04 15:57:01 csapuntz Exp $	*/
+/*	$OpenBSD: vfs_subr.c,v 1.27 1998/12/05 16:50:40 csapuntz Exp $	*/
 /*	$NetBSD: vfs_subr.c,v 1.53 1996/04/22 01:39:13 christos Exp $	*/
 
 /*
@@ -1040,6 +1040,9 @@ vclean(vp, flags, p)
 	vp->v_op = dead_vnodeop_p;
 	vp->v_tag = VT_NON;
 	vp->v_flag &= ~VXLOCK;
+#ifdef DIAGNOSTIC
+	vp->v_flag &= ~VLOCKSWORK;
+#endif
 	if (vp->v_flag & VXWANT) {
 		vp->v_flag &= ~VXWANT;
 		wakeup((caddr_t)vp);
@@ -1802,6 +1805,8 @@ fs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
 
 /*
  * Update outstanding I/O count and do wakeup if requested.
+ *
+ * Manipulates v_numoutput. Must be called at splbio()
  */
 void
 vwakeup(bp)
@@ -1853,6 +1858,7 @@ vinvalbuf(vp, flags, cred, p, slpflag, slptimeo)
 		}
 		splx(s);
 	}
+loop:
 	s = splbio();
 	for (;;) {
 		if ((blist = vp->v_cleanblkhd.lh_first) && 
@@ -1890,17 +1896,16 @@ vinvalbuf(vp, flags, cred, p, slpflag, slptimeo)
 			if ((bp->b_flags & B_DELWRI) && (flags & V_SAVE)) {
 				splx(s);
 				(void) VOP_BWRITE(bp);
-				s = splbio();
-				break;
+				goto loop;
 			}
 			bp->b_flags |= B_INVAL;
 			brelse(bp);
 		}
 	}
-	splx(s);
 	if (!(flags & V_SAVEMETA) &&
 	    (vp->v_dirtyblkhd.lh_first || vp->v_cleanblkhd.lh_first))
 		panic("vinvalbuf: flush failed");
+	splx(s);
 	return (0);
 }
 
@@ -1949,6 +1954,8 @@ loop:
 
 /*
  * Associate a buffer with a vnode.
+ *
+ * Manipulates buffer vnode queues. Must be called at splbio().
  */
 void
 bgetvp(vp, bp)
@@ -1972,6 +1979,8 @@ bgetvp(vp, bp)
 
 /*
  * Disassociate a buffer from a vnode.
+ * 
+ * Manipulates vnode buffer queues. Must be called at splbio().
  */
 void
 brelvp(bp)
@@ -1998,6 +2007,8 @@ brelvp(bp)
  * Reassign a buffer from one vnode to another. Used to assign buffers
  * to the appropriate clean or dirty list and to add newly dirty vnodes
  * to the appropriate filesystem syncer list.
+ *
+ * Manipulates vnode buffer queues. Must be called at splbio().
  */
 void
 reassignbuf(bp, newvp)
diff --git a/sys/kern/vnode_if.c b/sys/kern/vnode_if.c
index e2319524733..fb9ad91de03 100644
--- a/sys/kern/vnode_if.c
+++ b/sys/kern/vnode_if.c
@@ -58,6 +58,22 @@ struct vnodeop_desc vop_default_desc = {
 };
 
 
+int vop_islocked_vp_offsets[] = {
+	VOPARG_OFFSETOF(struct vop_islocked_args,a_vp),
+	VDESC_NO_OFFSET
+};
+struct vnodeop_desc vop_islocked_desc = {
+	0,
+	"vop_islocked",
+	0,
+	vop_islocked_vp_offsets,
+	VDESC_NO_OFFSET,
+	VDESC_NO_OFFSET,
+	VDESC_NO_OFFSET,
+	VDESC_NO_OFFSET,
+	NULL,
+};
+
 int vop_lookup_vp_offsets[] = {
 	VOPARG_OFFSETOF(struct vop_lookup_args,a_dvp),
 	VDESC_NO_OFFSET
@@ -576,22 +592,6 @@ struct vnodeop_desc vop_print_desc = {
 	NULL,
 };
 
-int vop_islocked_vp_offsets[] = {
-	VOPARG_OFFSETOF(struct vop_islocked_args,a_vp),
-	VDESC_NO_OFFSET
-};
-struct vnodeop_desc vop_islocked_desc = {
-	0,
-	"vop_islocked",
-	0,
-	vop_islocked_vp_offsets,
-	VDESC_NO_OFFSET,
-	VDESC_NO_OFFSET,
-	VDESC_NO_OFFSET,
-	VDESC_NO_OFFSET,
-	NULL,
-};
-
 int vop_pathconf_vp_offsets[] = {
 	VOPARG_OFFSETOF(struct vop_pathconf_args,a_vp),
 	VDESC_NO_OFFSET
@@ -791,6 +791,7 @@ struct vnodeop_desc *vfs_op_descs[] = {
 	&vop_strategy_desc,	/* XXX: SPECIAL CASE */
 	&vop_bwrite_desc,	/* XXX: SPECIAL CASE */
 
+	&vop_islocked_desc,
 	&vop_lookup_desc,
 	&vop_create_desc,
 	&vop_mknod_desc,
@@ -823,7 +824,6 @@ struct vnodeop_desc *vfs_op_descs[] = {
 	&vop_unlock_desc,
 	&vop_bmap_desc,
 	&vop_print_desc,
-	&vop_islocked_desc,
 	&vop_pathconf_desc,
 	&vop_advlock_desc,
 	&vop_blkatoff_desc,
diff --git a/sys/kern/vnode_if.sh b/sys/kern/vnode_if.sh
index b859ec7f9df..9ddf086f8f7 100644
--- a/sys/kern/vnode_if.sh
+++ b/sys/kern/vnode_if.sh
@@ -33,7 +33,7 @@ copyright="\
  * SUCH DAMAGE.
  */
 "
-SCRIPT_ID='$OpenBSD: vnode_if.sh,v 1.3 1996/04/19 16:09:13 niklas Exp $'
+SCRIPT_ID='$OpenBSD: vnode_if.sh,v 1.4 1998/12/05 16:50:41 csapuntz Exp $'
 # SCRIPT_ID='$NetBSD: vnode_if.sh,v 1.9 1996/02/29 20:58:22 cgd Exp $'
 
 # Script to produce VFS front-end sugar.
@@ -108,11 +108,19 @@ awk_parser='
 # Middle lines of description
 {
 	argdir[argc] = $1; i=2;
-	if ($2 == "WILLRELE") {
+	if ($2 == "WILLRELE" ||
+	    $3 == "WILLRELE") {
 		willrele[argc] = 1;
 		i++;
 	} else
 		willrele[argc] = 0;
+
+    if ($2 == "SHOULDBELOCKED") {
+	   shouldbelocked[argc] = 1;
+	   i++;
+	} else
+	   shouldbelocked[argc] = 0;
+
 	argtype[argc] = $i; i++;
 	while (i < NF) {
 		argtype[argc] = argtype[argc]" "$i;
@@ -154,6 +162,7 @@ echo '
 extern struct vnodeop_desc vop_default_desc;
 '
 
+echo '#include "systm.h"'
 # Body stuff
 # This awk program needs toupper() so define it if necessary.
 sed -e "$sed_prep" $src | $awk "$toupper"'
@@ -197,6 +206,11 @@ function doit() {
 	printf("\ta.a_desc = VDESC(%s);\n", name);
 	for (i=0; i<argc; i++) {
 		printf("\ta.a_%s = %s;\n", argname[i], argname[i]);
+		if (shouldbelocked[i]) {
+		    printf ("#ifdef DIAGNOSTIC\n");
+			printf ("\tif ((%s->v_flag & VLOCKSWORK) && !VOP_ISLOCKED(%s)) panic(\"%s: %s\");\n", argname[i], argname[i], name, argname[i]);
+			printf ("#endif\n");
+		}
 	}
 	printf("\treturn (VCALL(%s%s, VOFFSET(%s), &a));\n}\n",
 		argname[0], arg0special, name);
@@ -209,6 +223,7 @@ END	{
 	argc=1;
 	argtype[0]="struct buf *";
 	argname[0]="bp";
+	shouldbelocked[0] = 0;
 	arg0special="->b_vp";
 	name="vop_strategy";
 	doit();
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 9485d7012bd..99cb6a9a707 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vnode.h,v 1.18 1998/11/15 17:15:01 art Exp $	*/
+/*	$OpenBSD: vnode.h,v 1.19 1998/12/05 16:50:40 csapuntz Exp $	*/
 /*	$NetBSD: vnode.h,v 1.38 1996/02/29 20:59:05 cgd Exp $	*/
 
 /*
@@ -133,6 +133,7 @@ struct vnode {
 #define	VALIASED	0x0800	/* vnode has an alias */
 #define	VDIROP		0x1000	/* LFS: vnode is involved in a directory op */
 #define VONFREELIST     0x2000  /* Vnode is on a free list */
+#define VLOCKSWORK      0x4000  /* FS supports locking discipline */
 
 /*
  * Vnode attributes.  A field value of VNOVAL represents a field whose value