This function will be used in task_diag.
Signed-off-by: Andrey Vagin <ava...@openvz.org>
---
fs/proc/array.c | 67 ++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 40 insertions(+), 27 deletions(-)
diff --git a/fs/proc/array.c b/fs/proc/array.c
index ce065cf..52c4a7b 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -578,31 +578,26 @@ int proc_pid_statm(struct seq_file *m, struct
pid_namespace *ns,
}
#ifdef CONFIG_PROC_CHILDREN
-static struct pid *
-get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
+static struct task_struct *
+task_next_child(struct task_struct *parent, struct task_struct *prev, unsigned
int pos)
{
- struct task_struct *start, *task;
- struct pid *pid = NULL;
+ struct task_struct *task;
read_lock(&tasklist_lock);
-
- start = pid_task(proc_pid(inode), PIDTYPE_PID);
- if (!start)
- goto out;
-
/*
* Lets try to continue searching first, this gives
* us significant speedup on children-rich processes.
*/
- if (pid_prev) {
- task = pid_task(pid_prev, PIDTYPE_PID);
- if (task && task->real_parent == start &&
+ if (prev) {
+ task = prev;
+ if (task && task->real_parent == parent &&
!(list_empty(&task->sibling))) {
- if (list_is_last(&task->sibling, &start->children))
+ if (list_is_last(&task->sibling, &parent->children)) {
+ task = NULL;
goto out;
+ }
task = list_first_entry(&task->sibling,
struct task_struct, sibling);
- pid = get_pid(task_pid(task));
goto out;
}
}
@@ -622,16 +617,34 @@ get_children_pid(struct inode *inode, struct pid
*pid_prev, loff_t pos)
* So one need to stop or freeze the leader and all
* its children to get a precise result.
*/
- list_for_each_entry(task, &start->children, sibling) {
- if (pos-- == 0) {
- pid = get_pid(task_pid(task));
- break;
- }
+ list_for_each_entry(task, &parent->children, sibling) {
+ if (pos-- == 0)
+ goto out;
}
-
+ task = NULL;
out:
+ if (prev)
+ put_task_struct(prev);
+ if (task)
+ get_task_struct(task);
read_unlock(&tasklist_lock);
- return pid;
+ return task;
+}
+
+static struct task_struct *
+get_children_pid(struct inode *inode, struct task_struct *prev, loff_t pos)
+{
+ struct task_struct *start, *task = NULL;
+
+ start = get_proc_task(inode);
+ if (!start)
+ goto out;
+
+ task = task_next_child(start, prev, pos);
+
+ put_task_struct(start);
+out:
+ return task;
}
static int children_seq_show(struct seq_file *seq, void *v)
@@ -639,7 +652,7 @@ static int children_seq_show(struct seq_file *seq, void *v)
struct inode *inode = seq->private;
pid_t pid;
- pid = pid_nr_ns(v, inode->i_sb->s_fs_info);
+ pid = task_pid_nr_ns(v, inode->i_sb->s_fs_info);
seq_printf(seq, "%d ", pid);
return 0;
@@ -652,18 +665,18 @@ static void *children_seq_start(struct seq_file *seq,
loff_t *pos)
static void *children_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct pid *pid;
+ struct task_struct *task;
- pid = get_children_pid(seq->private, v, *pos + 1);
- put_pid(v);
+ task = get_children_pid(seq->private, v, *pos + 1);
++*pos;
- return pid;
+ return task;
}
static void children_seq_stop(struct seq_file *seq, void *v)
{
- put_pid(v);
+ if (v)
+ put_task_struct(v);
}
static const struct seq_operations children_seq_ops = {
--
2.1.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
