[Devel] [PATCH 13/13] Make all proc entres accessible in a namespace

[Pavel Emelianov]

This is a hack that must not go to any tree, but this
makes patch testing from shell possible.

When creating a new pid namespace one need to mount a new
proc instance in this space context. But the /proc will 
contain pids and self symlink only and this breaks some 
important tools like ps and sshd.

They expect /proc/stat, /proc/mounts and some other entries
to be present.

Without this patch the only possible way to test the
namespace is to make all the operations performed from
self-made programs. With it one may use general command
line tools.

This patch makes them visible, but this is ugly. Correct 
fix must make some kind of proc_entries namespace but this
is another interesting task.

Signed-off-by: Pavel Emelianov <xemul at openvz.org>

---

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 9401a6f..eec1eb6 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -393,6 +393,10 @@ struct dentry *proc_lookup(struct inode 
 	spin_lock(&proc_subdir_lock);
 	de = PDE(dir);
 	if (de) {
+#ifdef CONFIG_PID_NS
+		if (de->parent == de)
+			de = &proc_root;
+#endif
 		for (de = de->subdir; de ; de = de->next) {
 			if (de->namelen != dentry->d_name.len)
 				continue;
@@ -446,6 +450,10 @@ int proc_readdir(struct file * filp,
 		ret = -EINVAL;
 		goto out;
 	}
+#ifdef CONFIG_PID_NS
+	if (de->parent == de)
+		de = &proc_root;
+#endif
 	i = filp->f_pos;
 	switch (i) {
 		case 0: