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Message-Id: <1371096298-24402-7-git-send-email-tj@kernel.org>
Date: Wed, 12 Jun 2013 21:04:53 -0700
From: Tejun Heo <tj@...nel.org>
To: lizefan@...wei.com
Cc: containers@...ts.linux-foundation.org, cgroups@...r.kernel.org,
koverstreet@...gle.com, linux-kernel@...r.kernel.org,
cl@...ux-foundation.org, Tejun Heo <tj@...nel.org>
Subject: [PATCH 06/11] 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: Tejun Heo <tj@...nel.org>
---
include/linux/cgroup.h | 2 +-
kernel/cgroup.c | 30 ++++++++++++++----------------
2 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index a494636..c86a93a 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -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)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e308ee7..8f5fbcb 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -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);
@@ -2366,7 +2366,7 @@ 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);
@@ -2411,7 +2411,7 @@ 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)
@@ -2834,7 +2834,7 @@ 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);
@@ -3002,14 +3002,14 @@ 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;
@@ -4386,7 +4386,7 @@ 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.
*/
@@ -4396,7 +4396,7 @@ 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)
@@ -5066,7 +5066,7 @@ 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;
@@ -5212,9 +5212,7 @@ __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;
--
1.8.2.1
--
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