Unlock child temporarily while truncating directory. This prevents

a double locking bug in the soft updates code.

3 files changed, 32 insertions, 11 deletions

diff --git a/sys/ufs/ufs/ufs_extern.h b/sys/ufs/ufs/ufs_extern.h
index 6c49d78717c..8a20bbbac48 100644
--- a/sys/ufs/ufs/ufs_extern.h
+++ b/sys/ufs/ufs/ufs_extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ufs_extern.h,v 1.5 1997/11/06 05:59:26 csapuntz Exp $	*/
+/*	$OpenBSD: ufs_extern.h,v 1.6 1997/12/02 17:11:10 csapuntz Exp $	*/
 /*	$NetBSD: ufs_extern.h,v 1.5 1996/02/09 22:36:03 christos Exp $	*/
 
 /*-
@@ -127,7 +127,7 @@ void ufs_dirbad __P((struct inode *, doff_t, char *));
 int ufs_dirbadentry __P((struct vnode *, struct direct *, int));
 void ufs_makedirentry __P((struct inode *, struct componentname *,
 			   struct direct *));
-int ufs_direnter __P((struct vnode *, struct direct *,
+int ufs_direnter __P((struct vnode *, struct vnode *, struct direct *,
 		      struct componentname *, struct buf *));
 int ufs_dirremove __P((struct vnode *, struct inode *, int, int));
 int ufs_dirrewrite __P((struct inode *, struct inode *,
diff --git a/sys/ufs/ufs/ufs_lookup.c b/sys/ufs/ufs/ufs_lookup.c
index 31a7a5fd169..c89d4b7ee0c 100644
--- a/sys/ufs/ufs/ufs_lookup.c
+++ b/sys/ufs/ufs/ufs_lookup.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ufs_lookup.c,v 1.7 1997/11/06 05:59:27 csapuntz Exp $	*/
+/*	$OpenBSD: ufs_lookup.c,v 1.8 1997/12/02 17:11:11 csapuntz Exp $	*/
 /*	$NetBSD: ufs_lookup.c,v 1.7 1996/02/09 22:36:06 christos Exp $	*/
 
 /*
@@ -721,8 +721,9 @@ ufs_makedirentry(ip, cnp, newdirp)
  * soft dependency code).
  */
 int
-ufs_direnter(dvp, dirp, cnp, newdirbp)
+ufs_direnter(dvp, tvp, dirp, cnp, newdirbp)
   	struct vnode *dvp;
+	struct vnode *tvp;
   	struct direct *dirp;
  	struct componentname *cnp;
  	struct buf *newdirbp;
@@ -877,8 +878,23 @@ ufs_direnter(dvp, dirp, cnp, newdirbp)
   		error = VOP_BWRITE(bp);
   	}
 	dp->i_flag |= IN_CHANGE | IN_UPDATE;
-	if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_ffs_size)
+
+ 	/*
+ 	 * If all went well, and the directory can be shortened, proceed
+ 	 * with the truncation. Note that we have to unlock the inode for
+ 	 * the entry that we just entered, as the truncation may need to
+ 	 * lock other inodes which can lead to deadlock if we also hold a
+ 	 * lock on the newly entered node.
+ 	 */
+
+	if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_ffs_size) {
+	        if (tvp != NULL)
+			VOP_UNLOCK(tvp, 0, p);
+
 		error = VOP_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC, cr, p);
+		if (tvp != NULL)
+			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p);
+	}
 	return (error);
 }
 
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index a261a24c54f..1f71e54da9d 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ufs_vnops.c,v 1.16 1997/11/06 23:07:24 csapuntz Exp $	*/
+/*	$OpenBSD: ufs_vnops.c,v 1.17 1997/12/02 17:11:13 csapuntz Exp $	*/
 /*	$NetBSD: ufs_vnops.c,v 1.18 1996/05/11 18:28:04 mycroft Exp $	*/
 
 /*
@@ -737,7 +737,7 @@ ufs_link(v)
 	TIMEVAL_TO_TIMESPEC(&time, &ts);
 	if ((error = VOP_UPDATE(vp, &ts, &ts, !DOINGSOFTDEP(vp))) == 0) {
 		ufs_makedirentry(ip, cnp, &newdir);
-		error = ufs_direnter(dvp, &newdir, cnp, NULL);
+		error = ufs_direnter(dvp, vp, &newdir, cnp, NULL);
 	}
 	if (error) {
 		ip->i_effnlink--;
@@ -790,7 +790,7 @@ ufs_whiteout(v)
 		newdir.d_namlen = cnp->cn_namelen;
 		bcopy(cnp->cn_nameptr, newdir.d_name, (unsigned)cnp->cn_namelen + 1);
 		newdir.d_type = DT_WHT;
-		error = ufs_direnter(dvp, &newdir, cnp, NULL);
+		error = ufs_direnter(dvp, NULL, &newdir, cnp, NULL);
 		break;
 
 	case DELETE:
@@ -1042,7 +1042,7 @@ abortit:
 				goto bad;
 		}
 		ufs_makedirentry(ip, tcnp, &newdir);
-		if ((error = ufs_direnter(tdvp, &newdir, tcnp, NULL)) != 0) {
+		if ((error = ufs_direnter(tdvp, fvp, &newdir, tcnp, NULL)) != 0) {
 			if (doingdirectory && newparent) {
 				dp->i_effnlink--;
 				dp->i_ffs_nlink--;
@@ -1313,7 +1313,7 @@ ufs_mkdir(v)
         if (!DOINGSOFTDEP(dvp) && ((error = VOP_BWRITE(bp)) != 0))
                 goto bad;
         ufs_makedirentry(ip, cnp, &newdir);
-        error = ufs_direnter(dvp, &newdir, cnp, bp);
+        error = ufs_direnter(dvp, tvp, &newdir, cnp, bp);
   
 bad:
         if (error == 0) {
@@ -1728,6 +1728,11 @@ ufs_print(v)
 
 	printf("tag VT_UFS, ino %d, on dev %d, %d", ip->i_number,
 		major(ip->i_dev), minor(ip->i_dev));
+	printf(" flags 0x%x, effnlink %d, nlink %d\n",
+	       ip->i_flag, ip->i_effnlink, ip->i_ffs_nlink);
+	printf("\tmode 0%o, owner %d, group %d, size %qd",
+	       ip->i_ffs_mode, ip->i_ffs_uid, ip->i_ffs_gid, ip->i_ffs_size);
+
 #ifdef FIFO
 	if (vp->v_type == VFIFO)
 		fifo_printinfo(vp);
@@ -2064,7 +2069,7 @@ ufs_makeinode(mode, dvp, vpp, cnp)
 		goto bad;
 
 	ufs_makedirentry(ip, cnp, &newdir);
-	if ((error = ufs_direnter(dvp, &newdir, cnp, NULL)) != 0)
+	if ((error = ufs_direnter(dvp, tvp, &newdir, cnp, NULL)) != 0)
 		goto bad;
 
 	if ((cnp->cn_flags & SAVESTART) == 0)