Replace the MNT_VNODE_FOREACH interface with MNT_VNODE_FOREACH_ALL.

The primary changes are that the user of the interface no longer
needs to manage the mount-mutex locking and that the vnode that
is returned has its mutex locked (thus avoiding the need to check
to see if its is DOOMED or other possible end of life senarios).

To minimize compatibility issues for third-party developers, the
old MNT_VNODE_FOREACH interface will remain available so that this
change can be MFC'ed to 9. Following the MFC to 9, MNT_VNODE_FOREACH
will be removed in head.

The reason for this update is to prepare for the addition of the
MNT_VNODE_FOREACH_ACTIVE interface that will loop over just the
active vnodes associated with a mount point (typically less than
1% of the vnodes associated with the mount point).

Reviewed by: kib
Tested by:   Peter Holm
MFC after:   2 weeks

1 files changed, 18 insertions, 42 deletions

diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 936445a..7faf018 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -705,19 +705,12 @@ ffs_reload(struct mount *mp, struct thread *td)
 	}
 
 loop:
-	MNT_ILOCK(mp);
-	MNT_VNODE_FOREACH(vp, mp, mvp) {
-		VI_LOCK(vp);
-		if (vp->v_iflag & VI_DOOMED) {
-			VI_UNLOCK(vp);
-			continue;
-		}
-		MNT_IUNLOCK(mp);
+	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
 		/*
 		 * Step 4: invalidate all cached file data.
 		 */
 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
-			MNT_VNODE_FOREACH_ABORT(mp, mvp);
+			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 			goto loop;
 		}
 		if (vinvalbuf(vp, 0, 0, 0))
@@ -732,7 +725,7 @@ loop:
 		if (error) {
 			VOP_UNLOCK(vp, 0);
 			vrele(vp);
-			MNT_VNODE_FOREACH_ABORT(mp, mvp);
+			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 			return (error);
 		}
 		ffs_load_inode(bp, ip, fs, ip->i_number);
@@ -740,9 +733,7 @@ loop:
 		brelse(bp);
 		VOP_UNLOCK(vp, 0);
 		vrele(vp);
-		MNT_ILOCK(mp);
 	}
-	MNT_IUNLOCK(mp);
 	return (0);
 }
 
@@ -1441,10 +1432,8 @@ ffs_sync_lazy(mp)
 	td = curthread;
 	if ((mp->mnt_flag & MNT_NOATIME) != 0)
 		goto qupdate;
-	MNT_ILOCK(mp);
-	MNT_VNODE_FOREACH(vp, mp, mvp) {
-		VI_LOCK(vp);
-		if (vp->v_iflag & VI_DOOMED || vp->v_type == VNON) {
+	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
+		if (vp->v_type == VNON) {
 			VI_UNLOCK(vp);
 			continue;
 		}
@@ -1462,19 +1451,14 @@ ffs_sync_lazy(mp)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		MNT_IUNLOCK(mp);
 		if ((error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK,
-		    td)) != 0) {
-			MNT_ILOCK(mp);
+		    td)) != 0)
 			continue;
-		}
 		error = ffs_update(vp, 0);
 		if (error != 0)
 			allerror = error;
 		vput(vp);
-		MNT_ILOCK(mp);
 	}
-	MNT_IUNLOCK(mp);
 
 qupdate:
 #ifdef QUOTA
@@ -1538,41 +1522,37 @@ ffs_sync(mp, waitfor)
 		lockreq = LK_EXCLUSIVE;
 	}
 	lockreq |= LK_INTERLOCK | LK_SLEEPFAIL;
-	MNT_ILOCK(mp);
 loop:
 	/* Grab snapshot of secondary write counts */
+	MNT_ILOCK(mp);
 	secondary_writes = mp->mnt_secondary_writes;
 	secondary_accwrites = mp->mnt_secondary_accwrites;
+	MNT_IUNLOCK(mp);
 
 	/* Grab snapshot of softdep dependency counts */
-	MNT_IUNLOCK(mp);
 	softdep_get_depcounts(mp, &softdep_deps, &softdep_accdeps);
-	MNT_ILOCK(mp);
 
-	MNT_VNODE_FOREACH(vp, mp, mvp) {
+	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
 		/*
 		 * Depend on the vnode interlock to keep things stable enough
 		 * for a quick test.  Since there might be hundreds of
 		 * thousands of vnodes, we cannot afford even a subroutine
 		 * call unless there's a good chance that we have work to do.
 		 */
-		VI_LOCK(vp);
-		if (vp->v_iflag & VI_DOOMED) {
+		if (vp->v_type == VNON) {
 			VI_UNLOCK(vp);
 			continue;
 		}
 		ip = VTOI(vp);
-		if (vp->v_type == VNON || ((ip->i_flag &
+		if ((ip->i_flag &
 		    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
-		    vp->v_bufobj.bo_dirty.bv_cnt == 0)) {
+		    vp->v_bufobj.bo_dirty.bv_cnt == 0) {
 			VI_UNLOCK(vp);
 			continue;
 		}
-		MNT_IUNLOCK(mp);
 		if ((error = vget(vp, lockreq, td)) != 0) {
-			MNT_ILOCK(mp);
 			if (error == ENOENT || error == ENOLCK) {
-				MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp);
+				MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 				goto loop;
 			}
 			continue;
@@ -1580,9 +1560,7 @@ loop:
 		if ((error = ffs_syncvnode(vp, waitfor, 0)) != 0)
 			allerror = error;
 		vput(vp);
-		MNT_ILOCK(mp);
 	}
-	MNT_IUNLOCK(mp);
 	/*
 	 * Force stale filesystem control information to be flushed.
 	 */
@@ -1590,10 +1568,8 @@ loop:
 		if ((error = softdep_flushworklist(ump->um_mountp, &count, td)))
 			allerror = error;
 		/* Flushed work items may create new vnodes to clean */
-		if (allerror == 0 && count) {
-			MNT_ILOCK(mp);
+		if (allerror == 0 && count)
 			goto loop;
-		}
 	}
 #ifdef QUOTA
 	qsync(mp);
@@ -1608,18 +1584,18 @@ loop:
 		if ((error = VOP_FSYNC(devvp, waitfor, td)) != 0)
 			allerror = error;
 		VOP_UNLOCK(devvp, 0);
-		if (allerror == 0 && waitfor == MNT_WAIT) {
-			MNT_ILOCK(mp);
+		if (allerror == 0 && waitfor == MNT_WAIT)
 			goto loop;
-		}
 	} else if (suspend != 0) {
 		if (softdep_check_suspend(mp,
 					  devvp,
 					  softdep_deps,
 					  softdep_accdeps,
 					  secondary_writes,
-					  secondary_accwrites) != 0)
+					  secondary_accwrites) != 0) {
+			MNT_IUNLOCK(mp);
 			goto loop;	/* More work needed */
+		}
 		mtx_assert(MNT_MTX(mp), MA_OWNED);
 		mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
 		MNT_IUNLOCK(mp);