Commit e9414845 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup fixes from Tejun Heo:

 - cgroup.procs listing related fixes.

   It didn't interlock properly with exiting tasks leaving a short
   window where a cgroup has empty cgroup.procs but still can't be
   removed and misbehaved on short reads.

 - psi_show() crash fix on 32bit ino archs

 - Empty release_agent handling fix

* 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup1: don't call release_agent when it is ""
  cgroup: fix psi_show() crash on 32bit ino archs
  cgroup: Iterate tasks that did not finish do_exit()
  cgroup: cgroup_procs_next should increase position index
  cgroup-v1: cgroup_pidlist_next should update position index
parents 2c1aca4b 2e5383d7

include/linux/cgroup.h

+1 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ struct css_task_iter { 
	struct list_head		*mg_tasks_head;

	struct list_head		*dying_tasks_head;



	struct list_head		*cur_tasks_head;

	struct css_set			*cur_cset;

	struct css_set			*cur_dcset;

	struct task_struct		*cur_task;

kernel/cgroup/cgroup-v1.c

+2 −1
Original line number Diff line number Diff line
@@ -471,6 +471,7 @@ static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos) 
	 */

	p++;

	if (p >= end) {

		(*pos)++;

		return NULL;

	} else {

		*pos = *p;
@@ -782,7 +783,7 @@ void cgroup1_release_agent(struct work_struct *work) 


	pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);

	agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);

	if (!pathbuf || !agentbuf)

	if (!pathbuf || !agentbuf || !strlen(agentbuf))

		goto out;



	spin_lock_irq(&css_set_lock);

kernel/cgroup/cgroup.c

+26 −13
Original line number Diff line number Diff line
@@ -3542,21 +3542,21 @@ static int cpu_stat_show(struct seq_file *seq, void *v) 
static int cgroup_io_pressure_show(struct seq_file *seq, void *v)

{

	struct cgroup *cgrp = seq_css(seq)->cgroup;

	struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;

	struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;



	return psi_show(seq, psi, PSI_IO);

}

static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)

{

	struct cgroup *cgrp = seq_css(seq)->cgroup;

	struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;

	struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;



	return psi_show(seq, psi, PSI_MEM);

}

static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)

{

	struct cgroup *cgrp = seq_css(seq)->cgroup;

	struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;

	struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;



	return psi_show(seq, psi, PSI_CPU);

}
@@ -4400,12 +4400,16 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it) 
		}

	} while (!css_set_populated(cset) && list_empty(&cset->dying_tasks));



	if (!list_empty(&cset->tasks))

	if (!list_empty(&cset->tasks)) {

		it->task_pos = cset->tasks.next;

	else if (!list_empty(&cset->mg_tasks))

		it->cur_tasks_head = &cset->tasks;

	} else if (!list_empty(&cset->mg_tasks)) {

		it->task_pos = cset->mg_tasks.next;

	else

		it->cur_tasks_head = &cset->mg_tasks;

	} else {

		it->task_pos = cset->dying_tasks.next;

		it->cur_tasks_head = &cset->dying_tasks;

	}



	it->tasks_head = &cset->tasks;

	it->mg_tasks_head = &cset->mg_tasks;
@@ -4463,10 +4467,14 @@ repeat: 
		else

			it->task_pos = it->task_pos->next;



		if (it->task_pos == it->tasks_head)

		if (it->task_pos == it->tasks_head) {

			it->task_pos = it->mg_tasks_head->next;

		if (it->task_pos == it->mg_tasks_head)

			it->cur_tasks_head = it->mg_tasks_head;

		}

		if (it->task_pos == it->mg_tasks_head) {

			it->task_pos = it->dying_tasks_head->next;

			it->cur_tasks_head = it->dying_tasks_head;

		}

		if (it->task_pos == it->dying_tasks_head)

			css_task_iter_advance_css_set(it);

	} else {
@@ -4485,11 +4493,12 @@ repeat: 
			goto repeat;



		/* and dying leaders w/o live member threads */

		if (!atomic_read(&task->signal->live))

		if (it->cur_tasks_head == it->dying_tasks_head &&

		    !atomic_read(&task->signal->live))

			goto repeat;

	} else {

		/* skip all dying ones */

		if (task->flags & PF_EXITING)

		if (it->cur_tasks_head == it->dying_tasks_head)

			goto repeat;

	}

}
@@ -4595,6 +4604,9 @@ static void *cgroup_procs_next(struct seq_file *s, void *v, loff_t *pos) 
	struct kernfs_open_file *of = s->private;

	struct css_task_iter *it = of->priv;



	if (pos)

		(*pos)++;



	return css_task_iter_next(it);

}
@@ -4610,7 +4622,7 @@ static void *__cgroup_procs_start(struct seq_file *s, loff_t *pos, 
	 * from position 0, so we can simply keep iterating on !0 *pos.

	 */

	if (!it) {

		if (WARN_ON_ONCE((*pos)++))

		if (WARN_ON_ONCE((*pos)))

			return ERR_PTR(-EINVAL);



		it = kzalloc(sizeof(*it), GFP_KERNEL);
@@ -4618,10 +4630,11 @@ static void *__cgroup_procs_start(struct seq_file *s, loff_t *pos, 
			return ERR_PTR(-ENOMEM);

		of->priv = it;

		css_task_iter_start(&cgrp->self, iter_flags, it);

	} else if (!(*pos)++) {

	} else if (!(*pos)) {

		css_task_iter_end(it);

		css_task_iter_start(&cgrp->self, iter_flags, it);

	}

	} else

		return it->cur_task;



	return cgroup_procs_next(s, NULL, NULL);

}

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