1 files changed, 305 insertions, 200 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 87bdb5329c3..761e31bacbc 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -229,7 +229,7 @@ static void __d_free(struct rcu_head *head)
  */
 static void d_free(struct dentry *dentry)
 {
-	BUG_ON(dentry->d_count);
+	BUG_ON(dentry->d_lockref.count);
 	this_cpu_dec(nr_dentry);
 	if (dentry->d_op && dentry->d_op->d_release)
 		dentry->d_op->d_release(dentry);
@@ -467,12 +467,12 @@ relock:
 	}
 
 	if (ref)
-		dentry->d_count--;
+		dentry->d_lockref.count--;
 	/*
 	 * inform the fs via d_prune that this dentry is about to be
 	 * unhashed and destroyed.
 	 */
-	if (dentry->d_flags & DCACHE_OP_PRUNE)
+	if ((dentry->d_flags & DCACHE_OP_PRUNE) && !d_unhashed(dentry))
 		dentry->d_op->d_prune(dentry);
 
 	dentry_lru_del(dentry);
@@ -513,15 +513,10 @@ void dput(struct dentry *dentry)
 		return;
 
 repeat:
-	if (dentry->d_count == 1)
+	if (dentry->d_lockref.count == 1)
 		might_sleep();
-	spin_lock(&dentry->d_lock);
-	BUG_ON(!dentry->d_count);
-	if (dentry->d_count > 1) {
-		dentry->d_count--;
-		spin_unlock(&dentry->d_lock);
+	if (lockref_put_or_lock(&dentry->d_lockref))
 		return;
-	}
 
 	if (dentry->d_flags & DCACHE_OP_DELETE) {
 		if (dentry->d_op->d_delete(dentry))
@@ -535,7 +530,7 @@ repeat:
 	dentry->d_flags |= DCACHE_REFERENCED;
 	dentry_lru_add(dentry);
 
-	dentry->d_count--;
+	dentry->d_lockref.count--;
 	spin_unlock(&dentry->d_lock);
 	return;
 
@@ -590,7 +585,7 @@ int d_invalidate(struct dentry * dentry)
 	 * We also need to leave mountpoints alone,
 	 * directory or not.
 	 */
-	if (dentry->d_count > 1 && dentry->d_inode) {
+	if (dentry->d_lockref.count > 1 && dentry->d_inode) {
 		if (S_ISDIR(dentry->d_inode->i_mode) || d_mountpoint(dentry)) {
 			spin_unlock(&dentry->d_lock);
 			return -EBUSY;
@@ -606,20 +601,33 @@ EXPORT_SYMBOL(d_invalidate);
 /* This must be called with d_lock held */
 static inline void __dget_dlock(struct dentry *dentry)
 {
-	dentry->d_count++;
+	dentry->d_lockref.count++;
 }
 
 static inline void __dget(struct dentry *dentry)
 {
-	spin_lock(&dentry->d_lock);
-	__dget_dlock(dentry);
-	spin_unlock(&dentry->d_lock);
+	lockref_get(&dentry->d_lockref);
 }
 
 struct dentry *dget_parent(struct dentry *dentry)
 {
+	int gotref;
 	struct dentry *ret;
 
+	/*
+	 * Do optimistic parent lookup without any
+	 * locking.
+	 */
+	rcu_read_lock();
+	ret = ACCESS_ONCE(dentry->d_parent);
+	gotref = lockref_get_not_zero(&ret->d_lockref);
+	rcu_read_unlock();
+	if (likely(gotref)) {
+		if (likely(ret == ACCESS_ONCE(dentry->d_parent)))
+			return ret;
+		dput(ret);
+	}
+
 repeat:
 	/*
 	 * Don't need rcu_dereference because we re-check it was correct under
@@ -634,8 +642,8 @@ repeat:
 		goto repeat;
 	}
 	rcu_read_unlock();
-	BUG_ON(!ret->d_count);
-	ret->d_count++;
+	BUG_ON(!ret->d_lockref.count);
+	ret->d_lockref.count++;
 	spin_unlock(&ret->d_lock);
 	return ret;
 }
@@ -718,7 +726,15 @@ restart:
 	spin_lock(&inode->i_lock);
 	hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
 		spin_lock(&dentry->d_lock);
-		if (!dentry->d_count) {
+		if (!dentry->d_lockref.count) {
+			/*
+			 * inform the fs via d_prune that this dentry
+			 * is about to be unhashed and destroyed.
+			 */
+			if ((dentry->d_flags & DCACHE_OP_PRUNE) &&
+			    !d_unhashed(dentry))
+				dentry->d_op->d_prune(dentry);
+
 			__dget_dlock(dentry);
 			__d_drop(dentry);
 			spin_unlock(&dentry->d_lock);
@@ -763,12 +779,8 @@ static void try_prune_one_dentry(struct dentry *dentry)
 	/* Prune ancestors. */
 	dentry = parent;
 	while (dentry) {
-		spin_lock(&dentry->d_lock);
-		if (dentry->d_count > 1) {
-			dentry->d_count--;
-			spin_unlock(&dentry->d_lock);
+		if (lockref_put_or_lock(&dentry->d_lockref))
 			return;
-		}
 		dentry = dentry_kill(dentry, 1);
 	}
 }
@@ -793,7 +805,7 @@ static void shrink_dentry_list(struct list_head *list)
 		 * the LRU because of laziness during lookup.  Do not free
 		 * it - just keep it off the LRU list.
 		 */
-		if (dentry->d_count) {
+		if (dentry->d_lockref.count) {
 			dentry_lru_del(dentry);
 			spin_unlock(&dentry->d_lock);
 			continue;
@@ -907,13 +919,14 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 			 * inform the fs that this dentry is about to be
 			 * unhashed and destroyed.
 			 */
-			if (dentry->d_flags & DCACHE_OP_PRUNE)
+			if ((dentry->d_flags & DCACHE_OP_PRUNE) &&
+			    !d_unhashed(dentry))
 				dentry->d_op->d_prune(dentry);
 
 			dentry_lru_del(dentry);
 			__d_shrink(dentry);
 
-			if (dentry->d_count != 0) {
+			if (dentry->d_lockref.count != 0) {
 				printk(KERN_ERR
 				       "BUG: Dentry %p{i=%lx,n=%s}"
 				       " still in use (%d)"
@@ -922,7 +935,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 				       dentry->d_inode ?
 				       dentry->d_inode->i_ino : 0UL,
 				       dentry->d_name.name,
-				       dentry->d_count,
+				       dentry->d_lockref.count,
 				       dentry->d_sb->s_type->name,
 				       dentry->d_sb->s_id);
 				BUG();
@@ -933,7 +946,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
 				list_del(&dentry->d_u.d_child);
 			} else {
 				parent = dentry->d_parent;
-				parent->d_count--;
+				parent->d_lockref.count--;
 				list_del(&dentry->d_u.d_child);
 			}
 
@@ -981,7 +994,7 @@ void shrink_dcache_for_umount(struct super_block *sb)
 
 	dentry = sb->s_root;
 	sb->s_root = NULL;
-	dentry->d_count--;
+	dentry->d_lockref.count--;
 	shrink_dcache_for_umount_subtree(dentry);
 
 	while (!hlist_bl_empty(&sb->s_anon)) {
@@ -1018,34 +1031,56 @@ static struct dentry *try_to_ascend(struct dentry *old, int locked, unsigned seq
 	return new;
 }
 
+/**
+ * enum d_walk_ret - action to talke during tree walk
+ * @D_WALK_CONTINUE:	contrinue walk
+ * @D_WALK_QUIT:	quit walk
+ * @D_WALK_NORETRY:	quit when retry is needed
+ * @D_WALK_SKIP:	skip this dentry and its children
+ */
+enum d_walk_ret {
+	D_WALK_CONTINUE,
+	D_WALK_QUIT,
+	D_WALK_NORETRY,
+	D_WALK_SKIP,
+};
 
-/*
- * Search for at least 1 mount point in the dentry's subdirs.
- * We descend to the next level whenever the d_subdirs
- * list is non-empty and continue searching.
- */
- 
 /**
- * have_submounts - check for mounts over a dentry
- * @parent: dentry to check.
+ * d_walk - walk the dentry tree
+ * @parent:	start of walk
+ * @data:	data passed to @enter() and @finish()
+ * @enter:	callback when first entering the dentry
+ * @finish:	callback when successfully finished the walk
  *
- * Return true if the parent or its subdirectories contain
- * a mount point
+ * The @enter() and @finish() callbacks are called with d_lock held.
  */
-int have_submounts(struct dentry *parent)
+static void d_walk(struct dentry *parent, void *data,
+		   enum d_walk_ret (*enter)(void *, struct dentry *),
+		   void (*finish)(void *))
 {
 	struct dentry *this_parent;
 	struct list_head *next;
 	unsigned seq;
 	int locked = 0;
+	enum d_walk_ret ret;
+	bool retry = true;
 
 	seq = read_seqbegin(&rename_lock);
 again:
 	this_parent = parent;
-
-	if (d_mountpoint(parent))
-		goto positive;
 	spin_lock(&this_parent->d_lock);
+
+	ret = enter(data, this_parent);
+	switch (ret) {
+	case D_WALK_CONTINUE:
+		break;
+	case D_WALK_QUIT:
+	case D_WALK_SKIP:
+		goto out_unlock;
+	case D_WALK_NORETRY:
+		retry = false;
+		break;
+	}
 repeat:
 	next = this_parent->d_subdirs.next;
 resume:
@@ -1055,12 +1090,22 @@ resume:
 		next = tmp->next;
 
 		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
-		/* Have we found a mount point ? */
-		if (d_mountpoint(dentry)) {
+
+		ret = enter(data, dentry);
+		switch (ret) {
+		case D_WALK_CONTINUE:
+			break;
+		case D_WALK_QUIT:
 			spin_unlock(&dentry->d_lock);
-			spin_unlock(&this_parent->d_lock);
-			goto positive;
+			goto out_unlock;
+		case D_WALK_NORETRY:
+			retry = false;
+			break;
+		case D_WALK_SKIP:
+			spin_unlock(&dentry->d_lock);
+			continue;
 		}
+
 		if (!list_empty(&dentry->d_subdirs)) {
 			spin_unlock(&this_parent->d_lock);
 			spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
@@ -1081,29 +1126,97 @@ resume:
 		next = child->d_u.d_child.next;
 		goto resume;
 	}
-	spin_unlock(&this_parent->d_lock);
-	if (!locked && read_seqretry(&rename_lock, seq))
-		goto rename_retry;
-	if (locked)
-		write_sequnlock(&rename_lock);
-	return 0; /* No mount points found in tree */
-positive:
-	if (!locked && read_seqretry(&rename_lock, seq))
+	if (!locked && read_seqretry(&rename_lock, seq)) {
+		spin_unlock(&this_parent->d_lock);
 		goto rename_retry;
+	}
+	if (finish)
+		finish(data);
+
+out_unlock:
+	spin_unlock(&this_parent->d_lock);
 	if (locked)
 		write_sequnlock(&rename_lock);
-	return 1;
+	return;
 
 rename_retry:
+	if (!retry)
+		return;
 	if (locked)
 		goto again;
 	locked = 1;
 	write_seqlock(&rename_lock);
 	goto again;
 }
+
+/*
+ * Search for at least 1 mount point in the dentry's subdirs.
+ * We descend to the next level whenever the d_subdirs
+ * list is non-empty and continue searching.
+ */
+
+/**
+ * have_submounts - check for mounts over a dentry
+ * @parent: dentry to check.
+ *
+ * Return true if the parent or its subdirectories contain
+ * a mount point
+ */
+
+static enum d_walk_ret check_mount(void *data, struct dentry *dentry)
+{
+	int *ret = data;
+	if (d_mountpoint(dentry)) {
+		*ret = 1;
+		return D_WALK_QUIT;
+	}
+	return D_WALK_CONTINUE;
+}
+
+int have_submounts(struct dentry *parent)
+{
+	int ret = 0;
+
+	d_walk(parent, &ret, check_mount, NULL);
+
+	return ret;
+}
 EXPORT_SYMBOL(have_submounts);
 
 /*
+ * Called by mount code to set a mountpoint and check if the mountpoint is
+ * reachable (e.g. NFS can unhash a directory dentry and then the complete
+ * subtree can become unreachable).
+ *
+ * Only one of check_submounts_and_drop() and d_set_mounted() must succeed.  For
+ * this reason take rename_lock and d_lock on dentry and ancestors.
+ */
+int d_set_mounted(struct dentry *dentry)
+{
+	struct dentry *p;
+	int ret = -ENOENT;
+	write_seqlock(&rename_lock);
+	for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) {
+		/* Need exclusion wrt. check_submounts_and_drop() */
+		spin_lock(&p->d_lock);
+		if (unlikely(d_unhashed(p))) {
+			spin_unlock(&p->d_lock);
+			goto out;
+		}
+		spin_unlock(&p->d_lock);
+	}
+	spin_lock(&dentry->d_lock);
+	if (!d_unlinked(dentry)) {
+		dentry->d_flags |= DCACHE_MOUNTED;
+		ret = 0;
+	}
+ 	spin_unlock(&dentry->d_lock);
+out:
+	write_sequnlock(&rename_lock);
+	return ret;
+}
+
+/*
  * Search the dentry child list of the specified parent,
  * and move any unused dentries to the end of the unused
  * list for prune_dcache(). We descend to the next level
@@ -1117,93 +1230,46 @@ EXPORT_SYMBOL(have_submounts);
  * drop the lock and return early due to latency
  * constraints.
  */
-static int select_parent(struct dentry *parent, struct list_head *dispose)
-{
-	struct dentry *this_parent;
-	struct list_head *next;
-	unsigned seq;
-	int found = 0;
-	int locked = 0;
 
-	seq = read_seqbegin(&rename_lock);
-again:
-	this_parent = parent;
-	spin_lock(&this_parent->d_lock);
-repeat:
-	next = this_parent->d_subdirs.next;
-resume:
-	while (next != &this_parent->d_subdirs) {
-		struct list_head *tmp = next;
-		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
-		next = tmp->next;
-
-		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+struct select_data {
+	struct dentry *start;
+	struct list_head dispose;
+	int found;
+};
 
-		/*
-		 * move only zero ref count dentries to the dispose list.
-		 *
-		 * Those which are presently on the shrink list, being processed
-		 * by shrink_dentry_list(), shouldn't be moved.  Otherwise the
-		 * loop in shrink_dcache_parent() might not make any progress
-		 * and loop forever.
-		 */
-		if (dentry->d_count) {
-			dentry_lru_del(dentry);
-		} else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
-			dentry_lru_move_list(dentry, dispose);
-			dentry->d_flags |= DCACHE_SHRINK_LIST;
-			found++;
-		}
-		/*
-		 * We can return to the caller if we have found some (this
-		 * ensures forward progress). We'll be coming back to find
-		 * the rest.
-		 */
-		if (found && need_resched()) {
-			spin_unlock(&dentry->d_lock);
-			goto out;
-		}
+static enum d_walk_ret select_collect(void *_data, struct dentry *dentry)
+{
+	struct select_data *data = _data;
+	enum d_walk_ret ret = D_WALK_CONTINUE;
 
-		/*
-		 * Descend a level if the d_subdirs list is non-empty.
-		 */
-		if (!list_empty(&dentry->d_subdirs)) {
-			spin_unlock(&this_parent->d_lock);
-			spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
-			this_parent = dentry;
-			spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
-			goto repeat;
-		}
+	if (data->start == dentry)
+		goto out;
 
-		spin_unlock(&dentry->d_lock);
-	}
 	/*
-	 * All done at this level ... ascend and resume the search.
+	 * move only zero ref count dentries to the dispose list.
+	 *
+	 * Those which are presently on the shrink list, being processed
+	 * by shrink_dentry_list(), shouldn't be moved.  Otherwise the
+	 * loop in shrink_dcache_parent() might not make any progress
+	 * and loop forever.
 	 */
-	if (this_parent != parent) {
-		struct dentry *child = this_parent;
-		this_parent = try_to_ascend(this_parent, locked, seq);
-		if (!this_parent)
-			goto rename_retry;
-		next = child->d_u.d_child.next;
-		goto resume;
+	if (dentry->d_lockref.count) {
+		dentry_lru_del(dentry);
+	} else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
+		dentry_lru_move_list(dentry, &data->dispose);
+		dentry->d_flags |= DCACHE_SHRINK_LIST;
+		data->found++;
+		ret = D_WALK_NORETRY;
 	}
+	/*
+	 * We can return to the caller if we have found some (this
+	 * ensures forward progress). We'll be coming back to find
+	 * the rest.
+	 */
+	if (data->found && need_resched())
+		ret = D_WALK_QUIT;
 out:
-	spin_unlock(&this_parent->d_lock);
-	if (!locked && read_seqretry(&rename_lock, seq))
-		goto rename_retry;
-	if (locked)
-		write_sequnlock(&rename_lock);
-	return found;
-
-rename_retry:
-	if (found)
-		return found;
-	if (locked)
-		goto again;
-	locked = 1;
-	write_seqlock(&rename_lock);
-	goto again;
+	return ret;
 }
 
 /**
@@ -1212,18 +1278,90 @@ rename_retry:
  *
  * Prune the dcache to remove unused children of the parent dentry.
  */
-void shrink_dcache_parent(struct dentry * parent)
+void shrink_dcache_parent(struct dentry *parent)
 {
-	LIST_HEAD(dispose);
-	int found;
+	for (;;) {
+		struct select_data data;
+
+		INIT_LIST_HEAD(&data.dispose);
+		data.start = parent;
+		data.found = 0;
 
-	while ((found = select_parent(parent, &dispose)) != 0) {
-		shrink_dentry_list(&dispose);
+		d_walk(parent, &data, select_collect, NULL);
+		if (!data.found)
+			break;
+
+		shrink_dentry_list(&data.dispose);
 		cond_resched();
 	}
 }
 EXPORT_SYMBOL(shrink_dcache_parent);
 
+static enum d_walk_ret check_and_collect(void *_data, struct dentry *dentry)
+{
+	struct select_data *data = _data;
+
+	if (d_mountpoint(dentry)) {
+		data->found = -EBUSY;
+		return D_WALK_QUIT;
+	}
+
+	return select_collect(_data, dentry);
+}
+
+static void check_and_drop(void *_data)
+{
+	struct select_data *data = _data;
+
+	if (d_mountpoint(data->start))
+		data->found = -EBUSY;
+	if (!data->found)
+		__d_drop(data->start);
+}
+
+/**
+ * check_submounts_and_drop - prune dcache, check for submounts and drop
+ *
+ * All done as a single atomic operation relative to has_unlinked_ancestor().
+ * Returns 0 if successfully unhashed @parent.  If there were submounts then
+ * return -EBUSY.
+ *
+ * @dentry: dentry to prune and drop
+ */
+int check_submounts_and_drop(struct dentry *dentry)
+{
+	int ret = 0;
+
+	/* Negative dentries can be dropped without further checks */
+	if (!dentry->d_inode) {
+		d_drop(dentry);
+		goto out;
+	}
+
+	for (;;) {
+		struct select_data data;
+
+		INIT_LIST_HEAD(&data.dispose);
+		data.start = dentry;
+		data.found = 0;
+
+		d_walk(dentry, &data, check_and_collect, check_and_drop);
+		ret = data.found;
+
+		if (!list_empty(&data.dispose))
+			shrink_dentry_list(&data.dispose);
+
+		if (ret <= 0)
+			break;
+
+		cond_resched();
+	}
+
+out:
+	return ret;
+}
+EXPORT_SYMBOL(check_submounts_and_drop);
+
 /**
  * __d_alloc	-	allocate a dcache entry
  * @sb: filesystem it will belong to
@@ -1269,7 +1407,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
 	smp_wmb();
 	dentry->d_name.name = dname;
 
-	dentry->d_count = 1;
+	dentry->d_lockref.count = 1;
 	dentry->d_flags = 0;
 	spin_lock_init(&dentry->d_lock);
 	seqcount_init(&dentry->d_seq);
@@ -1782,7 +1920,7 @@ static noinline enum slow_d_compare slow_dentry_cmp(
  * without taking d_lock and checking d_seq sequence count against @seq
  * returned here.
  *
- * A refcount may be taken on the found dentry with the __d_rcu_to_refcount
+ * A refcount may be taken on the found dentry with the d_rcu_to_refcount
  * function.
  *
  * Alternatively, __d_lookup_rcu may be called again to look up the child of
@@ -1970,7 +2108,7 @@ struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name)
 				goto next;
 		}
 
-		dentry->d_count++;
+		dentry->d_lockref.count++;
 		found = dentry;
 		spin_unlock(&dentry->d_lock);
 		break;
@@ -2069,7 +2207,7 @@ again:
 	spin_lock(&dentry->d_lock);
 	inode = dentry->d_inode;
 	isdir = S_ISDIR(inode->i_mode);
-	if (dentry->d_count == 1) {
+	if (dentry->d_lockref.count == 1) {
 		if (!spin_trylock(&inode->i_lock)) {
 			spin_unlock(&dentry->d_lock);
 			cpu_relax();
@@ -2724,6 +2862,17 @@ char *dynamic_dname(struct dentry *dentry, char *buffer, int buflen,
 	return memcpy(buffer, temp, sz);
 }
 
+char *simple_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+	char *end = buffer + buflen;
+	/* these dentries are never renamed, so d_lock is not needed */
+	if (prepend(&end, &buflen, " (deleted)", 11) ||
+	    prepend_name(&end, &buflen, &dentry->d_name) ||
+	    prepend(&end, &buflen, "/", 1))  
+		end = ERR_PTR(-ENAMETOOLONG);
+	return end;  
+}
+
 /*
  * Write full pathname from the root of the filesystem into the buffer.
  */
@@ -2904,68 +3053,24 @@ int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
 	return result;
 }
 
-void d_genocide(struct dentry *root)
+static enum d_walk_ret d_genocide_kill(void *data, struct dentry *dentry)
 {
-	struct dentry *this_parent;
-	struct list_head *next;
-	unsigned seq;
-	int locked = 0;
+	struct dentry *root = data;
+	if (dentry != root) {
+		if (d_unhashed(dentry) || !dentry->d_inode)
+			return D_WALK_SKIP;
 
-	seq = read_seqbegin(&rename_lock);
-again:
-	this_parent = root;
-	spin_lock(&this_parent->d_lock);
-repeat:
-	next = this_parent->d_subdirs.next;
-resume:
-	while (next != &this_parent->d_subdirs) {
-		struct list_head *tmp = next;
-		struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
-		next = tmp->next;
-
-		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
-		if (d_unhashed(dentry) || !dentry->d_inode) {
-			spin_unlock(&dentry->d_lock);
-			continue;
-		}
-		if (!list_empty(&dentry->d_subdirs)) {
-			spin_unlock(&this_parent->d_lock);
-			spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
-			this_parent = dentry;
-			spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
-			goto repeat;
-		}
 		if (!(dentry->d_flags & DCACHE_GENOCIDE)) {
 			dentry->d_flags |= DCACHE_GENOCIDE;
-			dentry->d_count--;
+			dentry->d_lockref.count--;
 		}
-		spin_unlock(&dentry->d_lock);
 	}
-	if (this_parent != root) {
-		struct dentry *child = this_parent;
-		if (!(this_parent->d_flags & DCACHE_GENOCIDE)) {
-			this_parent->d_flags |= DCACHE_GENOCIDE;
-			this_parent->d_count--;
-		}
-		this_parent = try_to_ascend(this_parent, locked, seq);
-		if (!this_parent)
-			goto rename_retry;
-		next = child->d_u.d_child.next;
-		goto resume;
-	}
-	spin_unlock(&this_parent->d_lock);
-	if (!locked && read_seqretry(&rename_lock, seq))
-		goto rename_retry;
-	if (locked)
-		write_sequnlock(&rename_lock);
-	return;
+	return D_WALK_CONTINUE;
+}
 
-rename_retry:
-	if (locked)
-		goto again;
-	locked = 1;
-	write_seqlock(&rename_lock);
-	goto again;
+void d_genocide(struct dentry *parent)
+{
+	d_walk(parent, parent, d_genocide_kill, NULL);
 }
 
 void d_tmpfile(struct dentry *dentry, struct inode *inode)