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-rw-r--r--kernel/Makefile5
-rw-r--r--kernel/cgroup/Makefile6
-rw-r--r--kernel/cgroup/cgroup-internal.h214
-rw-r--r--kernel/cgroup/cgroup-v1.c1395
-rw-r--r--kernel/cgroup/cgroup.c (renamed from kernel/cgroup.c)2081
-rw-r--r--kernel/cgroup/cpuset.c (renamed from kernel/cpuset.c)0
-rw-r--r--kernel/cgroup/freezer.c (renamed from kernel/cgroup_freezer.c)0
-rw-r--r--kernel/cgroup/namespace.c155
-rw-r--r--kernel/cgroup/pids.c (renamed from kernel/cgroup_pids.c)0
-rw-r--r--kernel/cgroup/rdma.c619
-rw-r--r--kernel/events/core.c6
11 files changed, 2641 insertions, 1840 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 12c679f769c6..b302b4731d16 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -64,10 +64,7 @@ obj-$(CONFIG_KEXEC) += kexec.o
obj-$(CONFIG_KEXEC_FILE) += kexec_file.o
obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
obj-$(CONFIG_COMPAT) += compat.o
-obj-$(CONFIG_CGROUPS) += cgroup.o
-obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o
-obj-$(CONFIG_CGROUP_PIDS) += cgroup_pids.o
-obj-$(CONFIG_CPUSETS) += cpuset.o
+obj-$(CONFIG_CGROUPS) += cgroup/
obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_USER_NS) += user_namespace.o
obj-$(CONFIG_PID_NS) += pid_namespace.o
diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile
new file mode 100644
index 000000000000..387348a40c64
--- /dev/null
+++ b/kernel/cgroup/Makefile
@@ -0,0 +1,6 @@
+obj-y := cgroup.o namespace.o cgroup-v1.o
+
+obj-$(CONFIG_CGROUP_FREEZER) += freezer.o
+obj-$(CONFIG_CGROUP_PIDS) += pids.o
+obj-$(CONFIG_CGROUP_RDMA) += rdma.o
+obj-$(CONFIG_CPUSETS) += cpuset.o
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
new file mode 100644
index 000000000000..9203bfb05603
--- /dev/null
+++ b/kernel/cgroup/cgroup-internal.h
@@ -0,0 +1,214 @@
+#ifndef __CGROUP_INTERNAL_H
+#define __CGROUP_INTERNAL_H
+
+#include <linux/cgroup.h>
+#include <linux/kernfs.h>
+#include <linux/workqueue.h>
+#include <linux/list.h>
+
+/*
+ * A cgroup can be associated with multiple css_sets as different tasks may
+ * belong to different cgroups on different hierarchies. In the other
+ * direction, a css_set is naturally associated with multiple cgroups.
+ * This M:N relationship is represented by the following link structure
+ * which exists for each association and allows traversing the associations
+ * from both sides.
+ */
+struct cgrp_cset_link {
+ /* the cgroup and css_set this link associates */
+ struct cgroup *cgrp;
+ struct css_set *cset;
+
+ /* list of cgrp_cset_links anchored at cgrp->cset_links */
+ struct list_head cset_link;
+
+ /* list of cgrp_cset_links anchored at css_set->cgrp_links */
+ struct list_head cgrp_link;
+};
+
+/* used to track tasks and csets during migration */
+struct cgroup_taskset {
+ /* the src and dst cset list running through cset->mg_node */
+ struct list_head src_csets;
+ struct list_head dst_csets;
+
+ /* the subsys currently being processed */
+ int ssid;
+
+ /*
+ * Fields for cgroup_taskset_*() iteration.
+ *
+ * Before migration is committed, the target migration tasks are on
+ * ->mg_tasks of the csets on ->src_csets. After, on ->mg_tasks of
+ * the csets on ->dst_csets. ->csets point to either ->src_csets
+ * or ->dst_csets depending on whether migration is committed.
+ *
+ * ->cur_csets and ->cur_task point to the current task position
+ * during iteration.
+ */
+ struct list_head *csets;
+ struct css_set *cur_cset;
+ struct task_struct *cur_task;
+};
+
+/* migration context also tracks preloading */
+struct cgroup_mgctx {
+ /*
+ * Preloaded source and destination csets. Used to guarantee
+ * atomic success or failure on actual migration.
+ */
+ struct list_head preloaded_src_csets;
+ struct list_head preloaded_dst_csets;
+
+ /* tasks and csets to migrate */
+ struct cgroup_taskset tset;
+
+ /* subsystems affected by migration */
+ u16 ss_mask;
+};
+
+#define CGROUP_TASKSET_INIT(tset) \
+{ \
+ .src_csets = LIST_HEAD_INIT(tset.src_csets), \
+ .dst_csets = LIST_HEAD_INIT(tset.dst_csets), \
+ .csets = &tset.src_csets, \
+}
+
+#define CGROUP_MGCTX_INIT(name) \
+{ \
+ LIST_HEAD_INIT(name.preloaded_src_csets), \
+ LIST_HEAD_INIT(name.preloaded_dst_csets), \
+ CGROUP_TASKSET_INIT(name.tset), \
+}
+
+#define DEFINE_CGROUP_MGCTX(name) \
+ struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name)
+
+struct cgroup_sb_opts {
+ u16 subsys_mask;
+ unsigned int flags;
+ char *release_agent;
+ bool cpuset_clone_children;
+ char *name;
+ /* User explicitly requested empty subsystem */
+ bool none;
+};
+
+extern struct mutex cgroup_mutex;
+extern spinlock_t css_set_lock;
+extern struct cgroup_subsys *cgroup_subsys[];
+extern struct list_head cgroup_roots;
+extern struct file_system_type cgroup_fs_type;
+
+/* iterate across the hierarchies */
+#define for_each_root(root) \
+ list_for_each_entry((root), &cgroup_roots, root_list)
+
+/**
+ * for_each_subsys - iterate all enabled cgroup subsystems
+ * @ss: the iteration cursor
+ * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
+ */
+#define for_each_subsys(ss, ssid) \
+ for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT && \
+ (((ss) = cgroup_subsys[ssid]) || true); (ssid)++)
+
+static inline bool cgroup_is_dead(const struct cgroup *cgrp)
+{
+ return !(cgrp->self.flags & CSS_ONLINE);
+}
+
+static inline bool notify_on_release(const struct cgroup *cgrp)
+{
+ return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
+}
+
+void put_css_set_locked(struct css_set *cset);
+
+static inline void put_css_set(struct css_set *cset)
+{
+ unsigned long flags;
+
+ /*
+ * Ensure that the refcount doesn't hit zero while any readers
+ * can see it. Similar to atomic_dec_and_lock(), but for an
+ * rwlock
+ */
+ if (atomic_add_unless(&cset->refcount, -1, 1))
+ return;
+
+ spin_lock_irqsave(&css_set_lock, flags);
+ put_css_set_locked(cset);
+ spin_unlock_irqrestore(&css_set_lock, flags);
+}
+
+/*
+ * refcounted get/put for css_set objects
+ */
+static inline void get_css_set(struct css_set *cset)
+{
+ atomic_inc(&cset->refcount);
+}
+
+bool cgroup_ssid_enabled(int ssid);
+bool cgroup_on_dfl(const struct cgroup *cgrp);
+
+struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root);
+struct cgroup *task_cgroup_from_root(struct task_struct *task,
+ struct cgroup_root *root);
+struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn, bool drain_offline);
+void cgroup_kn_unlock(struct kernfs_node *kn);
+int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns);
+
+void cgroup_free_root(struct cgroup_root *root);
+void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts);
+int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask);
+int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);
+struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags,
+ struct cgroup_root *root, unsigned long magic,
+ struct cgroup_namespace *ns);
+
+bool cgroup_may_migrate_to(struct cgroup *dst_cgrp);
+void cgroup_migrate_finish(struct cgroup_mgctx *mgctx);
+void cgroup_migrate_add_src(struct css_set *src_cset, struct cgroup *dst_cgrp,
+ struct cgroup_mgctx *mgctx);
+int cgroup_migrate_prepare_dst(struct cgroup_mgctx *mgctx);
+int cgroup_migrate(struct task_struct *leader, bool threadgroup,
+ struct cgroup_mgctx *mgctx);
+
+int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader,
+ bool threadgroup);
+ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off, bool threadgroup);
+ssize_t cgroup_procs_write(struct kernfs_open_file *of, char *buf, size_t nbytes,
+ loff_t off);
+
+void cgroup_lock_and_drain_offline(struct cgroup *cgrp);
+
+int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode);
+int cgroup_rmdir(struct kernfs_node *kn);
+int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
+ struct kernfs_root *kf_root);
+
+/*
+ * namespace.c
+ */
+extern const struct proc_ns_operations cgroupns_operations;
+
+/*
+ * cgroup-v1.c
+ */
+extern struct cftype cgroup1_base_files[];
+extern const struct file_operations proc_cgroupstats_operations;
+extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
+
+bool cgroup1_ssid_disabled(int ssid);
+void cgroup1_pidlist_destroy_all(struct cgroup *cgrp);
+void cgroup1_release_agent(struct work_struct *work);
+void cgroup1_check_for_release(struct cgroup *cgrp);
+struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags,
+ void *data, unsigned long magic,
+ struct cgroup_namespace *ns);
+
+#endif /* __CGROUP_INTERNAL_H */
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
new file mode 100644
index 000000000000..fc34bcf2329f
--- /dev/null
+++ b/kernel/cgroup/cgroup-v1.c
@@ -0,0 +1,1395 @@
+#include "cgroup-internal.h"
+
+#include <linux/ctype.h>
+#include <linux/kmod.h>
+#include <linux/sort.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/delayacct.h>
+#include <linux/pid_namespace.h>
+#include <linux/cgroupstats.h>
+
+#include <trace/events/cgroup.h>
+
+/*
+ * pidlists linger the following amount before being destroyed. The goal
+ * is avoiding frequent destruction in the middle of consecutive read calls
+ * Expiring in the middle is a performance problem not a correctness one.
+ * 1 sec should be enough.
+ */
+#define CGROUP_PIDLIST_DESTROY_DELAY HZ
+
+/* Controllers blocked by the commandline in v1 */
+static u16 cgroup_no_v1_mask;
+
+/*
+ * pidlist destructions need to be flushed on cgroup destruction. Use a
+ * separate workqueue as flush domain.
+ */
+static struct workqueue_struct *cgroup_pidlist_destroy_wq;
+
+/*
+ * Protects cgroup_subsys->release_agent_path. Modifying it also requires
+ * cgroup_mutex. Reading requires either cgroup_mutex or this spinlock.
+ */
+static DEFINE_SPINLOCK(release_agent_path_lock);
+
+bool cgroup1_ssid_disabled(int ssid)
+{
+ return cgroup_no_v1_mask & (1 << ssid);
+}
+
+/**
+ * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from'
+ * @from: attach to all cgroups of a given task
+ * @tsk: the task to be attached
+ */
+int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
+{
+ struct cgroup_root *root;
+ int retval = 0;
+
+ mutex_lock(&cgroup_mutex);
+ percpu_down_write(&cgroup_threadgroup_rwsem);
+ for_each_root(root) {
+ struct cgroup *from_cgrp;
+
+ if (root == &cgrp_dfl_root)
+ continue;
+
+ spin_lock_irq(&css_set_lock);
+ from_cgrp = task_cgroup_from_root(from, root);
+ spin_unlock_irq(&css_set_lock);
+
+ retval = cgroup_attach_task(from_cgrp, tsk, false);
+ if (retval)
+ break;
+ }
+ percpu_up_write(&cgroup_threadgroup_rwsem);
+ mutex_unlock(&cgroup_mutex);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
+
+/**
+ * cgroup_trasnsfer_tasks - move tasks from one cgroup to another
+ * @to: cgroup to which the tasks will be moved
+ * @from: cgroup in which the tasks currently reside
+ *
+ * Locking rules between cgroup_post_fork() and the migration path
+ * guarantee that, if a task is forking while being migrated, the new child
+ * is guaranteed to be either visible in the source cgroup after the
+ * parent's migration is complete or put into the target cgroup. No task
+ * can slip out of migration through forking.
+ */
+int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
+{
+ DEFINE_CGROUP_MGCTX(mgctx);
+ struct cgrp_cset_link *link;
+ struct css_task_iter it;
+ struct task_struct *task;
+ int ret;
+
+ if (cgroup_on_dfl(to))
+ return -EINVAL;
+
+ if (!cgroup_may_migrate_to(to))
+ return -EBUSY;
+
+ mutex_lock(&cgroup_mutex);
+
+ percpu_down_write(&cgroup_threadgroup_rwsem);
+
+ /* all tasks in @from are being moved, all csets are source */
+ spin_lock_irq(&css_set_lock);
+ list_for_each_entry(link, &from->cset_links, cset_link)
+ cgroup_migrate_add_src(link->cset, to, &mgctx);
+ spin_unlock_irq(&css_set_lock);
+
+ ret = cgroup_migrate_prepare_dst(&mgctx);
+ if (ret)
+ goto out_err;
+
+ /*
+ * Migrate tasks one-by-one until @from is empty. This fails iff
+ * ->can_attach() fails.
+ */
+ do {
+ css_task_iter_start(&from->self, &it);
+ task = css_task_iter_next(&it);
+ if (task)
+ get_task_struct(task);
+ css_task_iter_end(&it);
+
+ if (task) {
+ ret = cgroup_migrate(task, false, &mgctx);
+ if (!ret)
+ trace_cgroup_transfer_tasks(to, task, false);
+ put_task_struct(task);
+ }
+ } while (task && !ret);
+out_err:
+ cgroup_migrate_finish(&mgctx);
+ percpu_up_write(&cgroup_threadgroup_rwsem);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+
+/*
+ * Stuff for reading the 'tasks'/'procs' files.
+ *
+ * Reading this file can return large amounts of data if a cgroup has
+ * *lots* of attached tasks. So it may need several calls to read(),
+ * but we cannot guarantee that the information we produce is correct
+ * unless we produce it entirely atomically.
+ *
+ */
+
+/* which pidlist file are we talking about? */
+enum cgroup_filetype {
+ CGROUP_FILE_PROCS,
+ CGROUP_FILE_TASKS,
+};
+
+/*
+ * A pidlist is a list of pids that virtually represents the contents of one
+ * of the cgroup files ("procs" or "tasks"). We keep a list of such pidlists,
+ * a pair (one each for procs, tasks) for each pid namespace that's relevant
+ * to the cgroup.
+ */
+struct cgroup_pidlist {
+ /*
+ * used to find which pidlist is wanted. doesn't change as long as
+ * this particular list stays in the list.
+ */
+ struct { enum cgroup_filetype type; struct pid_namespace *ns; } key;
+ /* array of xids */
+ pid_t *list;
+ /* how many elements the above list has */
+ int length;
+ /* each of these stored in a list by its cgroup */
+ struct list_head links;
+ /* pointer to the cgroup we belong to, for list removal purposes */
+ struct cgroup *owner;
+ /* for delayed destruction */
+ struct delayed_work destroy_dwork;
+};
+
+/*
+ * The following two functions "fix" the issue where there are more pids
+ * than kmalloc will give memory for; in such cases, we use vmalloc/vfree.
+ * TODO: replace with a kernel-wide solution to this problem
+ */
+#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
+static void *pidlist_allocate(int count)
+{
+ if (PIDLIST_TOO_LARGE(count))
+ return vmalloc(count * sizeof(pid_t));
+ else
+ return kmalloc(count * sizeof(pid_t), GFP_KERNEL);
+}
+
+static void pidlist_free(void *p)
+{
+ kvfree(p);
+}
+
+/*
+ * Used to destroy all pidlists lingering waiting for destroy timer. None
+ * should be left afterwards.
+ */
+void cgroup1_pidlist_destroy_all(struct cgroup *cgrp)
+{
+ struct cgroup_pidlist *l, *tmp_l;
+
+ mutex_lock(&cgrp->pidlist_mutex);
+ list_for_each_entry_safe(l, tmp_l, &cgrp->pidlists, links)
+ mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork, 0);
+ mutex_unlock(&cgrp->pidlist_mutex);
+
+ flush_workqueue(cgroup_pidlist_destroy_wq);
+ BUG_ON(!list_empty(&cgrp->pidlists));
+}
+
+static void cgroup_pidlist_destroy_work_fn(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct cgroup_pidlist *l = container_of(dwork, struct cgroup_pidlist,
+ destroy_dwork);
+ struct cgroup_pidlist *tofree = NULL;
+
+ mutex_lock(&l->owner->pidlist_mutex);
+
+ /*
+ * Destroy iff we didn't get queued again. The state won't change
+ * as destroy_dwork can only be queued while locked.
+ */
+ if (!delayed_work_pending(dwork)) {
+ list_del(&l->links);
+ pidlist_free(l->list);
+ put_pid_ns(l->key.ns);
+ tofree = l;
+ }
+
+ mutex_unlock(&l->owner->pidlist_mutex);
+ kfree(tofree);
+}
+
+/*
+ * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries
+ * Returns the number of unique elements.
+ */
+static int pidlist_uniq(pid_t *list, int length)
+{
+ int src, dest = 1;
+
+ /*
+ * we presume the 0th element is unique, so i starts at 1. trivial
+ * edge cases first; no work needs to be done for either
+ */
+ if (length == 0 || length == 1)
+ return length;
+ /* src and dest walk down the list; dest counts unique elements */
+ for (src = 1; src < length; src++) {
+ /* find next unique element */
+ while (list[src] == list[src-1]) {
+ src++;
+ if (src == length)
+ goto after;
+ }
+ /* dest always points to where the next unique element goes */
+ list[dest] = list[src];
+ dest++;
+ }
+after:
+ return dest;
+}
+
+/*
+ * The two pid files - task and cgroup.procs - guaranteed that the result
+ * is sorted, which forced this whole pidlist fiasco. As pid order is
+ * different per namespace, each namespace needs differently sorted list,
+ * making it impossible to use, for example, single rbtree of member tasks
+ * sorted by task pointer. As pidlists can be fairly large, allocating one
+ * per open file is dangerous, so cgroup had to implement shared pool of
+ * pidlists keyed by cgroup and namespace.
+ */
+static int cmppid(const void *a, const void *b)
+{
+ return *(pid_t *)a - *(pid_t *)b;
+}
+
+static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
+ enum cgroup_filetype type)
+{
+ struct cgroup_pidlist *l;
+ /* don't need task_nsproxy() if we're looking at ourself */
+ struct pid_namespace *ns = task_active_pid_ns(current);
+
+ lockdep_assert_held(&cgrp->pidlist_mutex);
+
+ list_for_each_entry(l, &cgrp->pidlists, links)
+ if (l->key.type == type && l->key.ns == ns)
+ return l;
+ return NULL;
+}
+
+/*
+ * find the appropriate pidlist for our purpose (given procs vs tasks)
+ * returns with the lock on that pidlist already held, and takes care
+ * of the use count, or returns NULL with no locks held if we're out of
+ * memory.
+ */
+static struct cgroup_pidlist *cgroup_pidlist_find_create(struct cgroup *cgrp,
+ enum cgroup_filetype type)
+{
+ struct cgroup_pidlist *l;
+
+ lockdep_assert_held(&cgrp->pidlist_mutex);
+
+ l = cgroup_pidlist_find(cgrp, type);
+ if (l)
+ return l;
+
+ /* entry not found; create a new one */
+ l = kzalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
+ if (!l)
+ return l;
+
+ INIT_DELAYED_WORK(&l->destroy_dwork, cgroup_pidlist_destroy_work_fn);
+ l->key.type = type;
+ /* don't need task_nsproxy() if we're looking at ourself */
+ l->key.ns = get_pid_ns(task_active_pid_ns(current));
+ l->owner = cgrp;
+ list_add(&l->links, &cgrp->pidlists);
+ return l;
+}
+
+/**
+ * cgroup_task_count - count the number of tasks in a cgroup.
+ * @cgrp: the cgroup in question
+ *
+ * Return the number of tasks in the cgroup. The returned number can be
+ * higher than the actual number of tasks due to css_set references from
+ * namespace roots and temporary usages.
+ */
+static int cgroup_task_count(const struct cgroup *cgrp)
+{
+ int count = 0;
+ struct cgrp_cset_link *link;
+
+ spin_lock_irq(&css_set_lock);
+ list_for_each_entry(link, &cgrp->cset_links, cset_link)
+ count += atomic_read(&link->cset->refcount);
+ spin_unlock_irq(&css_set_lock);
+ return count;
+}
+
+/*
+ * Load a cgroup's pidarray with either procs' tgids or tasks' pids
+ */
+static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
+ struct cgroup_pidlist **lp)
+{
+ pid_t *array;
+ int length;
+ int pid, n = 0; /* used for populating the array */
+ struct css_task_iter it;
+ struct task_struct *tsk;
+ struct cgroup_pidlist *l;
+
+ lockdep_assert_held(&cgrp->pidlist_mutex);
+
+ /*
+ * If cgroup gets more users after we read count, we won't have
+ * enough space - tough. This race is indistinguishable to the
+ * caller from the case that the additional cgroup users didn't
+ * show up until sometime later on.
+ */
+ length = cgroup_task_count(cgrp);
+ array = pidlist_allocate(length);
+ if (!array)
+ return -ENOMEM;
+ /* now, populate the array */
+ css_task_iter_start(&cgrp->self, &it);
+ while ((tsk = css_task_iter_next(&it))) {
+ if (unlikely(n == length))
+ break;
+ /* get tgid or pid for procs or tasks file respectively */
+ if (type == CGROUP_FILE_PROCS)
+ pid = task_tgid_vnr(tsk);
+ else
+ pid = task_pid_vnr(tsk);
+ if (pid > 0) /* make sure to only use valid results */
+ array[n++] = pid;
+ }
+ css_task_iter_end(&it);
+ length = n;
+ /* now sort & (if procs) strip out duplicates */
+ sort(array, length, sizeof(pid_t), cmppid, NULL);
+ if (type == CGROUP_FILE_PROCS)
+ length = pidlist_uniq(array, length);
+
+ l = cgroup_pidlist_find_create(cgrp, type);
+ if (!l) {
+ pidlist_free(array);
+ return -ENOMEM;
+ }
+
+ /* store array, freeing old if necessary */
+ pidlist_free(l->list);
+ l->list = array;
+ l->length = length;
+ *lp = l;
+ return 0;
+}
+
+/*
+ * seq_file methods for the tasks/procs files. The seq_file position is the
+ * next pid to display; the seq_file iterator is a pointer to the pid
+ * in the cgroup->l->list array.
+ */
+
+static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
+{
+ /*
+ * Initially we receive a position value that corresponds to
+ * one more than the last pid shown (or 0 on the first call or
+ * after a seek to the start). Use a binary-search to find the
+ * next pid to display, if any
+ */
+ struct kernfs_open_file *of = s->private;
+ struct cgroup *cgrp = seq_css(s)->cgroup;
+ struct cgroup_pidlist *l;
+ enum cgroup_filetype type = seq_cft(s)->private;
+ int index = 0, pid = *pos;
+ int *iter, ret;
+
+ mutex_lock(&cgrp->pidlist_mutex);
+
+ /*
+ * !NULL @of->priv indicates that this isn't the first start()
+ * after open. If the matching pidlist is around, we can use that.
+ * Look for it. Note that @of->priv can't be used directly. It
+ * could already have been destroyed.
+ */
+ if (of->priv)
+ of->priv = cgroup_pidlist_find(cgrp, type);
+
+ /*
+ * Either this is the first start() after open or the matching
+ * pidlist has been destroyed inbetween. Create a new one.
+ */
+ if (!of->priv) {
+ ret = pidlist_array_load(cgrp, type,
+ (struct cgroup_pidlist **)&of->priv);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+ l = of->priv;
+
+ if (pid) {
+ int end = l->length;
+
+ while (index < end) {
+ int mid = (index + end) / 2;
+ if (l->list[mid] == pid) {
+ index = mid;
+ break;
+ } else if (l->list[mid] <= pid)
+ index = mid + 1;
+ else
+ end = mid;
+ }
+ }
+ /* If we're off the end of the array, we're done */
+ if (index >= l->length)
+ return NULL;
+ /* Update the abstract position to be the actual pid that we found */
+ iter = l->list + index;
+ *pos = *iter;
+ return iter;
+}
+
+static void cgroup_pidlist_stop(struct seq_file *s, void *v)
+{
+ struct kernfs_open_file *of = s->private;
+ struct cgroup_pidlist *l = of->priv;
+
+ if (l)
+ mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork,
+ CGROUP_PIDLIST_DESTROY_DELAY);
+ mutex_unlock(&seq_css(s)->cgroup->pidlist_mutex);
+}
+
+static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ struct kernfs_open_file *of = s->private;
+ struct cgroup_pidlist *l = of->priv;
+ pid_t *p = v;
+ pid_t *end = l->list + l->length;
+ /*
+ * Advance to the next pid in the array. If this goes off the
+ * end, we're done
+ */
+ p++;
+ if (p >= end) {
+ return NULL;
+ } else {
+ *pos = *p;
+ return p;
+ }
+}
+
+static int cgroup_pidlist_show(struct seq_file *s, void *v)
+{
+ seq_printf(s, "%d\n", *(int *)v);
+
+ return 0;
+}
+
+static ssize_t cgroup_tasks_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ return __cgroup_procs_write(of, buf, nbytes, off, false);
+}
+
+static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct cgroup *cgrp;
+
+ BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+
+ cgrp = cgroup_kn_lock_live(of->kn, false);
+ if (!cgrp)
+ return -ENODEV;
+ spin_lock(&release_agent_path_lock);
+ strlcpy(cgrp->root->release_agent_path, strstrip(buf),
+ sizeof(cgrp->root->release_agent_path));
+ spin_unlock(&release_agent_path_lock);
+ cgroup_kn_unlock(of->kn);
+ return nbytes;
+}
+
+static int cgroup_release_agent_show(struct seq_file *seq, void *v)
+{
+ struct cgroup *cgrp = seq_css(seq)->cgroup;
+
+ spin_lock(&release_agent_path_lock);
+ seq_puts(seq, cgrp->root->release_agent_path);
+ spin_unlock(&release_agent_path_lock);
+ seq_putc(seq, '\n');
+ return 0;
+}
+
+static int cgroup_sane_behavior_show(struct seq_file *seq, void *v)
+{
+ seq_puts(seq, "0\n");
+ return 0;
+}
+
+static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return notify_on_release(css->cgroup);
+}
+
+static int cgroup_write_notify_on_release(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ if (val)
+ set_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
+ else
+ clear_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
+ return 0;
+}
+
+static u64 cgroup_clone_children_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
+}
+
+static int cgroup_clone_children_write(struct cgroup_subsys_state *css,
+ struct cftype *cft, u64 val)
+{
+ if (val)
+ set_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
+ else
+ clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
+ return 0;
+}
+
+/* cgroup core interface files for the legacy hierarchies */
+struct cftype cgroup1_base_files[] = {
+ {
+ .name = "cgroup.procs",
+ .seq_start = cgroup_pidlist_start,
+ .seq_next = cgroup_pidlist_next,
+ .seq_stop = cgroup_pidlist_stop,
+ .seq_show = cgroup_pidlist_show,
+ .private = CGROUP_FILE_PROCS,
+ .write = cgroup_procs_write,
+ },
+ {
+ .name = "cgroup.clone_children",
+ .read_u64 = cgroup_clone_children_read,
+ .write_u64 = cgroup_clone_children_write,
+ },
+ {
+ .name = "cgroup.sane_behavior",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .seq_show = cgroup_sane_behavior_show,
+ },
+ {
+ .name = "tasks",
+ .seq_start = cgroup_pidlist_start,
+ .seq_next = cgroup_pidlist_next,
+ .seq_stop = cgroup_pidlist_stop,
+ .seq_show = cgroup_pidlist_show,
+ .private = CGROUP_FILE_TASKS,
+ .write = cgroup_tasks_write,
+ },
+ {
+ .name = "notify_on_release",
+ .read_u64 = cgroup_read_notify_on_release,
+ .write_u64 = cgroup_write_notify_on_release,
+ },
+ {
+ .name = "release_agent",
+ .flags = CFTYPE_ONLY_ON_ROOT,
+ .seq_show = cgroup_release_agent_show,
+ .write = cgroup_release_agent_write,
+ .max_write_len = PATH_MAX - 1,
+ },
+ { } /* terminate */
+};
+
+/* Display information about each subsystem and each hierarchy */
+static int proc_cgroupstats_show(struct seq_file *m, void *v)
+{
+ struct cgroup_subsys *ss;
+ int i;
+
+ seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
+ /*
+ * ideally we don't want subsystems moving around while we do this.
+ * cgroup_mutex is also necessary to guarantee an atomic snapshot of
+ * subsys/hierarchy state.
+ */
+ mutex_lock(&cgroup_mutex);
+
+ for_each_subsys(ss, i)
+ seq_printf(m, "%s\t%d\t%d\t%d\n",
+ ss->legacy_name, ss->root->hierarchy_id,
+ atomic_read(&ss->root->nr_cgrps),
+ cgroup_ssid_enabled(i));
+
+ mutex_unlock(&cgroup_mutex);
+ return 0;
+}
+
+static int cgroupstats_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, proc_cgroupstats_show, NULL);
+}
+
+const struct file_operations proc_cgroupstats_operations = {
+ .open = cgroupstats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+/**
+ * cgroupstats_build - build and fill cgroupstats
+ * @stats: cgroupstats to fill information into
+ * @dentry: A dentry entry belonging to the cgroup for which stats have
+ * been requested.
+ *
+ * Build and fill cgroupstats so that taskstats can export it to user
+ * space.
+ */
+int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
+{
+ struct kernfs_node *kn = kernfs_node_from_dentry(dentry);
+ struct cgroup *cgrp;
+ struct css_task_iter it;
+ struct task_struct *tsk;
+
+ /* it should be kernfs_node belonging to cgroupfs and is a directory */
+ if (dentry->d_sb->s_type != &cgroup_fs_type || !kn ||
+ kernfs_type(kn) != KERNFS_DIR)
+ return -EINVAL;
+
+ mutex_lock(&cgroup_mutex);
+
+ /*
+ * We aren't being called from kernfs and there's no guarantee on
+ * @kn->priv's validity. For this and css_tryget_online_from_dir(),
+ * @kn->priv is RCU safe. Let's do the RCU dancing.
+ */
+ rcu_read_lock();
+ cgrp = rcu_dereference(*(void __rcu __force **)&kn->priv);
+ if (!cgrp || cgroup_is_dead(cgrp)) {
+ rcu_read_unlock();
+ mutex_unlock(&cgroup_mutex);
+ return -ENOENT;
+ }
+ rcu_read_unlock();
+
+ css_task_iter_start(&cgrp->self, &it);
+ while ((tsk = css_task_iter_next(&it))) {
+ switch (tsk->state) {
+ case TASK_RUNNING:
+ stats->nr_running++;
+ break;
+ case TASK_INTERRUPTIBLE:
+ stats->nr_sleeping++;
+ break;
+ case TASK_UNINTERRUPTIBLE:
+ stats->nr_uninterruptible++;
+ break;
+ case TASK_STOPPED:
+ stats->nr_stopped++;
+ break;
+ default:
+ if (delayacct_is_task_waiting_on_io(tsk))
+ stats->nr_io_wait++;
+ break;
+ }
+ }
+ css_task_iter_end(&it);
+
+ mutex_unlock(&cgroup_mutex);
+ return 0;
+}
+
+void cgroup1_check_for_release(struct cgroup *cgrp)
+{
+ if (notify_on_release(cgrp) && !cgroup_is_populated(cgrp) &&
+ !css_has_online_children(&cgrp->self) && !cgroup_is_dead(cgrp))
+ schedule_work(&cgrp->release_agent_work);
+}
+
+/*
+ * Notify userspace when a cgroup is released, by running the
+ * configured release agent with the name of the cgroup (path
+ * relative to the root of cgroup file system) as the argument.
+ *
+ * Most likely, this user command will try to rmdir this cgroup.
+ *
+ * This races with the possibility that some other task will be
+ * attached to this cgroup before it is removed, or that some other
+ * user task will 'mkdir' a child cgroup of this cgroup. That's ok.
+ * The presumed 'rmdir' will fail quietly if this cgroup is no longer
+ * unused, and this cgroup will be reprieved from its death sentence,
+ * to continue to serve a useful existence. Next time it's released,
+ * we will get notified again, if it still has 'notify_on_release' set.
+ *
+ * The final arg to call_usermodehelper() is UMH_WAIT_EXEC, which
+ * means only wait until the task is successfully execve()'d. The
+ * separate release agent task is forked by call_usermodehelper(),
+ * then control in this thread returns here, without waiting for the
+ * release agent task. We don't bother to wait because the caller of
+ * this routine has no use for the exit status of the release agent
+ * task, so no sense holding our caller up for that.
+ */
+void cgroup1_release_agent(struct work_struct *work)
+{
+ struct cgroup *cgrp =
+ container_of(work, struct cgroup, release_agent_work);
+ char *pathbuf = NULL, *agentbuf = NULL;
+ char *argv[3], *envp[3];
+ int ret;
+
+ mutex_lock(&cgroup_mutex);
+
+ pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
+ agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
+ if (!pathbuf || !agentbuf)
+ goto out;
+
+ spin_lock_irq(&css_set_lock);
+ ret = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
+ spin_unlock_irq(&css_set_lock);
+ if (ret < 0 || ret >= PATH_MAX)
+ goto out;
+
+ argv[0] = agentbuf;
+ argv[1] = pathbuf;
+ argv[2] = NULL;
+
+ /* minimal command environment */
+ envp[0] = "HOME=/";
+ envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+ envp[2] = NULL;
+
+ mutex_unlock(&cgroup_mutex);
+ call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
+ goto out_free;
+out:
+ mutex_unlock(&cgroup_mutex);
+out_free:
+ kfree(agentbuf);
+ kfree(pathbuf);
+}
+
+/*
+ * cgroup_rename - Only allow simple rename of directories in place.
+ */
+static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
+ const char *new_name_str)
+{
+ struct cgroup *cgrp = kn->priv;
+ int ret;
+
+ if (kernfs_type(kn) != KERNFS_DIR)
+ return -ENOTDIR;
+ if (kn->parent != new_parent)
+ return -EIO;
+
+ /*
+ * We're gonna grab cgroup_mutex which nests outside kernfs
+ * active_ref. kernfs_rename() doesn't require active_ref
+ * protection. Break them before grabbing cgroup_mutex.
+ */
+ kernfs_break_active_protection(new_parent);
+ kernfs_break_active_protection(kn);
+
+ mutex_lock(&cgroup_mutex);
+
+ ret = kernfs_rename(kn, new_parent, new_name_str);
+ if (!ret)
+ trace_cgroup_rename(cgrp);
+
+ mutex_unlock(&cgroup_mutex);
+
+ kernfs_unbreak_active_protection(kn);
+ kernfs_unbreak_active_protection(new_parent);
+ return ret;
+}
+
+static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_root)
+{
+ struct cgroup_root *root = cgroup_root_from_kf(kf_root);
+ struct cgroup_subsys *ss;
+ int ssid;
+
+ for_each_subsys(ss, ssid)
+ if (root->subsys_mask & (1 << ssid))
+ seq_show_option(seq, ss->legacy_name, NULL);
+ if (root->flags & CGRP_ROOT_NOPREFIX)
+ seq_puts(seq, ",noprefix");
+ if (root->flags & CGRP_ROOT_XATTR)
+ seq_puts(seq, ",xattr");
+
+ spin_lock(&release_agent_path_lock);
+ if (strlen(root->release_agent_path))
+ seq_show_option(seq, "release_agent",
+ root->release_agent_path);
+ spin_unlock(&release_agent_path_lock);
+
+ if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))
+ seq_puts(seq, ",clone_children");
+ if (strlen(root->name))
+ seq_show_option(seq, "name", root->name);
+ return 0;
+}
+
+static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
+{
+ char *token, *o = data;
+ bool all_ss = false, one_ss = false;
+ u16 mask = U16_MAX;
+ struct cgroup_subsys *ss;
+ int nr_opts = 0;
+ int i;
+
+#ifdef CONFIG_CPUSETS
+ mask = ~((u16)1 << cpuset_cgrp_id);
+#endif
+
+ memset(opts, 0, sizeof(*opts));
+
+ while ((token = strsep(&o, ",")) != NULL) {
+ nr_opts++;
+
+ if (!*token)
+ return -EINVAL;
+ if (!strcmp(token, "none")) {
+ /* Explicitly have no subsystems */
+ opts->none = true;
+ continue;
+ }
+ if (!strcmp(token, "all")) {
+ /* Mutually exclusive option 'all' + subsystem name */
+ if (one_ss)
+ return -EINVAL;
+ all_ss = true;
+ continue;
+ }
+ if (!strcmp(token, "noprefix")) {
+ opts->flags |= CGRP_ROOT_NOPREFIX;
+ continue;
+ }
+ if (!strcmp(token, "clone_children")) {
+ opts->cpuset_clone_children = true;
+ continue;
+ }
+ if (!strcmp(token, "xattr")) {
+ opts->flags |= CGRP_ROOT_XATTR;
+ continue;
+ }
+ if (!strncmp(token, "release_agent=", 14)) {
+ /* Specifying two release agents is forbidden */
+ if (opts->release_agent)
+ return -EINVAL;
+ opts->release_agent =
+ kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
+ if (!opts->release_agent)
+ return -ENOMEM;
+ continue;
+ }
+ if (!strncmp(token, "name=", 5)) {
+ const char *name = token + 5;
+ /* Can't specify an empty name */
+ if (!strlen(name))
+ return -EINVAL;
+ /* Must match [\w.-]+ */
+ for (i = 0; i < strlen(name); i++) {
+ char c = name[i];
+ if (isalnum(c))
+ continue;
+ if ((c == '.') || (c == '-') || (c == '_'))
+ continue;
+ return -EINVAL;
+ }
+ /* Specifying two names is forbidden */
+ if (opts->name)
+ return -EINVAL;
+ opts->name = kstrndup(name,
+ MAX_CGROUP_ROOT_NAMELEN - 1,
+ GFP_KERNEL);
+ if (!opts->name)
+ return -ENOMEM;
+
+ continue;
+ }
+
+ for_each_subsys(ss, i) {
+ if (strcmp(token, ss->legacy_name))
+ continue;
+ if (!cgroup_ssid_enabled(i))
+ continue;
+ if (cgroup1_ssid_disabled(i))
+ continue;
+
+ /* Mutually exclusive option 'all' + subsystem name */
+ if (all_ss)
+ return -EINVAL;
+ opts->subsys_mask |= (1 << i);
+ one_ss = true;
+
+ break;
+ }
+ if (i == CGROUP_SUBSYS_COUNT)
+ return -ENOENT;
+ }
+
+ /*
+ * If the 'all' option was specified select all the subsystems,
+ * otherwise if 'none', 'name=' and a subsystem name options were
+ * not specified, let's default to 'all'
+ */
+ if (all_ss || (!one_ss && !opts->none && !opts->name))
+ for_each_subsys(ss, i)
+ if (cgroup_ssid_enabled(i) && !cgroup1_ssid_disabled(i))
+ opts->subsys_mask |= (1 << i);
+
+ /*
+ * We either have to specify by name or by subsystems. (So all
+ * empty hierarchies must have a name).
+ */
+ if (!opts->subsys_mask && !opts->name)
+ return -EINVAL;
+
+ /*
+ * Option noprefix was introduced just for backward compatibility
+ * with the old cpuset, so we allow noprefix only if mounting just
+ * the cpuset subsystem.
+ */
+ if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
+ return -EINVAL;
+
+ /* Can't specify "none" and some subsystems */
+ if (opts->subsys_mask && opts->none)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)
+{
+ int ret = 0;
+ struct cgroup_root *root = cgroup_root_from_kf(kf_root);
+ struct cgroup_sb_opts opts;
+ u16 added_mask, removed_mask;
+
+ cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
+
+ /* See what subsystems are wanted */
+ ret = parse_cgroupfs_options(data, &opts);
+ if (ret)
+ goto out_unlock;
+
+ if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
+ pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
+ task_tgid_nr(current), current->comm);
+
+ added_mask = opts.subsys_mask & ~root->subsys_mask;
+ removed_mask = root->subsys_mask & ~opts.subsys_mask;
+
+ /* Don't allow flags or name to change at remount */
+ if ((opts.flags ^ root->flags) ||
+ (opts.name && strcmp(opts.name, root->name))) {
+ pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
+ opts.flags, opts.name ?: "", root->flags, root->name);
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* remounting is not allowed for populated hierarchies */
+ if (!list_empty(&root->cgrp.self.children)) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
+ ret = rebind_subsystems(root, added_mask);
+ if (ret)
+ goto out_unlock;
+
+ WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
+
+ if (opts.release_agent) {
+ spin_lock(&release_agent_path_lock);
+ strcpy(root->release_agent_path, opts.release_agent);
+ spin_unlock(&release_agent_path_lock);
+ }
+
+ trace_cgroup_remount(root);
+
+ out_unlock:
+ kfree(opts.release_agent);
+ kfree(opts.name);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+
+struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {
+ .rename = cgroup1_rename,
+ .show_options = cgroup1_show_options,
+ .remount_fs = cgroup1_remount,
+ .mkdir = cgroup_mkdir,
+ .rmdir = cgroup_rmdir,
+ .show_path = cgroup_show_path,
+};
+
+struct dentry *cgroup1_mount(struct file_system_type *fs_type, int flags,
+ void *data, unsigned long magic,
+ struct cgroup_namespace *ns)
+{
+ struct super_block *pinned_sb = NULL;
+ struct cgroup_sb_opts opts;
+ struct cgroup_root *root;
+ struct cgroup_subsys *ss;
+ struct dentry *dentry;
+ int i, ret;
+
+ cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
+
+ /* First find the desired set of subsystems */
+ ret = parse_cgroupfs_options(data, &opts);
+ if (ret)
+ goto out_unlock;
+
+ /*
+ * Destruction of cgroup root is asynchronous, so subsystems may
+ * still be dying after the previous unmount. Let's drain the
+ * dying subsystems. We just need to ensure that the ones
+ * unmounted previously finish dying and don't care about new ones
+ * starting. Testing ref liveliness is good enough.
+ */
+ for_each_subsys(ss, i) {
+ if (!(opts.subsys_mask & (1 << i)) ||
+ ss->root == &cgrp_dfl_root)
+ continue;
+
+ if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {
+ mutex_unlock(&cgroup_mutex);
+ msleep(10);
+ ret = restart_syscall();
+ goto out_free;
+ }
+ cgroup_put(&ss->root->cgrp);
+ }
+
+ for_each_root(root) {
+ bool name_match = false;
+
+ if (root == &cgrp_dfl_root)
+ continue;
+
+ /*
+ * If we asked for a name then it must match. Also, if
+ * name matches but sybsys_mask doesn't, we should fail.
+ * Remember whether name matched.
+ */
+ if (opts.name) {
+ if (strcmp(opts.name, root->name))
+ continue;
+ name_match = true;
+ }
+
+ /*
+ * If we asked for subsystems (or explicitly for no
+ * subsystems) then they must match.
+ */
+ if ((opts.subsys_mask || opts.none) &&
+ (opts.subsys_mask != root->subsys_mask)) {
+ if (!name_match)
+ continue;
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
+ if (root->flags ^ opts.flags)
+ pr_warn("new mount options do not match the existing superblock, will be ignored\n");
+
+ /*
+ * We want to reuse @root whose lifetime is governed by its
+ * ->cgrp. Let's check whether @root is alive and keep it
+ * that way. As cgroup_kill_sb() can happen anytime, we
+ * want to block it by pinning the sb so that @root doesn't
+ * get killed before mount is complete.
+ *
+ * With the sb pinned, tryget_live can reliably indicate
+ * whether @root can be reused. If it's being killed,
+ * drain it. We can use wait_queue for the wait but this
+ * path is super cold. Let's just sleep a bit and retry.
+ */
+ pinned_sb = kernfs_pin_sb(root->kf_root, NULL);
+ if (IS_ERR(pinned_sb) ||
+ !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {
+ mutex_unlock(&cgroup_mutex);
+ if (!IS_ERR_OR_NULL(pinned_sb))
+ deactivate_super(pinned_sb);
+ msleep(10);
+ ret = restart_syscall();
+ goto out_free;
+ }
+
+ ret = 0;
+ goto out_unlock;
+ }
+
+ /*
+ * No such thing, create a new one. name= matching without subsys
+ * specification is allowed for already existing hierarchies but we
+ * can't create new one without subsys specification.
+ */
+ if (!opts.subsys_mask && !opts.none) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* Hierarchies may only be created in the initial cgroup namespace. */
+ if (ns != &init_cgroup_ns) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ root = kzalloc(sizeof(*root), GFP_KERNEL);
+ if (!root) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ init_cgroup_root(root, &opts);
+
+ ret = cgroup_setup_root(root, opts.subsys_mask);
+ if (ret)
+ cgroup_free_root(root);
+
+out_unlock:
+ mutex_unlock(&cgroup_mutex);
+out_free:
+ kfree(opts.release_agent);
+ kfree(opts.name);
+
+ if (ret)
+ return ERR_PTR(ret);
+
+ dentry = cgroup_do_mount(&cgroup_fs_type, flags, root,
+ CGROUP_SUPER_MAGIC, ns);
+
+ /*
+ * If @pinned_sb, we're reusing an existing root and holding an
+ * extra ref on its sb. Mount is complete. Put the extra ref.
+ */
+ if (pinned_sb)
+ deactivate_super(pinned_sb);
+
+ return dentry;
+}
+
+static int __init cgroup1_wq_init(void)
+{
+ /*
+ * Used to destroy pidlists and separate to serve as flush domain.
+ * Cap @max_active to 1 too.
+ */
+ cgroup_pidlist_destroy_wq = alloc_workqueue("cgroup_pidlist_destroy",
+ 0, 1);
+ BUG_ON(!cgroup_pidlist_destroy_wq);
+ return 0;
+}
+core_initcall(cgroup1_wq_init);
+
+static int __init cgroup_no_v1(char *str)
+{
+ struct cgroup_subsys *ss;
+ char *token;
+ int i;
+
+ while ((token = strsep(&str, ",")) != NULL) {
+ if (!*token)
+ continue;
+
+ if (!strcmp(token, "all")) {
+ cgroup_no_v1_mask = U16_MAX;
+ break;
+ }
+
+ for_each_subsys(ss, i) {
+ if (strcmp(token, ss->name) &&
+ strcmp(token, ss->legacy_name))
+ continue;
+
+ cgroup_no_v1_mask |= 1 << i;
+ }
+ }
+ return 1;
+}
+__setup("cgroup_no_v1=", cgroup_no_v1);
+
+
+#ifdef CONFIG_CGROUP_DEBUG
+static struct cgroup_subsys_state *
+debug_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+ struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
+
+ if (!css)
+ return ERR_PTR(-ENOMEM);
+
+ return css;
+}
+
+static void debug_css_free(struct cgroup_subsys_state *css)
+{
+ kfree(css);
+}
+
+static u64 debug_taskcount_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return cgroup_task_count(css->cgroup);
+}
+
+static u64 current_css_set_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return (u64)(unsigned long)current->cgroups;
+}
+
+static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ u64 count;
+
+ rcu_read_lock();
+ count = atomic_read(&task_css_set(current)->refcount);
+ rcu_read_unlock();
+ return count;
+}
+
+static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
+{
+ struct cgrp_cset_link *link;
+ struct css_set *cset;
+ char *name_buf;
+
+ name_buf = kmalloc(NAME_MAX + 1, GFP_KERNEL);
+ if (!name_buf)
+ return -ENOMEM;
+
+ spin_lock_irq(&css_set_lock);
+ rcu_read_lock();
+ cset = rcu_dereference(current->cgroups);
+ list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
+ struct cgroup *c = link->cgrp;
+
+ cgroup_name(c, name_buf, NAME_MAX + 1);
+ seq_printf(seq, "Root %d group %s\n",
+ c->root->hierarchy_id, name_buf);
+ }
+ rcu_read_unlock();
+ spin_unlock_irq(&css_set_lock);
+ kfree(name_buf);
+ return 0;
+}
+
+#define MAX_TASKS_SHOWN_PER_CSS 25
+static int cgroup_css_links_read(struct seq_file *seq, void *v)
+{
+ struct cgroup_subsys_state *css = seq_css(seq);
+ struct cgrp_cset_link *link;
+
+ spin_lock_irq(&css_set_lock);
+ list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
+ struct css_set *cset = link->cset;
+ struct task_struct *task;
+ int count = 0;
+
+ seq_printf(seq, "css_set %p\n", cset);
+
+ list_for_each_entry(task, &cset->tasks, cg_list) {
+ if (count++ > MAX_TASKS_SHOWN_PER_CSS)
+ goto overflow;
+ seq_printf(seq, " task %d\n", task_pid_vnr(task));
+ }
+
+ list_for_each_entry(task, &cset->mg_tasks, cg_list) {
+ if (count++ > MAX_TASKS_SHOWN_PER_CSS)
+ goto overflow;
+ seq_printf(seq, " task %d\n", task_pid_vnr(task));
+ }
+ continue;
+ overflow:
+ seq_puts(seq, " ...\n");
+ }
+ spin_unlock_irq(&css_set_lock);
+ return 0;
+}
+
+static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
+{
+ return (!cgroup_is_populated(css->cgroup) &&
+ !css_has_online_children(&css->cgroup->self));
+}
+
+static struct cftype debug_files[] = {
+ {
+ .name = "taskcount",
+ .read_u64 = debug_taskcount_read,
+ },
+
+ {
+ .name = "current_css_set",
+ .read_u64 = current_css_set_read,
+ },
+
+ {
+ .name = "current_css_set_refcount",
+ .read_u64 = current_css_set_refcount_read,
+ },
+
+ {
+ .name = "current_css_set_cg_links",
+ .seq_show = current_css_set_cg_links_read,
+ },
+
+ {
+ .name = "cgroup_css_links",
+ .seq_show = cgroup_css_links_read,
+ },
+
+ {
+ .name = "releasable",
+ .read_u64 = releasable_read,
+ },
+
+ { } /* terminate */
+};
+
+struct cgroup_subsys debug_cgrp_subsys = {
+ .css_alloc = debug_css_alloc,
+ .css_free = debug_css_free,
+ .legacy_cftypes = debug_files,
+};
+#endif /* CONFIG_CGROUP_DEBUG */
diff --git a/kernel/cgroup.c b/kernel/cgroup/cgroup.c
index 53bbca7c4859..e8f87bf9840c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -28,15 +28,13 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/cgroup.h>
+#include "cgroup-internal.h"
+
#include <linux/cred.h>
-#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/init_task.h>
#include <linux/kernel.h>
-#include <linux/list.h>
#include <linux/magic.h>
-#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
@@ -47,16 +45,9 @@
#include <linux/spinlock.h>
#include <linux/percpu-rwsem.h>
#include <linux/string.h>
-#include <linux/sort.h>
-#include <linux/kmod.h>
-#include <linux/delayacct.h>
-#include <linux/cgroupstats.h>
#include <linux/hashtable.h>
-#include <linux/pid_namespace.h>
#include <linux/idr.h>
-#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
#include <linux/kthread.h>
-#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/cpuset.h>
#include <linux/proc_ns.h>
@@ -67,14 +58,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/cgroup.h>
-/*
- * pidlists linger the following amount before being destroyed. The goal
- * is avoiding frequent destruction in the middle of consecutive read calls
- * Expiring in the middle is a performance problem not a correctness one.
- * 1 sec should be enough.
- */
-#define CGROUP_PIDLIST_DESTROY_DELAY HZ
-
#define CGROUP_FILE_NAME_MAX (MAX_CGROUP_TYPE_NAMELEN + \
MAX_CFTYPE_NAME + 2)
@@ -88,14 +71,12 @@
* These locks are exported if CONFIG_PROVE_RCU so that accessors in
* cgroup.h can use them for lockdep annotations.
*/
-#ifdef CONFIG_PROVE_RCU
DEFINE_MUTEX(cgroup_mutex);
DEFINE_SPINLOCK(css_set_lock);
+
+#ifdef CONFIG_PROVE_RCU
EXPORT_SYMBOL_GPL(cgroup_mutex);
EXPORT_SYMBOL_GPL(css_set_lock);
-#else
-static DEFINE_MUTEX(cgroup_mutex);
-static DEFINE_SPINLOCK(css_set_lock);
#endif
/*
@@ -110,12 +91,6 @@ static DEFINE_SPINLOCK(cgroup_idr_lock);
*/
static DEFINE_SPINLOCK(cgroup_file_kn_lock);
-/*
- * Protects cgroup_subsys->release_agent_path. Modifying it also requires
- * cgroup_mutex. Reading requires either cgroup_mutex or this spinlock.
- */
-static DEFINE_SPINLOCK(release_agent_path_lock);
-
struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
#define cgroup_assert_mutex_or_rcu_locked() \
@@ -131,15 +106,9 @@ struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
*/
static struct workqueue_struct *cgroup_destroy_wq;
-/*
- * pidlist destructions need to be flushed on cgroup destruction. Use a
- * separate workqueue as flush domain.
- */
-static struct workqueue_struct *cgroup_pidlist_destroy_wq;
-
/* generate an array of cgroup subsystem pointers */
#define SUBSYS(_x) [_x ## _cgrp_id] = &_x ## _cgrp_subsys,
-static struct cgroup_subsys *cgroup_subsys[] = {
+struct cgroup_subsys *cgroup_subsys[] = {
#include <linux/cgroup_subsys.h>
};
#undef SUBSYS
@@ -186,18 +155,14 @@ EXPORT_SYMBOL_GPL(cgrp_dfl_root);
*/
static bool cgrp_dfl_visible;
-/* Controllers blocked by the commandline in v1 */
-static u16 cgroup_no_v1_mask;
-
/* some controllers are not supported in the default hierarchy */
static u16 cgrp_dfl_inhibit_ss_mask;
/* some controllers are implicitly enabled on the default hierarchy */
-static unsigned long cgrp_dfl_implicit_ss_mask;
+static u16 cgrp_dfl_implicit_ss_mask;
/* The list of hierarchy roots */
-
-static LIST_HEAD(cgroup_roots);
+LIST_HEAD(cgroup_roots);
static int cgroup_root_count;
/* hierarchy ID allocation and mapping, protected by cgroup_mutex */
@@ -213,13 +178,13 @@ static DEFINE_IDR(cgroup_hierarchy_idr);
static u64 css_serial_nr_next = 1;
/*
- * These bitmask flags indicate whether tasks in the fork and exit paths have
- * fork/exit handlers to call. This avoids us having to do extra work in the
- * fork/exit path to check which subsystems have fork/exit callbacks.
+ * These bitmasks identify subsystems with specific features to avoid
+ * having to do iterative checks repeatedly.
*/
static u16 have_fork_callback __read_mostly;
static u16 have_exit_callback __read_mostly;
static u16 have_free_callback __read_mostly;
+static u16 have_canfork_callback __read_mostly;
/* cgroup namespace for init task */
struct cgroup_namespace init_cgroup_ns = {
@@ -230,15 +195,9 @@ struct cgroup_namespace init_cgroup_ns = {
.root_cset = &init_css_set,
};
-/* Ditto for the can_fork callback. */
-static u16 have_canfork_callback __read_mostly;
-
static struct file_system_type cgroup2_fs_type;
-static struct cftype cgroup_dfl_base_files[];
-static struct cftype cgroup_legacy_base_files[];
+static struct cftype cgroup_base_files[];
-static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);
-static void cgroup_lock_and_drain_offline(struct cgroup *cgrp);
static int cgroup_apply_control(struct cgroup *cgrp);
static void cgroup_finalize_control(struct cgroup *cgrp, int ret);
static void css_task_iter_advance(struct css_task_iter *it);
@@ -259,7 +218,7 @@ static int cgroup_addrm_files(struct cgroup_subsys_state *css,
* is fine for individual subsystems but unsuitable for cgroup core. This
* is slower static_key_enabled() based test indexed by @ssid.
*/
-static bool cgroup_ssid_enabled(int ssid)
+bool cgroup_ssid_enabled(int ssid)
{
if (CGROUP_SUBSYS_COUNT == 0)
return false;
@@ -267,11 +226,6 @@ static bool cgroup_ssid_enabled(int ssid)
return static_key_enabled(cgroup_subsys_enabled_key[ssid]);
}
-static bool cgroup_ssid_no_v1(int ssid)
-{
- return cgroup_no_v1_mask & (1 << ssid);
-}
-
/**
* cgroup_on_dfl - test whether a cgroup is on the default hierarchy
* @cgrp: the cgroup of interest
@@ -325,7 +279,7 @@ static bool cgroup_ssid_no_v1(int ssid)
*
* - debug: disallowed on the default hierarchy.
*/
-static bool cgroup_on_dfl(const struct cgroup *cgrp)
+bool cgroup_on_dfl(const struct cgroup *cgrp)
{
return cgrp->root == &cgrp_dfl_root;
}
@@ -481,12 +435,6 @@ out_unlock:
return css;
}
-/* convenient tests for these bits */
-static inline bool cgroup_is_dead(const struct cgroup *cgrp)
-{
- return !(cgrp->self.flags & CSS_ONLINE);
-}
-
static void cgroup_get(struct cgroup *cgrp)
{
WARN_ON_ONCE(cgroup_is_dead(cgrp));
@@ -518,11 +466,6 @@ struct cgroup_subsys_state *of_css(struct kernfs_open_file *of)
}
EXPORT_SYMBOL_GPL(of_css);
-static int notify_on_release(const struct cgroup *cgrp)
-{
- return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
-}
-
/**
* for_each_css - iterate all css's of a cgroup
* @css: the iteration cursor
@@ -553,15 +496,6 @@ static int notify_on_release(const struct cgroup *cgrp)
else
/**
- * for_each_subsys - iterate all enabled cgroup subsystems
- * @ss: the iteration cursor
- * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
- */
-#define for_each_subsys(ss, ssid) \
- for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT && \
- (((ss) = cgroup_subsys[ssid]) || true); (ssid)++)
-
-/**
* do_each_subsys_mask - filter for_each_subsys with a bitmask
* @ss: the iteration cursor
* @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
@@ -585,10 +519,6 @@ static int notify_on_release(const struct cgroup *cgrp)
} \
} while (false)
-/* iterate across the hierarchies */
-#define for_each_root(root) \
- list_for_each_entry((root), &cgroup_roots, root_list)
-
/* iterate over child cgrps, lock should be held throughout iteration */
#define cgroup_for_each_live_child(child, cgrp) \
list_for_each_entry((child), &(cgrp)->self.children, self.sibling) \
@@ -615,29 +545,6 @@ static int notify_on_release(const struct cgroup *cgrp)
; \
else
-static void cgroup_release_agent(struct work_struct *work);
-static void check_for_release(struct cgroup *cgrp);
-
-/*
- * A cgroup can be associated with multiple css_sets as different tasks may
- * belong to different cgroups on different hierarchies. In the other
- * direction, a css_set is naturally associated with multiple cgroups.
- * This M:N relationship is represented by the following link structure
- * which exists for each association and allows traversing the associations
- * from both sides.
- */
-struct cgrp_cset_link {
- /* the cgroup and css_set this link associates */
- struct cgroup *cgrp;
- struct css_set *cset;
-
- /* list of cgrp_cset_links anchored at cgrp->cset_links */
- struct list_head cset_link;
-
- /* list of cgrp_cset_links anchored at css_set->cgrp_links */
- struct list_head cgrp_link;
-};
-
/*
* The default css_set - used by init and its children prior to any
* hierarchies being mounted. It contains a pointer to the root state
@@ -647,12 +554,12 @@ struct cgrp_cset_link {
*/
struct css_set init_css_set = {
.refcount = ATOMIC_INIT(1),
- .cgrp_links = LIST_HEAD_INIT(init_css_set.cgrp_links),
.tasks = LIST_HEAD_INIT(init_css_set.tasks),
.mg_tasks = LIST_HEAD_INIT(init_css_set.mg_tasks),
+ .task_iters = LIST_HEAD_INIT(init_css_set.task_iters),
+ .cgrp_links = LIST_HEAD_INIT(init_css_set.cgrp_links),
.mg_preload_node = LIST_HEAD_INIT(init_css_set.mg_preload_node),
.mg_node = LIST_HEAD_INIT(init_css_set.mg_node),
- .task_iters = LIST_HEAD_INIT(init_css_set.task_iters),
};
static int css_set_count = 1; /* 1 for init_css_set */
@@ -699,7 +606,7 @@ static void cgroup_update_populated(struct cgroup *cgrp, bool populated)
if (!trigger)
break;
- check_for_release(cgrp);
+ cgroup1_check_for_release(cgrp);
cgroup_file_notify(&cgrp->events_file);
cgrp = cgroup_parent(cgrp);
@@ -808,7 +715,7 @@ static unsigned long css_set_hash(struct cgroup_subsys_state *css[])
return key;
}
-static void put_css_set_locked(struct css_set *cset)
+void put_css_set_locked(struct css_set *cset)
{
struct cgrp_cset_link *link, *tmp_link;
struct cgroup_subsys *ss;
@@ -838,31 +745,6 @@ static void put_css_set_locked(struct css_set *cset)
kfree_rcu(cset, rcu_head);
}
-static void put_css_set(struct css_set *cset)
-{
- unsigned long flags;
-
- /*
- * Ensure that the refcount doesn't hit zero while any readers
- * can see it. Similar to atomic_dec_and_lock(), but for an
- * rwlock
- */
- if (atomic_add_unless(&cset->refcount, -1, 1))
- return;
-
- spin_lock_irqsave(&css_set_lock, flags);
- put_css_set_locked(cset);
- spin_unlock_irqrestore(&css_set_lock, flags);
-}
-
-/*
- * refcounted get/put for css_set objects
- */
-static inline void get_css_set(struct css_set *cset)
-{
- atomic_inc(&cset->refcount);
-}
-
/**
* compare_css_sets - helper function for find_existing_css_set().
* @cset: candidate css_set being tested
@@ -1095,13 +977,13 @@ static struct css_set *find_css_set(struct css_set *old_cset,
}
atomic_set(&cset->refcount, 1);
- INIT_LIST_HEAD(&cset->cgrp_links);
INIT_LIST_HEAD(&cset->tasks);
INIT_LIST_HEAD(&cset->mg_tasks);
- INIT_LIST_HEAD(&cset->mg_preload_node);
- INIT_LIST_HEAD(&cset->mg_node);
INIT_LIST_HEAD(&cset->task_iters);
INIT_HLIST_NODE(&cset->hlist);
+ INIT_LIST_HEAD(&cset->cgrp_links);
+ INIT_LIST_HEAD(&cset->mg_preload_node);
+ INIT_LIST_HEAD(&cset->mg_node);
/* Copy the set of subsystem state objects generated in
* find_existing_css_set() */
@@ -1138,7 +1020,7 @@ static struct css_set *find_css_set(struct css_set *old_cset,
return cset;
}
-static struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root)
+struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root)
{
struct cgroup *root_cgrp = kf_root->kn->priv;
@@ -1166,7 +1048,7 @@ static void cgroup_exit_root_id(struct cgroup_root *root)
idr_remove(&cgroup_hierarchy_idr, root->hierarchy_id);
}
-static void cgroup_free_root(struct cgroup_root *root)
+void cgroup_free_root(struct cgroup_root *root)
{
if (root) {
idr_destroy(&root->cgroup_idr);
@@ -1283,8 +1165,8 @@ static struct cgroup *cset_cgroup_from_root(struct css_set *cset,
* Return the cgroup for "task" from the given hierarchy. Must be
* called with cgroup_mutex and css_set_lock held.
*/
-static struct cgroup *task_cgroup_from_root(struct task_struct *task,
- struct cgroup_root *root)
+struct cgroup *task_cgroup_from_root(struct task_struct *task,
+ struct cgroup_root *root)
{
/*
* No need to lock the task - since we hold cgroup_mutex the
@@ -1321,7 +1203,6 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task,
*/
static struct kernfs_syscall_ops cgroup_kf_syscall_ops;
-static const struct file_operations proc_cgroupstats_operations;
static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
char *buf)
@@ -1415,7 +1296,7 @@ static u16 cgroup_calc_subtree_ss_mask(u16 subtree_control, u16 this_ss_mask)
* inaccessible any time. If the caller intends to continue to access the
* cgroup, it should pin it before invoking this function.
*/
-static void cgroup_kn_unlock(struct kernfs_node *kn)
+void cgroup_kn_unlock(struct kernfs_node *kn)
{
struct cgroup *cgrp;
@@ -1447,8 +1328,7 @@ static void cgroup_kn_unlock(struct kernfs_node *kn)
* locking under kernfs active protection and allows all kernfs operations
* including self-removal.
*/
-static struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn,
- bool drain_offline)
+struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn, bool drain_offline)
{
struct cgroup *cgrp;
@@ -1532,9 +1412,9 @@ static int css_populate_dir(struct cgroup_subsys_state *css)
if (!css->ss) {
if (cgroup_on_dfl(cgrp))
- cfts = cgroup_dfl_base_files;
+ cfts = cgroup_base_files;
else
- cfts = cgroup_legacy_base_files;
+ cfts = cgroup1_base_files;
return cgroup_addrm_files(&cgrp->self, cgrp, cfts, true);
}
@@ -1559,7 +1439,7 @@ err:
return ret;
}
-static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask)
+int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask)
{
struct cgroup *dcgrp = &dst_root->cgrp;
struct cgroup_subsys *ss;
@@ -1629,8 +1509,8 @@ static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask)
return 0;
}
-static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
- struct kernfs_root *kf_root)
+int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
+ struct kernfs_root *kf_root)
{
int len = 0;
char *buf = NULL;
@@ -1656,237 +1536,10 @@ static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
return len;
}
-static int cgroup_show_options(struct seq_file *seq,
- struct kernfs_root *kf_root)
-{
- struct cgroup_root *root = cgroup_root_from_kf(kf_root);
- struct cgroup_subsys *ss;
- int ssid;
-
- if (root != &cgrp_dfl_root)
- for_each_subsys(ss, ssid)
- if (root->subsys_mask & (1 << ssid))
- seq_show_option(seq, ss->legacy_name, NULL);
- if (root->flags & CGRP_ROOT_NOPREFIX)
- seq_puts(seq, ",noprefix");
- if (root->flags & CGRP_ROOT_XATTR)
- seq_puts(seq, ",xattr");
-
- spin_lock(&release_agent_path_lock);
- if (strlen(root->release_agent_path))
- seq_show_option(seq, "release_agent",
- root->release_agent_path);
- spin_unlock(&release_agent_path_lock);
-
- if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))
- seq_puts(seq, ",clone_children");
- if (strlen(root->name))
- seq_show_option(seq, "name", root->name);
- return 0;
-}
-
-struct cgroup_sb_opts {
- u16 subsys_mask;
- unsigned int flags;
- char *release_agent;
- bool cpuset_clone_children;
- char *name;
- /* User explicitly requested empty subsystem */
- bool none;
-};
-
-static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
-{
- char *token, *o = data;
- bool all_ss = false, one_ss = false;
- u16 mask = U16_MAX;
- struct cgroup_subsys *ss;
- int nr_opts = 0;
- int i;
-
-#ifdef CONFIG_CPUSETS
- mask = ~((u16)1 << cpuset_cgrp_id);
-#endif
-
- memset(opts, 0, sizeof(*opts));
-
- while ((token = strsep(&o, ",")) != NULL) {
- nr_opts++;
-
- if (!*token)
- return -EINVAL;
- if (!strcmp(token, "none")) {
- /* Explicitly have no subsystems */
- opts->none = true;
- continue;
- }
- if (!strcmp(token, "all")) {
- /* Mutually exclusive option 'all' + subsystem name */
- if (one_ss)
- return -EINVAL;
- all_ss = true;
- continue;
- }
- if (!strcmp(token, "noprefix")) {
- opts->flags |= CGRP_ROOT_NOPREFIX;
- continue;
- }
- if (!strcmp(token, "clone_children")) {
- opts->cpuset_clone_children = true;
- continue;
- }
- if (!strcmp(token, "xattr")) {
- opts->flags |= CGRP_ROOT_XATTR;
- continue;
- }
- if (!strncmp(token, "release_agent=", 14)) {
- /* Specifying two release agents is forbidden */
- if (opts->release_agent)
- return -EINVAL;
- opts->release_agent =
- kstrndup(token + 14, PATH_MAX - 1, GFP_KERNEL);
- if (!opts->release_agent)
- return -ENOMEM;
- continue;
- }
- if (!strncmp(token, "name=", 5)) {
- const char *name = token + 5;
- /* Can't specify an empty name */
- if (!strlen(name))
- return -EINVAL;
- /* Must match [\w.-]+ */
- for (i = 0; i < strlen(name); i++) {
- char c = name[i];
- if (isalnum(c))
- continue;
- if ((c == '.') || (c == '-') || (c == '_'))
- continue;
- return -EINVAL;
- }
- /* Specifying two names is forbidden */
- if (opts->name)
- return -EINVAL;
- opts->name = kstrndup(name,
- MAX_CGROUP_ROOT_NAMELEN - 1,
- GFP_KERNEL);
- if (!opts->name)
- return -ENOMEM;
-
- continue;
- }
-
- for_each_subsys(ss, i) {
- if (strcmp(token, ss->legacy_name))
- continue;
- if (!cgroup_ssid_enabled(i))
- continue;
- if (cgroup_ssid_no_v1(i))
- continue;
-
- /* Mutually exclusive option 'all' + subsystem name */
- if (all_ss)
- return -EINVAL;
- opts->subsys_mask |= (1 << i);
- one_ss = true;
-
- break;
- }
- if (i == CGROUP_SUBSYS_COUNT)
- return -ENOENT;
- }
-
- /*
- * If the 'all' option was specified select all the subsystems,
- * otherwise if 'none', 'name=' and a subsystem name options were
- * not specified, let's default to 'all'
- */
- if (all_ss || (!one_ss && !opts->none && !opts->name))
- for_each_subsys(ss, i)
- if (cgroup_ssid_enabled(i) && !cgroup_ssid_no_v1(i))
- opts->subsys_mask |= (1 << i);
-
- /*
- * We either have to specify by name or by subsystems. (So all
- * empty hierarchies must have a name).
- */
- if (!opts->subsys_mask && !opts->name)
- return -EINVAL;
-
- /*
- * Option noprefix was introduced just for backward compatibility
- * with the old cpuset, so we allow noprefix only if mounting just
- * the cpuset subsystem.
- */
- if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
- return -EINVAL;
-
- /* Can't specify "none" and some subsystems */
- if (opts->subsys_mask && opts->none)
- return -EINVAL;
-
- return 0;
-}
-
static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)
{
- int ret = 0;
- struct cgroup_root *root = cgroup_root_from_kf(kf_root);
- struct cgroup_sb_opts opts;
- u16 added_mask, removed_mask;
-
- if (root == &cgrp_dfl_root) {
- pr_err("remount is not allowed\n");
- return -EINVAL;
- }
-
- cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
-
- /* See what subsystems are wanted */
- ret = parse_cgroupfs_options(data, &opts);
- if (ret)
- goto out_unlock;
-
- if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
- pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
- task_tgid_nr(current), current->comm);
-
- added_mask = opts.subsys_mask & ~root->subsys_mask;
- removed_mask = root->subsys_mask & ~opts.subsys_mask;
-
- /* Don't allow flags or name to change at remount */
- if ((opts.flags ^ root->flags) ||
- (opts.name && strcmp(opts.name, root->name))) {
- pr_err("option or name mismatch, new: 0x%x \"%s\", old: 0x%x \"%s\"\n",
- opts.flags, opts.name ?: "", root->flags, root->name);
- ret = -EINVAL;
- goto out_unlock;
- }
-
- /* remounting is not allowed for populated hierarchies */
- if (!list_empty(&root->cgrp.self.children)) {
- ret = -EBUSY;
- goto out_unlock;
- }
-
- ret = rebind_subsystems(root, added_mask);
- if (ret)
- goto out_unlock;
-
- WARN_ON(rebind_subsystems(&cgrp_dfl_root, removed_mask));
-
- if (opts.release_agent) {
- spin_lock(&release_agent_path_lock);
- strcpy(root->release_agent_path, opts.release_agent);
- spin_unlock(&release_agent_path_lock);
- }
-
- trace_cgroup_remount(root);
-
- out_unlock:
- kfree(opts.release_agent);
- kfree(opts.name);
- mutex_unlock(&cgroup_mutex);
- return ret;
+ pr_err("remount is not allowed\n");
+ return -EINVAL;
}
/*
@@ -1964,11 +1617,10 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
INIT_LIST_HEAD(&cgrp->e_csets[ssid]);
init_waitqueue_head(&cgrp->offline_waitq);
- INIT_WORK(&cgrp->release_agent_work, cgroup_release_agent);
+ INIT_WORK(&cgrp->release_agent_work, cgroup1_release_agent);
}
-static void init_cgroup_root(struct cgroup_root *root,
- struct cgroup_sb_opts *opts)
+void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts)
{
struct cgroup *cgrp = &root->cgrp;
@@ -1987,10 +1639,11 @@ static void init_cgroup_root(struct cgroup_root *root,
set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags);
}
-static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
+int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
{
LIST_HEAD(tmp_links);
struct cgroup *root_cgrp = &root->cgrp;
+ struct kernfs_syscall_ops *kf_sops;
struct css_set *cset;
int i, ret;
@@ -2022,7 +1675,10 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
if (ret)
goto cancel_ref;
- root->kf_root = kernfs_create_root(&cgroup_kf_syscall_ops,
+ kf_sops = root == &cgrp_dfl_root ?
+ &cgroup_kf_syscall_ops : &cgroup1_kf_syscall_ops;
+
+ root->kf_root = kernfs_create_root(kf_sops,
KERNFS_ROOT_CREATE_DEACTIVATED,
root_cgrp);
if (IS_ERR(root->kf_root)) {
@@ -2080,182 +1736,18 @@ out:
return ret;
}
-static struct dentry *cgroup_mount(struct file_system_type *fs_type,
- int flags, const char *unused_dev_name,
- void *data)
+struct dentry *cgroup_do_mount(struct file_system_type *fs_type, int flags,
+ struct cgroup_root *root, unsigned long magic,
+ struct cgroup_namespace *ns)
{
- bool is_v2 = fs_type == &cgroup2_fs_type;
- struct super_block *pinned_sb = NULL;
- struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
- struct cgroup_subsys *ss;
- struct cgroup_root *root;
- struct cgroup_sb_opts opts;
struct dentry *dentry;
- int ret;
- int i;
bool new_sb;
- get_cgroup_ns(ns);
-
- /* Check if the caller has permission to mount. */
- if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) {
- put_cgroup_ns(ns);
- return ERR_PTR(-EPERM);
- }
-
- /*
- * The first time anyone tries to mount a cgroup, enable the list
- * linking each css_set to its tasks and fix up all existing tasks.
- */
- if (!use_task_css_set_links)
- cgroup_enable_task_cg_lists();
-
- if (is_v2) {
- if (data) {
- pr_err("cgroup2: unknown option \"%s\"\n", (char *)data);
- put_cgroup_ns(ns);
- return ERR_PTR(-EINVAL);
- }
- cgrp_dfl_visible = true;
- root = &cgrp_dfl_root;
- cgroup_get(&root->cgrp);
- goto out_mount;
- }
-
- cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);
-
- /* First find the desired set of subsystems */
- ret = parse_cgroupfs_options(data, &opts);
- if (ret)
- goto out_unlock;
-
- /*
- * Destruction of cgroup root is asynchronous, so subsystems may
- * still be dying after the previous unmount. Let's drain the
- * dying subsystems. We just need to ensure that the ones
- * unmounted previously finish dying and don't care about new ones
- * starting. Testing ref liveliness is good enough.
- */
- for_each_subsys(ss, i) {
- if (!(opts.subsys_mask & (1 << i)) ||
- ss->root == &cgrp_dfl_root)
- continue;
-
- if (!percpu_ref_tryget_live(&ss->root->cgrp.self.refcnt)) {
- mutex_unlock(&cgroup_mutex);
- msleep(10);
- ret = restart_syscall();
- goto out_free;
- }
- cgroup_put(&ss->root->cgrp);
- }
-
- for_each_root(root) {
- bool name_match = false;
-
- if (root == &cgrp_dfl_root)
- continue;
-
- /*
- * If we asked for a name then it must match. Also, if
- * name matches but sybsys_mask doesn't, we should fail.
- * Remember whether name matched.
- */
- if (opts.name) {
- if (strcmp(opts.name, root->name))
- continue;
- name_match = true;
- }
-
- /*
- * If we asked for subsystems (or explicitly for no
- * subsystems) then they must match.
- */
- if ((opts.subsys_mask || opts.none) &&
- (opts.subsys_mask != root->subsys_mask)) {
- if (!name_match)
- continue;
- ret = -EBUSY;
- goto out_unlock;
- }
-
- if (root->flags ^ opts.flags)
- pr_warn("new mount options do not match the existing superblock, will be ignored\n");
-
- /*
- * We want to reuse @root whose lifetime is governed by its
- * ->cgrp. Let's check whether @root is alive and keep it
- * that way. As cgroup_kill_sb() can happen anytime, we
- * want to block it by pinning the sb so that @root doesn't
- * get killed before mount is complete.
- *
- * With the sb pinned, tryget_live can reliably indicate
- * whether @root can be reused. If it's being killed,
- * drain it. We can use wait_queue for the wait but this
- * path is super cold. Let's just sleep a bit and retry.
- */
- pinned_sb = kernfs_pin_sb(root->kf_root, NULL);
- if (IS_ERR(pinned_sb) ||
- !percpu_ref_tryget_live(&root->cgrp.self.refcnt)) {
- mutex_unlock(&cgroup_mutex);
- if (!IS_ERR_OR_NULL(pinned_sb))
- deactivate_super(pinned_sb);
- msleep(10);
- ret = restart_syscall();
- goto out_free;
- }
-
- ret = 0;
- goto out_unlock;
- }
+ dentry = kernfs_mount(fs_type, flags, root->kf_root, magic, &new_sb);
/*
- * No such thing, create a new one. name= matching without subsys
- * specification is allowed for already existing hierarchies but we
- * can't create new one without subsys specification.
- */
- if (!opts.subsys_mask && !opts.none) {
- ret = -EINVAL;
- goto out_unlock;
- }
-
- /* Hierarchies may only be created in the initial cgroup namespace. */
- if (ns != &init_cgroup_ns) {
- ret = -EPERM;
- goto out_unlock;
- }
-
- root = kzalloc(sizeof(*root), GFP_KERNEL);
- if (!root) {
- ret = -ENOMEM;
- goto out_unlock;
- }
-
- init_cgroup_root(root, &opts);
-
- ret = cgroup_setup_root(root, opts.subsys_mask);
- if (ret)
- cgroup_free_root(root);
-
-out_unlock:
- mutex_unlock(&cgroup_mutex);
-out_free:
- kfree(opts.release_agent);
- kfree(opts.name);
-
- if (ret) {
- put_cgroup_ns(ns);
- return ERR_PTR(ret);
- }
-out_mount:
- dentry = kernfs_mount(fs_type, flags, root->kf_root,
- is_v2 ? CGROUP2_SUPER_MAGIC : CGROUP_SUPER_MAGIC,
- &new_sb);
-
- /*
- * In non-init cgroup namespace, instead of root cgroup's
- * dentry, we return the dentry corresponding to the
- * cgroupns->root_cgrp.
+ * In non-init cgroup namespace, instead of root cgroup's dentry,
+ * we return the dentry corresponding to the cgroupns->root_cgrp.
*/
if (!IS_ERR(dentry) && ns != &init_cgroup_ns) {
struct dentry *nsdentry;
@@ -2277,13 +1769,45 @@ out_mount:
if (IS_ERR(dentry) || !new_sb)
cgroup_put(&root->cgrp);
+ return dentry;
+}
+
+static struct dentry *cgroup_mount(struct file_system_type *fs_type,
+ int flags, const char *unused_dev_name,
+ void *data)
+{
+ struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
+ struct dentry *dentry;
+
+ get_cgroup_ns(ns);
+
+ /* Check if the caller has permission to mount. */
+ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) {
+ put_cgroup_ns(ns);
+ return ERR_PTR(-EPERM);
+ }
+
/*
- * If @pinned_sb, we're reusing an existing root and holding an
- * extra ref on its sb. Mount is complete. Put the extra ref.
+ * The first time anyone tries to mount a cgroup, enable the list
+ * linking each css_set to its tasks and fix up all existing tasks.
*/
- if (pinned_sb) {
- WARN_ON(new_sb);
- deactivate_super(pinned_sb);
+ if (!use_task_css_set_links)
+ cgroup_enable_task_cg_lists();
+
+ if (fs_type == &cgroup2_fs_type) {
+ if (data) {
+ pr_err("cgroup2: unknown option \"%s\"\n", (char *)data);
+ put_cgroup_ns(ns);
+ return ERR_PTR(-EINVAL);
+ }
+ cgrp_dfl_visible = true;
+ cgroup_get(&cgrp_dfl_root.cgrp);
+
+ dentry = cgroup_do_mount(&cgroup2_fs_type, flags, &cgrp_dfl_root,
+ CGROUP2_SUPER_MAGIC, ns);
+ } else {
+ dentry = cgroup1_mount(&cgroup_fs_type, flags, data,
+ CGROUP_SUPER_MAGIC, ns);
}
put_cgroup_ns(ns);
@@ -2311,7 +1835,7 @@ static void cgroup_kill_sb(struct super_block *sb)
kernfs_kill_sb(sb);
}
-static struct file_system_type cgroup_fs_type = {
+struct file_system_type cgroup_fs_type = {
.name = "cgroup",
.mount = cgroup_mount,
.kill_sb = cgroup_kill_sb,
@@ -2325,8 +1849,8 @@ static struct file_system_type cgroup2_fs_type = {
.fs_flags = FS_USERNS_MOUNT,
};
-static int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
- struct cgroup_namespace *ns)
+int cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen,
+ struct cgroup_namespace *ns)
{
struct cgroup *root = cset_cgroup_from_root(ns->root_cset, cgrp->root);
@@ -2389,49 +1913,18 @@ int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
}
EXPORT_SYMBOL_GPL(task_cgroup_path);
-/* used to track tasks and other necessary states during migration */
-struct cgroup_taskset {
- /* the src and dst cset list running through cset->mg_node */
- struct list_head src_csets;
- struct list_head dst_csets;
-
- /* the subsys currently being processed */
- int ssid;
-
- /*
- * Fields for cgroup_taskset_*() iteration.
- *
- * Before migration is committed, the target migration tasks are on
- * ->mg_tasks of the csets on ->src_csets. After, on ->mg_tasks of
- * the csets on ->dst_csets. ->csets point to either ->src_csets
- * or ->dst_csets depending on whether migration is committed.
- *
- * ->cur_csets and ->cur_task point to the current task position
- * during iteration.
- */
- struct list_head *csets;
- struct css_set *cur_cset;
- struct task_struct *cur_task;
-};
-
-#define CGROUP_TASKSET_INIT(tset) (struct cgroup_taskset){ \
- .src_csets = LIST_HEAD_INIT(tset.src_csets), \
- .dst_csets = LIST_HEAD_INIT(tset.dst_csets), \
- .csets = &tset.src_csets, \
-}
-
/**
- * cgroup_taskset_add - try to add a migration target task to a taskset
+ * cgroup_migrate_add_task - add a migration target task to a migration context
* @task: target task
- * @tset: target taskset
+ * @mgctx: target migration context
*
- * Add @task, which is a migration target, to @tset. This function becomes
- * noop if @task doesn't need to be migrated. @task's css_set should have
- * been added as a migration source and @task->cg_list will be moved from
- * the css_set's tasks list to mg_tasks one.
+ * Add @task, which is a migration target, to @mgctx->tset. This function
+ * becomes noop if @task doesn't need to be migrated. @task's css_set
+ * should have been added as a migration source and @task->cg_list will be
+ * moved from the css_set's tasks list to mg_tasks one.
*/
-static void cgroup_taskset_add(struct task_struct *task,
- struct cgroup_taskset *tset)
+static void cgroup_migrate_add_task(struct task_struct *task,
+ struct cgroup_mgctx *mgctx)
{
struct css_set *cset;
@@ -2451,10 +1944,11 @@ static void cgroup_taskset_add(struct task_struct *task,
list_move_tail(&task->cg_list, &cset->mg_tasks);
if (list_empty(&cset->mg_node))
- list_add_tail(&cset->mg_node, &tset->src_csets);
+ list_add_tail(&cset->mg_node,
+ &mgctx->tset.src_csets);
if (list_empty(&cset->mg_dst_cset->mg_node))
- list_move_tail(&cset->mg_dst_cset->mg_node,
- &tset->dst_csets);
+ list_add_tail(&cset->mg_dst_cset->mg_node,
+ &mgctx->tset.dst_csets);
}
/**
@@ -2521,17 +2015,16 @@ struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset,
/**
* cgroup_taskset_migrate - migrate a taskset
- * @tset: taget taskset
- * @root: cgroup root the migration is taking place on
+ * @mgctx: migration context
*
- * Migrate tasks in @tset as setup by migration preparation functions.
+ * Migrate tasks in @mgctx as setup by migration preparation functions.
* This function fails iff one of the ->can_attach callbacks fails and
- * guarantees that either all or none of the tasks in @tset are migrated.
- * @tset is consumed regardless of success.
+ * guarantees that either all or none of the tasks in @mgctx are migrated.
+ * @mgctx is consumed regardless of success.
*/
-static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
- struct cgroup_root *root)
+static int cgroup_migrate_execute(struct cgroup_mgctx *mgctx)
{
+ struct cgroup_taskset *tset = &mgctx->tset;
struct cgroup_subsys *ss;
struct task_struct *task, *tmp_task;
struct css_set *cset, *tmp_cset;
@@ -2542,7 +2035,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
return 0;
/* check that we can legitimately attach to the cgroup */
- do_each_subsys_mask(ss, ssid, root->subsys_mask) {
+ do_each_subsys_mask(ss, ssid, mgctx->ss_mask) {
if (ss->can_attach) {
tset->ssid = ssid;
ret = ss->can_attach(tset);
@@ -2578,7 +2071,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
*/
tset->csets = &tset->dst_csets;
- do_each_subsys_mask(ss, ssid, root->subsys_mask) {
+ do_each_subsys_mask(ss, ssid, mgctx->ss_mask) {
if (ss->attach) {
tset->ssid = ssid;
ss->attach(tset);
@@ -2589,7 +2082,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
goto out_release_tset;
out_cancel_attach:
- do_each_subsys_mask(ss, ssid, root->subsys_mask) {
+ do_each_subsys_mask(ss, ssid, mgctx->ss_mask) {
if (ssid == failed_ssid)
break;
if (ss->cancel_attach) {
@@ -2616,7 +2109,7 @@ out_release_tset:
* zero for migration destination cgroups with tasks so that child cgroups
* don't compete against tasks.
*/
-static bool cgroup_may_migrate_to(struct cgroup *dst_cgrp)
+bool cgroup_may_migrate_to(struct cgroup *dst_cgrp)
{
return !cgroup_on_dfl(dst_cgrp) || !cgroup_parent(dst_cgrp) ||
!dst_cgrp->subtree_control;
@@ -2624,25 +2117,31 @@ static bool cgroup_may_migrate_to(struct cgroup *dst_cgrp)
/**
* cgroup_migrate_finish - cleanup after attach
- * @preloaded_csets: list of preloaded css_sets
+ * @mgctx: migration context
*
* Undo cgroup_migrate_add_src() and cgroup_migrate_prepare_dst(). See
* those functions for details.
*/
-static void cgroup_migrate_finish(struct list_head *preloaded_csets)
+void cgroup_migrate_finish(struct cgroup_mgctx *mgctx)
{
+ LIST_HEAD(preloaded);
struct css_set *cset, *tmp_cset;
lockdep_assert_held(&cgroup_mutex);
spin_lock_irq(&css_set_lock);
- list_for_each_entry_safe(cset, tmp_cset, preloaded_csets, mg_preload_node) {
+
+ list_splice_tail_init(&mgctx->preloaded_src_csets, &preloaded);
+ list_splice_tail_init(&mgctx->preloaded_dst_csets, &preloaded);
+
+ list_for_each_entry_safe(cset, tmp_cset, &preloaded, mg_preload_node) {
cset->mg_src_cgrp = NULL;
cset->mg_dst_cgrp = NULL;
cset->mg_dst_cset = NULL;
list_del_init(&cset->mg_preload_node);
put_css_set_locked(cset);
}
+
spin_unlock_irq(&css_set_lock);
}
@@ -2650,10 +2149,10 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
* cgroup_migrate_add_src - add a migration source css_set
* @src_cset: the source css_set to add
* @dst_cgrp: the destination cgroup
- * @preloaded_csets: list of preloaded css_sets
+ * @mgctx: migration context
*
* Tasks belonging to @src_cset are about to be migrated to @dst_cgrp. Pin
- * @src_cset and add it to @preloaded_csets, which should later be cleaned
+ * @src_cset and add it to @mgctx->src_csets, which should later be cleaned
* up by cgroup_migrate_finish().
*
* This function may be called without holding cgroup_threadgroup_rwsem
@@ -2662,9 +2161,9 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
* into play and the preloaded css_sets are guaranteed to cover all
* migrations.
*/
-static void cgroup_migrate_add_src(struct css_set *src_cset,
- struct cgroup *dst_cgrp,
- struct list_head *preloaded_csets)
+void cgroup_migrate_add_src(struct css_set *src_cset,
+ struct cgroup *dst_cgrp,
+ struct cgroup_mgctx *mgctx)
{
struct cgroup *src_cgrp;
@@ -2692,33 +2191,35 @@ static void cgroup_migrate_add_src(struct css_set *src_cset,
src_cset->mg_src_cgrp = src_cgrp;
src_cset->mg_dst_cgrp = dst_cgrp;
get_css_set(src_cset);
- list_add(&src_cset->mg_preload_node, preloaded_csets);
+ list_add_tail(&src_cset->mg_preload_node, &mgctx->preloaded_src_csets);
}
/**
* cgroup_migrate_prepare_dst - prepare destination css_sets for migration
- * @preloaded_csets: list of preloaded source css_sets
+ * @mgctx: migration context
*
* Tasks are about to be moved and all the source css_sets have been
- * preloaded to @preloaded_csets. This function looks up and pins all
- * destination css_sets, links each to its source, and append them to
- * @preloaded_csets.
+ * preloaded to @mgctx->preloaded_src_csets. This function looks up and
+ * pins all destination css_sets, links each to its source, and append them
+ * to @mgctx->preloaded_dst_csets.
*
* This function must be called after cgroup_migrate_add_src() has been
* called on each migration source css_set. After migration is performed
* using cgroup_migrate(), cgroup_migrate_finish() must be called on
- * @preloaded_csets.
+ * @mgctx.
*/
-static int cgroup_migrate_prepare_dst(struct list_head *preloaded_csets)
+int cgroup_migrate_prepare_dst(struct cgroup_mgctx *mgctx)
{
- LIST_HEAD(csets);
struct css_set *src_cset, *tmp_cset;
lockdep_assert_held(&cgroup_mutex);
/* look up the dst cset for each src cset and link it to src */
- list_for_each_entry_safe(src_cset, tmp_cset, preloaded_csets, mg_preload_node) {
+ list_for_each_entry_safe(src_cset, tmp_cset, &mgctx->preloaded_src_csets,
+ mg_preload_node) {
struct css_set *dst_cset;
+ struct cgroup_subsys *ss;
+ int ssid;
dst_cset = find_css_set(src_cset, src_cset->mg_dst_cgrp);
if (!dst_cset)
@@ -2743,15 +2244,19 @@ static int cgroup_migrate_prepare_dst(struct list_head *preloaded_csets)
src_cset->mg_dst_cset = dst_cset;
if (list_empty(&dst_cset->mg_preload_node))
- list_add(&dst_cset->mg_preload_node, &csets);
+ list_add_tail(&dst_cset->mg_preload_node,
+ &mgctx->preloaded_dst_csets);
else
put_css_set(dst_cset);
+
+ for_each_subsys(ss, ssid)
+ if (src_cset->subsys[ssid] != dst_cset->subsys[ssid])
+ mgctx->ss_mask |= 1 << ssid;
}
- list_splice_tail(&csets, preloaded_csets);
return 0;
err:
- cgroup_migrate_finish(&csets);
+ cgroup_migrate_finish(mgctx);
return -ENOMEM;
}
@@ -2759,7 +2264,7 @@ err:
* cgroup_migrate - migrate a process or task to a cgroup
* @leader: the leader of the process or the task to migrate
* @threadgroup: whether @leader points to the whole process or a single task
- * @root: cgroup root migration is taking place on
+ * @mgctx: migration context
*
* Migrate a process or task denoted by @leader. If migrating a process,
* the caller must be holding cgroup_threadgroup_rwsem. The caller is also
@@ -2773,10 +2278,9 @@ err:
* decided for all targets by invoking group_migrate_prepare_dst() before
* actually starting migrating.
*/
-static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
- struct cgroup_root *root)
+int cgroup_migrate(struct task_struct *leader, bool threadgroup,
+ struct cgroup_mgctx *mgctx)
{
- struct cgroup_taskset tset = CGROUP_TASKSET_INIT(tset);
struct task_struct *task;
/*
@@ -2788,14 +2292,14 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
rcu_read_lock();
task = leader;
do {
- cgroup_taskset_add(task, &tset);
+ cgroup_migrate_add_task(task, mgctx);
if (!threadgroup)
break;
} while_each_thread(leader, task);
rcu_read_unlock();
spin_unlock_irq(&css_set_lock);
- return cgroup_taskset_migrate(&tset, root);
+ return cgroup_migrate_execute(mgctx);
}
/**
@@ -2806,10 +2310,10 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
*
* Call holding cgroup_mutex and cgroup_threadgroup_rwsem.
*/
-static int cgroup_attach_task(struct cgroup *dst_cgrp,
- struct task_struct *leader, bool threadgroup)
+int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader,
+ bool threadgroup)
{
- LIST_HEAD(preloaded_csets);
+ DEFINE_CGROUP_MGCTX(mgctx);
struct task_struct *task;
int ret;
@@ -2821,8 +2325,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp,
rcu_read_lock();
task = leader;
do {
- cgroup_migrate_add_src(task_css_set(task), dst_cgrp,
- &preloaded_csets);
+ cgroup_migrate_add_src(task_css_set(task), dst_cgrp, &mgctx);
if (!threadgroup)
break;
} while_each_thread(leader, task);
@@ -2830,11 +2333,11 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp,
spin_unlock_irq(&css_set_lock);
/* prepare dst csets and commit */
- ret = cgroup_migrate_prepare_dst(&preloaded_csets);
+ ret = cgroup_migrate_prepare_dst(&mgctx);
if (!ret)
- ret = cgroup_migrate(leader, threadgroup, dst_cgrp->root);
+ ret = cgroup_migrate(leader, threadgroup, &mgctx);
- cgroup_migrate_finish(&preloaded_csets);
+ cgroup_migrate_finish(&mgctx);
if (!ret)
trace_cgroup_attach_task(dst_cgrp, leader, threadgroup);
@@ -2846,20 +2349,9 @@ static int cgroup_procs_write_permission(struct task_struct *task,
struct cgroup *dst_cgrp,
struct kernfs_open_file *of)
{
- const struct cred *cred = current_cred();
- const struct cred *tcred = get_task_cred(task);
int ret = 0;
- /*
- * even if we're attaching all tasks in the thread group, we only
- * need to check permissions on one of them.
- */
- if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
- !uid_eq(cred->euid, tcred->uid) &&
- !uid_eq(cred->euid, tcred->suid))
- ret = -EACCES;
-
- if (!ret && cgroup_on_dfl(dst_cgrp)) {
+ if (cgroup_on_dfl(dst_cgrp)) {
struct super_block *sb = of->file->f_path.dentry->d_sb;
struct cgroup *cgrp;
struct inode *inode;
@@ -2877,9 +2369,21 @@ static int cgroup_procs_write_permission(struct task_struct *task,
ret = inode_permission(inode, MAY_WRITE);
iput(inode);
}
+ } else {
+ const struct cred *cred = current_cred();
+ const struct cred *tcred = get_task_cred(task);
+
+ /*
+ * even if we're attaching all tasks in the thread group,
+ * we only need to check permissions on one of them.
+ */
+ if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
+ !uid_eq(cred->euid, tcred->uid) &&
+ !uid_eq(cred->euid, tcred->suid))
+ ret = -EACCES;
+ put_cred(tcred);
}
- put_cred(tcred);
return ret;
}
@@ -2888,8 +2392,8 @@ static int cgroup_procs_write_permission(struct task_struct *task,
* function to attach either it or all tasks in its threadgroup. Will lock
* cgroup_mutex and threadgroup.
*/
-static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
- size_t nbytes, loff_t off, bool threadgroup)
+ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off, bool threadgroup)
{
struct task_struct *tsk;
struct cgroup_subsys *ss;
@@ -2950,86 +2454,12 @@ out_unlock_threadgroup:
return ret ?: nbytes;
}
-/**
- * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from'
- * @from: attach to all cgroups of a given task
- * @tsk: the task to be attached
- */
-int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
-{
- struct cgroup_root *root;
- int retval = 0;
-
- mutex_lock(&cgroup_mutex);
- percpu_down_write(&cgroup_threadgroup_rwsem);
- for_each_root(root) {
- struct cgroup *from_cgrp;
-
- if (root == &cgrp_dfl_root)
- continue;
-
- spin_lock_irq(&css_set_lock);
- from_cgrp = task_cgroup_from_root(from, root);
- spin_unlock_irq(&css_set_lock);
-
- retval = cgroup_attach_task(from_cgrp, tsk, false);
- if (retval)
- break;
- }
- percpu_up_write(&cgroup_threadgroup_rwsem);
- mutex_unlock(&cgroup_mutex);
-
- return retval;
-}
-EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
-
-static ssize_t cgroup_tasks_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- return __cgroup_procs_write(of, buf, nbytes, off, false);
-}
-
-static ssize_t cgroup_procs_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+ssize_t cgroup_procs_write(struct kernfs_open_file *of, char *buf, size_t nbytes,
+ loff_t off)
{
return __cgroup_procs_write(of, buf, nbytes, off, true);
}
-static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
-{
- struct cgroup *cgrp;
-
- BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
-
- cgrp = cgroup_kn_lock_live(of->kn, false);
- if (!cgrp)
- return -ENODEV;
- spin_lock(&release_agent_path_lock);
- strlcpy(cgrp->root->release_agent_path, strstrip(buf),
- sizeof(cgrp->root->release_agent_path));
- spin_unlock(&release_agent_path_lock);
- cgroup_kn_unlock(of->kn);
- return nbytes;
-}
-
-static int cgroup_release_agent_show(struct seq_file *seq, void *v)
-{
- struct cgroup *cgrp = seq_css(seq)->cgroup;
-
- spin_lock(&release_agent_path_lock);
- seq_puts(seq, cgrp->root->release_agent_path);
- spin_unlock(&release_agent_path_lock);
- seq_putc(seq, '\n');
- return 0;
-}
-
-static int cgroup_sane_behavior_show(struct seq_file *seq, void *v)
-{
- seq_puts(seq, "0\n");
- return 0;
-}
-
static void cgroup_print_ss_mask(struct seq_file *seq, u16 ss_mask)
{
struct cgroup_subsys *ss;
@@ -3075,8 +2505,7 @@ static int cgroup_subtree_control_show(struct seq_file *seq, void *v)
*/
static int cgroup_update_dfl_csses(struct cgroup *cgrp)
{
- LIST_HEAD(preloaded_csets);
- struct cgroup_taskset tset = CGROUP_TASKSET_INIT(tset);
+ DEFINE_CGROUP_MGCTX(mgctx);
struct cgroup_subsys_state *d_css;
struct cgroup *dsct;
struct css_set *src_cset;
@@ -3092,33 +2521,28 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
struct cgrp_cset_link *link;
list_for_each_entry(link, &dsct->cset_links, cset_link)
- cgroup_migrate_add_src(link->cset, dsct,
- &preloaded_csets);
+ cgroup_migrate_add_src(link->cset, dsct, &mgctx);
}
spin_unlock_irq(&css_set_lock);
/* NULL dst indicates self on default hierarchy */
- ret = cgroup_migrate_prepare_dst(&preloaded_csets);
+ ret = cgroup_migrate_prepare_dst(&mgctx);
if (ret)
goto out_finish;
spin_lock_irq(&css_set_lock);
- list_for_each_entry(src_cset, &preloaded_csets, mg_preload_node) {
+ list_for_each_entry(src_cset, &mgctx.preloaded_src_csets, mg_preload_node) {
struct task_struct *task, *ntask;
- /* src_csets precede dst_csets, break on the first dst_cset */
- if (!src_cset->mg_src_cgrp)
- break;
-
/* all tasks in src_csets need to be migrated */
list_for_each_entry_safe(task, ntask, &src_cset->tasks, cg_list)
- cgroup_taskset_add(task, &tset);
+ cgroup_migrate_add_task(task, &mgctx);
}
spin_unlock_irq(&css_set_lock);
- ret = cgroup_taskset_migrate(&tset, cgrp->root);
+ ret = cgroup_migrate_execute(&mgctx);
out_finish:
- cgroup_migrate_finish(&preloaded_csets);
+ cgroup_migrate_finish(&mgctx);
percpu_up_write(&cgroup_threadgroup_rwsem);
return ret;
}
@@ -3131,7 +2555,7 @@ out_finish:
* controller while the previous css is still around. This function grabs
* cgroup_mutex and drains the previous css instances of @cgrp's subtree.
*/
-static void cgroup_lock_and_drain_offline(struct cgroup *cgrp)
+void cgroup_lock_and_drain_offline(struct cgroup *cgrp)
__acquires(&cgroup_mutex)
{
struct cgroup *dsct;
@@ -3503,6 +2927,23 @@ static int cgroup_events_show(struct seq_file *seq, void *v)
return 0;
}
+static int cgroup_file_open(struct kernfs_open_file *of)
+{
+ struct cftype *cft = of->kn->priv;
+
+ if (cft->open)
+ return cft->open(of);
+ return 0;
+}
+
+static void cgroup_file_release(struct kernfs_open_file *of)
+{
+ struct cftype *cft = of->kn->priv;
+
+ if (cft->release)
+ cft->release(of);
+}
+
static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf,
size_t nbytes, loff_t off)
{
@@ -3553,7 +2994,8 @@ static void *cgroup_seqfile_next(struct seq_file *seq, void *v, loff_t *ppos)
static void cgroup_seqfile_stop(struct seq_file *seq, void *v)
{
- seq_cft(seq)->seq_stop(seq, v);
+ if (seq_cft(seq)->seq_stop)
+ seq_cft(seq)->seq_stop(seq, v);
}
static int cgroup_seqfile_show(struct seq_file *m, void *arg)
@@ -3575,12 +3017,16 @@ static int cgroup_seqfile_show(struct seq_file *m, void *arg)
static struct kernfs_ops cgroup_kf_single_ops = {
.atomic_write_len = PAGE_SIZE,
+ .open = cgroup_file_open,
+ .release = cgroup_file_release,
.write = cgroup_file_write,
.seq_show = cgroup_seqfile_show,
};
static struct kernfs_ops cgroup_kf_ops = {
.atomic_write_len = PAGE_SIZE,
+ .open = cgroup_file_open,
+ .release = cgroup_file_release,
.write = cgroup_file_write,
.seq_start = cgroup_seqfile_start,
.seq_next = cgroup_seqfile_next,
@@ -3588,48 +3034,6 @@ static struct kernfs_ops cgroup_kf_ops = {
.seq_show = cgroup_seqfile_show,
};
-/*
- * cgroup_rename - Only allow simple rename of directories in place.
- */
-static int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,
- const char *new_name_str)
-{
- struct cgroup *cgrp = kn->priv;
- int ret;
-
- if (kernfs_type(kn) != KERNFS_DIR)
- return -ENOTDIR;
- if (kn->parent != new_parent)
- return -EIO;
-
- /*
- * This isn't a proper migration and its usefulness is very
- * limited. Disallow on the default hierarchy.
- */
- if (cgroup_on_dfl(cgrp))
- return -EPERM;
-
- /*
- * We're gonna grab cgroup_mutex which nests outside kernfs
- * active_ref. kernfs_rename() doesn't require active_ref
- * protection. Break them before grabbing cgroup_mutex.
- */
- kernfs_break_active_protection(new_parent);
- kernfs_break_active_protection(kn);
-
- mutex_lock(&cgroup_mutex);
-
- ret = kernfs_rename(kn, new_parent, new_name_str);
- if (!ret)
- trace_cgroup_rename(cgrp);
-
- mutex_unlock(&cgroup_mutex);
-
- kernfs_unbreak_active_protection(kn);
- kernfs_unbreak_active_protection(new_parent);
- return ret;
-}
-
/* set uid and gid of cgroup dirs and files to that of the creator */
static int cgroup_kn_set_ugid(struct kernfs_node *kn)
{
@@ -3926,26 +3330,6 @@ void cgroup_file_notify(struct cgroup_file *cfile)
}
/**
- * cgroup_task_count - count the number of tasks in a cgroup.
- * @cgrp: the cgroup in question
- *
- * Return the number of tasks in the cgroup. The returned number can be
- * higher than the actual number of tasks due to css_set references from
- * namespace roots and temporary usages.
- */
-static int cgroup_task_count(const struct cgroup *cgrp)
-{
- int count = 0;
- struct cgrp_cset_link *link;
-
- spin_lock_irq(&css_set_lock);
- list_for_each_entry(link, &cgrp->cset_links, cset_link)
- count += atomic_read(&link->cset->refcount);
- spin_unlock_irq(&css_set_lock);
- return count;
-}
-
-/**
* css_next_child - find the next child of a given css
* @pos: the current position (%NULL to initiate traversal)
* @parent: css whose children to walk
@@ -4343,560 +3727,69 @@ void css_task_iter_end(struct css_task_iter *it)
put_task_struct(it->cur_task);
}
-/**
- * cgroup_trasnsfer_tasks - move tasks from one cgroup to another
- * @to: cgroup to which the tasks will be moved
- * @from: cgroup in which the tasks currently reside
- *
- * Locking rules between cgroup_post_fork() and the migration path
- * guarantee that, if a task is forking while being migrated, the new child
- * is guaranteed to be either visible in the source cgroup after the
- * parent's migration is complete or put into the target cgroup. No task
- * can slip out of migration through forking.
- */
-int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
-{
- LIST_HEAD(preloaded_csets);
- struct cgrp_cset_link *link;
- struct css_task_iter it;
- struct task_struct *task;
- int ret;
-
- if (!cgroup_may_migrate_to(to))
- return -EBUSY;
-
- mutex_lock(&cgroup_mutex);
-
- percpu_down_write(&cgroup_threadgroup_rwsem);
-
- /* all tasks in @from are being moved, all csets are source */
- spin_lock_irq(&css_set_lock);
- list_for_each_entry(link, &from->cset_links, cset_link)
- cgroup_migrate_add_src(link->cset, to, &preloaded_csets);
- spin_unlock_irq(&css_set_lock);
-
- ret = cgroup_migrate_prepare_dst(&preloaded_csets);
- if (ret)
- goto out_err;
-
- /*
- * Migrate tasks one-by-one until @from is empty. This fails iff
- * ->can_attach() fails.
- */
- do {
- css_task_iter_start(&from->self, &it);
- task = css_task_iter_next(&it);
- if (task)
- get_task_struct(task);
- css_task_iter_end(&it);
-
- if (task) {
- ret = cgroup_migrate(task, false, to->root);
- if (!ret)
- trace_cgroup_transfer_tasks(to, task, false);
- put_task_struct(task);
- }
- } while (task && !ret);
-out_err:
- cgroup_migrate_finish(&preloaded_csets);
- percpu_up_write(&cgroup_threadgroup_rwsem);
- mutex_unlock(&cgroup_mutex);
- return ret;
-}
-
-/*
- * Stuff for reading the 'tasks'/'procs' files.
- *
- * Reading this file can return large amounts of data if a cgroup has
- * *lots* of attached tasks. So it may need several calls to read(),
- * but we cannot guarantee that the information we produce is correct
- * unless we produce it entirely atomically.
- *
- */
-
-/* which pidlist file are we talking about? */
-enum cgroup_filetype {
- CGROUP_FILE_PROCS,
- CGROUP_FILE_TASKS,
-};
-
-/*
- * A pidlist is a list of pids that virtually represents the contents of one
- * of the cgroup files ("procs" or "tasks"). We keep a list of such pidlists,
- * a pair (one each for procs, tasks) for each pid namespace that's relevant
- * to the cgroup.
- */
-struct cgroup_pidlist {
- /*
- * used to find which pidlist is wanted. doesn't change as long as
- * this particular list stays in the list.
- */
- struct { enum cgroup_filetype type; struct pid_namespace *ns; } key;
- /* array of xids */
- pid_t *list;
- /* how many elements the above list has */
- int length;
- /* each of these stored in a list by its cgroup */
- struct list_head links;
- /* pointer to the cgroup we belong to, for list removal purposes */
- struct cgroup *owner;
- /* for delayed destruction */
- struct delayed_work destroy_dwork;
-};
-
-/*
- * The following two functions "fix" the issue where there are more pids
- * than kmalloc will give memory for; in such cases, we use vmalloc/vfree.
- * TODO: replace with a kernel-wide solution to this problem
- */
-#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
-static void *pidlist_allocate(int count)
-{
- if (PIDLIST_TOO_LARGE(count))
- return vmalloc(count * sizeof(pid_t));
- else
- return kmalloc(count * sizeof(pid_t), GFP_KERNEL);
-}
-
-static void pidlist_free(void *p)
-{
- kvfree(p);
-}
-
-/*
- * Used to destroy all pidlists lingering waiting for destroy timer. None
- * should be left afterwards.
- */
-static void cgroup_pidlist_destroy_all(struct cgroup *cgrp)
-{
- struct cgroup_pidlist *l, *tmp_l;
-
- mutex_lock(&cgrp->pidlist_mutex);
- list_for_each_entry_safe(l, tmp_l, &cgrp->pidlists, links)
- mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork, 0);
- mutex_unlock(&cgrp->pidlist_mutex);
-
- flush_workqueue(cgroup_pidlist_destroy_wq);
- BUG_ON(!list_empty(&cgrp->pidlists));
-}
-
-static void cgroup_pidlist_destroy_work_fn(struct work_struct *work)
-{
- struct delayed_work *dwork = to_delayed_work(work);
- struct cgroup_pidlist *l = container_of(dwork, struct cgroup_pidlist,
- destroy_dwork);
- struct cgroup_pidlist *tofree = NULL;
-
- mutex_lock(&l->owner->pidlist_mutex);
-
- /*
- * Destroy iff we didn't get queued again. The state won't change
- * as destroy_dwork can only be queued while locked.
- */
- if (!delayed_work_pending(dwork)) {
- list_del(&l->links);
- pidlist_free(l->list);
- put_pid_ns(l->key.ns);
- tofree = l;
- }
-
- mutex_unlock(&l->owner->pidlist_mutex);
- kfree(tofree);
-}
-
-/*
- * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries
- * Returns the number of unique elements.
- */
-static int pidlist_uniq(pid_t *list, int length)
-{
- int src, dest = 1;
-
- /*
- * we presume the 0th element is unique, so i starts at 1. trivial
- * edge cases first; no work needs to be done for either
- */
- if (length == 0 || length == 1)
- return length;
- /* src and dest walk down the list; dest counts unique elements */
- for (src = 1; src < length; src++) {
- /* find next unique element */
- while (list[src] == list[src-1]) {
- src++;
- if (src == length)
- goto after;
- }
- /* dest always points to where the next unique element goes */
- list[dest] = list[src];
- dest++;
- }
-after:
- return dest;
-}
-
-/*
- * The two pid files - task and cgroup.procs - guaranteed that the result
- * is sorted, which forced this whole pidlist fiasco. As pid order is
- * different per namespace, each namespace needs differently sorted list,
- * making it impossible to use, for example, single rbtree of member tasks
- * sorted by task pointer. As pidlists can be fairly large, allocating one
- * per open file is dangerous, so cgroup had to implement shared pool of
- * pidlists keyed by cgroup and namespace.
- *
- * All this extra complexity was caused by the original implementation
- * committing to an entirely unnecessary property. In the long term, we
- * want to do away with it. Explicitly scramble sort order if on the
- * default hierarchy so that no such expectation exists in the new
- * interface.
- *
- * Scrambling is done by swapping every two consecutive bits, which is
- * non-identity one-to-one mapping which disturbs sort order sufficiently.
- */
-static pid_t pid_fry(pid_t pid)
+static void cgroup_procs_release(struct kernfs_open_file *of)
{
- unsigned a = pid & 0x55555555;
- unsigned b = pid & 0xAAAAAAAA;
-
- return (a << 1) | (b >> 1);
-}
-
-static pid_t cgroup_pid_fry(struct cgroup *cgrp, pid_t pid)
-{
- if (cgroup_on_dfl(cgrp))
- return pid_fry(pid);
- else
- return pid;
-}
-
-static int cmppid(const void *a, const void *b)
-{
- return *(pid_t *)a - *(pid_t *)b;
-}
-
-static int fried_cmppid(const void *a, const void *b)
-{
- return pid_fry(*(pid_t *)a) - pid_fry(*(pid_t *)b);
-}
-
-static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
- enum cgroup_filetype type)
-{
- struct cgroup_pidlist *l;
- /* don't need task_nsproxy() if we're looking at ourself */
- struct pid_namespace *ns = task_active_pid_ns(current);
-
- lockdep_assert_held(&cgrp->pidlist_mutex);
-
- list_for_each_entry(l, &cgrp->pidlists, links)
- if (l->key.type == type && l->key.ns == ns)
- return l;
- return NULL;
-}
-
-/*
- * find the appropriate pidlist for our purpose (given procs vs tasks)
- * returns with the lock on that pidlist already held, and takes care
- * of the use count, or returns NULL with no locks held if we're out of
- * memory.
- */
-static struct cgroup_pidlist *cgroup_pidlist_find_create(struct cgroup *cgrp,
- enum cgroup_filetype type)
-{
- struct cgroup_pidlist *l;
-
- lockdep_assert_held(&cgrp->pidlist_mutex);
-
- l = cgroup_pidlist_find(cgrp, type);
- if (l)
- return l;
-
- /* entry not found; create a new one */
- l = kzalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
- if (!l)
- return l;
-
- INIT_DELAYED_WORK(&l->destroy_dwork, cgroup_pidlist_destroy_work_fn);
- l->key.type = type;
- /* don't need task_nsproxy() if we're looking at ourself */
- l->key.ns = get_pid_ns(task_active_pid_ns(current));
- l->owner = cgrp;
- list_add(&l->links, &cgrp->pidlists);
- return l;
-}
-
-/*
- * Load a cgroup's pidarray with either procs' tgids or tasks' pids
- */
-static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
- struct cgroup_pidlist **lp)
-{
- pid_t *array;
- int length;
- int pid, n = 0; /* used for populating the array */
- struct css_task_iter it;
- struct task_struct *tsk;
- struct cgroup_pidlist *l;
-
- lockdep_assert_held(&cgrp->pidlist_mutex);
-
- /*
- * If cgroup gets more users after we read count, we won't have
- * enough space - tough. This race is indistinguishable to the
- * caller from the case that the additional cgroup users didn't
- * show up until sometime later on.
- */
- length = cgroup_task_count(cgrp);
- array = pidlist_allocate(length);
- if (!array)
- return -ENOMEM;
- /* now, populate the array */
- css_task_iter_start(&cgrp->self, &it);
- while ((tsk = css_task_iter_next(&it))) {
- if (unlikely(n == length))
- break;
- /* get tgid or pid for procs or tasks file respectively */
- if (type == CGROUP_FILE_PROCS)
- pid = task_tgid_vnr(tsk);
- else
- pid = task_pid_vnr(tsk);
- if (pid > 0) /* make sure to only use valid results */
- array[n++] = pid;
- }
- css_task_iter_end(&it);
- length = n;
- /* now sort & (if procs) strip out duplicates */
- if (cgroup_on_dfl(cgrp))
- sort(array, length, sizeof(pid_t), fried_cmppid, NULL);
- else
- sort(array, length, sizeof(pid_t), cmppid, NULL);
- if (type == CGROUP_FILE_PROCS)
- length = pidlist_uniq(array, length);
-
- l = cgroup_pidlist_find_create(cgrp, type);
- if (!l) {
- pidlist_free(array);
- return -ENOMEM;
+ if (of->priv) {
+ css_task_iter_end(of->priv);
+ kfree(of->priv);
}
-
- /* store array, freeing old if necessary */
- pidlist_free(l->list);
- l->list = array;
- l->length = length;
- *lp = l;
- return 0;
}
-/**
- * cgroupstats_build - build and fill cgroupstats
- * @stats: cgroupstats to fill information into
- * @dentry: A dentry entry belonging to the cgroup for which stats have
- * been requested.
- *
- * Build and fill cgroupstats so that taskstats can export it to user
- * space.
- */
-int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
+static void *cgroup_procs_next(struct seq_file *s, void *v, loff_t *pos)
{
- struct kernfs_node *kn = kernfs_node_from_dentry(dentry);
- struct cgroup *cgrp;
- struct css_task_iter it;
- struct task_struct *tsk;
-
- /* it should be kernfs_node belonging to cgroupfs and is a directory */
- if (dentry->d_sb->s_type != &cgroup_fs_type || !kn ||
- kernfs_type(kn) != KERNFS_DIR)
- return -EINVAL;
-
- mutex_lock(&cgroup_mutex);
-
- /*
- * We aren't being called from kernfs and there's no guarantee on
- * @kn->priv's validity. For this and css_tryget_online_from_dir(),
- * @kn->priv is RCU safe. Let's do the RCU dancing.
- */
- rcu_read_lock();
- cgrp = rcu_dereference(kn->priv);
- if (!cgrp || cgroup_is_dead(cgrp)) {
- rcu_read_unlock();
- mutex_unlock(&cgroup_mutex);
- return -ENOENT;
- }
- rcu_read_unlock();
+ struct kernfs_open_file *of = s->private;
+ struct css_task_iter *it = of->priv;
+ struct task_struct *task;
- css_task_iter_start(&cgrp->self, &it);
- while ((tsk = css_task_iter_next(&it))) {
- switch (tsk->state) {
- case TASK_RUNNING:
- stats->nr_running++;
- break;
- case TASK_INTERRUPTIBLE:
- stats->nr_sleeping++;
- break;
- case TASK_UNINTERRUPTIBLE:
- stats->nr_uninterruptible++;
- break;
- case TASK_STOPPED:
- stats->nr_stopped++;
- break;
- default:
- if (delayacct_is_task_waiting_on_io(tsk))
- stats->nr_io_wait++;
- break;
- }
- }
- css_task_iter_end(&it);
+ do {
+ task = css_task_iter_next(it);
+ } while (task && !thread_group_leader(task));
- mutex_unlock(&cgroup_mutex);
- return 0;
+ return task;
}
-
-/*
- * seq_file methods for the tasks/procs files. The seq_file position is the
- * next pid to display; the seq_file iterator is a pointer to the pid
- * in the cgroup->l->list array.
- */
-
-static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
+static void *cgroup_procs_start(struct seq_file *s, loff_t *pos)
{
- /*
- * Initially we receive a position value that corresponds to
- * one more than the last pid shown (or 0 on the first call or
- * after a seek to the start). Use a binary-search to find the
- * next pid to display, if any
- */
struct kernfs_open_file *of = s->private;
struct cgroup *cgrp = seq_css(s)->cgroup;
- struct cgroup_pidlist *l;
- enum cgroup_filetype type = seq_cft(s)->private;
- int index = 0, pid = *pos;
- int *iter, ret;
-
- mutex_lock(&cgrp->pidlist_mutex);
+ struct css_task_iter *it = of->priv;
/*
- * !NULL @of->priv indicates that this isn't the first start()
- * after open. If the matching pidlist is around, we can use that.
- * Look for it. Note that @of->priv can't be used directly. It
- * could already have been destroyed.
+ * When a seq_file is seeked, it's always traversed sequentially
+ * from position 0, so we can simply keep iterating on !0 *pos.
*/
- if (of->priv)
- of->priv = cgroup_pidlist_find(cgrp, type);
-
- /*
- * Either this is the first start() after open or the matching
- * pidlist has been destroyed inbetween. Create a new one.
- */
- if (!of->priv) {
- ret = pidlist_array_load(cgrp, type,
- (struct cgroup_pidlist **)&of->priv);
- if (ret)
- return ERR_PTR(ret);
- }
- l = of->priv;
-
- if (pid) {
- int end = l->length;
-
- while (index < end) {
- int mid = (index + end) / 2;
- if (cgroup_pid_fry(cgrp, l->list[mid]) == pid) {
- index = mid;
- break;
- } else if (cgroup_pid_fry(cgrp, l->list[mid]) <= pid)
- index = mid + 1;
- else
- end = mid;
- }
- }
- /* If we're off the end of the array, we're done */
- if (index >= l->length)
- return NULL;
- /* Update the abstract position to be the actual pid that we found */
- iter = l->list + index;
- *pos = cgroup_pid_fry(cgrp, *iter);
- return iter;
-}
-
-static void cgroup_pidlist_stop(struct seq_file *s, void *v)
-{
- struct kernfs_open_file *of = s->private;
- struct cgroup_pidlist *l = of->priv;
-
- if (l)
- mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork,
- CGROUP_PIDLIST_DESTROY_DELAY);
- mutex_unlock(&seq_css(s)->cgroup->pidlist_mutex);
-}
+ if (!it) {
+ if (WARN_ON_ONCE((*pos)++))
+ return ERR_PTR(-EINVAL);
-static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
-{
- struct kernfs_open_file *of = s->private;
- struct cgroup_pidlist *l = of->priv;
- pid_t *p = v;
- pid_t *end = l->list + l->length;
- /*
- * Advance to the next pid in the array. If this goes off the
- * end, we're done
- */
- p++;
- if (p >= end) {
- return NULL;
- } else {
- *pos = cgroup_pid_fry(seq_css(s)->cgroup, *p);
- return p;
+ it = kzalloc(sizeof(*it), GFP_KERNEL);
+ if (!it)
+ return ERR_PTR(-ENOMEM);
+ of->priv = it;
+ css_task_iter_start(&cgrp->self, it);
+ } else if (!(*pos)++) {
+ css_task_iter_end(it);
+ css_task_iter_start(&cgrp->self, it);
}
-}
-
-static int cgroup_pidlist_show(struct seq_file *s, void *v)
-{
- seq_printf(s, "%d\n", *(int *)v);
- return 0;
+ return cgroup_procs_next(s, NULL, NULL);
}
-static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
- struct cftype *cft)
+static int cgroup_procs_show(struct seq_file *s, void *v)
{
- return notify_on_release(css->cgroup);
-}
-
-static int cgroup_write_notify_on_release(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- if (val)
- set_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
- else
- clear_bit(CGRP_NOTIFY_ON_RELEASE, &css->cgroup->flags);
- return 0;
-}
-
-static u64 cgroup_clone_children_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
-}
-
-static int cgroup_clone_children_write(struct cgroup_subsys_state *css,
- struct cftype *cft, u64 val)
-{
- if (val)
- set_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
- else
- clear_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags);
+ seq_printf(s, "%d\n", task_tgid_vnr(v));
return 0;
}
/* cgroup core interface files for the default hierarchy */
-static struct cftype cgroup_dfl_base_files[] = {
+static struct cftype cgroup_base_files[] = {
{
.name = "cgroup.procs",
.file_offset = offsetof(struct cgroup, procs_file),
- .seq_start = cgroup_pidlist_start,
- .seq_next = cgroup_pidlist_next,
- .seq_stop = cgroup_pidlist_stop,
- .seq_show = cgroup_pidlist_show,
- .private = CGROUP_FILE_PROCS,
+ .release = cgroup_procs_release,
+ .seq_start = cgroup_procs_start,
+ .seq_next = cgroup_procs_next,
+ .seq_show = cgroup_procs_show,
.write = cgroup_procs_write,
},
{
@@ -4917,51 +3810,6 @@ static struct cftype cgroup_dfl_base_files[] = {
{ } /* terminate */
};
-/* cgroup core interface files for the legacy hierarchies */
-static struct cftype cgroup_legacy_base_files[] = {
- {
- .name = "cgroup.procs",
- .seq_start = cgroup_pidlist_start,
- .seq_next = cgroup_pidlist_next,
- .seq_stop = cgroup_pidlist_stop,
- .seq_show = cgroup_pidlist_show,
- .private = CGROUP_FILE_PROCS,
- .write = cgroup_procs_write,
- },
- {
- .name = "cgroup.clone_children",
- .read_u64 = cgroup_clone_children_read,
- .write_u64 = cgroup_clone_children_write,
- },
- {
- .name = "cgroup.sane_behavior",
- .flags = CFTYPE_ONLY_ON_ROOT,
- .seq_show = cgroup_sane_behavior_show,
- },
- {
- .name = "tasks",
- .seq_start = cgroup_pidlist_start,
- .seq_next = cgroup_pidlist_next,
- .seq_stop = cgroup_pidlist_stop,
- .seq_show = cgroup_pidlist_show,
- .private = CGROUP_FILE_TASKS,
- .write = cgroup_tasks_write,
- },
- {
- .name = "notify_on_release",
- .read_u64 = cgroup_read_notify_on_release,
- .write_u64 = cgroup_write_notify_on_release,
- },
- {
- .name = "release_agent",
- .flags = CFTYPE_ONLY_ON_ROOT,
- .seq_show = cgroup_release_agent_show,
- .write = cgroup_release_agent_write,
- .max_write_len = PATH_MAX - 1,
- },
- { } /* terminate */
-};
-
/*
* css destruction is four-stage process.
*
@@ -5007,7 +3855,7 @@ static void css_free_work_fn(struct work_struct *work)
} else {
/* cgroup free path */
atomic_dec(&cgrp->root->nr_cgrps);
- cgroup_pidlist_destroy_all(cgrp);
+ cgroup1_pidlist_destroy_all(cgrp);
cancel_work_sync(&cgrp->release_agent_work);
if (cgroup_parent(cgrp)) {
@@ -5302,8 +4150,7 @@ out_free_cgrp:
return ERR_PTR(ret);
}
-static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
- umode_t mode)
+int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode)
{
struct cgroup *parent, *cgrp;
struct kernfs_node *kn;
@@ -5507,7 +4354,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
*/
kernfs_remove(cgrp->kn);
- check_for_release(cgroup_parent(cgrp));
+ cgroup1_check_for_release(cgroup_parent(cgrp));
/* put the base reference */
percpu_ref_kill(&cgrp->self.refcnt);
@@ -5515,7 +4362,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
return 0;
};
-static int cgroup_rmdir(struct kernfs_node *kn)
+int cgroup_rmdir(struct kernfs_node *kn)
{
struct cgroup *cgrp;
int ret = 0;
@@ -5535,10 +4382,8 @@ static int cgroup_rmdir(struct kernfs_node *kn)
static struct kernfs_syscall_ops cgroup_kf_syscall_ops = {
.remount_fs = cgroup_remount,
- .show_options = cgroup_show_options,
.mkdir = cgroup_mkdir,
.rmdir = cgroup_rmdir,
- .rename = cgroup_rename,
.show_path = cgroup_show_path,
};
@@ -5646,8 +4491,8 @@ int __init cgroup_init(void)
BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16);
BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem));
- BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));
- BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));
+ BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files));
+ BUG_ON(cgroup_init_cftypes(NULL, cgroup1_base_files));
/*
* The latency of the synchronize_sched() is too high for cgroups,
@@ -5697,7 +4542,7 @@ int __init cgroup_init(void)
continue;
}
- if (cgroup_ssid_no_v1(ssid))
+ if (cgroup1_ssid_disabled(ssid))
printk(KERN_INFO "Disabling %s control group subsystem in v1 mounts\n",
ss->name);
@@ -5744,15 +4589,6 @@ static int __init cgroup_wq_init(void)
*/
cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1);
BUG_ON(!cgroup_destroy_wq);
-
- /*
- * Used to destroy pidlists and separate to serve as flush domain.
- * Cap @max_active to 1 too.
- */
- cgroup_pidlist_destroy_wq = alloc_workqueue("cgroup_pidlist_destroy",
- 0, 1);
- BUG_ON(!cgroup_pidlist_destroy_wq);
-
return 0;
}
core_initcall(cgroup_wq_init);
@@ -5835,42 +4671,6 @@ out:
return retval;
}
-/* Display information about each subsystem and each hierarchy */
-static int proc_cgroupstats_show(struct seq_file *m, void *v)
-{
- struct cgroup_subsys *ss;
- int i;
-
- seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");
- /*
- * ideally we don't want subsystems moving around while we do this.
- * cgroup_mutex is also necessary to guarantee an atomic snapshot of
- * subsys/hierarchy state.
- */
- mutex_lock(&cgroup_mutex);
-
- for_each_subsys(ss, i)
- seq_printf(m, "%s\t%d\t%d\t%d\n",
- ss->legacy_name, ss->root->hierarchy_id,
- atomic_read(&ss->root->nr_cgrps),
- cgroup_ssid_enabled(i));
-
- mutex_unlock(&cgroup_mutex);
- return 0;
-}
-
-static int cgroupstats_open(struct inode *inode, struct file *file)
-{
- return single_open(file, proc_cgroupstats_show, NULL);
-}
-
-static const struct file_operations proc_cgroupstats_operations = {
- .open = cgroupstats_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-
/**
* cgroup_fork - initialize cgroup related fields during copy_process()
* @child: pointer to task_struct of forking parent process.
@@ -6050,76 +4850,6 @@ void cgroup_free(struct task_struct *task)
put_css_set(cset);
}
-static void check_for_release(struct cgroup *cgrp)
-{
- if (notify_on_release(cgrp) && !cgroup_is_populated(cgrp) &&
- !css_has_online_children(&cgrp->self) && !cgroup_is_dead(cgrp))
- schedule_work(&cgrp->release_agent_work);
-}
-
-/*
- * Notify userspace when a cgroup is released, by running the
- * configured release agent with the name of the cgroup (path
- * relative to the root of cgroup file system) as the argument.
- *
- * Most likely, this user command will try to rmdir this cgroup.
- *
- * This races with the possibility that some other task will be
- * attached to this cgroup before it is removed, or that some other
- * user task will 'mkdir' a child cgroup of this cgroup. That's ok.
- * The presumed 'rmdir' will fail quietly if this cgroup is no longer
- * unused, and this cgroup will be reprieved from its death sentence,
- * to continue to serve a useful existence. Next time it's released,
- * we will get notified again, if it still has 'notify_on_release' set.
- *
- * The final arg to call_usermodehelper() is UMH_WAIT_EXEC, which
- * means only wait until the task is successfully execve()'d. The
- * separate release agent task is forked by call_usermodehelper(),
- * then control in this thread returns here, without waiting for the
- * release agent task. We don't bother to wait because the caller of
- * this routine has no use for the exit status of the release agent
- * task, so no sense holding our caller up for that.
- */
-static void cgroup_release_agent(struct work_struct *work)
-{
- struct cgroup *cgrp =
- container_of(work, struct cgroup, release_agent_work);
- char *pathbuf = NULL, *agentbuf = NULL;
- char *argv[3], *envp[3];
- int ret;
-
- mutex_lock(&cgroup_mutex);
-
- pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
- agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL);
- if (!pathbuf || !agentbuf)
- goto out;
-
- spin_lock_irq(&css_set_lock);
- ret = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
- spin_unlock_irq(&css_set_lock);
- if (ret < 0 || ret >= PATH_MAX)
- goto out;
-
- argv[0] = agentbuf;
- argv[1] = pathbuf;
- argv[2] = NULL;
-
- /* minimal command environment */
- envp[0] = "HOME=/";
- envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
- envp[2] = NULL;
-
- mutex_unlock(&cgroup_mutex);
- call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
- goto out_free;
-out:
- mutex_unlock(&cgroup_mutex);
-out_free:
- kfree(agentbuf);
- kfree(pathbuf);
-}
-
static int __init cgroup_disable(char *str)
{
struct cgroup_subsys *ss;
@@ -6141,33 +4871,6 @@ static int __init cgroup_disable(char *str)
}
__setup("cgroup_disable=", cgroup_disable);
-static int __init cgroup_no_v1(char *str)
-{
- struct cgroup_subsys *ss;
- char *token;
- int i;
-
- while ((token = strsep(&str, ",")) != NULL) {
- if (!*token)
- continue;
-
- if (!strcmp(token, "all")) {
- cgroup_no_v1_mask = U16_MAX;
- break;
- }
-
- for_each_subsys(ss, i) {
- if (strcmp(token, ss->name) &&
- strcmp(token, ss->legacy_name))
- continue;
-
- cgroup_no_v1_mask |= 1 << i;
- }
- }
- return 1;
-}
-__setup("cgroup_no_v1=", cgroup_no_v1);
-
/**
* css_tryget_online_from_dir - get corresponding css from a cgroup dentry
* @dentry: directory dentry of interest
@@ -6197,7 +4900,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
* have been or be removed at any point. @kn->priv is RCU
* protected for this access. See css_release_work_fn() for details.
*/
- cgrp = rcu_dereference(kn->priv);
+ cgrp = rcu_dereference(*(void __rcu __force **)&kn->priv);
if (cgrp)
css = cgroup_css(cgrp, ss);
@@ -6349,154 +5052,6 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd)
#endif /* CONFIG_SOCK_CGROUP_DATA */
-/* cgroup namespaces */
-
-static struct ucounts *inc_cgroup_namespaces(struct user_namespace *ns)
-{
- return inc_ucount(ns, current_euid(), UCOUNT_CGROUP_NAMESPACES);
-}
-
-static void dec_cgroup_namespaces(struct ucounts *ucounts)
-{
- dec_ucount(ucounts, UCOUNT_CGROUP_NAMESPACES);
-}
-
-static struct cgroup_namespace *alloc_cgroup_ns(void)
-{
- struct cgroup_namespace *new_ns;
- int ret;
-
- new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL);
- if (!new_ns)
- return ERR_PTR(-ENOMEM);
- ret = ns_alloc_inum(&new_ns->ns);
- if (ret) {
- kfree(new_ns);
- return ERR_PTR(ret);
- }
- atomic_set(&new_ns->count, 1);
- new_ns->ns.ops = &cgroupns_operations;
- return new_ns;
-}
-
-void free_cgroup_ns(struct cgroup_namespace *ns)
-{
- put_css_set(ns->root_cset);
- dec_cgroup_namespaces(ns->ucounts);
- put_user_ns(ns->user_ns);
- ns_free_inum(&ns->ns);
- kfree(ns);
-}
-EXPORT_SYMBOL(free_cgroup_ns);
-
-struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
- struct user_namespace *user_ns,
- struct cgroup_namespace *old_ns)
-{
- struct cgroup_namespace *new_ns;
- struct ucounts *ucounts;
- struct css_set *cset;
-
- BUG_ON(!old_ns);
-
- if (!(flags & CLONE_NEWCGROUP)) {
- get_cgroup_ns(old_ns);
- return old_ns;
- }
-
- /* Allow only sysadmin to create cgroup namespace. */
- if (!ns_capable(user_ns, CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
-
- ucounts = inc_cgroup_namespaces(user_ns);
- if (!ucounts)
- return ERR_PTR(-ENOSPC);
-
- /* It is not safe to take cgroup_mutex here */
- spin_lock_irq(&css_set_lock);
- cset = task_css_set(current);
- get_css_set(cset);
- spin_unlock_irq(&css_set_lock);
-
- new_ns = alloc_cgroup_ns();
- if (IS_ERR(new_ns)) {
- put_css_set(cset);
- dec_cgroup_namespaces(ucounts);
- return new_ns;
- }
-
- new_ns->user_ns = get_user_ns(user_ns);
- new_ns->ucounts = ucounts;
- new_ns->root_cset = cset;
-
- return new_ns;
-}
-
-static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns)
-{
- return container_of(ns, struct cgroup_namespace, ns);
-}
-
-static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns)
-{
- struct cgroup_namespace *cgroup_ns = to_cg_ns(ns);
-
- if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) ||
- !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN))
- return -EPERM;
-
- /* Don't need to do anything if we are attaching to our own cgroupns. */
- if (cgroup_ns == nsproxy->cgroup_ns)
- return 0;
-
- get_cgroup_ns(cgroup_ns);
- put_cgroup_ns(nsproxy->cgroup_ns);
- nsproxy->cgroup_ns = cgroup_ns;
-
- return 0;
-}
-
-static struct ns_common *cgroupns_get(struct task_struct *task)
-{
- struct cgroup_namespace *ns = NULL;
- struct nsproxy *nsproxy;
-
- task_lock(task);
- nsproxy = task->nsproxy;
- if (nsproxy) {
- ns = nsproxy->cgroup_ns;
- get_cgroup_ns(ns);
- }
- task_unlock(task);
-
- return ns ? &ns->ns : NULL;
-}
-
-static void cgroupns_put(struct ns_common *ns)
-{
- put_cgroup_ns(to_cg_ns(ns));
-}
-
-static struct user_namespace *cgroupns_owner(struct ns_common *ns)
-{
- return to_cg_ns(ns)->user_ns;
-}
-
-const struct proc_ns_operations cgroupns_operations = {
- .name = "cgroup",
- .type = CLONE_NEWCGROUP,
- .get = cgroupns_get,
- .put = cgroupns_put,
- .install = cgroupns_install,
- .owner = cgroupns_owner,
-};
-
-static __init int cgroup_namespaces_init(void)
-{
- return 0;
-}
-subsys_initcall(cgroup_namespaces_init);
-
#ifdef CONFIG_CGROUP_BPF
int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog,
enum bpf_attach_type type, bool overridable)
@@ -6510,149 +5065,3 @@ int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog,
return ret;
}
#endif /* CONFIG_CGROUP_BPF */
-
-#ifdef CONFIG_CGROUP_DEBUG
-static struct cgroup_subsys_state *
-debug_css_alloc(struct cgroup_subsys_state *parent_css)
-{
- struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
-
- if (!css)
- return ERR_PTR(-ENOMEM);
-
- return css;
-}
-
-static void debug_css_free(struct cgroup_subsys_state *css)
-{
- kfree(css);
-}
-
-static u64 debug_taskcount_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return cgroup_task_count(css->cgroup);
-}
-
-static u64 current_css_set_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- return (u64)(unsigned long)current->cgroups;
-}
-
-static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- u64 count;
-
- rcu_read_lock();
- count = atomic_read(&task_css_set(current)->refcount);
- rcu_read_unlock();
- return count;
-}
-
-static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
-{
- struct cgrp_cset_link *link;
- struct css_set *cset;
- char *name_buf;
-
- name_buf = kmalloc(NAME_MAX + 1, GFP_KERNEL);
- if (!name_buf)
- return -ENOMEM;
-
- spin_lock_irq(&css_set_lock);
- rcu_read_lock();
- cset = rcu_dereference(current->cgroups);
- list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
- struct cgroup *c = link->cgrp;
-
- cgroup_name(c, name_buf, NAME_MAX + 1);
- seq_printf(seq, "Root %d group %s\n",
- c->root->hierarchy_id, name_buf);
- }
- rcu_read_unlock();
- spin_unlock_irq(&css_set_lock);
- kfree(name_buf);
- return 0;
-}
-
-#define MAX_TASKS_SHOWN_PER_CSS 25
-static int cgroup_css_links_read(struct seq_file *seq, void *v)
-{
- struct cgroup_subsys_state *css = seq_css(seq);
- struct cgrp_cset_link *link;
-
- spin_lock_irq(&css_set_lock);
- list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
- struct css_set *cset = link->cset;
- struct task_struct *task;
- int count = 0;
-
- seq_printf(seq, "css_set %p\n", cset);
-
- list_for_each_entry(task, &cset->tasks, cg_list) {
- if (count++ > MAX_TASKS_SHOWN_PER_CSS)
- goto overflow;
- seq_printf(seq, " task %d\n", task_pid_vnr(task));
- }
-
- list_for_each_entry(task, &cset->mg_tasks, cg_list) {
- if (count++ > MAX_TASKS_SHOWN_PER_CSS)
- goto overflow;
- seq_printf(seq, " task %d\n", task_pid_vnr(task));
- }
- continue;
- overflow:
- seq_puts(seq, " ...\n");
- }
- spin_unlock_irq(&css_set_lock);
- return 0;
-}
-
-static u64 releasable_read(struct cgroup_subsys_state *css, struct cftype *cft)
-{
- return (!cgroup_is_populated(css->cgroup) &&
- !css_has_online_children(&css->cgroup->self));
-}
-
-static struct cftype debug_files[] = {
- {
- .name = "taskcount",
- .read_u64 = debug_taskcount_read,
- },
-
- {
- .name = "current_css_set",
- .read_u64 = current_css_set_read,
- },
-
- {
- .name = "current_css_set_refcount",
- .read_u64 = current_css_set_refcount_read,
- },
-
- {
- .name = "current_css_set_cg_links",
- .seq_show = current_css_set_cg_links_read,
- },
-
- {
- .name = "cgroup_css_links",
- .seq_show = cgroup_css_links_read,
- },
-
- {
- .name = "releasable",
- .read_u64 = releasable_read,
- },
-
- { } /* terminate */
-};
-
-struct cgroup_subsys debug_cgrp_subsys = {
- .css_alloc = debug_css_alloc,
- .css_free = debug_css_free,
- .legacy_cftypes = debug_files,
-};
-#endif /* CONFIG_CGROUP_DEBUG */
diff --git a/kernel/cpuset.c b/kernel/cgroup/cpuset.c
index b3088886cd37..b3088886cd37 100644
--- a/kernel/cpuset.c
+++ b/kernel/cgroup/cpuset.c
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup/freezer.c
index 1b72d56edce5..1b72d56edce5 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup/freezer.c
diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c
new file mode 100644
index 000000000000..cff7ea62c38f
--- /dev/null
+++ b/kernel/cgroup/namespace.c
@@ -0,0 +1,155 @@
+#include "cgroup-internal.h"
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/nsproxy.h>
+#include <linux/proc_ns.h>
+
+
+/* cgroup namespaces */
+
+static struct ucounts *inc_cgroup_namespaces(struct user_namespace *ns)
+{
+ return inc_ucount(ns, current_euid(), UCOUNT_CGROUP_NAMESPACES);
+}
+
+static void dec_cgroup_namespaces(struct ucounts *ucounts)
+{
+ dec_ucount(ucounts, UCOUNT_CGROUP_NAMESPACES);
+}
+
+static struct cgroup_namespace *alloc_cgroup_ns(void)
+{
+ struct cgroup_namespace *new_ns;
+ int ret;
+
+ new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL);
+ if (!new_ns)
+ return ERR_PTR(-ENOMEM);
+ ret = ns_alloc_inum(&new_ns->ns);
+ if (ret) {
+ kfree(new_ns);
+ return ERR_PTR(ret);
+ }
+ atomic_set(&new_ns->count, 1);
+ new_ns->ns.ops = &cgroupns_operations;
+ return new_ns;
+}
+
+void free_cgroup_ns(struct cgroup_namespace *ns)
+{
+ put_css_set(ns->root_cset);
+ dec_cgroup_namespaces(ns->ucounts);
+ put_user_ns(ns->user_ns);
+ ns_free_inum(&ns->ns);
+ kfree(ns);
+}
+EXPORT_SYMBOL(free_cgroup_ns);
+
+struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
+ struct user_namespace *user_ns,
+ struct cgroup_namespace *old_ns)
+{
+ struct cgroup_namespace *new_ns;
+ struct ucounts *ucounts;
+ struct css_set *cset;
+
+ BUG_ON(!old_ns);
+
+ if (!(flags & CLONE_NEWCGROUP)) {
+ get_cgroup_ns(old_ns);
+ return old_ns;
+ }
+
+ /* Allow only sysadmin to create cgroup namespace. */
+ if (!ns_capable(user_ns, CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ ucounts = inc_cgroup_namespaces(user_ns);
+ if (!ucounts)
+ return ERR_PTR(-ENOSPC);
+
+ /* It is not safe to take cgroup_mutex here */
+ spin_lock_irq(&css_set_lock);
+ cset = task_css_set(current);
+ get_css_set(cset);
+ spin_unlock_irq(&css_set_lock);
+
+ new_ns = alloc_cgroup_ns();
+ if (IS_ERR(new_ns)) {
+ put_css_set(cset);
+ dec_cgroup_namespaces(ucounts);
+ return new_ns;
+ }
+
+ new_ns->user_ns = get_user_ns(user_ns);
+ new_ns->ucounts = ucounts;
+ new_ns->root_cset = cset;
+
+ return new_ns;
+}
+
+static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns)
+{
+ return container_of(ns, struct cgroup_namespace, ns);
+}
+
+static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns)
+{
+ struct cgroup_namespace *cgroup_ns = to_cg_ns(ns);
+
+ if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) ||
+ !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* Don't need to do anything if we are attaching to our own cgroupns. */
+ if (cgroup_ns == nsproxy->cgroup_ns)
+ return 0;
+
+ get_cgroup_ns(cgroup_ns);
+ put_cgroup_ns(nsproxy->cgroup_ns);
+ nsproxy->cgroup_ns = cgroup_ns;
+
+ return 0;
+}
+
+static struct ns_common *cgroupns_get(struct task_struct *task)
+{
+ struct cgroup_namespace *ns = NULL;
+ struct nsproxy *nsproxy;
+
+ task_lock(task);
+ nsproxy = task->nsproxy;
+ if (nsproxy) {
+ ns = nsproxy->cgroup_ns;
+ get_cgroup_ns(ns);
+ }
+ task_unlock(task);
+
+ return ns ? &ns->ns : NULL;
+}
+
+static void cgroupns_put(struct ns_common *ns)
+{
+ put_cgroup_ns(to_cg_ns(ns));
+}
+
+static struct user_namespace *cgroupns_owner(struct ns_common *ns)
+{
+ return to_cg_ns(ns)->user_ns;
+}
+
+const struct proc_ns_operations cgroupns_operations = {
+ .name = "cgroup",
+ .type = CLONE_NEWCGROUP,
+ .get = cgroupns_get,
+ .put = cgroupns_put,
+ .install = cgroupns_install,
+ .owner = cgroupns_owner,
+};
+
+static __init int cgroup_namespaces_init(void)
+{
+ return 0;
+}
+subsys_initcall(cgroup_namespaces_init);
diff --git a/kernel/cgroup_pids.c b/kernel/cgroup/pids.c
index 2bd673783f1a..2bd673783f1a 100644
--- a/kernel/cgroup_pids.c
+++ b/kernel/cgroup/pids.c
diff --git a/kernel/cgroup/rdma.c b/kernel/cgroup/rdma.c
new file mode 100644
index 000000000000..defad3c5e7dc
--- /dev/null
+++ b/kernel/cgroup/rdma.c
@@ -0,0 +1,619 @@
+/*
+ * RDMA resource limiting controller for cgroups.
+ *
+ * Used to allow a cgroup hierarchy to stop processes from consuming
+ * additional RDMA resources after a certain limit is reached.
+ *
+ * Copyright (C) 2016 Parav Pandit <pandit.parav@gmail.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of the GNU
+ * General Public License. See the file COPYING in the main directory of the
+ * Linux distribution for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/cgroup.h>
+#include <linux/parser.h>
+#include <linux/cgroup_rdma.h>
+
+#define RDMACG_MAX_STR "max"
+
+/*
+ * Protects list of resource pools maintained on per cgroup basis
+ * and rdma device list.
+ */
+static DEFINE_MUTEX(rdmacg_mutex);
+static LIST_HEAD(rdmacg_devices);
+
+enum rdmacg_file_type {
+ RDMACG_RESOURCE_TYPE_MAX,
+ RDMACG_RESOURCE_TYPE_STAT,
+};
+
+/*
+ * resource table definition as to be seen by the user.
+ * Need to add entries to it when more resources are
+ * added/defined at IB verb/core layer.
+ */
+static char const *rdmacg_resource_names[] = {
+ [RDMACG_RESOURCE_HCA_HANDLE] = "hca_handle",
+ [RDMACG_RESOURCE_HCA_OBJECT] = "hca_object",
+};
+
+/* resource tracker for each resource of rdma cgroup */
+struct rdmacg_resource {
+ int max;
+ int usage;
+};
+
+/*
+ * resource pool object which represents per cgroup, per device
+ * resources. There are multiple instances of this object per cgroup,
+ * therefore it cannot be embedded within rdma_cgroup structure. It
+ * is maintained as list.
+ */
+struct rdmacg_resource_pool {
+ struct rdmacg_device *device;
+ struct rdmacg_resource resources[RDMACG_RESOURCE_MAX];
+
+ struct list_head cg_node;
+ struct list_head dev_node;
+
+ /* count active user tasks of this pool */
+ u64 usage_sum;
+ /* total number counts which are set to max */
+ int num_max_cnt;
+};
+
+static struct rdma_cgroup *css_rdmacg(struct cgroup_subsys_state *css)
+{
+ return container_of(css, struct rdma_cgroup, css);
+}
+
+static struct rdma_cgroup *parent_rdmacg(struct rdma_cgroup *cg)
+{
+ return css_rdmacg(cg->css.parent);
+}
+
+static inline struct rdma_cgroup *get_current_rdmacg(void)
+{
+ return css_rdmacg(task_get_css(current, rdma_cgrp_id));
+}
+
+static void set_resource_limit(struct rdmacg_resource_pool *rpool,
+ int index, int new_max)
+{
+ if (new_max == S32_MAX) {
+ if (rpool->resources[index].max != S32_MAX)
+ rpool->num_max_cnt++;
+ } else {
+ if (rpool->resources[index].max == S32_MAX)
+ rpool->num_max_cnt--;
+ }
+ rpool->resources[index].max = new_max;
+}
+
+static void set_all_resource_max_limit(struct rdmacg_resource_pool *rpool)
+{
+ int i;
+
+ for (i = 0; i < RDMACG_RESOURCE_MAX; i++)
+ set_resource_limit(rpool, i, S32_MAX);
+}
+
+static void free_cg_rpool_locked(struct rdmacg_resource_pool *rpool)
+{
+ lockdep_assert_held(&rdmacg_mutex);
+
+ list_del(&rpool->cg_node);
+ list_del(&rpool->dev_node);
+ kfree(rpool);
+}
+
+static struct rdmacg_resource_pool *
+find_cg_rpool_locked(struct rdma_cgroup *cg,
+ struct rdmacg_device *device)
+
+{
+ struct rdmacg_resource_pool *pool;
+
+ lockdep_assert_held(&rdmacg_mutex);
+
+ list_for_each_entry(pool, &cg->rpools, cg_node)
+ if (pool->device == device)
+ return pool;
+
+ return NULL;
+}
+
+static struct rdmacg_resource_pool *
+get_cg_rpool_locked(struct rdma_cgroup *cg, struct rdmacg_device *device)
+{
+ struct rdmacg_resource_pool *rpool;
+
+ rpool = find_cg_rpool_locked(cg, device);
+ if (rpool)
+ return rpool;
+
+ rpool = kzalloc(sizeof(*rpool), GFP_KERNEL);
+ if (!rpool)
+ return ERR_PTR(-ENOMEM);
+
+ rpool->device = device;
+ set_all_resource_max_limit(rpool);
+
+ INIT_LIST_HEAD(&rpool->cg_node);
+ INIT_LIST_HEAD(&rpool->dev_node);
+ list_add_tail(&rpool->cg_node, &cg->rpools);
+ list_add_tail(&rpool->dev_node, &device->rpools);
+ return rpool;
+}
+
+/**
+ * uncharge_cg_locked - uncharge resource for rdma cgroup
+ * @cg: pointer to cg to uncharge and all parents in hierarchy
+ * @device: pointer to rdmacg device
+ * @index: index of the resource to uncharge in cg (resource pool)
+ *
+ * It also frees the resource pool which was created as part of
+ * charging operation when there are no resources attached to
+ * resource pool.
+ */
+static void
+uncharge_cg_locked(struct rdma_cgroup *cg,
+ struct rdmacg_device *device,
+ enum rdmacg_resource_type index)
+{
+ struct rdmacg_resource_pool *rpool;
+
+ rpool = find_cg_rpool_locked(cg, device);
+
+ /*
+ * rpool cannot be null at this stage. Let kernel operate in case
+ * if there a bug in IB stack or rdma controller, instead of crashing
+ * the system.
+ */
+ if (unlikely(!rpool)) {
+ pr_warn("Invalid device %p or rdma cgroup %p\n", cg, device);
+ return;
+ }
+
+ rpool->resources[index].usage--;
+
+ /*
+ * A negative count (or overflow) is invalid,
+ * it indicates a bug in the rdma controller.
+ */
+ WARN_ON_ONCE(rpool->resources[index].usage < 0);
+ rpool->usage_sum--;
+ if (rpool->usage_sum == 0 &&
+ rpool->num_max_cnt == RDMACG_RESOURCE_MAX) {
+ /*
+ * No user of the rpool and all entries are set to max, so
+ * safe to delete this rpool.
+ */
+ free_cg_rpool_locked(rpool);
+ }
+}
+
+/**
+ * rdmacg_uncharge_hierarchy - hierarchically uncharge rdma resource count
+ * @device: pointer to rdmacg device
+ * @stop_cg: while traversing hirerchy, when meet with stop_cg cgroup
+ * stop uncharging
+ * @index: index of the resource to uncharge in cg in given resource pool
+ */
+static void rdmacg_uncharge_hierarchy(struct rdma_cgroup *cg,
+ struct rdmacg_device *device,
+ struct rdma_cgroup *stop_cg,
+ enum rdmacg_resource_type index)
+{
+ struct rdma_cgroup *p;
+
+ mutex_lock(&rdmacg_mutex);
+
+ for (p = cg; p != stop_cg; p = parent_rdmacg(p))
+ uncharge_cg_locked(p, device, index);
+
+ mutex_unlock(&rdmacg_mutex);
+
+ css_put(&cg->css);
+}
+
+/**
+ * rdmacg_uncharge - hierarchically uncharge rdma resource count
+ * @device: pointer to rdmacg device
+ * @index: index of the resource to uncharge in cgroup in given resource pool
+ */
+void rdmacg_uncharge(struct rdma_cgroup *cg,
+ struct rdmacg_device *device,
+ enum rdmacg_resource_type index)
+{
+ if (index >= RDMACG_RESOURCE_MAX)
+ return;
+
+ rdmacg_uncharge_hierarchy(cg, device, NULL, index);
+}
+EXPORT_SYMBOL(rdmacg_uncharge);
+
+/**
+ * rdmacg_try_charge - hierarchically try to charge the rdma resource
+ * @rdmacg: pointer to rdma cgroup which will own this resource
+ * @device: pointer to rdmacg device
+ * @index: index of the resource to charge in cgroup (resource pool)
+ *
+ * This function follows charging resource in hierarchical way.
+ * It will fail if the charge would cause the new value to exceed the
+ * hierarchical limit.
+ * Returns 0 if the charge succeded, otherwise -EAGAIN, -ENOMEM or -EINVAL.
+ * Returns pointer to rdmacg for this resource when charging is successful.
+ *
+ * Charger needs to account resources on two criteria.
+ * (a) per cgroup & (b) per device resource usage.
+ * Per cgroup resource usage ensures that tasks of cgroup doesn't cross
+ * the configured limits. Per device provides granular configuration
+ * in multi device usage. It allocates resource pool in the hierarchy
+ * for each parent it come across for first resource. Later on resource
+ * pool will be available. Therefore it will be much faster thereon
+ * to charge/uncharge.
+ */
+int rdmacg_try_charge(struct rdma_cgroup **rdmacg,
+ struct rdmacg_device *device,
+ enum rdmacg_resource_type index)
+{
+ struct rdma_cgroup *cg, *p;
+ struct rdmacg_resource_pool *rpool;
+ s64 new;
+ int ret = 0;
+
+ if (index >= RDMACG_RESOURCE_MAX)
+ return -EINVAL;
+
+ /*
+ * hold on to css, as cgroup can be removed but resource
+ * accounting happens on css.
+ */
+ cg = get_current_rdmacg();
+
+ mutex_lock(&rdmacg_mutex);
+ for (p = cg; p; p = parent_rdmacg(p)) {
+ rpool = get_cg_rpool_locked(p, device);
+ if (IS_ERR(rpool)) {
+ ret = PTR_ERR(rpool);
+ goto err;
+ } else {
+ new = rpool->resources[index].usage + 1;
+ if (new > rpool->resources[index].max) {
+ ret = -EAGAIN;
+ goto err;
+ } else {
+ rpool->resources[index].usage = new;
+ rpool->usage_sum++;
+ }
+ }
+ }
+ mutex_unlock(&rdmacg_mutex);
+
+ *rdmacg = cg;
+ return 0;
+
+err:
+ mutex_unlock(&rdmacg_mutex);
+ rdmacg_uncharge_hierarchy(cg, device, p, index);
+ return ret;
+}
+EXPORT_SYMBOL(rdmacg_try_charge);
+
+/**
+ * rdmacg_register_device - register rdmacg device to rdma controller.
+ * @device: pointer to rdmacg device whose resources need to be accounted.
+ *
+ * If IB stack wish a device to participate in rdma cgroup resource
+ * tracking, it must invoke this API to register with rdma cgroup before
+ * any user space application can start using the RDMA resources.
+ * Returns 0 on success or EINVAL when table length given is beyond
+ * supported size.
+ */
+int rdmacg_register_device(struct rdmacg_device *device)
+{
+ INIT_LIST_HEAD(&device->dev_node);
+ INIT_LIST_HEAD(&device->rpools);
+
+ mutex_lock(&rdmacg_mutex);
+ list_add_tail(&device->dev_node, &rdmacg_devices);
+ mutex_unlock(&rdmacg_mutex);
+ return 0;
+}
+EXPORT_SYMBOL(rdmacg_register_device);
+
+/**
+ * rdmacg_unregister_device - unregister rdmacg device from rdma controller.
+ * @device: pointer to rdmacg device which was previously registered with rdma
+ * controller using rdmacg_register_device().
+ *
+ * IB stack must invoke this after all the resources of the IB device
+ * are destroyed and after ensuring that no more resources will be created
+ * when this API is invoked.
+ */
+void rdmacg_unregister_device(struct rdmacg_device *device)
+{
+ struct rdmacg_resource_pool *rpool, *tmp;
+
+ /*
+ * Synchronize with any active resource settings,
+ * usage query happening via configfs.
+ */
+ mutex_lock(&rdmacg_mutex);
+ list_del_init(&device->dev_node);
+
+ /*
+ * Now that this device is off the cgroup list, its safe to free
+ * all the rpool resources.
+ */
+ list_for_each_entry_safe(rpool, tmp, &device->rpools, dev_node)
+ free_cg_rpool_locked(rpool);
+
+ mutex_unlock(&rdmacg_mutex);
+}
+EXPORT_SYMBOL(rdmacg_unregister_device);
+
+static int parse_resource(char *c, int *intval)
+{
+ substring_t argstr;
+ const char **table = &rdmacg_resource_names[0];
+ char *name, *value = c;
+ size_t len;
+ int ret, i = 0;
+
+ name = strsep(&value, "=");
+ if (!name || !value)
+ return -EINVAL;
+
+ len = strlen(value);
+
+ for (i = 0; i < RDMACG_RESOURCE_MAX; i++) {
+ if (strcmp(table[i], name))
+ continue;
+
+ argstr.from = value;
+ argstr.to = value + len;
+
+ ret = match_int(&argstr, intval);
+ if (ret >= 0) {
+ if (*intval < 0)
+ break;
+ return i;
+ }
+ if (strncmp(value, RDMACG_MAX_STR, len) == 0) {
+ *intval = S32_MAX;
+ return i;
+ }
+ break;
+ }
+ return -EINVAL;
+}
+
+static int rdmacg_parse_limits(char *options,
+ int *new_limits, unsigned long *enables)
+{
+ char *c;
+ int err = -EINVAL;
+
+ /* parse resource options */
+ while ((c = strsep(&options, " ")) != NULL) {
+ int index, intval;
+
+ index = parse_resource(c, &intval);
+ if (index < 0)
+ goto err;
+
+ new_limits[index] = intval;
+ *enables |= BIT(index);
+ }
+ return 0;
+
+err:
+ return err;
+}
+
+static struct rdmacg_device *rdmacg_get_device_locked(const char *name)
+{
+ struct rdmacg_device *device;
+
+ lockdep_assert_held(&rdmacg_mutex);
+
+ list_for_each_entry(device, &rdmacg_devices, dev_node)
+ if (!strcmp(name, device->name))
+ return device;
+
+ return NULL;
+}
+
+static ssize_t rdmacg_resource_set_max(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdma_cgroup *cg = css_rdmacg(of_css(of));
+ const char *dev_name;
+ struct rdmacg_resource_pool *rpool;
+ struct rdmacg_device *device;
+ char *options = strstrip(buf);
+ int *new_limits;
+ unsigned long enables = 0;
+ int i = 0, ret = 0;
+
+ /* extract the device name first */
+ dev_name = strsep(&options, " ");
+ if (!dev_name) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ new_limits = kcalloc(RDMACG_RESOURCE_MAX, sizeof(int), GFP_KERNEL);
+ if (!new_limits) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ ret = rdmacg_parse_limits(options, new_limits, &enables);
+ if (ret)
+ goto parse_err;
+
+ /* acquire lock to synchronize with hot plug devices */
+ mutex_lock(&rdmacg_mutex);
+
+ device = rdmacg_get_device_locked(dev_name);
+ if (!device) {
+ ret = -ENODEV;
+ goto dev_err;
+ }
+
+ rpool = get_cg_rpool_locked(cg, device);
+ if (IS_ERR(rpool)) {
+ ret = PTR_ERR(rpool);
+ goto dev_err;
+ }
+
+ /* now set the new limits of the rpool */
+ for_each_set_bit(i, &enables, RDMACG_RESOURCE_MAX)
+ set_resource_limit(rpool, i, new_limits[i]);
+
+ if (rpool->usage_sum == 0 &&
+ rpool->num_max_cnt == RDMACG_RESOURCE_MAX) {
+ /*
+ * No user of the rpool and all entries are set to max, so
+ * safe to delete this rpool.
+ */
+ free_cg_rpool_locked(rpool);
+ }
+
+dev_err:
+ mutex_unlock(&rdmacg_mutex);
+
+parse_err:
+ kfree(new_limits);
+
+err:
+ return ret ?: nbytes;
+}
+
+static void print_rpool_values(struct seq_file *sf,
+ struct rdmacg_resource_pool *rpool)
+{
+ enum rdmacg_file_type sf_type;
+ int i;
+ u32 value;
+
+ sf_type = seq_cft(sf)->private;
+
+ for (i = 0; i < RDMACG_RESOURCE_MAX; i++) {
+ seq_puts(sf, rdmacg_resource_names[i]);
+ seq_putc(sf, '=');
+ if (sf_type == RDMACG_RESOURCE_TYPE_MAX) {
+ if (rpool)
+ value = rpool->resources[i].max;
+ else
+ value = S32_MAX;
+ } else {
+ if (rpool)
+ value = rpool->resources[i].usage;
+ else
+ value = 0;
+ }
+
+ if (value == S32_MAX)
+ seq_puts(sf, RDMACG_MAX_STR);
+ else
+ seq_printf(sf, "%d", value);
+ seq_putc(sf, ' ');
+ }
+}
+
+static int rdmacg_resource_read(struct seq_file *sf, void *v)
+{
+ struct rdmacg_device *device;
+ struct rdmacg_resource_pool *rpool;
+ struct rdma_cgroup *cg = css_rdmacg(seq_css(sf));
+
+ mutex_lock(&rdmacg_mutex);
+
+ list_for_each_entry(device, &rdmacg_devices, dev_node) {
+ seq_printf(sf, "%s ", device->name);
+
+ rpool = find_cg_rpool_locked(cg, device);
+ print_rpool_values(sf, rpool);
+
+ seq_putc(sf, '\n');
+ }
+
+ mutex_unlock(&rdmacg_mutex);
+ return 0;
+}
+
+static struct cftype rdmacg_files[] = {
+ {
+ .name = "max",
+ .write = rdmacg_resource_set_max,
+ .seq_show = rdmacg_resource_read,
+ .private = RDMACG_RESOURCE_TYPE_MAX,
+ .flags = CFTYPE_NOT_ON_ROOT,
+ },
+ {
+ .name = "current",
+ .seq_show = rdmacg_resource_read,
+ .private = RDMACG_RESOURCE_TYPE_STAT,
+ .flags = CFTYPE_NOT_ON_ROOT,
+ },
+ { } /* terminate */
+};
+
+static struct cgroup_subsys_state *
+rdmacg_css_alloc(struct cgroup_subsys_state *parent)
+{
+ struct rdma_cgroup *cg;
+
+ cg = kzalloc(sizeof(*cg), GFP_KERNEL);
+ if (!cg)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&cg->rpools);
+ return &cg->css;
+}
+
+static void rdmacg_css_free(struct cgroup_subsys_state *css)
+{
+ struct rdma_cgroup *cg = css_rdmacg(css);
+
+ kfree(cg);
+}
+
+/**
+ * rdmacg_css_offline - cgroup css_offline callback
+ * @css: css of interest
+ *
+ * This function is called when @css is about to go away and responsible
+ * for shooting down all rdmacg associated with @css. As part of that it
+ * marks all the resource pool entries to max value, so that when resources are
+ * uncharged, associated resource pool can be freed as well.
+ */
+static void rdmacg_css_offline(struct cgroup_subsys_state *css)
+{
+ struct rdma_cgroup *cg = css_rdmacg(css);
+ struct rdmacg_resource_pool *rpool;
+
+ mutex_lock(&rdmacg_mutex);
+
+ list_for_each_entry(rpool, &cg->rpools, cg_node)
+ set_all_resource_max_limit(rpool);
+
+ mutex_unlock(&rdmacg_mutex);
+}
+
+struct cgroup_subsys rdma_cgrp_subsys = {
+ .css_alloc = rdmacg_css_alloc,
+ .css_free = rdmacg_css_free,
+ .css_offline = rdmacg_css_offline,
+ .legacy_cftypes = rdmacg_files,
+ .dfl_cftypes = rdmacg_files,
+};
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b2eb3542e829..5b4e0b98f4eb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10959,5 +10959,11 @@ struct cgroup_subsys perf_event_cgrp_subsys = {
.css_alloc = perf_cgroup_css_alloc,
.css_free = perf_cgroup_css_free,
.attach = perf_cgroup_attach,
+ /*
+ * Implicitly enable on dfl hierarchy so that perf events can
+ * always be filtered by cgroup2 path as long as perf_event
+ * controller is not mounted on a legacy hierarchy.
+ */
+ .implicit_on_dfl = true,
};
#endif /* CONFIG_CGROUP_PERF */