[PATCH] proc: Fix namespace mountpoint path in /proc/mounts

[Aditya Kali <adityakali@google.com>]

Commit bf056bfa80596a5d14b26b17276a56a0dcb080e5:
"proc: Fix the namespace inode permission checks." converted
the namespace files into symlinks. The same commit changed
the way namespace bind mounts appear in /proc/mounts:
  $ mount --bind /proc/self/ns/ipc /mnt/ipc
Originally:
  $ cat /proc/mounts | grep ipc
  proc /mnt/ipc proc rw,nosuid,nodev,noexec 0 0

After commit bf056bfa80596a5d14b26b17276a56a0dcb080e5:
  $ cat /proc/mounts | grep ipc
  proc ipc:[4026531839] proc rw,nosuid,nodev,noexec 0 0

This breaks userspace which expects the 2nd field in
/proc/mounts to be a valid path. This patch restores the
original format of namespace bind-mount entries in
/proc/mounts.

Signed-off-by: Aditya Kali <adityakali@google.com>
---
 fs/proc/namespaces.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 49a7fff..d19989d 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -48,19 +48,9 @@ static int ns_delete_dentry(const struct dentry *dentry)
 	return 1;
 }
 
-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;
-
-	return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
-		ns_ops->name, inode->i_ino);
-}
-
 const struct dentry_operations ns_dentry_operations =
 {
 	.d_delete	= ns_delete_dentry,
-	.d_dname	= ns_dname,
 };
 
 static struct dentry *proc_ns_get_dentry(struct super_block *sb,
-- 
1.8.4.1