[PATCH] proc: Remove tasklist_lock from proc_pid_readdir
We don't need the tasklist_lock to safely iterate through processes
anymore.
This depends on my previous to task patches that make get_task_struct rcu
safe, and that make next_task() rcu safe. I haven't gotten
first_tid/next_tid yet only because next_thread is missing an
rcu_dereference.
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>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 2236f7d..cc578a3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2043,7 +2043,7 @@
static struct task_struct *first_tgid(int tgid, int nr)
{
struct task_struct *pos = NULL;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
if (tgid && nr) {
pos = find_task_by_pid(tgid);
if (pos && !thread_group_leader(pos))
@@ -2069,7 +2069,7 @@
}
pos = NULL;
done:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
return pos;
}
@@ -2082,7 +2082,7 @@
static struct task_struct *next_tgid(struct task_struct *start)
{
struct task_struct *pos;
- read_lock(&tasklist_lock);
+ rcu_read_lock();
pos = start;
if (pid_alive(start))
pos = next_task(start);
@@ -2092,7 +2092,7 @@
}
pos = NULL;
done:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
put_task_struct(start);
return pos;
}