do_lookup() fix
do_lookup() has a path leading from LOOKUP_RCU case to non-RCU
crossing of mountpoints, which breaks things badly. If we
hit need_revalidate: and do nothing in there, we need to come
back into LOOKUP_RCU half of things, not to done: in non-RCU
one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 8df7a78..529e917 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1089,6 +1089,7 @@
nd->seq = seq;
if (dentry->d_flags & DCACHE_OP_REVALIDATE)
goto need_revalidate;
+done2:
path->mnt = mnt;
path->dentry = dentry;
__follow_mount_rcu(nd, path, inode);
@@ -1143,6 +1144,8 @@
goto need_lookup;
if (IS_ERR(dentry))
goto fail;
+ if (nd->flags & LOOKUP_RCU)
+ goto done2;
goto done;
fail: