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Subject[PATCH 2/7] kernel: move next_tgid from fs/proc
Date
This function will be used in task_diag.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
---
fs/proc/base.c | 43 -------------------------------------------
include/linux/proc_fs.h | 7 +++++++
kernel/pid.c | 39 +++++++++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+), 43 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 3f3d7ae..24ed43d 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2795,49 +2795,6 @@ out:
return ERR_PTR(result);
}

-/*
- * Find the first task with tgid >= tgid
- *
- */
-struct tgid_iter {
- unsigned int tgid;
- struct task_struct *task;
-};
-static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
-{
- struct pid *pid;
-
- if (iter.task)
- put_task_struct(iter.task);
- rcu_read_lock();
-retry:
- iter.task = NULL;
- pid = find_ge_pid(iter.tgid, ns);
- if (pid) {
- iter.tgid = pid_nr_ns(pid, ns);
- iter.task = pid_task(pid, PIDTYPE_PID);
- /* What we to know is if the pid we have find is the
- * pid of a thread_group_leader. Testing for task
- * being a thread_group_leader is the obvious thing
- * todo but there is a window when it fails, due to
- * the pid transfer logic in de_thread.
- *
- * So we perform the straight forward test of seeing
- * if the pid we have found is the pid of a thread
- * group leader, and don't worry if the task we have
- * found doesn't happen to be a thread group leader.
- * As we don't care in the case of readdir.
- */
- if (!iter.task || !has_group_leader_pid(iter.task)) {
- iter.tgid += 1;
- goto retry;
- }
- get_task_struct(iter.task);
- }
- rcu_read_unlock();
- return iter;
-}
-
#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)

/* for the /proc/ directory itself, after non-process stuff has been done */
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index b97bf2e..136b6ed 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -82,4 +82,11 @@ static inline struct proc_dir_entry *proc_net_mkdir(
return proc_mkdir_data(name, 0, parent, net);
}

+struct tgid_iter {
+ unsigned int tgid;
+ struct task_struct *task;
+};
+
+struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter);
+
#endif /* _LINUX_PROC_FS_H */
diff --git a/kernel/pid.c b/kernel/pid.c
index cd36a5e..082307a 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -568,6 +568,45 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
}

/*
+ * Find the first task with tgid >= tgid
+ *
+ */
+struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
+{
+ struct pid *pid;
+
+ if (iter.task)
+ put_task_struct(iter.task);
+ rcu_read_lock();
+retry:
+ iter.task = NULL;
+ pid = find_ge_pid(iter.tgid, ns);
+ if (pid) {
+ iter.tgid = pid_nr_ns(pid, ns);
+ iter.task = pid_task(pid, PIDTYPE_PID);
+ /* What we to know is if the pid we have find is the
+ * pid of a thread_group_leader. Testing for task
+ * being a thread_group_leader is the obvious thing
+ * todo but there is a window when it fails, due to
+ * the pid transfer logic in de_thread.
+ *
+ * So we perform the straight forward test of seeing
+ * if the pid we have found is the pid of a thread
+ * group leader, and don't worry if the task we have
+ * found doesn't happen to be a thread group leader.
+ * As we don't care in the case of readdir.
+ */
+ if (!iter.task || !has_group_leader_pid(iter.task)) {
+ iter.tgid += 1;
+ goto retry;
+ }
+ get_task_struct(iter.task);
+ }
+ rcu_read_unlock();
+ return iter;
+}
+
+/*
* The pid hash table is scaled according to the amount of memory in the
* machine. From a minimum of 16 slots up to 4096 slots at one gigabyte or
* more.
--
2.1.0


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