bury struct proc_ns in fs/proc

a) make get_proc_ns() return a pointer to struct ns_common
b) mirror ns_ops in dentry->d_fsdata of ns dentries, so that
is_mnt_ns_file() could get away with fewer dereferences.

That way struct proc_ns becomes invisible outside of fs/proc/*.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 11 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index f815218f92d3..9dfb4cac0c41 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1570,16 +1570,7 @@ static bool is_mnt_ns_file(struct dentry *dentry)
 {
         /* Is this a proxy for a mount namespace? */
         struct inode *inode = dentry->d_inode;
-        struct proc_ns *ei;
-
-        if (!proc_ns_inode(inode))
-                return false;
-
-        ei = get_proc_ns(inode);
-        if (ei->ns_ops != &mntns_operations)
-                return false;
-
-        return true;
+        return proc_ns_inode(inode) && dentry->d_fsdata == &mntns_operations;
 }
 
 struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
@@ -1596,7 +1587,7 @@ static bool mnt_ns_loop(struct dentry *dentry)
         if (!is_mnt_ns_file(dentry))
                 return false;
 
-        mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode)->ns);
+        mnt_ns = to_mnt_ns(get_proc_ns(dentry->d_inode));
         return current->nsproxy->mnt_ns->seq >= mnt_ns->seq;
 }