nothing in do_follow_link() is going to see RCU
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index ec4b2d0..9ce6d27 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -668,9 +668,6 @@
return 0;
if (!status) {
- /* Don't d_invalidate in rcu-walk mode */
- if (nameidata_drop_rcu(nd))
- return -ECHILD;
d_invalidate(dentry);
status = -ESTALE;
}
@@ -777,6 +774,8 @@
int error;
struct dentry *dentry = link->dentry;
+ BUG_ON(nd->flags & LOOKUP_RCU);
+
touch_atime(link->mnt, dentry);
nd_set_link(nd, NULL);
@@ -811,6 +810,11 @@
{
void *cookie;
int err = -ELOOP;
+
+ /* We drop rcu-walk here */
+ if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry))
+ return -ECHILD;
+
if (current->link_count >= MAX_NESTED_LINKS)
goto loop;
if (current->total_link_count >= 40)
@@ -1419,9 +1423,6 @@
goto out_dput;
if (inode->i_op->follow_link) {
- /* We commonly drop rcu-walk here */
- if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
- return -ECHILD;
BUG_ON(inode != next.dentry->d_inode);
err = do_follow_link(&next, nd);
if (err)
@@ -1467,8 +1468,6 @@
break;
if (inode && unlikely(inode->i_op->follow_link) &&
(lookup_flags & LOOKUP_FOLLOW)) {
- if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
- return -ECHILD;
BUG_ON(inode != next.dentry->d_inode);
err = do_follow_link(&next, nd);
if (err)