Received-SPF: pass (google.com: domain of linux-kernel+bounces-193296-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Message-ID: <tencent_72297DA3B4444FF762977666C65361437E05@qq.com>
From: Edward Adam Davis <eadavis@qq.com>
To: syzbot+fe42a669c87e4a980051@syzkaller.appspotmail.com
Cc: adilger.kernel@dilger.ca,
	linux-ext4@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com,
	tytso@mit.edu
Subject: [PATCH] fs/dcache: fix warning in ext4_xattr_inode_lookup_create
Date: Wed, 29 May 2024 09:15:02 +0800
In-Reply-To: <0000000000002b03350619853096@google.com>
References: <0000000000002b03350619853096@google.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

ext4_xattr_inode_lookup_create() will use s_root, so set it to NULL
after do_one_tree().

Reported-and-tested-by: syzbot+fe42a669c87e4a980051@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 fs/dcache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 407095188f83..e2f1a3f92ce9 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1551,8 +1551,8 @@ void shrink_dcache_for_umount(struct super_block *sb)
 	WARN(down_read_trylock(&sb->s_umount), "s_umount should've been locked");
 
 	dentry = sb->s_root;
-	sb->s_root = NULL;
 	do_one_tree(dentry);
+	sb->s_root = NULL;
 
 	while (!hlist_bl_empty(&sb->s_roots)) {
 		dentry = dget(hlist_bl_entry(hlist_bl_first(&sb->s_roots), struct dentry, d_hash));
-- 
2.43.0