The patch titled
devcgroup: avoid using cgroup_lock
has been added to the -mm tree. Its filename is
devcgroup-avoid-using-cgroup_lock.patch
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------------------------------------------------------
Subject: devcgroup: avoid using cgroup_lock
From: Li Zefan <lizf@xxxxxxxxxxxxxx>
There is nothing special that has to be protected by cgroup_lock,
so introduce devcgroup_mtuex for it's own use.
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: Serge Hallyn <serue@xxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
security/device_cgroup.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff -puN security/device_cgroup.c~devcgroup-avoid-using-cgroup_lock security/device_cgroup.c
--- a/security/device_cgroup.c~devcgroup-avoid-using-cgroup_lock
+++ a/security/device_cgroup.c
@@ -11,6 +11,7 @@
#include <linux/uaccess.h>
#include <linux/seq_file.h>
#include <linux/rcupdate.h>
+#include <linux/mutex.h>
#define ACC_MKNOD 1
#define ACC_READ 2
@@ -21,9 +22,11 @@
#define DEV_CHAR 2
#define DEV_ALL 4 /* this represents all devices */
+static DEFINE_MUTEX(devcgroup_mutex);
+
/*
* whitelist locking rules:
- * hold cgroup_lock() for update/read.
+ * hold devcgroup_mutex for update/read.
* hold rcu_read_lock() for read.
*/
@@ -67,7 +70,7 @@ static int devcgroup_can_attach(struct c
}
/*
- * called under cgroup_lock()
+ * called under devcgroup_mutex
*/
static int dev_whitelist_copy(struct list_head *dest, struct list_head *orig)
{
@@ -92,7 +95,7 @@ free_and_exit:
/* Stupid prototype - don't bother combining existing entries */
/*
- * called under cgroup_lock()
+ * called under devcgroup_mutex
*/
static int dev_whitelist_add(struct dev_cgroup *dev_cgroup,
struct dev_whitelist_item *wh)
@@ -130,7 +133,7 @@ static void whitelist_item_free(struct r
}
/*
- * called under cgroup_lock()
+ * called under devcgroup_mutex
*/
static void dev_whitelist_rm(struct dev_cgroup *dev_cgroup,
struct dev_whitelist_item *wh)
@@ -185,8 +188,10 @@ static struct cgroup_subsys_state *devcg
list_add(&wh->list, &dev_cgroup->whitelist);
} else {
parent_dev_cgroup = cgroup_to_devcgroup(parent_cgroup);
+ mutex_lock(&devcgroup_mutex);
ret = dev_whitelist_copy(&dev_cgroup->whitelist,
&parent_dev_cgroup->whitelist);
+ mutex_unlock(&devcgroup_mutex);
if (ret) {
kfree(dev_cgroup);
return ERR_PTR(ret);
@@ -273,7 +278,7 @@ static int devcgroup_seq_read(struct cgr
* does the access granted to dev_cgroup c contain the access
* requested in whitelist item refwh.
* return 1 if yes, 0 if no.
- * call with c->lock held
+ * call with devcgroup_mutex held
*/
static int may_access_whitelist(struct dev_cgroup *c,
struct dev_whitelist_item *refwh)
@@ -426,11 +431,11 @@ static int devcgroup_access_write(struct
const char *buffer)
{
int retval;
- if (!cgroup_lock_live_group(cgrp))
- return -ENODEV;
+
+ mutex_lock(&devcgroup_mutex);
retval = devcgroup_update_access(cgroup_to_devcgroup(cgrp),
cft->private, buffer);
- cgroup_unlock();
+ mutex_unlock(&devcgroup_mutex);
return retval;
}
_
Patches currently in -mm which might be from lizf@xxxxxxxxxxxxxx are
linux-next.patch
cls_cgroup-remove-unneeded-cgroup_lock.patch
memdup_user-introduce.patch
memdup_user-introduce-fix.patch
relax-ns_can_attach-checks-to-allow-attaching-to-grandchild-cgroups.patch
cgroup-css-id-support.patch
cgroup-css-id-support-remove-rcu_read_lock-from-css_get_next.patch
cgroup-fix-frequent-ebusy-at-rmdir.patch
cgroups-more-documentation-for-remount-and-release_agent.patch
cgroups-show-correct-file-mode.patch
cgroups-show-correct-file-mode-fix.patch
cgroups-dont-change-release_agent-when-remount-failed.patch
debug-cgroup-remove-unneeded-cgroup_lock.patch
devcgroup-avoid-using-cgroup_lock.patch
memcg-use-css-id.patch
memcg-hierarchical-stat.patch
memcg-fix-shrinking-memory-to-return-ebusy-by-fixing-retry-algorithm.patch
memcg-fix-oom-killer-under-memcg.patch
memcg-fix-oom-killer-under-memcg-fix2.patch
memcg-fix-oom-killer-under-memcg-fix.patch
memcg-show-memcg-information-during-oom.patch
memcg-show-memcg-information-during-oom-fix2.patch
memcg-show-memcg-information-during-oom-fix.patch
memcg-show-memcg-information-during-oom-fix-fix.patch
memcg-show-memcg-information-during-oom-fix-fix-checkpatch-fixes.patch
memcg-charge-swapcache-to-proper-memcg.patch
cgroups-use-css-id-in-swap-cgroup-for-saving-memory-v5.patch
cpuset-fix-possible-races-in-cpu-memory-hotplug.patch
cgroups-add-data-field-to-struct-cgroup_scanner.patch
cpuset-rewrite-update_tasks_nodemask.patch
cpuset-avoid-changing-cpusets-mems-when-errno-returned.patch
cpuset-remove-struct-cpuset_hotplug_scanner.patch
cpusets-allow-cpusets-to-be-configured-built-on-non-smp-systems.patch
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