[PATCH 2/7] kernel: move next_tgid from fs/proc
From: Andrey Vagin <hidden>
Date: 2015-02-17 08:41:07
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), proc filesystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
This function will be used in task_diag. Signed-off-by: Andrey Vagin <redacted> --- 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.
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2.1.0