[PATCH] proc: Rewrite the proc dentry flush on exit optimization

To keep the dcache from filling up with dead /proc entries we flush them on
process exit.  However over the years that code has gotten hairy with a
dentry_pointer and a lock in task_struct and misdocumented as a correctness
feature.

I have rewritten this code to look and see if we have a corresponding entry in
the dcache and if so flush it on process exit.  This removes the extra fields
in the task_struct and allows me to trivially handle the case of a
/proc/<tgid>/task/<pid> entry as well as the current /proc/<pid> entries.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 3 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index dfd10cb370c3..79e91046f36e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -993,13 +993,10 @@ static task_t *copy_process(unsigned long clone_flags,
                 if (put_user(p->pid, parent_tidptr))
                         goto bad_fork_cleanup;
 
-        p->proc_dentry = NULL;
-
         INIT_LIST_HEAD(&p->children);
         INIT_LIST_HEAD(&p->sibling);
         p->vfork_done = NULL;
         spin_lock_init(&p->alloc_lock);
-        spin_lock_init(&p->proc_lock);
 
         clear_tsk_thread_flag(p, TIF_SIGPENDING);
         init_sigpending(&p->pending);