From aab407fc5c0ce63e9fd4a34a790d7290d3e116a1 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 29 Sep 2013 10:59:59 -0400
Subject: don't bother with vfsmount_lock in mounts_poll()
wake_up_interruptible/poll_wait provide sufficient barriers;
just use ACCESS_ONCE() to fetch ns->event and that's it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/proc_namespace.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
(limited to 'fs')
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 5fe34c355e85..439406e081af 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -20,15 +20,15 @@ static unsigned mounts_poll(struct file *file, poll_table *wait)
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;
}
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