proc: implement proc_single_file_operations

Currently many /proc/pid files use a crufty precursor to the current seq_file
api, and they don't have direct access to the pid_namespace or the pid of for
which they are displaying data.

So implement proc_single_file_operations to make the seq_file routines easy to
use, and to give access to the full state of the pid of we are displaying data
for.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index e43551516831..b04ebf09fb91 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -262,6 +262,9 @@ extern void kclist_add(struct kcore_list *, void *, size_t);
 union proc_op {
         int (*proc_get_link)(struct inode *, struct dentry **, struct vfsmount **);
         int (*proc_read)(struct task_struct *task, char *page);
+        int (*proc_show)(struct seq_file *m,
+                struct pid_namespace *ns, struct pid *pid,
+                struct task_struct *task);
 };
 
 struct proc_inode {