[Containers] [PATCH 3/7] proc: Give the root directory a task.

[Eric W. Biederman]

Helper functions in base.c like proc_pident_readdir and proc_pident_lookup
assume the directories have an associated task, and cannot currently be used on
the /proc root directory because it does not have such a task.

This small changes allows for base.c to be simplified and later when multiple
pid spaces are introduced it makes getting the needed context information trivial.

Signed-off-by: Eric W. Biederman <ebiederm at xmission.com>
---
 fs/proc/root.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/fs/proc/root.c b/fs/proc/root.c
index 8901c65..ffe66c3 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -16,6 +16,7 @@ #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/bitops.h>
 #include <linux/smp_lock.h>
+#include <linux/mount.h>
 
 #include "internal.h"
 
@@ -28,6 +29,17 @@ #endif
 static int proc_get_sb(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 {
+	if (proc_mnt) {
+		/* Seed the root directory with a pid so it doesn't need
+		 * to be special in base.c.  I would do this earlier but
+		 * the only task alive when /proc is mounted the first time
+		 * is the init_task and it doesn't have any pids.
+		 */
+		struct proc_inode *ei;
+		ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode);
+		if (!ei->pid)
+			ei->pid = find_get_pid(1);
+	}
 	return get_sb_single(fs_type, flags, data, proc_fill_super, mnt);
 }
 
-- 
1.4.2.rc3.g7e18e-dirty