1 files changed, 9 insertions, 14 deletions

diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 12412852d88..1a81373947f 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -17,18 +17,18 @@
 
 static unsigned mounts_poll(struct file *file, poll_table *wait)
 {
-	struct proc_mounts *p = file->private_data;
+	struct proc_mounts *p = proc_mounts(file->private_data);
 	struct mnt_namespace *ns = p->ns;
 	unsigned res = POLLIN | POLLRDNORM;
+	int event;
 
 	poll_wait(file, &p->ns->poll, wait);
 
-	br_read_lock(vfsmount_lock);
-	if (p->m.poll_event != ns->event) {
-		p->m.poll_event = ns->event;
+	event = ACCESS_ONCE(ns->event);
+	if (p->m.poll_event != event) {
+		p->m.poll_event = event;
 		res |= POLLERR | POLLPRI;
 	}
-	br_read_unlock(vfsmount_lock);
 
 	return res;
 }
@@ -121,7 +121,7 @@ out:
 
 static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
 {
-	struct proc_mounts *p = m->private;
+	struct proc_mounts *p = proc_mounts(m);
 	struct mount *r = real_mount(mnt);
 	struct super_block *sb = mnt->mnt_sb;
 	struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
@@ -234,17 +234,12 @@ static int mounts_open_common(struct inode *inode, struct file *file,
 
 	rcu_read_lock();
 	nsp = task_nsproxy(task);
-	if (!nsp) {
+	if (!nsp || !nsp->mnt_ns) {
 		rcu_read_unlock();
 		put_task_struct(task);
 		goto err;
 	}
 	ns = nsp->mnt_ns;
-	if (!ns) {
-		rcu_read_unlock();
-		put_task_struct(task);
-		goto err;
-	}
 	get_mnt_ns(ns);
 	rcu_read_unlock();
 	task_lock(task);
@@ -268,11 +263,11 @@ static int mounts_open_common(struct inode *inode, struct file *file,
 	if (ret)
 		goto err_free;
 
-	p->m.private = p;
 	p->ns = ns;
 	p->root = root;
 	p->m.poll_event = ns->event;
 	p->show = show;
+	p->cached_event = ~0ULL;
 
 	return 0;
 
@@ -288,7 +283,7 @@ static int mounts_open_common(struct inode *inode, struct file *file,
 
 static int mounts_release(struct inode *inode, struct file *file)
 {
-	struct proc_mounts *p = file->private_data;
+	struct proc_mounts *p = proc_mounts(file->private_data);
 	path_put(&p->root);
 	put_mnt_ns(p->ns);
 	return seq_release(inode, file);