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-rw-r--r--Documentation/cgroups/cgroups.txt31
-rw-r--r--include/linux/cgroup.h28
-rw-r--r--kernel/cgroup.c99
-rw-r--r--kernel/cgroup_freezer.c2
-rw-r--r--kernel/cpuset.c18
-rw-r--r--mm/memcontrol.c16
-rw-r--r--security/device_cgroup.c7
7 files changed, 158 insertions, 43 deletions
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index 9c452ef2328c..8a2f302327fa 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -594,15 +594,25 @@ rmdir() will fail with it. From this behavior, pre_destroy() can be
called multiple times against a cgroup.
int can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *task)
+ struct cgroup_taskset *tset)
(cgroup_mutex held by caller)
-Called prior to moving a task into a cgroup; if the subsystem
-returns an error, this will abort the attach operation. If a NULL
-task is passed, then a successful result indicates that *any*
-unspecified task can be moved into the cgroup. Note that this isn't
-called on a fork. If this method returns 0 (success) then this should
-remain valid while the caller holds cgroup_mutex and it is ensured that either
+Called prior to moving one or more tasks into a cgroup; if the
+subsystem returns an error, this will abort the attach operation.
+@tset contains the tasks to be attached and is guaranteed to have at
+least one task in it.
+
+If there are multiple tasks in the taskset, then:
+ - it's guaranteed that all are from the same thread group
+ - @tset contains all tasks from the thread group whether or not
+ they're switching cgroups
+ - the first task is the leader
+
+Each @tset entry also contains the task's old cgroup and tasks which
+aren't switching cgroup can be skipped easily using the
+cgroup_taskset_for_each() iterator. Note that this isn't called on a
+fork. If this method returns 0 (success) then this should remain valid
+while the caller holds cgroup_mutex and it is ensured that either
attach() or cancel_attach() will be called in future.
int can_attach_task(struct cgroup *cgrp, struct task_struct *tsk);
@@ -613,14 +623,14 @@ attached (possibly many when using cgroup_attach_proc). Called after
can_attach.
void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *task, bool threadgroup)
+ struct cgroup_taskset *tset)
(cgroup_mutex held by caller)
Called when a task attach operation has failed after can_attach() has succeeded.
A subsystem whose can_attach() has some side-effects should provide this
function, so that the subsystem can implement a rollback. If not, not necessary.
This will be called only about subsystems whose can_attach() operation have
-succeeded.
+succeeded. The parameters are identical to can_attach().
void pre_attach(struct cgroup *cgrp);
(cgroup_mutex held by caller)
@@ -629,11 +639,12 @@ For any non-per-thread attachment work that needs to happen before
attach_task. Needed by cpuset.
void attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cgrp, struct task_struct *task)
+ struct cgroup_taskset *tset)
(cgroup_mutex held by caller)
Called after the task has been attached to the cgroup, to allow any
post-attachment activity that requires memory allocations or blocking.
+The parameters are identical to can_attach().
void attach_task(struct cgroup *cgrp, struct task_struct *tsk);
(cgroup_mutex held by caller)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 1b7f9d525013..34256ad9e553 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -457,6 +457,28 @@ void cgroup_exclude_rmdir(struct cgroup_subsys_state *css);
void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css);
/*
+ * Control Group taskset, used to pass around set of tasks to cgroup_subsys
+ * methods.
+ */
+struct cgroup_taskset;
+struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset);
+struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset);
+struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset);
+int cgroup_taskset_size(struct cgroup_taskset *tset);
+
+/**
+ * cgroup_taskset_for_each - iterate cgroup_taskset
+ * @task: the loop cursor
+ * @skip_cgrp: skip if task's cgroup matches this, %NULL to iterate through all
+ * @tset: taskset to iterate
+ */
+#define cgroup_taskset_for_each(task, skip_cgrp, tset) \
+ for ((task) = cgroup_taskset_first((tset)); (task); \
+ (task) = cgroup_taskset_next((tset))) \
+ if (!(skip_cgrp) || \
+ cgroup_taskset_cur_cgroup((tset)) != (skip_cgrp))
+
+/*
* Control Group subsystem type.
* See Documentation/cgroups/cgroups.txt for details
*/
@@ -467,14 +489,14 @@ struct cgroup_subsys {
int (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp);
int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *tsk);
+ struct cgroup_taskset *tset);
int (*can_attach_task)(struct cgroup *cgrp, struct task_struct *tsk);
void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *tsk);
+ struct cgroup_taskset *tset);
void (*pre_attach)(struct cgroup *cgrp);
void (*attach_task)(struct cgroup *cgrp, struct task_struct *tsk);
void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cgrp, struct task_struct *tsk);
+ struct cgroup_taskset *tset);
void (*fork)(struct cgroup_subsys *ss, struct task_struct *task);
void (*exit)(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup *old_cgrp, struct task_struct *task);
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 0f2d00519d37..41ee01e392e6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1757,11 +1757,85 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
}
EXPORT_SYMBOL_GPL(cgroup_path);
+/*
+ * Control Group taskset
+ */
struct task_and_cgroup {
struct task_struct *task;
struct cgroup *cgrp;
};
+struct cgroup_taskset {
+ struct task_and_cgroup single;
+ struct flex_array *tc_array;
+ int tc_array_len;
+ int idx;
+ struct cgroup *cur_cgrp;
+};
+
+/**
+ * cgroup_taskset_first - reset taskset and return the first task
+ * @tset: taskset of interest
+ *
+ * @tset iteration is initialized and the first task is returned.
+ */
+struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset)
+{
+ if (tset->tc_array) {
+ tset->idx = 0;
+ return cgroup_taskset_next(tset);
+ } else {
+ tset->cur_cgrp = tset->single.cgrp;
+ return tset->single.task;
+ }
+}
+EXPORT_SYMBOL_GPL(cgroup_taskset_first);
+
+/**
+ * cgroup_taskset_next - iterate to the next task in taskset
+ * @tset: taskset of interest
+ *
+ * Return the next task in @tset. Iteration must have been initialized
+ * with cgroup_taskset_first().
+ */
+struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset)
+{
+ struct task_and_cgroup *tc;
+
+ if (!tset->tc_array || tset->idx >= tset->tc_array_len)
+ return NULL;
+
+ tc = flex_array_get(tset->tc_array, tset->idx++);
+ tset->cur_cgrp = tc->cgrp;
+ return tc->task;
+}
+EXPORT_SYMBOL_GPL(cgroup_taskset_next);
+
+/**
+ * cgroup_taskset_cur_cgroup - return the matching cgroup for the current task
+ * @tset: taskset of interest
+ *
+ * Return the cgroup for the current (last returned) task of @tset. This
+ * function must be preceded by either cgroup_taskset_first() or
+ * cgroup_taskset_next().
+ */
+struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset)
+{
+ return tset->cur_cgrp;
+}
+EXPORT_SYMBOL_GPL(cgroup_taskset_cur_cgroup);
+
+/**
+ * cgroup_taskset_size - return the number of tasks in taskset
+ * @tset: taskset of interest
+ */
+int cgroup_taskset_size(struct cgroup_taskset *tset)
+{
+ return tset->tc_array ? tset->tc_array_len : 1;
+}
+EXPORT_SYMBOL_GPL(cgroup_taskset_size);
+
+
/*
* cgroup_task_migrate - move a task from one cgroup to another.
*
@@ -1842,6 +1916,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
struct cgroup_subsys *ss, *failed_ss = NULL;
struct cgroup *oldcgrp;
struct cgroupfs_root *root = cgrp->root;
+ struct cgroup_taskset tset = { };
/* @tsk either already exited or can't exit until the end */
if (tsk->flags & PF_EXITING)
@@ -1852,9 +1927,12 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
if (cgrp == oldcgrp)
return 0;
+ tset.single.task = tsk;
+ tset.single.cgrp = oldcgrp;
+
for_each_subsys(root, ss) {
if (ss->can_attach) {
- retval = ss->can_attach(ss, cgrp, tsk);
+ retval = ss->can_attach(ss, cgrp, &tset);
if (retval) {
/*
* Remember on which subsystem the can_attach()
@@ -1885,7 +1963,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
if (ss->attach_task)
ss->attach_task(cgrp, tsk);
if (ss->attach)
- ss->attach(ss, cgrp, oldcgrp, tsk);
+ ss->attach(ss, cgrp, &tset);
}
synchronize_rcu();
@@ -1907,7 +1985,7 @@ out:
*/
break;
if (ss->cancel_attach)
- ss->cancel_attach(ss, cgrp, tsk);
+ ss->cancel_attach(ss, cgrp, &tset);
}
}
return retval;
@@ -2023,6 +2101,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
struct task_struct *tsk;
struct task_and_cgroup *tc;
struct flex_array *group;
+ struct cgroup_taskset tset = { };
/*
* we need to make sure we have css_sets for all the tasks we're
* going to move -before- we actually start moving them, so that in
@@ -2089,6 +2168,8 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
} while_each_thread(leader, tsk);
/* remember the number of threads in the array for later. */
group_size = i;
+ tset.tc_array = group;
+ tset.tc_array_len = group_size;
read_unlock(&tasklist_lock);
/* methods shouldn't be called if no task is actually migrating */
@@ -2101,7 +2182,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
*/
for_each_subsys(root, ss) {
if (ss->can_attach) {
- retval = ss->can_attach(ss, cgrp, leader);
+ retval = ss->can_attach(ss, cgrp, &tset);
if (retval) {
failed_ss = ss;
goto out_cancel_attach;
@@ -2183,10 +2264,8 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
* being moved, this call will need to be reworked to communicate that.
*/
for_each_subsys(root, ss) {
- if (ss->attach) {
- tc = flex_array_get(group, 0);
- ss->attach(ss, cgrp, tc->cgrp, tc->task);
- }
+ if (ss->attach)
+ ss->attach(ss, cgrp, &tset);
}
/*
@@ -2208,11 +2287,11 @@ out_cancel_attach:
for_each_subsys(root, ss) {
if (ss == failed_ss) {
if (cancel_failed_ss && ss->cancel_attach)
- ss->cancel_attach(ss, cgrp, leader);
+ ss->cancel_attach(ss, cgrp, &tset);
break;
}
if (ss->cancel_attach)
- ss->cancel_attach(ss, cgrp, leader);
+ ss->cancel_attach(ss, cgrp, &tset);
}
}
out_put_tasks:
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index e411a60cc2c8..e95c6fb65cc0 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -159,7 +159,7 @@ static void freezer_destroy(struct cgroup_subsys *ss,
*/
static int freezer_can_attach(struct cgroup_subsys *ss,
struct cgroup *new_cgroup,
- struct task_struct *task)
+ struct cgroup_taskset *tset)
{
struct freezer *freezer;
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 9fe58c46a426..512bd59e8627 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1371,10 +1371,10 @@ static int fmeter_getrate(struct fmeter *fmp)
}
/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
- struct task_struct *tsk)
+static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct cgroup_taskset *tset)
{
- struct cpuset *cs = cgroup_cs(cont);
+ struct cpuset *cs = cgroup_cs(cgrp);
if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
@@ -1387,7 +1387,7 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
* set_cpus_allowed_ptr() on all attached tasks before cpus_allowed may
* be changed.
*/
- if (tsk->flags & PF_THREAD_BOUND)
+ if (cgroup_taskset_first(tset)->flags & PF_THREAD_BOUND)
return -EINVAL;
return 0;
@@ -1437,12 +1437,14 @@ static void cpuset_attach_task(struct cgroup *cont, struct task_struct *tsk)
cpuset_update_task_spread_flag(cs, tsk);
}
-static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
- struct cgroup *oldcont, struct task_struct *tsk)
+static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
+ struct cgroup_taskset *tset)
{
struct mm_struct *mm;
- struct cpuset *cs = cgroup_cs(cont);
- struct cpuset *oldcs = cgroup_cs(oldcont);
+ struct task_struct *tsk = cgroup_taskset_first(tset);
+ struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset);
+ struct cpuset *cs = cgroup_cs(cgrp);
+ struct cpuset *oldcs = cgroup_cs(oldcgrp);
/*
* Change mm, possibly for multiple threads in a threadgroup. This is
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6aff93c98aca..81640e74a709 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5298,8 +5298,9 @@ static void mem_cgroup_clear_mc(void)
static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
+ struct task_struct *p = cgroup_taskset_first(tset);
int ret = 0;
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgroup);
@@ -5337,7 +5338,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
mem_cgroup_clear_mc();
}
@@ -5454,9 +5455,9 @@ retry:
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
struct cgroup *cont,
- struct cgroup *old_cont,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
+ struct task_struct *p = cgroup_taskset_first(tset);
struct mm_struct *mm = get_task_mm(p);
if (mm) {
@@ -5471,19 +5472,18 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
#else /* !CONFIG_MMU */
static int mem_cgroup_can_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
return 0;
}
static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss,
struct cgroup *cgroup,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
}
static void mem_cgroup_move_task(struct cgroup_subsys *ss,
struct cgroup *cont,
- struct cgroup *old_cont,
- struct task_struct *p)
+ struct cgroup_taskset *tset)
{
}
#endif
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 4450fbeec411..8b5b5d8612c6 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -62,11 +62,12 @@ static inline struct dev_cgroup *task_devcgroup(struct task_struct *task)
struct cgroup_subsys devices_subsys;
static int devcgroup_can_attach(struct cgroup_subsys *ss,
- struct cgroup *new_cgroup, struct task_struct *task)
+ struct cgroup *new_cgrp, struct cgroup_taskset *set)
{
- if (current != task && !capable(CAP_SYS_ADMIN))
- return -EPERM;
+ struct task_struct *task = cgroup_taskset_first(set);
+ if (current != task && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 15:43:01 +0000