- Replace v_flag with v_iflag and v_vflag

 - v_vflag is protected by the vnode lock and is used when synchronization
   with VOP calls is needed.
 - v_iflag is protected by interlock and is used for dealing with vnode
   management issues.  These flags include X/O LOCK, FREE, DOOMED, etc.
 - All accesses to v_iflag and v_vflag have either been locked or marked with
   mp_fixme's.
 - Many ASSERT_VOP_LOCKED calls have been added where the locking was not
   clear.
 - Many functions in vfs_subr.c were restructured to provide for stronger
   locking.

Idea stolen from:	BSD/OS

3 files changed, 14 insertions, 6 deletions

diff --git a/sys/nfsclient/nfs_bio.c b/sys/nfsclient/nfs_bio.c
index 685c6d1..d8243ae 100644
--- a/sys/nfsclient/nfs_bio.c
+++ b/sys/nfsclient/nfs_bio.c
@@ -1063,9 +1063,13 @@ nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred,
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	int error = 0, slpflag, slptimeo;
 
-	if (vp->v_flag & VXLOCK) {
+	VI_LOCK(vp);
+	if (vp->v_iflag & VI_XLOCK) {
+		/* XXX Should we wait here? */
+		VI_UNLOCK(vp);
 		return (0);
 	}
+	VI_UNLOCK(vp);
 
 	if ((nmp->nm_flag & NFSMNT_INT) == 0)
 		intrflg = 0;
@@ -1340,7 +1344,8 @@ nfs_doio(struct buf *bp, struct ucred *cr, struct thread *td)
 			uiop->uio_resid = 0;
 		    }
 		}
-		if (p && (vp->v_flag & VTEXT) &&
+		mp_fixme("Accessing VV_TEXT without a lock.");
+		if (p && (vp->v_vflag & VV_TEXT) &&
 			(np->n_mtime != np->n_vattr.va_mtime.tv_sec)) {
 			uprintf("Process killed due to text file modification\n");
 			PROC_LOCK(p);
diff --git a/sys/nfsclient/nfs_vfsops.c b/sys/nfsclient/nfs_vfsops.c
index 45ad218..4ac930e 100644
--- a/sys/nfsclient/nfs_vfsops.c
+++ b/sys/nfsclient/nfs_vfsops.c
@@ -505,7 +505,8 @@ nfs_mountroot(struct mount *mp, struct thread *td)
 		 * hack it to a regular file.
 		 */
 		vp->v_type = VREG;
-		vp->v_flag = 0;
+		vp->v_vflag = 0;
+		vp->v_iflag = 0;
 		VREF(vp);
 		swaponvp(td, vp, NODEV, nd->swap_nblks);
 	}
@@ -951,7 +952,7 @@ nfs_root(struct mount *mp, struct vnode **vpp)
 	vp = NFSTOV(np);
 	if (vp->v_type == VNON)
 	    vp->v_type = VDIR;
-	vp->v_flag = VROOT;
+	vp->v_vflag |= VV_ROOT;
 	*vpp = vp;
 	return (0);
 }
diff --git a/sys/nfsclient/nfs_vnops.c b/sys/nfsclient/nfs_vnops.c
index a2aa645..37b9264 100644
--- a/sys/nfsclient/nfs_vnops.c
+++ b/sys/nfsclient/nfs_vnops.c
@@ -2807,9 +2807,10 @@ loop:
 		goto again;
 	}
 	if (waitfor == MNT_WAIT) {
+		VI_LOCK(vp);
 		while (vp->v_numoutput) {
-			vp->v_flag |= VBWAIT;
-			error = tsleep((caddr_t)&vp->v_numoutput,
+			vp->v_iflag |= VI_BWAIT;
+			error = msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp),
 				slpflag | (PRIBIO + 1), "nfsfsync", slptimeo);
 			if (error) {
 			    if (nfs_sigintr(nmp, NULL, td)) {
@@ -2822,6 +2823,7 @@ loop:
 			    }
 			}
 		}
+		VI_UNLOCK(vp);
 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) && commit) {
 			goto loop;
 		}