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>

2 files changed, 9 insertions, 3 deletions

diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index aa7a0ee182e1..0fabc48d905f 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -57,6 +57,11 @@ union proc_op {
                 struct task_struct *task);
 };
 
+struct proc_ns {
+        struct ns_common *ns;
+        const struct proc_ns_operations *ns_ops;
+};
+
 struct proc_inode {
         struct pid *pid;
         int fd;
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 995e8e98237d..18fc1cf899de 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -45,7 +45,7 @@ static const struct inode_operations ns_inode_operations = {
 static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
 {
         struct inode *inode = dentry->d_inode;
-        const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns.ns_ops;
+        const struct proc_ns_operations *ns_ops = dentry->d_fsdata;
 
         return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
                 ns_ops->name, inode->i_ino);
@@ -75,6 +75,7 @@ static struct dentry *proc_ns_get_dentry(struct super_block *sb,
                 ns_ops->put(ns);
                 return ERR_PTR(-ENOMEM);
         }
+        dentry->d_fsdata = (void *)ns_ops;
 
         inode = iget_locked(sb, ns->inum);
         if (!inode) {
@@ -286,9 +287,9 @@ out_invalid:
         return ERR_PTR(-EINVAL);
 }
 
-struct proc_ns *get_proc_ns(struct inode *inode)
+struct ns_common *get_proc_ns(struct inode *inode)
 {
-        return &PROC_I(inode)->ns;
+        return PROC_I(inode)->ns.ns;
 }
 
 bool proc_ns_inode(struct inode *inode)