forked from luck/tmp_suning_uos_patched
Task Control Groups: automatic userspace notification of idle cgroups
Add the following files to the cgroup filesystem: notify_on_release - configures/reports whether the cgroup subsystem should attempt to run a release script when this cgroup becomes unused release_agent - configures/reports the release agent to be used for this hierarchy (top level in each hierarchy only) releasable - reports whether this cgroup would have been auto-released if notify_on_release was true and a release agent was configured (mainly useful for debugging) To avoid locking issues, invoking the userspace release agent is done via a workqueue task; cgroups that need to have their release agents invoked by the workqueue task are linked on to a list. [pj@sgi.com: Need to include kmod.h] Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
817929ec27
commit
81a6a5cdd2
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@ -77,10 +77,11 @@ static inline void css_get(struct cgroup_subsys_state *css)
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* css_get()
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*/
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extern void __css_put(struct cgroup_subsys_state *css);
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static inline void css_put(struct cgroup_subsys_state *css)
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{
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if (!test_bit(CSS_ROOT, &css->flags))
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atomic_dec(&css->refcnt);
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__css_put(css);
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}
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struct cgroup {
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@ -112,6 +113,13 @@ struct cgroup {
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* tasks in this cgroup. Protected by css_set_lock
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*/
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struct list_head css_sets;
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/*
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* Linked list running through all cgroups that can
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* potentially be reaped by the release agent. Protected by
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* release_list_lock
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*/
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struct list_head release_list;
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};
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/* A css_set is a structure holding pointers to a set of
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@ -293,7 +301,6 @@ struct task_struct *cgroup_iter_next(struct cgroup *cont,
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struct cgroup_iter *it);
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void cgroup_iter_end(struct cgroup *cont, struct cgroup_iter *it);
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#else /* !CONFIG_CGROUPS */
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static inline int cgroup_init_early(void) { return 0; }
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400
kernel/cgroup.c
400
kernel/cgroup.c
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@ -43,8 +43,11 @@
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/sort.h>
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#include <linux/kmod.h>
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#include <asm/atomic.h>
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static DEFINE_MUTEX(cgroup_mutex);
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/* Generate an array of cgroup subsystem pointers */
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#define SUBSYS(_x) &_x ## _subsys,
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@ -83,6 +86,13 @@ struct cgroupfs_root {
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/* Hierarchy-specific flags */
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unsigned long flags;
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/* The path to use for release notifications. No locking
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* between setting and use - so if userspace updates this
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* while child cgroups exist, you could miss a
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* notification. We ensure that it's always a valid
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* NUL-terminated string */
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char release_agent_path[PATH_MAX];
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};
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@ -110,7 +120,13 @@ static int need_forkexit_callback;
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/* bits in struct cgroup flags field */
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enum {
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/* Control Group is dead */
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CONT_REMOVED,
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/* Control Group has previously had a child cgroup or a task,
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* but no longer (only if CONT_NOTIFY_ON_RELEASE is set) */
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CONT_RELEASABLE,
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/* Control Group requires release notifications to userspace */
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CONT_NOTIFY_ON_RELEASE,
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};
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/* convenient tests for these bits */
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@ -124,6 +140,19 @@ enum {
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ROOT_NOPREFIX, /* mounted subsystems have no named prefix */
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};
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inline int cgroup_is_releasable(const struct cgroup *cont)
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{
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const int bits =
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(1 << CONT_RELEASABLE) |
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(1 << CONT_NOTIFY_ON_RELEASE);
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return (cont->flags & bits) == bits;
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}
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inline int notify_on_release(const struct cgroup *cont)
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{
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return test_bit(CONT_NOTIFY_ON_RELEASE, &cont->flags);
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}
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/*
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* for_each_subsys() allows you to iterate on each subsystem attached to
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* an active hierarchy
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@ -135,6 +164,14 @@ list_for_each_entry(_ss, &_root->subsys_list, sibling)
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#define for_each_root(_root) \
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list_for_each_entry(_root, &roots, root_list)
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/* the list of cgroups eligible for automatic release. Protected by
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* release_list_lock */
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static LIST_HEAD(release_list);
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static DEFINE_SPINLOCK(release_list_lock);
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static void cgroup_release_agent(struct work_struct *work);
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static DECLARE_WORK(release_agent_work, cgroup_release_agent);
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static void check_for_release(struct cgroup *cont);
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/* Link structure for associating css_set objects with cgroups */
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struct cg_cgroup_link {
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/*
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@ -189,11 +226,8 @@ static int use_task_css_set_links;
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/*
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* unlink a css_set from the list and free it
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*/
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static void release_css_set(struct kref *k)
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static void unlink_css_set(struct css_set *cg)
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{
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struct css_set *cg = container_of(k, struct css_set, ref);
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int i;
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write_lock(&css_set_lock);
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list_del(&cg->list);
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css_set_count--;
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@ -206,11 +240,39 @@ static void release_css_set(struct kref *k)
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kfree(link);
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}
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write_unlock(&css_set_lock);
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for (i = 0; i < CGROUP_SUBSYS_COUNT; i++)
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atomic_dec(&cg->subsys[i]->cgroup->count);
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}
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static void __release_css_set(struct kref *k, int taskexit)
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{
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int i;
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struct css_set *cg = container_of(k, struct css_set, ref);
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unlink_css_set(cg);
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rcu_read_lock();
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for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
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struct cgroup *cont = cg->subsys[i]->cgroup;
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if (atomic_dec_and_test(&cont->count) &&
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notify_on_release(cont)) {
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if (taskexit)
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set_bit(CONT_RELEASABLE, &cont->flags);
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check_for_release(cont);
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}
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}
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rcu_read_unlock();
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kfree(cg);
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}
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static void release_css_set(struct kref *k)
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{
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__release_css_set(k, 0);
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}
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static void release_css_set_taskexit(struct kref *k)
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{
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__release_css_set(k, 1);
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}
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/*
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* refcounted get/put for css_set objects
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*/
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@ -224,6 +286,11 @@ static inline void put_css_set(struct css_set *cg)
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kref_put(&cg->ref, release_css_set);
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}
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static inline void put_css_set_taskexit(struct css_set *cg)
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{
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kref_put(&cg->ref, release_css_set_taskexit);
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}
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/*
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* find_existing_css_set() is a helper for
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* find_css_set(), and checks to see whether an existing
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@ -465,8 +532,6 @@ static struct css_set *find_css_set(
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* update of a tasks cgroup pointer by attach_task()
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*/
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static DEFINE_MUTEX(cgroup_mutex);
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/**
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* cgroup_lock - lock out any changes to cgroup structures
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*
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@ -526,6 +591,13 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
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if (S_ISDIR(inode->i_mode)) {
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struct cgroup *cont = dentry->d_fsdata;
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BUG_ON(!(cgroup_is_removed(cont)));
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/* It's possible for external users to be holding css
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* reference counts on a cgroup; css_put() needs to
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* be able to access the cgroup after decrementing
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* the reference count in order to know if it needs to
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* queue the cgroup to be handled by the release
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* agent */
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synchronize_rcu();
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kfree(cont);
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}
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iput(inode);
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@ -657,6 +729,8 @@ static int cgroup_show_options(struct seq_file *seq, struct vfsmount *vfs)
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seq_printf(seq, ",%s", ss->name);
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if (test_bit(ROOT_NOPREFIX, &root->flags))
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seq_puts(seq, ",noprefix");
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if (strlen(root->release_agent_path))
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seq_printf(seq, ",release_agent=%s", root->release_agent_path);
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mutex_unlock(&cgroup_mutex);
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return 0;
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}
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@ -664,6 +738,7 @@ static int cgroup_show_options(struct seq_file *seq, struct vfsmount *vfs)
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struct cgroup_sb_opts {
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unsigned long subsys_bits;
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unsigned long flags;
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char *release_agent;
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};
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/* Convert a hierarchy specifier into a bitmask of subsystems and
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opts->subsys_bits = 0;
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opts->flags = 0;
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opts->release_agent = NULL;
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while ((token = strsep(&o, ",")) != NULL) {
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if (!*token)
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opts->subsys_bits = (1 << CGROUP_SUBSYS_COUNT) - 1;
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} else if (!strcmp(token, "noprefix")) {
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set_bit(ROOT_NOPREFIX, &opts->flags);
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} else if (!strncmp(token, "release_agent=", 14)) {
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/* Specifying two release agents is forbidden */
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if (opts->release_agent)
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return -EINVAL;
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opts->release_agent = kzalloc(PATH_MAX, GFP_KERNEL);
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if (!opts->release_agent)
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return -ENOMEM;
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strncpy(opts->release_agent, token + 14, PATH_MAX - 1);
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opts->release_agent[PATH_MAX - 1] = 0;
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} else {
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struct cgroup_subsys *ss;
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int i;
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if (!ret)
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cgroup_populate_dir(cont);
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if (opts.release_agent)
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strcpy(root->release_agent_path, opts.release_agent);
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out_unlock:
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if (opts.release_agent)
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kfree(opts.release_agent);
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mutex_unlock(&cgroup_mutex);
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mutex_unlock(&cont->dentry->d_inode->i_mutex);
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return ret;
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INIT_LIST_HEAD(&cont->sibling);
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INIT_LIST_HEAD(&cont->children);
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INIT_LIST_HEAD(&cont->css_sets);
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INIT_LIST_HEAD(&cont->release_list);
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}
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static int cgroup_test_super(struct super_block *sb, void *data)
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/* First find the desired set of subsystems */
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ret = parse_cgroupfs_options(data, &opts);
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if (ret)
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if (ret) {
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if (opts.release_agent)
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kfree(opts.release_agent);
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return ret;
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}
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root = kzalloc(sizeof(*root), GFP_KERNEL);
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if (!root)
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init_cgroup_root(root);
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root->subsys_bits = opts.subsys_bits;
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root->flags = opts.flags;
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if (opts.release_agent) {
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strcpy(root->release_agent_path, opts.release_agent);
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kfree(opts.release_agent);
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}
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sb = sget(fs_type, cgroup_test_super, cgroup_set_super, root);
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@ -1120,7 +1217,7 @@ static int attach_task(struct cgroup *cont, struct task_struct *tsk)
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ss->attach(ss, cont, oldcont, tsk);
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}
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}
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set_bit(CONT_RELEASABLE, &oldcont->flags);
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synchronize_rcu();
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put_css_set(cg);
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return 0;
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@ -1170,6 +1267,9 @@ enum cgroup_filetype {
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FILE_ROOT,
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FILE_DIR,
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FILE_TASKLIST,
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FILE_NOTIFY_ON_RELEASE,
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FILE_RELEASABLE,
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FILE_RELEASE_AGENT,
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};
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static ssize_t cgroup_write_uint(struct cgroup *cont, struct cftype *cft,
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@ -1240,6 +1340,32 @@ static ssize_t cgroup_common_file_write(struct cgroup *cont,
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case FILE_TASKLIST:
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retval = attach_task_by_pid(cont, buffer);
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break;
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case FILE_NOTIFY_ON_RELEASE:
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clear_bit(CONT_RELEASABLE, &cont->flags);
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if (simple_strtoul(buffer, NULL, 10) != 0)
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set_bit(CONT_NOTIFY_ON_RELEASE, &cont->flags);
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else
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clear_bit(CONT_NOTIFY_ON_RELEASE, &cont->flags);
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break;
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case FILE_RELEASE_AGENT:
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{
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struct cgroupfs_root *root = cont->root;
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/* Strip trailing newline */
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if (nbytes && (buffer[nbytes-1] == '\n')) {
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buffer[nbytes-1] = 0;
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}
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if (nbytes < sizeof(root->release_agent_path)) {
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/* We never write anything other than '\0'
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* into the last char of release_agent_path,
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* so it always remains a NUL-terminated
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* string */
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strncpy(root->release_agent_path, buffer, nbytes);
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root->release_agent_path[nbytes] = 0;
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} else {
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retval = -ENOSPC;
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}
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break;
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}
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default:
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retval = -EINVAL;
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goto out2;
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@ -1281,6 +1407,49 @@ static ssize_t cgroup_read_uint(struct cgroup *cont, struct cftype *cft,
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return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
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}
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static ssize_t cgroup_common_file_read(struct cgroup *cont,
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struct cftype *cft,
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struct file *file,
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char __user *buf,
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size_t nbytes, loff_t *ppos)
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{
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enum cgroup_filetype type = cft->private;
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char *page;
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ssize_t retval = 0;
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char *s;
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if (!(page = (char *)__get_free_page(GFP_KERNEL)))
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return -ENOMEM;
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s = page;
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switch (type) {
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case FILE_RELEASE_AGENT:
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{
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struct cgroupfs_root *root;
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size_t n;
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mutex_lock(&cgroup_mutex);
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root = cont->root;
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n = strnlen(root->release_agent_path,
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sizeof(root->release_agent_path));
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n = min(n, (size_t) PAGE_SIZE);
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strncpy(s, root->release_agent_path, n);
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mutex_unlock(&cgroup_mutex);
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s += n;
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break;
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}
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default:
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retval = -EINVAL;
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goto out;
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}
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*s++ = '\n';
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retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page);
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out:
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free_page((unsigned long)page);
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return retval;
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}
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static ssize_t cgroup_file_read(struct file *file, char __user *buf,
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size_t nbytes, loff_t *ppos)
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{
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@ -1699,16 +1868,49 @@ static int cgroup_tasks_release(struct inode *unused_inode,
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return 0;
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}
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static u64 cgroup_read_notify_on_release(struct cgroup *cont,
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struct cftype *cft)
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{
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return notify_on_release(cont);
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}
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static u64 cgroup_read_releasable(struct cgroup *cont, struct cftype *cft)
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{
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return test_bit(CONT_RELEASABLE, &cont->flags);
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}
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/*
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* for the common functions, 'private' gives the type of file
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*/
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static struct cftype cft_tasks = {
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static struct cftype files[] = {
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{
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.name = "tasks",
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.open = cgroup_tasks_open,
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.read = cgroup_tasks_read,
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.write = cgroup_common_file_write,
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.release = cgroup_tasks_release,
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.private = FILE_TASKLIST,
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},
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{
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.name = "notify_on_release",
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.read_uint = cgroup_read_notify_on_release,
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.write = cgroup_common_file_write,
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.private = FILE_NOTIFY_ON_RELEASE,
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},
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{
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.name = "releasable",
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.read_uint = cgroup_read_releasable,
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.private = FILE_RELEASABLE,
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}
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};
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static struct cftype cft_release_agent = {
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.name = "release_agent",
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.read = cgroup_common_file_read,
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.write = cgroup_common_file_write,
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.private = FILE_RELEASE_AGENT,
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};
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|
||||
static int cgroup_populate_dir(struct cgroup *cont)
|
||||
|
@ -1719,10 +1921,15 @@ static int cgroup_populate_dir(struct cgroup *cont)
|
|||
/* First clear out any existing files */
|
||||
cgroup_clear_directory(cont->dentry);
|
||||
|
||||
err = cgroup_add_file(cont, NULL, &cft_tasks);
|
||||
err = cgroup_add_files(cont, NULL, files, ARRAY_SIZE(files));
|
||||
if (err < 0)
|
||||
return err;
|
||||
|
||||
if (cont == cont->top_cgroup) {
|
||||
if ((err = cgroup_add_file(cont, NULL, &cft_release_agent)) < 0)
|
||||
return err;
|
||||
}
|
||||
|
||||
for_each_subsys(cont->root, ss) {
|
||||
if (ss->populate && (err = ss->populate(ss, cont)) < 0)
|
||||
return err;
|
||||
|
@ -1779,6 +1986,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
|
|||
INIT_LIST_HEAD(&cont->sibling);
|
||||
INIT_LIST_HEAD(&cont->children);
|
||||
INIT_LIST_HEAD(&cont->css_sets);
|
||||
INIT_LIST_HEAD(&cont->release_list);
|
||||
|
||||
cont->parent = parent;
|
||||
cont->root = parent->root;
|
||||
|
@ -1840,6 +2048,38 @@ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode)
|
|||
return cgroup_create(c_parent, dentry, mode | S_IFDIR);
|
||||
}
|
||||
|
||||
static inline int cgroup_has_css_refs(struct cgroup *cont)
|
||||
{
|
||||
/* Check the reference count on each subsystem. Since we
|
||||
* already established that there are no tasks in the
|
||||
* cgroup, if the css refcount is also 0, then there should
|
||||
* be no outstanding references, so the subsystem is safe to
|
||||
* destroy. We scan across all subsystems rather than using
|
||||
* the per-hierarchy linked list of mounted subsystems since
|
||||
* we can be called via check_for_release() with no
|
||||
* synchronization other than RCU, and the subsystem linked
|
||||
* list isn't RCU-safe */
|
||||
int i;
|
||||
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
|
||||
struct cgroup_subsys *ss = subsys[i];
|
||||
struct cgroup_subsys_state *css;
|
||||
/* Skip subsystems not in this hierarchy */
|
||||
if (ss->root != cont->root)
|
||||
continue;
|
||||
css = cont->subsys[ss->subsys_id];
|
||||
/* When called from check_for_release() it's possible
|
||||
* that by this point the cgroup has been removed
|
||||
* and the css deleted. But a false-positive doesn't
|
||||
* matter, since it can only happen if the cgroup
|
||||
* has been deleted and hence no longer needs the
|
||||
* release agent to be called anyway. */
|
||||
if (css && atomic_read(&css->refcnt)) {
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
|
||||
{
|
||||
struct cgroup *cont = dentry->d_fsdata;
|
||||
|
@ -1848,7 +2088,6 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
|
|||
struct cgroup_subsys *ss;
|
||||
struct super_block *sb;
|
||||
struct cgroupfs_root *root;
|
||||
int css_busy = 0;
|
||||
|
||||
/* the vfs holds both inode->i_mutex already */
|
||||
|
||||
|
@ -1866,20 +2105,7 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
|
|||
root = cont->root;
|
||||
sb = root->sb;
|
||||
|
||||
/* Check the reference count on each subsystem. Since we
|
||||
* already established that there are no tasks in the
|
||||
* cgroup, if the css refcount is also 0, then there should
|
||||
* be no outstanding references, so the subsystem is safe to
|
||||
* destroy */
|
||||
for_each_subsys(root, ss) {
|
||||
struct cgroup_subsys_state *css;
|
||||
css = cont->subsys[ss->subsys_id];
|
||||
if (atomic_read(&css->refcnt)) {
|
||||
css_busy = 1;
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (css_busy) {
|
||||
if (cgroup_has_css_refs(cont)) {
|
||||
mutex_unlock(&cgroup_mutex);
|
||||
return -EBUSY;
|
||||
}
|
||||
|
@ -1889,7 +2115,11 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
|
|||
ss->destroy(ss, cont);
|
||||
}
|
||||
|
||||
spin_lock(&release_list_lock);
|
||||
set_bit(CONT_REMOVED, &cont->flags);
|
||||
if (!list_empty(&cont->release_list))
|
||||
list_del(&cont->release_list);
|
||||
spin_unlock(&release_list_lock);
|
||||
/* delete my sibling from parent->children */
|
||||
list_del(&cont->sibling);
|
||||
spin_lock(&cont->dentry->d_lock);
|
||||
|
@ -1901,6 +2131,9 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
|
|||
dput(d);
|
||||
root->number_of_cgroups--;
|
||||
|
||||
set_bit(CONT_RELEASABLE, &parent->flags);
|
||||
check_for_release(parent);
|
||||
|
||||
mutex_unlock(&cgroup_mutex);
|
||||
/* Drop the active superblock reference that we took when we
|
||||
* created the cgroup */
|
||||
|
@ -2263,7 +2496,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
|
|||
tsk->cgroups = &init_css_set;
|
||||
task_unlock(tsk);
|
||||
if (cg)
|
||||
put_css_set(cg);
|
||||
put_css_set_taskexit(cg);
|
||||
}
|
||||
|
||||
/**
|
||||
|
@ -2374,7 +2607,10 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys)
|
|||
|
||||
out_release:
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
|
||||
mutex_lock(&cgroup_mutex);
|
||||
put_css_set(cg);
|
||||
mutex_unlock(&cgroup_mutex);
|
||||
deactivate_super(parent->root->sb);
|
||||
return ret;
|
||||
}
|
||||
|
@ -2404,3 +2640,111 @@ int cgroup_is_descendant(const struct cgroup *cont)
|
|||
ret = (cont == target);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void check_for_release(struct cgroup *cont)
|
||||
{
|
||||
/* All of these checks rely on RCU to keep the cgroup
|
||||
* structure alive */
|
||||
if (cgroup_is_releasable(cont) && !atomic_read(&cont->count)
|
||||
&& list_empty(&cont->children) && !cgroup_has_css_refs(cont)) {
|
||||
/* Control Group is currently removeable. If it's not
|
||||
* already queued for a userspace notification, queue
|
||||
* it now */
|
||||
int need_schedule_work = 0;
|
||||
spin_lock(&release_list_lock);
|
||||
if (!cgroup_is_removed(cont) &&
|
||||
list_empty(&cont->release_list)) {
|
||||
list_add(&cont->release_list, &release_list);
|
||||
need_schedule_work = 1;
|
||||
}
|
||||
spin_unlock(&release_list_lock);
|
||||
if (need_schedule_work)
|
||||
schedule_work(&release_agent_work);
|
||||
}
|
||||
}
|
||||
|
||||
void __css_put(struct cgroup_subsys_state *css)
|
||||
{
|
||||
struct cgroup *cont = css->cgroup;
|
||||
rcu_read_lock();
|
||||
if (atomic_dec_and_test(&css->refcnt) && notify_on_release(cont)) {
|
||||
set_bit(CONT_RELEASABLE, &cont->flags);
|
||||
check_for_release(cont);
|
||||
}
|
||||
rcu_read_unlock();
|
||||
}
|
||||
|
||||
/*
|
||||
* 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)
|
||||
{
|
||||
BUG_ON(work != &release_agent_work);
|
||||
mutex_lock(&cgroup_mutex);
|
||||
spin_lock(&release_list_lock);
|
||||
while (!list_empty(&release_list)) {
|
||||
char *argv[3], *envp[3];
|
||||
int i;
|
||||
char *pathbuf;
|
||||
struct cgroup *cont = list_entry(release_list.next,
|
||||
struct cgroup,
|
||||
release_list);
|
||||
list_del_init(&cont->release_list);
|
||||
spin_unlock(&release_list_lock);
|
||||
pathbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
||||
if (!pathbuf) {
|
||||
spin_lock(&release_list_lock);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (cgroup_path(cont, pathbuf, PAGE_SIZE) < 0) {
|
||||
kfree(pathbuf);
|
||||
spin_lock(&release_list_lock);
|
||||
continue;
|
||||
}
|
||||
|
||||
i = 0;
|
||||
argv[i++] = cont->root->release_agent_path;
|
||||
argv[i++] = (char *)pathbuf;
|
||||
argv[i] = NULL;
|
||||
|
||||
i = 0;
|
||||
/* minimal command environment */
|
||||
envp[i++] = "HOME=/";
|
||||
envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
|
||||
envp[i] = NULL;
|
||||
|
||||
/* Drop the lock while we invoke the usermode helper,
|
||||
* since the exec could involve hitting disk and hence
|
||||
* be a slow process */
|
||||
mutex_unlock(&cgroup_mutex);
|
||||
call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
|
||||
kfree(pathbuf);
|
||||
mutex_lock(&cgroup_mutex);
|
||||
spin_lock(&release_list_lock);
|
||||
}
|
||||
spin_unlock(&release_list_lock);
|
||||
mutex_unlock(&cgroup_mutex);
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue
Block a user