Commit 54766d4a authored by Tejun Heo's avatar Tejun Heo
Browse files

cgroup: rename CGRP_REMOVED to CGRP_DEAD 



We will add another flag indicating that the cgroup is in the process
of being killed.  REMOVING / REMOVED is more difficult to distinguish
and cgroup_is_removing()/cgroup_is_removed() are a bit awkward.  Also,
later percpu_ref usage will involve "kill"ing the refcnt.

 s/CGRP_REMOVED/CGRP_DEAD/
 s/cgroup_is_removed()/cgroup_is_dead()

This patch is purely cosmetic.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
parent 5de0107e

include/linux/cgroup.h

+1 −1
Original line number Diff line number Diff line
@@ -143,7 +143,7 @@ static inline void css_put(struct cgroup_subsys_state *css) 
/* bits in struct cgroup flags field */

enum {

	/* Control Group is dead */

	CGRP_REMOVED,

	CGRP_DEAD,

	/*

	 * Control Group has previously had a child cgroup or a task,

	 * but no longer (only if CGRP_NOTIFY_ON_RELEASE is set)

kernel/cgroup.c

+14 −16
Original line number Diff line number Diff line
@@ -226,9 +226,9 @@ static int css_refcnt(struct cgroup_subsys_state *css) 
}



/* convenient tests for these bits */

static inline bool cgroup_is_removed(const struct cgroup *cgrp)

static inline bool cgroup_is_dead(const struct cgroup *cgrp)

{

	return test_bit(CGRP_REMOVED, &cgrp->flags);

	return test_bit(CGRP_DEAD, &cgrp->flags);

}



/**
@@ -300,7 +300,7 @@ static inline struct cftype *__d_cft(struct dentry *dentry) 
static bool cgroup_lock_live_group(struct cgroup *cgrp)

{

	mutex_lock(&cgroup_mutex);

	if (cgroup_is_removed(cgrp)) {

	if (cgroup_is_dead(cgrp)) {

		mutex_unlock(&cgroup_mutex);

		return false;

	}
@@ -892,7 +892,7 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode) 
	if (S_ISDIR(inode->i_mode)) {

		struct cgroup *cgrp = dentry->d_fsdata;



		BUG_ON(!(cgroup_is_removed(cgrp)));

		BUG_ON(!(cgroup_is_dead(cgrp)));

		call_rcu(&cgrp->rcu_head, cgroup_free_rcu);

	} else {

		struct cfent *cfe = __d_cfe(dentry);
@@ -2363,7 +2363,7 @@ static ssize_t cgroup_file_write(struct file *file, const char __user *buf, 
	struct cftype *cft = __d_cft(file->f_dentry);

	struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);



	if (cgroup_is_removed(cgrp))

	if (cgroup_is_dead(cgrp))

		return -ENODEV;

	if (cft->write)

		return cft->write(cgrp, cft, file, buf, nbytes, ppos);
@@ -2408,7 +2408,7 @@ static ssize_t cgroup_file_read(struct file *file, char __user *buf, 
	struct cftype *cft = __d_cft(file->f_dentry);

	struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);



	if (cgroup_is_removed(cgrp))

	if (cgroup_is_dead(cgrp))

		return -ENODEV;



	if (cft->read)
@@ -2831,7 +2831,7 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss, 


		mutex_lock(&inode->i_mutex);

		mutex_lock(&cgroup_mutex);

		if (!cgroup_is_removed(cgrp))

		if (!cgroup_is_dead(cgrp))

			cgroup_addrm_files(cgrp, ss, cfts, is_add);

		mutex_unlock(&cgroup_mutex);

		mutex_unlock(&inode->i_mutex);
@@ -2999,14 +2999,14 @@ struct cgroup *cgroup_next_sibling(struct cgroup *pos) 
	/*

	 * @pos could already have been removed.  Once a cgroup is removed,

	 * its ->sibling.next is no longer updated when its next sibling

	 * changes.  As CGRP_REMOVED is set on removal which is fully

	 * changes.  As CGRP_DEAD is set on removal which is fully

	 * serialized, if we see it unasserted, it's guaranteed that the

	 * next sibling hasn't finished its grace period even if it's

	 * already removed, and thus safe to dereference from this RCU

	 * critical section.  If ->sibling.next is inaccessible,

	 * cgroup_is_removed() is guaranteed to be visible as %true here.

	 * cgroup_is_dead() is guaranteed to be visible as %true here.

	 */

	if (likely(!cgroup_is_removed(pos))) {

	if (likely(!cgroup_is_dead(pos))) {

		next = list_entry_rcu(pos->sibling.next, struct cgroup, sibling);

		if (&next->sibling != &pos->parent->children)

			return next;
@@ -4383,7 +4383,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) 
	 * attempts fail thus maintaining the removal conditions verified

	 * above.

	 *

	 * Note that CGRP_REMVOED clearing is depended upon by

	 * Note that CGRP_DEAD assertion is depended upon by

	 * cgroup_next_sibling() to resume iteration after dropping RCU

	 * read lock.  See cgroup_next_sibling() for details.

	 */
@@ -4393,7 +4393,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) 
		WARN_ON(atomic_read(&css->refcnt) < 0);

		atomic_add(CSS_DEACT_BIAS, &css->refcnt);

	}

	set_bit(CGRP_REMOVED, &cgrp->flags);

	set_bit(CGRP_DEAD, &cgrp->flags);



	/* tell subsystems to initate destruction */

	for_each_subsys(cgrp->root, ss)
@@ -5063,7 +5063,7 @@ static void check_for_release(struct cgroup *cgrp) 
		int need_schedule_work = 0;



		raw_spin_lock(&release_list_lock);

		if (!cgroup_is_removed(cgrp) &&

		if (!cgroup_is_dead(cgrp) &&

		    list_empty(&cgrp->release_list)) {

			list_add(&cgrp->release_list, &release_list);

			need_schedule_work = 1;
@@ -5209,9 +5209,7 @@ __setup("cgroup_disable=", cgroup_disable); 
 * Functons for CSS ID.

 */



/*

 *To get ID other than 0, this should be called when !cgroup_is_removed().

 */

/* to get ID other than 0, this should be called when !cgroup_is_dead() */

unsigned short css_id(struct cgroup_subsys_state *css)

{

	struct css_id *cssid;

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