--- a/fs/file_table.c	2022-05-16 19:54:05.244159900 +0800
+++ b/fs/file_table.c	2022-05-16 19:55:14.706577300 +0800
@@ -330,7 +330,7 @@ static void __fput(struct file *file)
 	dput(dentry);
 	if (unlikely(mode & FMODE_NEED_UNMOUNT))
 		dissolve_on_fput(mnt);
-	mntput(mnt);
+	//mntput(mnt);
 out:
 	file_free(file);
 }
--- a/fs/mount.h	2022-05-16 19:33:29.792582900 +0800
+++ b/fs/mount.h	2022-05-16 19:38:05.627715000 +0800
@@ -77,6 +77,7 @@ struct mount {
 	int mnt_expiry_mark;		/* true if marked for expiry */
 	struct hlist_head mnt_pins;
 	struct hlist_head mnt_stuck_children;
+	struct wait_queue_head wwq;	/* writer wq */
 } __randomize_layout;
 
 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
--- a/fs/namespace.c	2022-05-16 19:34:10.676163000 +0800
+++ b/fs/namespace.c	2022-05-16 19:51:59.915219000 +0800
@@ -233,6 +233,7 @@ static struct mount *alloc_vfsmnt(const
 		INIT_LIST_HEAD(&mnt->mnt_umounting);
 		INIT_HLIST_HEAD(&mnt->mnt_stuck_children);
 		mnt->mnt.mnt_userns = &init_user_ns;
+		init_waitqueue_head(&mnt->wwq);
 	}
 	return mnt;
 
@@ -469,6 +470,12 @@ void mnt_drop_write(struct vfsmount *mnt
 {
 	__mnt_drop_write(mnt);
 	sb_end_write(mnt->mnt_sb);
+	if (mnt->mnt_flags & MNT_DOOMED) {
+		struct mount *m = real_mount(mnt);
+
+		if (!m->mnt_ns && !mnt_get_writers(m))
+			wake_up(&m->wwq);
+	}
 }
 EXPORT_SYMBOL_GPL(mnt_drop_write);
 
@@ -1174,7 +1181,7 @@ static void cleanup_mnt(struct mount *mn
 	 * The locking used to deal with mnt_count decrement provides barriers,
 	 * so mnt_get_writers() below is safe.
 	 */
-	WARN_ON(mnt_get_writers(mnt));
+	wait_event(mnt->wwq, !mnt_get_writers(mnt));
 	if (unlikely(mnt->mnt_pins.first))
 		mnt_pin_kill(mnt);
 	hlist_for_each_entry_safe(m, p, &mnt->mnt_stuck_children, mnt_umount) {
@@ -1221,10 +1228,16 @@ static void mntput_no_expire(struct moun
 		 * we are dropping is not the final one.
 		 */
 		mnt_add_count(mnt, -1);
+		count = mnt_get_count(mnt);
+		WARN_ON(count == 0);
+		WARN_ON(count < 0);
 		rcu_read_unlock();
 		return;
 	}
 	lock_mount_hash();
+	count = mnt_get_count(mnt);
+	WARN_ON(count == 0);
+	WARN_ON(count < 0);
 	/*
 	 * make sure that if __legitimize_mnt() has not seen us grab
 	 * mount_lock, we'll see their refcount increment here.
--- a/include/linux/cgroup-defs.h	2022-05-16 20:01:41.873691800 +0800
+++ b/include/linux/cgroup-defs.h	2022-05-16 20:05:57.239210800 +0800
@@ -179,7 +179,7 @@ struct cgroup_subsys_state {
 	atomic_t online_cnt;
 
 	/* percpu_ref killing and RCU release */
-	struct work_struct destroy_work;
+	struct work_struct destroy_work, release_work;
 	struct rcu_work destroy_rwork;
 
 	/*
--- a/kernel/cgroup/cgroup.c	2022-05-16 20:03:31.595702700 +0800
+++ b/kernel/cgroup/cgroup.c	2022-05-16 20:05:57.255709200 +0800
@@ -5154,7 +5154,7 @@ static void css_free_rwork_fn(struct wor
 static void css_release_work_fn(struct work_struct *work)
 {
 	struct cgroup_subsys_state *css =
-		container_of(work, struct cgroup_subsys_state, destroy_work);
+		container_of(work, struct cgroup_subsys_state, release_work);
 	struct cgroup_subsys *ss = css->ss;
 	struct cgroup *cgrp = css->cgroup;
 
@@ -5210,8 +5210,8 @@ static void css_release(struct percpu_re
 	struct cgroup_subsys_state *css =
 		container_of(ref, struct cgroup_subsys_state, refcnt);
 
-	INIT_WORK(&css->destroy_work, css_release_work_fn);
-	queue_work(cgroup_destroy_wq, &css->destroy_work);
+	INIT_WORK(&css->release_work, css_release_work_fn);
+	queue_work(cgroup_destroy_wq, &css->release_work);
 }
 
 static void init_and_link_css(struct cgroup_subsys_state *css,
--- a/net/ipv4/tcp_input.c	2022-05-16 19:59:50.885069300 +0800
+++ b/net/ipv4/tcp_input.c	2022-05-16 20:05:57.183788500 +0800
@@ -5926,6 +5926,7 @@ void tcp_rcv_established(struct sock *sk
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPHPHITS);
 
 			/* Bulk data transfer: receiver */
+			skb_dst_drop(skb);
 			__skb_pull(skb, tcp_header_len);
 			eaten = tcp_queue_rcv(sk, skb, &fragstolen);