- Added support for vfs_cache on unionfs. As a result, you can use

  applications that use procfs on unionfs.
- Removed unionfs internal cache mechanism because it has
  vfs_cache support instead. As a result, it just simplified code of
  unionfs.
- Fixed kern/111262 issue.

Submitted by:   Masanori Ozawa <ozawa@ongs.co.jp> (unionfs developer)
Reviewed by:    jeff, kensmith
Approved by:    re (kensmith)
MFC after:      1 week

3 files changed, 43 insertions, 171 deletions

diff --git a/sys/fs/unionfs/union.h b/sys/fs/unionfs/union.h
index e2df553..302b384 100644
--- a/sys/fs/unionfs/union.h
+++ b/sys/fs/unionfs/union.h
@@ -72,7 +72,6 @@ struct unionfs_node_status {
 
 /* A cache of vnode references */
 struct unionfs_node {
-	LIST_ENTRY(unionfs_node) un_hash;	/* Hash list */
 	struct vnode   *un_lowervp;		/* lower side vnode */
 	struct vnode   *un_uppervp;		/* upper side vnode */
 	struct vnode   *un_dvp;			/* parent unionfs vnode */
@@ -82,10 +81,12 @@ struct unionfs_node {
 	int		un_flag;		/* unionfs node flag */
 };
 
-/* unionfs node flags */
-#define UNIONFS_CACHED		0x01	/* is cached */
-#define UNIONFS_OPENEXTL	0x02	/* openextattr (lower) */
-#define UNIONFS_OPENEXTU	0x04	/* openextattr (upper) */
+/*
+ * unionfs node flags
+ * It needs the vnode with exclusive lock, when changing the un_flag variable.
+ */
+#define UNIONFS_OPENEXTL	0x01	/* openextattr (lower) */
+#define UNIONFS_OPENEXTU	0x02	/* openextattr (upper) */
 
 #define	MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
 #define	VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
@@ -94,7 +95,7 @@ struct unionfs_node {
 int unionfs_init(struct vfsconf *vfsp);
 int unionfs_uninit(struct vfsconf *vfsp);
 int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td);
-void unionfs_hashrem(struct vnode *vp, struct thread *td);
+void unionfs_noderem(struct vnode *vp, struct thread *td);
 void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp);
 void unionfs_tryrem_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status *unsp);
 
diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c
index 6156da6..fc5e27c 100644
--- a/sys/fs/unionfs/union_subr.c
+++ b/sys/fs/unionfs/union_subr.c
@@ -60,135 +60,29 @@
 
 #include <fs/unionfs/union.h>
 
-#define	NUNIONFSNODECACHE 32
-
-#define	UNIONFS_NHASH(upper, lower) \
-	(&unionfs_node_hashtbl[(((uintptr_t)upper + (uintptr_t)lower) >> 8) & unionfs_node_hash])
-
-static LIST_HEAD(unionfs_node_hashhead, unionfs_node) *unionfs_node_hashtbl;
-static u_long	unionfs_node_hash;
-struct mtx	unionfs_hashmtx;
-
-static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table");
 MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part");
 MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part");
 
 /*
- * Initialize cache headers
+ * Initialize
  */
 int 
 unionfs_init(struct vfsconf *vfsp)
 {
 	UNIONFSDEBUG("unionfs_init\n");	/* printed during system boot */
-	unionfs_node_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, &unionfs_node_hash);
-	mtx_init(&unionfs_hashmtx, "unionfs", NULL, MTX_DEF);
-
 	return (0);
 }
 
 /*
- * Destroy cache headers
+ * Uninitialize
  */
 int 
 unionfs_uninit(struct vfsconf *vfsp)
 {
-	mtx_destroy(&unionfs_hashmtx);
-	free(unionfs_node_hashtbl, M_UNIONFSHASH);
 	return (0);
 }
 
 /*
- * Return a VREF'ed alias for unionfs vnode if already exists, else 0.
- */
-static struct vnode *
-unionfs_hashget(struct mount *mp, struct vnode *uppervp,
-		struct vnode *lowervp, struct vnode *dvp, char *path,
-		int lkflags, struct thread *td)
-{
-	struct unionfs_node_hashhead *hd;
-	struct unionfs_node *unp;
-	struct vnode   *vp;
-	int error;
-
-	if (lkflags & LK_TYPE_MASK)
-		lkflags |= LK_RETRY;
-	hd = UNIONFS_NHASH(uppervp, lowervp);
-
-	mtx_lock(&unionfs_hashmtx);
-	LIST_FOREACH(unp, hd, un_hash) {
-		if (unp->un_uppervp == uppervp &&
-		    unp->un_lowervp == lowervp &&
-		    unp->un_dvp == dvp &&
-		    UNIONFSTOV(unp)->v_mount == mp &&
-		    (!path || !(unp->un_path) || !strcmp(unp->un_path, path))) {
-			vp = UNIONFSTOV(unp);
-			VI_LOCK(vp);
-			mtx_unlock(&unionfs_hashmtx);
-			/*
-			 * We need to clear the OWEINACT flag here as this
-			 * may lead vget() to try to lock our vnode which is
-			 * already locked via vp.
-			 */
-			vp->v_iflag &= ~VI_OWEINACT;
-			error = vget(vp, LK_INTERLOCK, td);
-			if (error != 0)
-				panic("unionfs_hashget: vget error %d", error);
-			if (lkflags & LK_TYPE_MASK)
-				vn_lock(vp, lkflags, td);
-			return (vp);
-		}
-	}
-
-	mtx_unlock(&unionfs_hashmtx);
-
-	return (NULLVP);
-}
-
-/*
- * Act like unionfs_hashget, but add passed unionfs_node to hash if no existing
- * node found.
- */
-static struct vnode *
-unionfs_hashins(struct mount *mp, struct unionfs_node *uncp,
-		char *path, int lkflags, struct thread *td)
-{
-	struct unionfs_node_hashhead *hd;
-	struct unionfs_node *unp;
-	struct vnode   *vp;
-	int error;
-
-	if (lkflags & LK_TYPE_MASK)
-		lkflags |= LK_RETRY;
-	hd = UNIONFS_NHASH(uncp->un_uppervp, uncp->un_lowervp);
-
-	mtx_lock(&unionfs_hashmtx);
-	LIST_FOREACH(unp, hd, un_hash) {
-		if (unp->un_uppervp == uncp->un_uppervp &&
-		    unp->un_lowervp == uncp->un_lowervp &&
-		    unp->un_dvp == uncp->un_dvp &&
-		    UNIONFSTOV(unp)->v_mount == mp &&
-		    (!path || !(unp->un_path) || !strcmp(unp->un_path, path))) {
-			vp = UNIONFSTOV(unp);
-			VI_LOCK(vp);
-			mtx_unlock(&unionfs_hashmtx);
-			vp->v_iflag &= ~VI_OWEINACT;
-			error = vget(vp, LK_INTERLOCK, td);
-			if (error)
-				panic("unionfs_hashins: vget error %d", error);
-			if (lkflags & LK_TYPE_MASK)
-				vn_lock(vp, lkflags, td);
-			return (vp);
-		}
-	}
-
-	LIST_INSERT_HEAD(hd, uncp, un_hash);
-	uncp->un_flag |= UNIONFS_CACHED;
-	mtx_unlock(&unionfs_hashmtx);
-
-	return (NULLVP);
-}
-
-/*
  * Make a new or get existing unionfs node.
  * 
  * uppervp and lowervp should be unlocked. Because if new unionfs vnode is
@@ -210,20 +104,15 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 
 	ump = MOUNTTOUNIONFSMOUNT(mp);
 	lkflags = (cnp ? cnp->cn_lkflags : 0);
-	path = (cnp ? cnp->cn_nameptr : "");
+	path = (cnp ? cnp->cn_nameptr : NULL);
 
 	if (uppervp == NULLVP && lowervp == NULLVP)
 		panic("unionfs_nodeget: upper and lower is null");
 
 	/* If it has no ISLASTCN flag, path check is skipped. */
-	if (!cnp || !(cnp->cn_flags & ISLASTCN))
+	if (cnp && !(cnp->cn_flags & ISLASTCN))
 		path = NULL;
 
-	/* Lookup the hash first. */
-	*vpp = unionfs_hashget(mp, uppervp, lowervp, dvp, path, lkflags, td);
-	if (*vpp != NULLVP)
-		return (0);
-
 	if ((uppervp == NULLVP || ump->um_uppervp != uppervp) ||
 	    (lowervp == NULLVP || ump->um_lowervp != lowervp)) {
 		if (dvp == NULLVP)
@@ -239,7 +128,7 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 	    M_UNIONFSNODE, M_WAITOK | M_ZERO);
 
 	error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp);
-	if (error) {
+	if (error != 0) {
 		FREE(unp, M_UNIONFSNODE);
 		return (error);
 	}
@@ -264,9 +153,9 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 	else
 		vp->v_vnlock = lowervp->v_vnlock;
 
-	if (cnp) {
+	if (path != NULL) {
 		unp->un_path = (char *)
-		    malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK | M_ZERO);
+		    malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO);
 		bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen);
 		unp->un_path[cnp->cn_namelen] = '\0';
 	}
@@ -277,23 +166,6 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 	    (lowervp != NULLVP && ump->um_lowervp == lowervp))
 		vp->v_vflag |= VV_ROOT;
 
-	*vpp = unionfs_hashins(mp, unp, path, lkflags, td);
-	if (*vpp != NULLVP) {
-		if (dvp != NULLVP)
-			vrele(dvp);
-		if (uppervp != NULLVP)
-			vrele(uppervp);
-		if (lowervp != NULLVP)
-			vrele(lowervp);
-
-		unp->un_uppervp = NULLVP;
-		unp->un_lowervp = NULLVP;
-		unp->un_dvp = NULLVP;
-		vrele(vp);
-
-		return (0);
-	}
-
 	if (lkflags & LK_TYPE_MASK)
 		vn_lock(vp, lkflags | LK_RETRY, td);
 
@@ -303,10 +175,10 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 }
 
 /*
- * Remove node from hash.
+ * Clean up the unionfs node.
  */
 void
-unionfs_hashrem(struct vnode *vp, struct thread *td)
+unionfs_noderem(struct vnode *vp, struct thread *td)
 {
 	int		vfslocked;
 	struct unionfs_node *unp;
@@ -331,13 +203,6 @@ unionfs_hashrem(struct vnode *vp, struct thread *td)
 		VOP_UNLOCK(lvp, 0, td);
 	if (uvp != NULLVP)
 		VOP_UNLOCK(uvp, 0, td);
-
-	mtx_lock(&unionfs_hashmtx);
-	if (unp->un_flag & UNIONFS_CACHED) {
-		LIST_REMOVE(unp, un_hash);
-		unp->un_flag &= ~UNIONFS_CACHED;
-	}
-	mtx_unlock(&unionfs_hashmtx);
 	vp->v_object = NULL;
 
 	if (lvp != NULLVP) {
@@ -692,16 +557,6 @@ unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp,
 	VI_UNLOCK(vp);
 	for (count = 1; count < lockcnt; count++)
 		vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY, td);
-
-	/*
-	 * cache update
-	 */
-	mtx_lock(&unionfs_hashmtx);
-	if (unp->un_flag & UNIONFS_CACHED)
-		LIST_REMOVE(unp, un_hash);
-	LIST_INSERT_HEAD(UNIONFS_NHASH(uvp, lvp), unp, un_hash);
-	unp->un_flag |= UNIONFS_CACHED;
-	mtx_unlock(&unionfs_hashmtx);
 }
 
 /*
diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c
index 3d46ab8..cd6663f 100644
--- a/sys/fs/unionfs/union_vnops.c
+++ b/sys/fs/unionfs/union_vnops.c
@@ -88,7 +88,7 @@ static struct lk_lr_table un_llt[] = {
 
 
 static int
-unionfs_lookup(struct vop_lookup_args *ap)
+unionfs_lookup(struct vop_cachedlookup_args *ap)
 {
 	int		iswhiteout;
 	int		lockflag;
@@ -171,7 +171,9 @@ unionfs_lookup(struct vop_lookup_args *ap)
 				vn_lock(dunp->un_dvp, cnp->cn_lkflags | LK_RETRY, td);
 
 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
-		}
+		} else if (error == ENOENT && (cnflags & MAKEENTRY) &&
+		    nameiop != CREATE)
+			cache_enter(dvp, NULLVP, cnp);
 
 		UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
 
@@ -318,12 +320,18 @@ unionfs_lookup(struct vop_lookup_args *ap)
 
 	*(ap->a_vpp) = vp;
 
+	if (cnflags & MAKEENTRY)
+		cache_enter(dvp, vp, cnp);
+
 unionfs_lookup_out:
 	if (uvp != NULLVP)
 		vrele(uvp);
 	if (lvp != NULLVP)
 		vrele(lvp);
 
+	if (error == ENOENT && (cnflags & MAKEENTRY) && nameiop != CREATE)
+		cache_enter(dvp, NULLVP, cnp);
+
 	UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
 
 	return (error);
@@ -1178,6 +1186,13 @@ unionfs_rename(struct vop_rename_args *ap)
 
 	error = VOP_RENAME(rfdvp, rfvp, fcnp, rtdvp, rtvp, tcnp);
 
+	if (error == 0) {
+		if (rtvp != NULLVP && rtvp->v_type == VDIR)
+			cache_purge(tdvp);
+		if (fvp->v_type == VDIR && fdvp != tdvp)
+			cache_purge(fdvp);
+	}
+
 	if (fdvp != rfdvp)
 		vrele(fdvp);
 	if (fvp != rfvp)
@@ -1310,6 +1325,11 @@ unionfs_rmdir(struct vop_rmdir_args *ap)
 	else if (lvp != NULLVP)
 		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
 
+	if (error == 0) {
+		cache_purge(ap->a_dvp);
+		cache_purge(ap->a_vp);
+	}
+
 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: leave (%d)\n", error);
 
 	return (error);
@@ -1564,13 +1584,8 @@ unionfs_getwritemount(struct vop_getwritemount_args *ap)
 static int
 unionfs_inactive(struct vop_inactive_args *ap)
 {
-	struct unionfs_node *unp;
-
-	unp = VTOUNIONFS(ap->a_vp);
-
-	if (unp == NULL || !(unp->un_flag & UNIONFS_CACHED))
-		vgone(ap->a_vp);
-
+	ap->a_vp->v_object = NULL;
+	vrecycle(ap->a_vp, ap->a_td);
 	return (0);
 }
 
@@ -1579,7 +1594,7 @@ unionfs_reclaim(struct vop_reclaim_args *ap)
 {
 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: enter\n"); */
 
-	unionfs_hashrem(ap->a_vp, ap->a_td);
+	unionfs_noderem(ap->a_vp, ap->a_td);
 
 	/* UNIONFS_INTERNAL_DEBUG("unionfs_reclaim: leave\n"); */
 
@@ -2240,6 +2255,7 @@ struct vop_vector unionfs_vnodeops = {
 	.vop_aclcheck =		unionfs_aclcheck,
 	.vop_advlock =		unionfs_advlock,
 	.vop_bmap =		VOP_EOPNOTSUPP,
+	.vop_cachedlookup =	unionfs_lookup,
 	.vop_close =		unionfs_close,
 	.vop_closeextattr =	unionfs_closeextattr,
 	.vop_create =		unionfs_create,
@@ -2255,7 +2271,7 @@ struct vop_vector unionfs_vnodeops = {
 	.vop_link =		unionfs_link,
 	.vop_listextattr =	unionfs_listextattr,
 	.vop_lock1 =		unionfs_lock,
-	.vop_lookup =		unionfs_lookup,
+	.vop_lookup =		vfs_cache_lookup,
 	.vop_mkdir =		unionfs_mkdir,
 	.vop_mknod =		unionfs_mknod,
 	.vop_open =		unionfs_open,