From 6a8bb0562e6cb74f99e8138886708c3468d418fd Mon Sep 17 00:00:00 2001
From: Augustin Cavalier <waddlesplash@gmail.com>
Date: Wed, 30 Nov 2022 00:17:58 -0500
Subject: [PATCH] ramfs: Correct usage of Nodes in Entry.

 * We do not want to set fNode in the constructor but let the invocation
   of Link() take care of doing so instead.

 * Link/Unlink manipulate linked-lists. Thus it is dangerous to use them
   in tandem on the same Node object. Add a check for this.

 * Minor cleanup.
---
 .../kernel/file_systems/ramfs/Entry.cpp       | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/add-ons/kernel/file_systems/ramfs/Entry.cpp b/src/add-ons/kernel/file_systems/ramfs/Entry.cpp
index d4ff177f35..f0877a7163 100644
--- a/src/add-ons/kernel/file_systems/ramfs/Entry.cpp
+++ b/src/add-ons/kernel/file_systems/ramfs/Entry.cpp
@@ -13,7 +13,7 @@
 // constructor
 Entry::Entry(const char *name, Node *node, Directory *parent)
 	: fParent(parent),
-	  fNode(node),
+	  fNode(NULL),
 	  fName(name),
 	  fReferrerLink(),
 	  fIterators()
@@ -40,17 +40,18 @@ Entry::InitCheck() const
 status_t
 Entry::Link(Node *node)
 {
-	status_t error = (node ? B_OK : B_BAD_VALUE);
+	if (node == NULL)
+		return B_BAD_VALUE;
+	if (node == fNode)
+		return B_OK;
+
+	// We first link to the new node and then unlink the old one.
+	Node *oldNode = fNode;
+	status_t error = node->Link(this);
 	if (error == B_OK) {
-		// We first link to the new node and then unlink the old one. So, no
-		// harm is done, if both are the same.
-		Node *oldNode = fNode;
-		error = node->Link(this);
-		if (error == B_OK) {
-			fNode = node;
-			if (oldNode)
-				oldNode->Unlink(this);
-		}
+		fNode = node;
+		if (oldNode)
+			oldNode->Unlink(this);
 	}
 	return error;
 }
@@ -101,4 +102,3 @@ Entry::GetAllocationInfo(AllocationInfo &info)
 	info.AddStringAllocation(fName.GetLength());
 	fNode->GetAllocationInfo(info);
 }
-