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kernel/cgroup.c
127 KB
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/* |
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* Generic process-grouping system. * * Based originally on the cpuset system, extracted by Paul Menage * Copyright (C) 2006 Google, Inc * |
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* Notifications support * Copyright (C) 2009 Nokia Corporation * Author: Kirill A. Shutemov * |
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* Copyright notices from the original cpuset code: * -------------------------------------------------- * Copyright (C) 2003 BULL SA. * Copyright (C) 2004-2006 Silicon Graphics, Inc. * * Portions derived from Patrick Mochel's sysfs code. * sysfs is Copyright (c) 2001-3 Patrick Mochel * * 2003-10-10 Written by Simon Derr. * 2003-10-22 Updates by Stephen Hemminger. * 2004 May-July Rework by Paul Jackson. * --------------------------------------------------- * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of the Linux * distribution for more details. */ #include <linux/cgroup.h> |
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#include <linux/ctype.h> |
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#include <linux/errno.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/mm.h> #include <linux/mutex.h> #include <linux/mount.h> #include <linux/pagemap.h> |
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#include <linux/proc_fs.h> |
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#include <linux/rcupdate.h> #include <linux/sched.h> |
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#include <linux/backing-dev.h> |
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#include <linux/seq_file.h> #include <linux/slab.h> #include <linux/magic.h> #include <linux/spinlock.h> #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 <linux/module.h> |
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#include <linux/delayacct.h> #include <linux/cgroupstats.h> |
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#include <linux/hash.h> |
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#include <linux/namei.h> |
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#include <linux/smp_lock.h> |
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#include <linux/pid_namespace.h> |
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#include <linux/idr.h> |
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#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */ |
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#include <linux/eventfd.h> #include <linux/poll.h> |
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|
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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. At boot time, this is * populated up to CGROUP_BUILTIN_SUBSYS_COUNT, and modular subsystems are * registered after that. The mutable section of this array is protected by * cgroup_mutex. */ |
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#define SUBSYS(_x) &_x ## _subsys, |
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static struct cgroup_subsys *subsys[CGROUP_SUBSYS_COUNT] = { |
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#include <linux/cgroup_subsys.h> }; |
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#define MAX_CGROUP_ROOT_NAMELEN 64 |
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/* * A cgroupfs_root represents the root of a cgroup hierarchy, * and may be associated with a superblock to form an active * hierarchy */ struct cgroupfs_root { struct super_block *sb; /* * The bitmask of subsystems intended to be attached to this * hierarchy */ unsigned long subsys_bits; |
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/* Unique id for this hierarchy. */ int hierarchy_id; |
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/* The bitmask of subsystems currently attached to this hierarchy */ unsigned long actual_subsys_bits; /* A list running through the attached subsystems */ struct list_head subsys_list; /* The root cgroup for this hierarchy */ struct cgroup top_cgroup; /* Tracks how many cgroups are currently defined in hierarchy.*/ int number_of_cgroups; |
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/* A list running through the active hierarchies */ |
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struct list_head root_list; /* Hierarchy-specific flags */ unsigned long flags; |
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/* The path to use for release notifications. */ |
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char release_agent_path[PATH_MAX]; |
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/* The name for this hierarchy - may be empty */ char name[MAX_CGROUP_ROOT_NAMELEN]; |
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}; |
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/* * The "rootnode" hierarchy is the "dummy hierarchy", reserved for the * subsystems that are otherwise unattached - it never has more than a * single cgroup, and all tasks are part of that cgroup. */ static struct cgroupfs_root rootnode; |
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/* * CSS ID -- ID per subsys's Cgroup Subsys State(CSS). used only when * cgroup_subsys->use_id != 0. */ #define CSS_ID_MAX (65535) struct css_id { /* * The css to which this ID points. This pointer is set to valid value * after cgroup is populated. If cgroup is removed, this will be NULL. * This pointer is expected to be RCU-safe because destroy() * is called after synchronize_rcu(). But for safe use, css_is_removed() * css_tryget() should be used for avoiding race. */ struct cgroup_subsys_state *css; /* * ID of this css. */ unsigned short id; /* * Depth in hierarchy which this ID belongs to. */ unsigned short depth; /* * ID is freed by RCU. (and lookup routine is RCU safe.) */ struct rcu_head rcu_head; /* * Hierarchy of CSS ID belongs to. */ unsigned short stack[0]; /* Array of Length (depth+1) */ }; |
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/* * cgroup_event represents events which userspace want to recieve. */ struct cgroup_event { /* * Cgroup which the event belongs to. */ struct cgroup *cgrp; /* * Control file which the event associated. */ struct cftype *cft; /* * eventfd to signal userspace about the event. */ struct eventfd_ctx *eventfd; /* * Each of these stored in a list by the cgroup. */ struct list_head list; /* * All fields below needed to unregister event when * userspace closes eventfd. */ poll_table pt; wait_queue_head_t *wqh; wait_queue_t wait; struct work_struct remove; }; |
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/* The list of hierarchy roots */ static LIST_HEAD(roots); |
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static int root_count; |
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static DEFINE_IDA(hierarchy_ida); static int next_hierarchy_id; static DEFINE_SPINLOCK(hierarchy_id_lock); |
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/* dummytop is a shorthand for the dummy hierarchy's top cgroup */ #define dummytop (&rootnode.top_cgroup) /* This flag indicates whether tasks in the fork and exit paths should |
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* check for fork/exit handlers to call. This avoids us having to do * extra work in the fork/exit path if none of the subsystems need to * be called. |
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*/ |
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static int need_forkexit_callback __read_mostly; |
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#ifdef CONFIG_PROVE_LOCKING int cgroup_lock_is_held(void) { return lockdep_is_held(&cgroup_mutex); } #else /* #ifdef CONFIG_PROVE_LOCKING */ int cgroup_lock_is_held(void) { return mutex_is_locked(&cgroup_mutex); } #endif /* #else #ifdef CONFIG_PROVE_LOCKING */ EXPORT_SYMBOL_GPL(cgroup_lock_is_held); |
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/* convenient tests for these bits */ |
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inline int cgroup_is_removed(const struct cgroup *cgrp) |
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{ |
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return test_bit(CGRP_REMOVED, &cgrp->flags); |
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} /* bits in struct cgroupfs_root flags field */ enum { ROOT_NOPREFIX, /* mounted subsystems have no named prefix */ }; |
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static int cgroup_is_releasable(const struct cgroup *cgrp) |
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{ const int bits = |
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(1 << CGRP_RELEASABLE) | (1 << CGRP_NOTIFY_ON_RELEASE); return (cgrp->flags & bits) == bits; |
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} |
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static int notify_on_release(const struct cgroup *cgrp) |
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{ |
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return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); |
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} |
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/* * for_each_subsys() allows you to iterate on each subsystem attached to * an active hierarchy */ #define for_each_subsys(_root, _ss) \ list_for_each_entry(_ss, &_root->subsys_list, sibling) |
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/* for_each_active_root() allows you to iterate across the active hierarchies */ #define for_each_active_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 * release_list_lock */ static LIST_HEAD(release_list); static DEFINE_SPINLOCK(release_list_lock); static void cgroup_release_agent(struct work_struct *work); static DECLARE_WORK(release_agent_work, cgroup_release_agent); |
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static void check_for_release(struct cgroup *cgrp); |
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/* Link structure for associating css_set objects with cgroups */ struct cg_cgroup_link { /* * List running through cg_cgroup_links associated with a * cgroup, anchored on cgroup->css_sets */ |
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struct list_head cgrp_link_list; |
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struct cgroup *cgrp; |
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/* * List running through cg_cgroup_links pointing at a * single css_set object, anchored on css_set->cg_links */ struct list_head cg_link_list; struct css_set *cg; }; /* The default css_set - used by init and its children prior to any * hierarchies being mounted. It contains a pointer to the root state * for each subsystem. Also used to anchor the list of css_sets. Not * reference-counted, to improve performance when child cgroups * haven't been created. */ static struct css_set init_css_set; static struct cg_cgroup_link init_css_set_link; |
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static int cgroup_init_idr(struct cgroup_subsys *ss, struct cgroup_subsys_state *css); |
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|
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/* css_set_lock protects the list of css_set objects, and the * chain of tasks off each css_set. Nests outside task->alloc_lock * due to cgroup_iter_start() */ static DEFINE_RWLOCK(css_set_lock); static int css_set_count; |
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/* * hash table for cgroup groups. This improves the performance to find * an existing css_set. This hash doesn't (currently) take into * account cgroups in empty hierarchies. */ |
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#define CSS_SET_HASH_BITS 7 #define CSS_SET_TABLE_SIZE (1 << CSS_SET_HASH_BITS) static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE]; static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) { int i; int index; unsigned long tmp = 0UL; for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) tmp += (unsigned long)css[i]; tmp = (tmp >> 16) ^ tmp; index = hash_long(tmp, CSS_SET_HASH_BITS); return &css_set_table[index]; } |
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static void free_css_set_rcu(struct rcu_head *obj) { struct css_set *cg = container_of(obj, struct css_set, rcu_head); kfree(cg); } |
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/* We don't maintain the lists running through each css_set to its * task until after the first call to cgroup_iter_start(). This * reduces the fork()/exit() overhead for people who have cgroups * compiled into their kernel but not actually in use */ |
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static int use_task_css_set_links __read_mostly; |
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static void __put_css_set(struct css_set *cg, int taskexit) |
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{ |
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struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; |
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/* * 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(&cg->refcount, -1, 1)) return; write_lock(&css_set_lock); if (!atomic_dec_and_test(&cg->refcount)) { write_unlock(&css_set_lock); return; } |
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/* This css_set is dead. unlink it and release cgroup refcounts */ hlist_del(&cg->hlist); css_set_count--; list_for_each_entry_safe(link, saved_link, &cg->cg_links, cg_link_list) { struct cgroup *cgrp = link->cgrp; list_del(&link->cg_link_list); list_del(&link->cgrp_link_list); |
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if (atomic_dec_and_test(&cgrp->count) && notify_on_release(cgrp)) { |
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if (taskexit) |
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set_bit(CGRP_RELEASABLE, &cgrp->flags); check_for_release(cgrp); |
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} |
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kfree(link); |
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} |
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write_unlock(&css_set_lock); |
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call_rcu(&cg->rcu_head, free_css_set_rcu); |
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} |
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/* * refcounted get/put for css_set objects */ static inline void get_css_set(struct css_set *cg) { |
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atomic_inc(&cg->refcount); |
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} static inline void put_css_set(struct css_set *cg) { |
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__put_css_set(cg, 0); |
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} |
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static inline void put_css_set_taskexit(struct css_set *cg) { |
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__put_css_set(cg, 1); |
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} |
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/* |
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* compare_css_sets - helper function for find_existing_css_set(). * @cg: candidate css_set being tested * @old_cg: existing css_set for a task * @new_cgrp: cgroup that's being entered by the task * @template: desired set of css pointers in css_set (pre-calculated) * * Returns true if "cg" matches "old_cg" except for the hierarchy * which "new_cgrp" belongs to, for which it should match "new_cgrp". */ static bool compare_css_sets(struct css_set *cg, struct css_set *old_cg, struct cgroup *new_cgrp, struct cgroup_subsys_state *template[]) { struct list_head *l1, *l2; if (memcmp(template, cg->subsys, sizeof(cg->subsys))) { /* Not all subsystems matched */ return false; } /* * Compare cgroup pointers in order to distinguish between * different cgroups in heirarchies with no subsystems. We * could get by with just this check alone (and skip the * memcmp above) but on most setups the memcmp check will * avoid the need for this more expensive check on almost all * candidates. */ l1 = &cg->cg_links; l2 = &old_cg->cg_links; while (1) { struct cg_cgroup_link *cgl1, *cgl2; struct cgroup *cg1, *cg2; l1 = l1->next; l2 = l2->next; /* See if we reached the end - both lists are equal length. */ if (l1 == &cg->cg_links) { BUG_ON(l2 != &old_cg->cg_links); break; } else { BUG_ON(l2 == &old_cg->cg_links); } /* Locate the cgroups associated with these links. */ cgl1 = list_entry(l1, struct cg_cgroup_link, cg_link_list); cgl2 = list_entry(l2, struct cg_cgroup_link, cg_link_list); cg1 = cgl1->cgrp; cg2 = cgl2->cgrp; /* Hierarchies should be linked in the same order. */ BUG_ON(cg1->root != cg2->root); /* * If this hierarchy is the hierarchy of the cgroup * that's changing, then we need to check that this * css_set points to the new cgroup; if it's any other * hierarchy, then this css_set should point to the * same cgroup as the old css_set. */ if (cg1->root == new_cgrp->root) { if (cg1 != new_cgrp) return false; } else { if (cg1 != cg2) return false; } } return true; } /* |
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* find_existing_css_set() is a helper for * find_css_set(), and checks to see whether an existing |
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* css_set is suitable. |
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* * oldcg: the cgroup group that we're using before the cgroup * transition * |
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* cgrp: the cgroup that we're moving into |
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* * template: location in which to build the desired set of subsystem * state objects for the new cgroup group */ |
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static struct css_set *find_existing_css_set( struct css_set *oldcg, |
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struct cgroup *cgrp, |
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struct cgroup_subsys_state *template[]) |
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{ int i; |
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struct cgroupfs_root *root = cgrp->root; |
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struct hlist_head *hhead; struct hlist_node *node; struct css_set *cg; |
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/* * Build the set of subsystem state objects that we want to see in the * new css_set. while subsystems can change globally, the entries here * won't change, so no need for locking. */ |
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for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { |
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if (root->subsys_bits & (1UL << i)) { |
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/* Subsystem is in this hierarchy. So we want * the subsystem state from the new * cgroup */ |
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template[i] = cgrp->subsys[i]; |
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} else { /* Subsystem is not in this hierarchy, so we * don't want to change the subsystem state */ template[i] = oldcg->subsys[i]; } } |
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hhead = css_set_hash(template); hlist_for_each_entry(cg, node, hhead, hlist) { |
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if (!compare_css_sets(cg, oldcg, cgrp, template)) continue; /* This css_set matches what we need */ return cg; |
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} |
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/* No existing cgroup group matched */ return NULL; } |
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static void free_cg_links(struct list_head *tmp) { struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; list_for_each_entry_safe(link, saved_link, tmp, cgrp_link_list) { list_del(&link->cgrp_link_list); kfree(link); } } |
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/* * allocate_cg_links() allocates "count" cg_cgroup_link structures |
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* and chains them on tmp through their cgrp_link_list fields. Returns 0 on |
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* success or a negative error */ |
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static int allocate_cg_links(int count, struct list_head *tmp) { struct cg_cgroup_link *link; int i; INIT_LIST_HEAD(tmp); for (i = 0; i < count; i++) { link = kmalloc(sizeof(*link), GFP_KERNEL); if (!link) { |
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free_cg_links(tmp); |
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return -ENOMEM; } |
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list_add(&link->cgrp_link_list, tmp); |
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} return 0; } |
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/** * link_css_set - a helper function to link a css_set to a cgroup * @tmp_cg_links: cg_cgroup_link objects allocated by allocate_cg_links() * @cg: the css_set to be linked * @cgrp: the destination cgroup */ static void link_css_set(struct list_head *tmp_cg_links, struct css_set *cg, struct cgroup *cgrp) { struct cg_cgroup_link *link; BUG_ON(list_empty(tmp_cg_links)); link = list_first_entry(tmp_cg_links, struct cg_cgroup_link, cgrp_link_list); link->cg = cg; |
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link->cgrp = cgrp; |
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atomic_inc(&cgrp->count); |
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list_move(&link->cgrp_link_list, &cgrp->css_sets); |
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/* * Always add links to the tail of the list so that the list * is sorted by order of hierarchy creation */ list_add_tail(&link->cg_link_list, &cg->cg_links); |
c12f65d43 cgroups: introduc... |
549 |
} |
817929ec2 Task Control Grou... |
550 551 552 553 554 555 556 |
/* * find_css_set() takes an existing cgroup group and a * cgroup object, and returns a css_set object that's * equivalent to the old group, but with the given cgroup * substituted into the appropriate hierarchy. Must be called with * cgroup_mutex held */ |
817929ec2 Task Control Grou... |
557 |
static struct css_set *find_css_set( |
bd89aabc6 Control groups: R... |
558 |
struct css_set *oldcg, struct cgroup *cgrp) |
817929ec2 Task Control Grou... |
559 560 561 |
{ struct css_set *res; struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT]; |
817929ec2 Task Control Grou... |
562 563 |
struct list_head tmp_cg_links; |
817929ec2 Task Control Grou... |
564 |
|
472b1053f cgroups: use a ha... |
565 |
struct hlist_head *hhead; |
7717f7ba9 cgroups: add a ba... |
566 |
struct cg_cgroup_link *link; |
472b1053f cgroups: use a ha... |
567 |
|
817929ec2 Task Control Grou... |
568 569 |
/* First see if we already have a cgroup group that matches * the desired set */ |
7e9abd89c cgroup: use read ... |
570 |
read_lock(&css_set_lock); |
bd89aabc6 Control groups: R... |
571 |
res = find_existing_css_set(oldcg, cgrp, template); |
817929ec2 Task Control Grou... |
572 573 |
if (res) get_css_set(res); |
7e9abd89c cgroup: use read ... |
574 |
read_unlock(&css_set_lock); |
817929ec2 Task Control Grou... |
575 576 577 578 579 580 581 582 583 584 585 586 587 |
if (res) return res; res = kmalloc(sizeof(*res), GFP_KERNEL); if (!res) return NULL; /* Allocate all the cg_cgroup_link objects that we'll need */ if (allocate_cg_links(root_count, &tmp_cg_links) < 0) { kfree(res); return NULL; } |
146aa1bd0 cgroups: fix prob... |
588 |
atomic_set(&res->refcount, 1); |
817929ec2 Task Control Grou... |
589 590 |
INIT_LIST_HEAD(&res->cg_links); INIT_LIST_HEAD(&res->tasks); |
472b1053f cgroups: use a ha... |
591 |
INIT_HLIST_NODE(&res->hlist); |
817929ec2 Task Control Grou... |
592 593 594 595 596 597 598 |
/* Copy the set of subsystem state objects generated in * find_existing_css_set() */ memcpy(res->subsys, template, sizeof(res->subsys)); write_lock(&css_set_lock); /* Add reference counts and links from the new css_set. */ |
7717f7ba9 cgroups: add a ba... |
599 600 601 602 603 604 |
list_for_each_entry(link, &oldcg->cg_links, cg_link_list) { struct cgroup *c = link->cgrp; if (c->root == cgrp->root) c = cgrp; link_css_set(&tmp_cg_links, res, c); } |
817929ec2 Task Control Grou... |
605 606 |
BUG_ON(!list_empty(&tmp_cg_links)); |
817929ec2 Task Control Grou... |
607 |
css_set_count++; |
472b1053f cgroups: use a ha... |
608 609 610 611 |
/* Add this cgroup group to the hash table */ hhead = css_set_hash(res->subsys); hlist_add_head(&res->hlist, hhead); |
817929ec2 Task Control Grou... |
612 613 614 |
write_unlock(&css_set_lock); return res; |
b4f48b636 Task Control Grou... |
615 |
} |
ddbcc7e8e Task Control Grou... |
616 |
/* |
7717f7ba9 cgroups: add a ba... |
617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 |
* Return the cgroup for "task" from the given hierarchy. Must be * called with cgroup_mutex held. */ static struct cgroup *task_cgroup_from_root(struct task_struct *task, struct cgroupfs_root *root) { struct css_set *css; struct cgroup *res = NULL; BUG_ON(!mutex_is_locked(&cgroup_mutex)); read_lock(&css_set_lock); /* * No need to lock the task - since we hold cgroup_mutex the * task can't change groups, so the only thing that can happen * is that it exits and its css is set back to init_css_set. */ css = task->cgroups; if (css == &init_css_set) { res = &root->top_cgroup; } else { struct cg_cgroup_link *link; list_for_each_entry(link, &css->cg_links, cg_link_list) { struct cgroup *c = link->cgrp; if (c->root == root) { res = c; break; } } } read_unlock(&css_set_lock); BUG_ON(!res); return res; } /* |
ddbcc7e8e Task Control Grou... |
652 653 654 655 656 657 658 659 660 |
* There is one global cgroup mutex. We also require taking * task_lock() when dereferencing a task's cgroup subsys pointers. * See "The task_lock() exception", at the end of this comment. * * A task must hold cgroup_mutex to modify cgroups. * * Any task can increment and decrement the count field without lock. * So in general, code holding cgroup_mutex can't rely on the count * field not changing. However, if the count goes to zero, then only |
956db3ca0 hotplug cpu: move... |
661 |
* cgroup_attach_task() can increment it again. Because a count of zero |
ddbcc7e8e Task Control Grou... |
662 663 664 665 666 667 668 669 |
* means that no tasks are currently attached, therefore there is no * way a task attached to that cgroup can fork (the other way to * increment the count). So code holding cgroup_mutex can safely * assume that if the count is zero, it will stay zero. Similarly, if * a task holds cgroup_mutex on a cgroup with zero count, it * knows that the cgroup won't be removed, as cgroup_rmdir() * needs that mutex. * |
ddbcc7e8e Task Control Grou... |
670 671 672 673 674 |
* The fork and exit callbacks cgroup_fork() and cgroup_exit(), don't * (usually) take cgroup_mutex. These are the two most performance * critical pieces of code here. The exception occurs on cgroup_exit(), * when a task in a notify_on_release cgroup exits. Then cgroup_mutex * is taken, and if the cgroup count is zero, a usermode call made |
a043e3b2c cgroup: fix comments |
675 676 |
* to the release agent with the name of the cgroup (path relative to * the root of cgroup file system) as the argument. |
ddbcc7e8e Task Control Grou... |
677 678 679 680 681 682 683 684 685 686 687 |
* * A cgroup can only be deleted if both its 'count' of using tasks * is zero, and its list of 'children' cgroups is empty. Since all * tasks in the system use _some_ cgroup, and since there is always at * least one task in the system (init, pid == 1), therefore, top_cgroup * always has either children cgroups and/or using tasks. So we don't * need a special hack to ensure that top_cgroup cannot be deleted. * * The task_lock() exception * * The need for this exception arises from the action of |
956db3ca0 hotplug cpu: move... |
688 |
* cgroup_attach_task(), which overwrites one tasks cgroup pointer with |
a043e3b2c cgroup: fix comments |
689 |
* another. It does so using cgroup_mutex, however there are |
ddbcc7e8e Task Control Grou... |
690 691 692 |
* several performance critical places that need to reference * task->cgroup without the expense of grabbing a system global * mutex. Therefore except as noted below, when dereferencing or, as |
956db3ca0 hotplug cpu: move... |
693 |
* in cgroup_attach_task(), modifying a task'ss cgroup pointer we use |
ddbcc7e8e Task Control Grou... |
694 695 696 697 |
* task_lock(), which acts on a spinlock (task->alloc_lock) already in * the task_struct routinely used for such matters. * * P.S. One more locking exception. RCU is used to guard the |
956db3ca0 hotplug cpu: move... |
698 |
* update of a tasks cgroup pointer by cgroup_attach_task() |
ddbcc7e8e Task Control Grou... |
699 |
*/ |
ddbcc7e8e Task Control Grou... |
700 701 702 703 |
/** * cgroup_lock - lock out any changes to cgroup structures * */ |
ddbcc7e8e Task Control Grou... |
704 705 706 707 |
void cgroup_lock(void) { mutex_lock(&cgroup_mutex); } |
67523c48a cgroups: blkio su... |
708 |
EXPORT_SYMBOL_GPL(cgroup_lock); |
ddbcc7e8e Task Control Grou... |
709 710 711 712 713 714 |
/** * cgroup_unlock - release lock on cgroup changes * * Undo the lock taken in a previous cgroup_lock() call. */ |
ddbcc7e8e Task Control Grou... |
715 716 717 718 |
void cgroup_unlock(void) { mutex_unlock(&cgroup_mutex); } |
67523c48a cgroups: blkio su... |
719 |
EXPORT_SYMBOL_GPL(cgroup_unlock); |
ddbcc7e8e Task Control Grou... |
720 721 722 723 724 725 726 727 728 729 |
/* * A couple of forward declarations required, due to cyclic reference loop: * cgroup_mkdir -> cgroup_create -> cgroup_populate_dir -> * cgroup_add_file -> cgroup_create_file -> cgroup_dir_inode_operations * -> cgroup_mkdir. */ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode); static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry); |
bd89aabc6 Control groups: R... |
730 |
static int cgroup_populate_dir(struct cgroup *cgrp); |
6e1d5dcc2 const: mark remai... |
731 |
static const struct inode_operations cgroup_dir_inode_operations; |
828c09509 const: constify r... |
732 |
static const struct file_operations proc_cgroupstats_operations; |
a424316ca Task Control Grou... |
733 734 |
static struct backing_dev_info cgroup_backing_dev_info = { |
d993831fa writeback: add na... |
735 |
.name = "cgroup", |
e4ad08fe6 mm: bdi: add sepa... |
736 |
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, |
a424316ca Task Control Grou... |
737 |
}; |
ddbcc7e8e Task Control Grou... |
738 |
|
38460b48d cgroup: CSS ID su... |
739 740 |
static int alloc_css_id(struct cgroup_subsys *ss, struct cgroup *parent, struct cgroup *child); |
ddbcc7e8e Task Control Grou... |
741 742 743 |
static struct inode *cgroup_new_inode(mode_t mode, struct super_block *sb) { struct inode *inode = new_inode(sb); |
ddbcc7e8e Task Control Grou... |
744 745 746 |
if (inode) { inode->i_mode = mode; |
76aac0e9a CRED: Wrap task c... |
747 748 |
inode->i_uid = current_fsuid(); inode->i_gid = current_fsgid(); |
ddbcc7e8e Task Control Grou... |
749 750 751 752 753 |
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_mapping->backing_dev_info = &cgroup_backing_dev_info; } return inode; } |
4fca88c87 memory cgroup enh... |
754 755 756 757 |
/* * Call subsys's pre_destroy handler. * This is called before css refcnt check. */ |
ec64f5154 cgroup: fix frequ... |
758 |
static int cgroup_call_pre_destroy(struct cgroup *cgrp) |
4fca88c87 memory cgroup enh... |
759 760 |
{ struct cgroup_subsys *ss; |
ec64f5154 cgroup: fix frequ... |
761 |
int ret = 0; |
4fca88c87 memory cgroup enh... |
762 |
for_each_subsys(cgrp->root, ss) |
ec64f5154 cgroup: fix frequ... |
763 764 765 |
if (ss->pre_destroy) { ret = ss->pre_destroy(ss, cgrp); if (ret) |
4ab78683c cgroups: fix race... |
766 |
break; |
ec64f5154 cgroup: fix frequ... |
767 |
} |
0dea11687 cgroup: implement... |
768 |
|
ec64f5154 cgroup: fix frequ... |
769 |
return ret; |
4fca88c87 memory cgroup enh... |
770 |
} |
a47295e6b cgroups: make cgr... |
771 772 773 774 775 776 |
static void free_cgroup_rcu(struct rcu_head *obj) { struct cgroup *cgrp = container_of(obj, struct cgroup, rcu_head); kfree(cgrp); } |
ddbcc7e8e Task Control Grou... |
777 778 779 780 |
static void cgroup_diput(struct dentry *dentry, struct inode *inode) { /* is dentry a directory ? if so, kfree() associated cgroup */ if (S_ISDIR(inode->i_mode)) { |
bd89aabc6 Control groups: R... |
781 |
struct cgroup *cgrp = dentry->d_fsdata; |
8dc4f3e17 cgroups: move cgr... |
782 |
struct cgroup_subsys *ss; |
bd89aabc6 Control groups: R... |
783 |
BUG_ON(!(cgroup_is_removed(cgrp))); |
81a6a5cdd Task Control Grou... |
784 785 786 787 788 789 790 |
/* It's possible for external users to be holding css * reference counts on a cgroup; css_put() needs to * be able to access the cgroup after decrementing * the reference count in order to know if it needs to * queue the cgroup to be handled by the release * agent */ synchronize_rcu(); |
8dc4f3e17 cgroups: move cgr... |
791 792 793 794 795 |
mutex_lock(&cgroup_mutex); /* * Release the subsystem state objects. */ |
75139b827 cgroups: remove s... |
796 797 |
for_each_subsys(cgrp->root, ss) ss->destroy(ss, cgrp); |
8dc4f3e17 cgroups: move cgr... |
798 799 800 |
cgrp->root->number_of_cgroups--; mutex_unlock(&cgroup_mutex); |
a47295e6b cgroups: make cgr... |
801 802 803 804 |
/* * Drop the active superblock reference that we took when we * created the cgroup */ |
8dc4f3e17 cgroups: move cgr... |
805 |
deactivate_super(cgrp->root->sb); |
72a8cb30d cgroups: ensure c... |
806 807 808 809 810 |
/* * if we're getting rid of the cgroup, refcount should ensure * that there are no pidlists left. */ BUG_ON(!list_empty(&cgrp->pidlists)); |
a47295e6b cgroups: make cgr... |
811 |
call_rcu(&cgrp->rcu_head, free_cgroup_rcu); |
ddbcc7e8e Task Control Grou... |
812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 |
} iput(inode); } static void remove_dir(struct dentry *d) { struct dentry *parent = dget(d->d_parent); d_delete(d); simple_rmdir(parent->d_inode, d); dput(parent); } static void cgroup_clear_directory(struct dentry *dentry) { struct list_head *node; BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); spin_lock(&dcache_lock); node = dentry->d_subdirs.next; while (node != &dentry->d_subdirs) { struct dentry *d = list_entry(node, struct dentry, d_u.d_child); list_del_init(node); if (d->d_inode) { /* This should never be called on a cgroup * directory with child cgroups */ BUG_ON(d->d_inode->i_mode & S_IFDIR); d = dget_locked(d); spin_unlock(&dcache_lock); d_delete(d); simple_unlink(dentry->d_inode, d); dput(d); spin_lock(&dcache_lock); } node = dentry->d_subdirs.next; } spin_unlock(&dcache_lock); } /* * NOTE : the dentry must have been dget()'ed */ static void cgroup_d_remove_dir(struct dentry *dentry) { cgroup_clear_directory(dentry); spin_lock(&dcache_lock); list_del_init(&dentry->d_u.d_child); spin_unlock(&dcache_lock); remove_dir(dentry); } |
ec64f5154 cgroup: fix frequ... |
863 864 865 866 867 868 |
/* * A queue for waiters to do rmdir() cgroup. A tasks will sleep when * cgroup->count == 0 && list_empty(&cgroup->children) && subsys has some * reference to css->refcnt. In general, this refcnt is expected to goes down * to zero, soon. * |
887032670 cgroup avoid perm... |
869 |
* CGRP_WAIT_ON_RMDIR flag is set under cgroup's inode->i_mutex; |
ec64f5154 cgroup: fix frequ... |
870 871 |
*/ DECLARE_WAIT_QUEUE_HEAD(cgroup_rmdir_waitq); |
887032670 cgroup avoid perm... |
872 |
static void cgroup_wakeup_rmdir_waiter(struct cgroup *cgrp) |
ec64f5154 cgroup: fix frequ... |
873 |
{ |
887032670 cgroup avoid perm... |
874 |
if (unlikely(test_and_clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags))) |
ec64f5154 cgroup: fix frequ... |
875 876 |
wake_up_all(&cgroup_rmdir_waitq); } |
887032670 cgroup avoid perm... |
877 878 879 880 881 882 883 884 885 886 |
void cgroup_exclude_rmdir(struct cgroup_subsys_state *css) { css_get(css); } void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css) { cgroup_wakeup_rmdir_waiter(css->cgroup); css_put(css); } |
aae8aab40 cgroups: revamp s... |
887 |
/* |
cf5d5941f cgroups: subsyste... |
888 889 890 |
* Call with cgroup_mutex held. Drops reference counts on modules, including * any duplicate ones that parse_cgroupfs_options took. If this function * returns an error, no reference counts are touched. |
aae8aab40 cgroups: revamp s... |
891 |
*/ |
ddbcc7e8e Task Control Grou... |
892 893 894 895 |
static int rebind_subsystems(struct cgroupfs_root *root, unsigned long final_bits) { unsigned long added_bits, removed_bits; |
bd89aabc6 Control groups: R... |
896 |
struct cgroup *cgrp = &root->top_cgroup; |
ddbcc7e8e Task Control Grou... |
897 |
int i; |
aae8aab40 cgroups: revamp s... |
898 |
BUG_ON(!mutex_is_locked(&cgroup_mutex)); |
ddbcc7e8e Task Control Grou... |
899 900 901 902 |
removed_bits = root->actual_subsys_bits & ~final_bits; added_bits = final_bits & ~root->actual_subsys_bits; /* Check that any added subsystems are currently free */ for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { |
8d53d55d2 cgroup: fix subsy... |
903 |
unsigned long bit = 1UL << i; |
ddbcc7e8e Task Control Grou... |
904 905 906 |
struct cgroup_subsys *ss = subsys[i]; if (!(bit & added_bits)) continue; |
aae8aab40 cgroups: revamp s... |
907 908 909 910 911 912 |
/* * Nobody should tell us to do a subsys that doesn't exist: * parse_cgroupfs_options should catch that case and refcounts * ensure that subsystems won't disappear once selected. */ BUG_ON(ss == NULL); |
ddbcc7e8e Task Control Grou... |
913 914 915 916 917 918 919 920 921 922 |
if (ss->root != &rootnode) { /* Subsystem isn't free */ return -EBUSY; } } /* Currently we don't handle adding/removing subsystems when * any child cgroups exist. This is theoretically supportable * but involves complex error handling, so it's being left until * later */ |
307257cf4 cgroups: fix a ra... |
923 |
if (root->number_of_cgroups > 1) |
ddbcc7e8e Task Control Grou... |
924 925 926 927 928 929 930 931 |
return -EBUSY; /* Process each subsystem */ for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; unsigned long bit = 1UL << i; if (bit & added_bits) { /* We're binding this subsystem to this hierarchy */ |
aae8aab40 cgroups: revamp s... |
932 |
BUG_ON(ss == NULL); |
bd89aabc6 Control groups: R... |
933 |
BUG_ON(cgrp->subsys[i]); |
ddbcc7e8e Task Control Grou... |
934 935 |
BUG_ON(!dummytop->subsys[i]); BUG_ON(dummytop->subsys[i]->cgroup != dummytop); |
999cd8a45 cgroups: add a pe... |
936 |
mutex_lock(&ss->hierarchy_mutex); |
bd89aabc6 Control groups: R... |
937 938 |
cgrp->subsys[i] = dummytop->subsys[i]; cgrp->subsys[i]->cgroup = cgrp; |
33a68ac1c cgroups: add inac... |
939 |
list_move(&ss->sibling, &root->subsys_list); |
b2aa30f7b cgroups: don't pu... |
940 |
ss->root = root; |
ddbcc7e8e Task Control Grou... |
941 |
if (ss->bind) |
bd89aabc6 Control groups: R... |
942 |
ss->bind(ss, cgrp); |
999cd8a45 cgroups: add a pe... |
943 |
mutex_unlock(&ss->hierarchy_mutex); |
cf5d5941f cgroups: subsyste... |
944 |
/* refcount was already taken, and we're keeping it */ |
ddbcc7e8e Task Control Grou... |
945 946 |
} else if (bit & removed_bits) { /* We're removing this subsystem */ |
aae8aab40 cgroups: revamp s... |
947 |
BUG_ON(ss == NULL); |
bd89aabc6 Control groups: R... |
948 949 |
BUG_ON(cgrp->subsys[i] != dummytop->subsys[i]); BUG_ON(cgrp->subsys[i]->cgroup != cgrp); |
999cd8a45 cgroups: add a pe... |
950 |
mutex_lock(&ss->hierarchy_mutex); |
ddbcc7e8e Task Control Grou... |
951 952 953 |
if (ss->bind) ss->bind(ss, dummytop); dummytop->subsys[i]->cgroup = dummytop; |
bd89aabc6 Control groups: R... |
954 |
cgrp->subsys[i] = NULL; |
b2aa30f7b cgroups: don't pu... |
955 |
subsys[i]->root = &rootnode; |
33a68ac1c cgroups: add inac... |
956 |
list_move(&ss->sibling, &rootnode.subsys_list); |
999cd8a45 cgroups: add a pe... |
957 |
mutex_unlock(&ss->hierarchy_mutex); |
cf5d5941f cgroups: subsyste... |
958 959 |
/* subsystem is now free - drop reference on module */ module_put(ss->module); |
ddbcc7e8e Task Control Grou... |
960 961 |
} else if (bit & final_bits) { /* Subsystem state should already exist */ |
aae8aab40 cgroups: revamp s... |
962 |
BUG_ON(ss == NULL); |
bd89aabc6 Control groups: R... |
963 |
BUG_ON(!cgrp->subsys[i]); |
cf5d5941f cgroups: subsyste... |
964 965 966 967 968 969 970 971 |
/* * a refcount was taken, but we already had one, so * drop the extra reference. */ module_put(ss->module); #ifdef CONFIG_MODULE_UNLOAD BUG_ON(ss->module && !module_refcount(ss->module)); #endif |
ddbcc7e8e Task Control Grou... |
972 973 |
} else { /* Subsystem state shouldn't exist */ |
bd89aabc6 Control groups: R... |
974 |
BUG_ON(cgrp->subsys[i]); |
ddbcc7e8e Task Control Grou... |
975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 |
} } root->subsys_bits = root->actual_subsys_bits = final_bits; synchronize_rcu(); return 0; } static int cgroup_show_options(struct seq_file *seq, struct vfsmount *vfs) { struct cgroupfs_root *root = vfs->mnt_sb->s_fs_info; struct cgroup_subsys *ss; mutex_lock(&cgroup_mutex); for_each_subsys(root, ss) seq_printf(seq, ",%s", ss->name); if (test_bit(ROOT_NOPREFIX, &root->flags)) seq_puts(seq, ",noprefix"); |
81a6a5cdd Task Control Grou... |
993 994 |
if (strlen(root->release_agent_path)) seq_printf(seq, ",release_agent=%s", root->release_agent_path); |
c6d57f331 cgroups: support ... |
995 996 |
if (strlen(root->name)) seq_printf(seq, ",name=%s", root->name); |
ddbcc7e8e Task Control Grou... |
997 998 999 1000 1001 1002 1003 |
mutex_unlock(&cgroup_mutex); return 0; } struct cgroup_sb_opts { unsigned long subsys_bits; unsigned long flags; |
81a6a5cdd Task Control Grou... |
1004 |
char *release_agent; |
c6d57f331 cgroups: support ... |
1005 |
char *name; |
2c6ab6d20 cgroups: allow cg... |
1006 1007 |
/* User explicitly requested empty subsystem */ bool none; |
c6d57f331 cgroups: support ... |
1008 1009 |
struct cgroupfs_root *new_root; |
2c6ab6d20 cgroups: allow cg... |
1010 |
|
ddbcc7e8e Task Control Grou... |
1011 |
}; |
aae8aab40 cgroups: revamp s... |
1012 1013 |
/* * Convert a hierarchy specifier into a bitmask of subsystems and flags. Call |
cf5d5941f cgroups: subsyste... |
1014 1015 1016 |
* with cgroup_mutex held to protect the subsys[] array. This function takes * refcounts on subsystems to be used, unless it returns error, in which case * no refcounts are taken. |
aae8aab40 cgroups: revamp s... |
1017 |
*/ |
cf5d5941f cgroups: subsyste... |
1018 |
static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) |
ddbcc7e8e Task Control Grou... |
1019 1020 |
{ char *token, *o = data ?: "all"; |
f9ab5b5b0 cgroups: forbid n... |
1021 |
unsigned long mask = (unsigned long)-1; |
cf5d5941f cgroups: subsyste... |
1022 1023 |
int i; bool module_pin_failed = false; |
f9ab5b5b0 cgroups: forbid n... |
1024 |
|
aae8aab40 cgroups: revamp s... |
1025 |
BUG_ON(!mutex_is_locked(&cgroup_mutex)); |
f9ab5b5b0 cgroups: forbid n... |
1026 1027 1028 |
#ifdef CONFIG_CPUSETS mask = ~(1UL << cpuset_subsys_id); #endif |
ddbcc7e8e Task Control Grou... |
1029 |
|
c6d57f331 cgroups: support ... |
1030 |
memset(opts, 0, sizeof(*opts)); |
ddbcc7e8e Task Control Grou... |
1031 1032 1033 1034 1035 |
while ((token = strsep(&o, ",")) != NULL) { if (!*token) return -EINVAL; if (!strcmp(token, "all")) { |
8bab8dded cgroups: add cgro... |
1036 |
/* Add all non-disabled subsystems */ |
8bab8dded cgroups: add cgro... |
1037 1038 1039 |
opts->subsys_bits = 0; for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; |
aae8aab40 cgroups: revamp s... |
1040 1041 |
if (ss == NULL) continue; |
8bab8dded cgroups: add cgro... |
1042 1043 1044 |
if (!ss->disabled) opts->subsys_bits |= 1ul << i; } |
2c6ab6d20 cgroups: allow cg... |
1045 1046 1047 |
} else if (!strcmp(token, "none")) { /* Explicitly have no subsystems */ opts->none = true; |
ddbcc7e8e Task Control Grou... |
1048 1049 |
} else if (!strcmp(token, "noprefix")) { set_bit(ROOT_NOPREFIX, &opts->flags); |
81a6a5cdd Task Control Grou... |
1050 1051 1052 1053 |
} else if (!strncmp(token, "release_agent=", 14)) { /* Specifying two release agents is forbidden */ if (opts->release_agent) return -EINVAL; |
c6d57f331 cgroups: support ... |
1054 1055 |
opts->release_agent = kstrndup(token + 14, PATH_MAX, GFP_KERNEL); |
81a6a5cdd Task Control Grou... |
1056 1057 |
if (!opts->release_agent) return -ENOMEM; |
c6d57f331 cgroups: support ... |
1058 |
} else if (!strncmp(token, "name=", 5)) { |
c6d57f331 cgroups: support ... |
1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 |
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, GFP_KERNEL); if (!opts->name) return -ENOMEM; |
ddbcc7e8e Task Control Grou... |
1080 1081 |
} else { struct cgroup_subsys *ss; |
ddbcc7e8e Task Control Grou... |
1082 1083 |
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { ss = subsys[i]; |
aae8aab40 cgroups: revamp s... |
1084 1085 |
if (ss == NULL) continue; |
ddbcc7e8e Task Control Grou... |
1086 |
if (!strcmp(token, ss->name)) { |
8bab8dded cgroups: add cgro... |
1087 1088 |
if (!ss->disabled) set_bit(i, &opts->subsys_bits); |
ddbcc7e8e Task Control Grou... |
1089 1090 1091 1092 1093 1094 1095 |
break; } } if (i == CGROUP_SUBSYS_COUNT) return -ENOENT; } } |
2c6ab6d20 cgroups: allow cg... |
1096 |
/* Consistency checks */ |
f9ab5b5b0 cgroups: forbid n... |
1097 1098 1099 1100 1101 1102 1103 1104 |
/* * Option noprefix was introduced just for backward compatibility * with the old cpuset, so we allow noprefix only if mounting just * the cpuset subsystem. */ if (test_bit(ROOT_NOPREFIX, &opts->flags) && (opts->subsys_bits & mask)) return -EINVAL; |
2c6ab6d20 cgroups: allow cg... |
1105 1106 1107 1108 1109 1110 1111 1112 1113 |
/* Can't specify "none" and some subsystems */ if (opts->subsys_bits && opts->none) return -EINVAL; /* * We either have to specify by name or by subsystems. (So all * empty hierarchies must have a name). */ |
c6d57f331 cgroups: support ... |
1114 |
if (!opts->subsys_bits && !opts->name) |
ddbcc7e8e Task Control Grou... |
1115 |
return -EINVAL; |
cf5d5941f cgroups: subsyste... |
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 |
/* * Grab references on all the modules we'll need, so the subsystems * don't dance around before rebind_subsystems attaches them. This may * take duplicate reference counts on a subsystem that's already used, * but rebind_subsystems handles this case. */ for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) { unsigned long bit = 1UL << i; if (!(bit & opts->subsys_bits)) continue; if (!try_module_get(subsys[i]->module)) { module_pin_failed = true; break; } } if (module_pin_failed) { /* * oops, one of the modules was going away. this means that we * raced with a module_delete call, and to the user this is * essentially a "subsystem doesn't exist" case. */ for (i--; i >= CGROUP_BUILTIN_SUBSYS_COUNT; i--) { /* drop refcounts only on the ones we took */ unsigned long bit = 1UL << i; if (!(bit & opts->subsys_bits)) continue; module_put(subsys[i]->module); } return -ENOENT; } |
ddbcc7e8e Task Control Grou... |
1148 1149 |
return 0; } |
cf5d5941f cgroups: subsyste... |
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 |
static void drop_parsed_module_refcounts(unsigned long subsys_bits) { int i; for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) { unsigned long bit = 1UL << i; if (!(bit & subsys_bits)) continue; module_put(subsys[i]->module); } } |
ddbcc7e8e Task Control Grou... |
1161 1162 1163 1164 |
static int cgroup_remount(struct super_block *sb, int *flags, char *data) { int ret = 0; struct cgroupfs_root *root = sb->s_fs_info; |
bd89aabc6 Control groups: R... |
1165 |
struct cgroup *cgrp = &root->top_cgroup; |
ddbcc7e8e Task Control Grou... |
1166 |
struct cgroup_sb_opts opts; |
337eb00a2 Push BKL down int... |
1167 |
lock_kernel(); |
bd89aabc6 Control groups: R... |
1168 |
mutex_lock(&cgrp->dentry->d_inode->i_mutex); |
ddbcc7e8e Task Control Grou... |
1169 1170 1171 1172 1173 1174 |
mutex_lock(&cgroup_mutex); /* See what subsystems are wanted */ ret = parse_cgroupfs_options(data, &opts); if (ret) goto out_unlock; |
cf5d5941f cgroups: subsyste... |
1175 1176 1177 |
/* Don't allow flags or name to change at remount */ if (opts.flags != root->flags || (opts.name && strcmp(opts.name, root->name))) { |
c6d57f331 cgroups: support ... |
1178 |
ret = -EINVAL; |
cf5d5941f cgroups: subsyste... |
1179 |
drop_parsed_module_refcounts(opts.subsys_bits); |
c6d57f331 cgroups: support ... |
1180 1181 |
goto out_unlock; } |
ddbcc7e8e Task Control Grou... |
1182 |
ret = rebind_subsystems(root, opts.subsys_bits); |
cf5d5941f cgroups: subsyste... |
1183 1184 |
if (ret) { drop_parsed_module_refcounts(opts.subsys_bits); |
0670e08bd cgroups: don't ch... |
1185 |
goto out_unlock; |
cf5d5941f cgroups: subsyste... |
1186 |
} |
ddbcc7e8e Task Control Grou... |
1187 1188 |
/* (re)populate subsystem files */ |
0670e08bd cgroups: don't ch... |
1189 |
cgroup_populate_dir(cgrp); |
ddbcc7e8e Task Control Grou... |
1190 |
|
81a6a5cdd Task Control Grou... |
1191 1192 |
if (opts.release_agent) strcpy(root->release_agent_path, opts.release_agent); |
ddbcc7e8e Task Control Grou... |
1193 |
out_unlock: |
66bdc9cfc kernel/cgroup.c: ... |
1194 |
kfree(opts.release_agent); |
c6d57f331 cgroups: support ... |
1195 |
kfree(opts.name); |
ddbcc7e8e Task Control Grou... |
1196 |
mutex_unlock(&cgroup_mutex); |
bd89aabc6 Control groups: R... |
1197 |
mutex_unlock(&cgrp->dentry->d_inode->i_mutex); |
337eb00a2 Push BKL down int... |
1198 |
unlock_kernel(); |
ddbcc7e8e Task Control Grou... |
1199 1200 |
return ret; } |
b87221de6 const: mark remai... |
1201 |
static const struct super_operations cgroup_ops = { |
ddbcc7e8e Task Control Grou... |
1202 1203 1204 1205 1206 |
.statfs = simple_statfs, .drop_inode = generic_delete_inode, .show_options = cgroup_show_options, .remount_fs = cgroup_remount, }; |
cc31edcee cgroups: convert ... |
1207 1208 1209 1210 1211 1212 |
static void init_cgroup_housekeeping(struct cgroup *cgrp) { INIT_LIST_HEAD(&cgrp->sibling); INIT_LIST_HEAD(&cgrp->children); INIT_LIST_HEAD(&cgrp->css_sets); INIT_LIST_HEAD(&cgrp->release_list); |
72a8cb30d cgroups: ensure c... |
1213 1214 |
INIT_LIST_HEAD(&cgrp->pidlists); mutex_init(&cgrp->pidlist_mutex); |
0dea11687 cgroup: implement... |
1215 1216 |
INIT_LIST_HEAD(&cgrp->event_list); spin_lock_init(&cgrp->event_list_lock); |
cc31edcee cgroups: convert ... |
1217 |
} |
c6d57f331 cgroups: support ... |
1218 |
|
ddbcc7e8e Task Control Grou... |
1219 1220 |
static void init_cgroup_root(struct cgroupfs_root *root) { |
bd89aabc6 Control groups: R... |
1221 |
struct cgroup *cgrp = &root->top_cgroup; |
ddbcc7e8e Task Control Grou... |
1222 1223 1224 |
INIT_LIST_HEAD(&root->subsys_list); INIT_LIST_HEAD(&root->root_list); root->number_of_cgroups = 1; |
bd89aabc6 Control groups: R... |
1225 1226 |
cgrp->root = root; cgrp->top_cgroup = cgrp; |
cc31edcee cgroups: convert ... |
1227 |
init_cgroup_housekeeping(cgrp); |
ddbcc7e8e Task Control Grou... |
1228 |
} |
2c6ab6d20 cgroups: allow cg... |
1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 |
static bool init_root_id(struct cgroupfs_root *root) { int ret = 0; do { if (!ida_pre_get(&hierarchy_ida, GFP_KERNEL)) return false; spin_lock(&hierarchy_id_lock); /* Try to allocate the next unused ID */ ret = ida_get_new_above(&hierarchy_ida, next_hierarchy_id, &root->hierarchy_id); if (ret == -ENOSPC) /* Try again starting from 0 */ ret = ida_get_new(&hierarchy_ida, &root->hierarchy_id); if (!ret) { next_hierarchy_id = root->hierarchy_id + 1; } else if (ret != -EAGAIN) { /* Can only get here if the 31-bit IDR is full ... */ BUG_ON(ret); } spin_unlock(&hierarchy_id_lock); } while (ret); return true; } |
ddbcc7e8e Task Control Grou... |
1253 1254 |
static int cgroup_test_super(struct super_block *sb, void *data) { |
c6d57f331 cgroups: support ... |
1255 |
struct cgroup_sb_opts *opts = data; |
ddbcc7e8e Task Control Grou... |
1256 |
struct cgroupfs_root *root = sb->s_fs_info; |
c6d57f331 cgroups: support ... |
1257 1258 1259 |
/* If we asked for a name then it must match */ if (opts->name && strcmp(opts->name, root->name)) return 0; |
ddbcc7e8e Task Control Grou... |
1260 |
|
2c6ab6d20 cgroups: allow cg... |
1261 1262 1263 1264 1265 1266 |
/* * If we asked for subsystems (or explicitly for no * subsystems) then they must match */ if ((opts->subsys_bits || opts->none) && (opts->subsys_bits != root->subsys_bits)) |
ddbcc7e8e Task Control Grou... |
1267 1268 1269 1270 |
return 0; return 1; } |
c6d57f331 cgroups: support ... |
1271 1272 1273 |
static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) { struct cgroupfs_root *root; |
2c6ab6d20 cgroups: allow cg... |
1274 |
if (!opts->subsys_bits && !opts->none) |
c6d57f331 cgroups: support ... |
1275 1276 1277 1278 1279 |
return NULL; root = kzalloc(sizeof(*root), GFP_KERNEL); if (!root) return ERR_PTR(-ENOMEM); |
2c6ab6d20 cgroups: allow cg... |
1280 1281 1282 1283 |
if (!init_root_id(root)) { kfree(root); return ERR_PTR(-ENOMEM); } |
c6d57f331 cgroups: support ... |
1284 |
init_cgroup_root(root); |
2c6ab6d20 cgroups: allow cg... |
1285 |
|
c6d57f331 cgroups: support ... |
1286 1287 1288 1289 1290 1291 1292 1293 |
root->subsys_bits = opts->subsys_bits; root->flags = opts->flags; if (opts->release_agent) strcpy(root->release_agent_path, opts->release_agent); if (opts->name) strcpy(root->name, opts->name); return root; } |
2c6ab6d20 cgroups: allow cg... |
1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 |
static void cgroup_drop_root(struct cgroupfs_root *root) { if (!root) return; BUG_ON(!root->hierarchy_id); spin_lock(&hierarchy_id_lock); ida_remove(&hierarchy_ida, root->hierarchy_id); spin_unlock(&hierarchy_id_lock); kfree(root); } |
ddbcc7e8e Task Control Grou... |
1305 1306 1307 |
static int cgroup_set_super(struct super_block *sb, void *data) { int ret; |
c6d57f331 cgroups: support ... |
1308 1309 1310 1311 1312 |
struct cgroup_sb_opts *opts = data; /* If we don't have a new root, we can't set up a new sb */ if (!opts->new_root) return -EINVAL; |
2c6ab6d20 cgroups: allow cg... |
1313 |
BUG_ON(!opts->subsys_bits && !opts->none); |
ddbcc7e8e Task Control Grou... |
1314 1315 1316 1317 |
ret = set_anon_super(sb, NULL); if (ret) return ret; |
c6d57f331 cgroups: support ... |
1318 1319 |
sb->s_fs_info = opts->new_root; opts->new_root->sb = sb; |
ddbcc7e8e Task Control Grou... |
1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 |
sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = CGROUP_SUPER_MAGIC; sb->s_op = &cgroup_ops; return 0; } static int cgroup_get_rootdir(struct super_block *sb) { struct inode *inode = cgroup_new_inode(S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR, sb); struct dentry *dentry; if (!inode) return -ENOMEM; |
ddbcc7e8e Task Control Grou... |
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 |
inode->i_fop = &simple_dir_operations; inode->i_op = &cgroup_dir_inode_operations; /* directories start off with i_nlink == 2 (for "." entry) */ inc_nlink(inode); dentry = d_alloc_root(inode); if (!dentry) { iput(inode); return -ENOMEM; } sb->s_root = dentry; return 0; } static int cgroup_get_sb(struct file_system_type *fs_type, int flags, const char *unused_dev_name, void *data, struct vfsmount *mnt) { struct cgroup_sb_opts opts; |
c6d57f331 cgroups: support ... |
1355 |
struct cgroupfs_root *root; |
ddbcc7e8e Task Control Grou... |
1356 1357 |
int ret = 0; struct super_block *sb; |
c6d57f331 cgroups: support ... |
1358 |
struct cgroupfs_root *new_root; |
ddbcc7e8e Task Control Grou... |
1359 1360 |
/* First find the desired set of subsystems */ |
aae8aab40 cgroups: revamp s... |
1361 |
mutex_lock(&cgroup_mutex); |
ddbcc7e8e Task Control Grou... |
1362 |
ret = parse_cgroupfs_options(data, &opts); |
aae8aab40 cgroups: revamp s... |
1363 |
mutex_unlock(&cgroup_mutex); |
c6d57f331 cgroups: support ... |
1364 1365 |
if (ret) goto out_err; |
ddbcc7e8e Task Control Grou... |
1366 |
|
c6d57f331 cgroups: support ... |
1367 1368 1369 1370 1371 1372 1373 |
/* * Allocate a new cgroup root. We may not need it if we're * reusing an existing hierarchy. */ new_root = cgroup_root_from_opts(&opts); if (IS_ERR(new_root)) { ret = PTR_ERR(new_root); |
cf5d5941f cgroups: subsyste... |
1374 |
goto drop_modules; |
81a6a5cdd Task Control Grou... |
1375 |
} |
c6d57f331 cgroups: support ... |
1376 |
opts.new_root = new_root; |
ddbcc7e8e Task Control Grou... |
1377 |
|
c6d57f331 cgroups: support ... |
1378 1379 |
/* Locate an existing or new sb for this hierarchy */ sb = sget(fs_type, cgroup_test_super, cgroup_set_super, &opts); |
ddbcc7e8e Task Control Grou... |
1380 |
if (IS_ERR(sb)) { |
c6d57f331 cgroups: support ... |
1381 |
ret = PTR_ERR(sb); |
2c6ab6d20 cgroups: allow cg... |
1382 |
cgroup_drop_root(opts.new_root); |
cf5d5941f cgroups: subsyste... |
1383 |
goto drop_modules; |
ddbcc7e8e Task Control Grou... |
1384 |
} |
c6d57f331 cgroups: support ... |
1385 1386 1387 1388 1389 |
root = sb->s_fs_info; BUG_ON(!root); if (root == opts.new_root) { /* We used the new root structure, so this is a new hierarchy */ struct list_head tmp_cg_links; |
c12f65d43 cgroups: introduc... |
1390 |
struct cgroup *root_cgrp = &root->top_cgroup; |
817929ec2 Task Control Grou... |
1391 |
struct inode *inode; |
c6d57f331 cgroups: support ... |
1392 |
struct cgroupfs_root *existing_root; |
28fd5dfc1 cgroups: remove t... |
1393 |
int i; |
ddbcc7e8e Task Control Grou... |
1394 1395 1396 1397 1398 1399 |
BUG_ON(sb->s_root != NULL); ret = cgroup_get_rootdir(sb); if (ret) goto drop_new_super; |
817929ec2 Task Control Grou... |
1400 |
inode = sb->s_root->d_inode; |
ddbcc7e8e Task Control Grou... |
1401 |
|
817929ec2 Task Control Grou... |
1402 |
mutex_lock(&inode->i_mutex); |
ddbcc7e8e Task Control Grou... |
1403 |
mutex_lock(&cgroup_mutex); |
c6d57f331 cgroups: support ... |
1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 |
if (strlen(root->name)) { /* Check for name clashes with existing mounts */ for_each_active_root(existing_root) { if (!strcmp(existing_root->name, root->name)) { ret = -EBUSY; mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); goto drop_new_super; } } } |
817929ec2 Task Control Grou... |
1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 |
/* * We're accessing css_set_count without locking * css_set_lock here, but that's OK - it can only be * increased by someone holding cgroup_lock, and * that's us. The worst that can happen is that we * have some link structures left over */ ret = allocate_cg_links(css_set_count, &tmp_cg_links); if (ret) { mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); goto drop_new_super; } |
ddbcc7e8e Task Control Grou... |
1428 1429 1430 |
ret = rebind_subsystems(root, root->subsys_bits); if (ret == -EBUSY) { mutex_unlock(&cgroup_mutex); |
817929ec2 Task Control Grou... |
1431 |
mutex_unlock(&inode->i_mutex); |
c6d57f331 cgroups: support ... |
1432 1433 |
free_cg_links(&tmp_cg_links); goto drop_new_super; |
ddbcc7e8e Task Control Grou... |
1434 |
} |
cf5d5941f cgroups: subsyste... |
1435 1436 1437 1438 1439 |
/* * There must be no failure case after here, since rebinding * takes care of subsystems' refcounts, which are explicitly * dropped in the failure exit path. */ |
ddbcc7e8e Task Control Grou... |
1440 1441 1442 1443 1444 |
/* EBUSY should be the only error here */ BUG_ON(ret); list_add(&root->root_list, &roots); |
817929ec2 Task Control Grou... |
1445 |
root_count++; |
ddbcc7e8e Task Control Grou... |
1446 |
|
c12f65d43 cgroups: introduc... |
1447 |
sb->s_root->d_fsdata = root_cgrp; |
ddbcc7e8e Task Control Grou... |
1448 |
root->top_cgroup.dentry = sb->s_root; |
817929ec2 Task Control Grou... |
1449 1450 1451 |
/* Link the top cgroup in this hierarchy into all * the css_set objects */ write_lock(&css_set_lock); |
28fd5dfc1 cgroups: remove t... |
1452 1453 1454 |
for (i = 0; i < CSS_SET_TABLE_SIZE; i++) { struct hlist_head *hhead = &css_set_table[i]; struct hlist_node *node; |
817929ec2 Task Control Grou... |
1455 |
struct css_set *cg; |
28fd5dfc1 cgroups: remove t... |
1456 |
|
c12f65d43 cgroups: introduc... |
1457 1458 |
hlist_for_each_entry(cg, node, hhead, hlist) link_css_set(&tmp_cg_links, cg, root_cgrp); |
28fd5dfc1 cgroups: remove t... |
1459 |
} |
817929ec2 Task Control Grou... |
1460 1461 1462 |
write_unlock(&css_set_lock); free_cg_links(&tmp_cg_links); |
c12f65d43 cgroups: introduc... |
1463 1464 |
BUG_ON(!list_empty(&root_cgrp->sibling)); BUG_ON(!list_empty(&root_cgrp->children)); |
ddbcc7e8e Task Control Grou... |
1465 |
BUG_ON(root->number_of_cgroups != 1); |
c12f65d43 cgroups: introduc... |
1466 |
cgroup_populate_dir(root_cgrp); |
ddbcc7e8e Task Control Grou... |
1467 |
mutex_unlock(&cgroup_mutex); |
34f77a90f cgroups: make unl... |
1468 |
mutex_unlock(&inode->i_mutex); |
c6d57f331 cgroups: support ... |
1469 1470 1471 1472 1473 |
} else { /* * We re-used an existing hierarchy - the new root (if * any) is not needed */ |
2c6ab6d20 cgroups: allow cg... |
1474 |
cgroup_drop_root(opts.new_root); |
cf5d5941f cgroups: subsyste... |
1475 1476 |
/* no subsys rebinding, so refcounts don't change */ drop_parsed_module_refcounts(opts.subsys_bits); |
ddbcc7e8e Task Control Grou... |
1477 |
} |
a3ec947c8 vfs: simple_set_m... |
1478 |
simple_set_mnt(mnt, sb); |
c6d57f331 cgroups: support ... |
1479 1480 |
kfree(opts.release_agent); kfree(opts.name); |
a3ec947c8 vfs: simple_set_m... |
1481 |
return 0; |
ddbcc7e8e Task Control Grou... |
1482 1483 |
drop_new_super: |
6f5bbff9a Convert obvious p... |
1484 |
deactivate_locked_super(sb); |
cf5d5941f cgroups: subsyste... |
1485 1486 |
drop_modules: drop_parsed_module_refcounts(opts.subsys_bits); |
c6d57f331 cgroups: support ... |
1487 1488 1489 |
out_err: kfree(opts.release_agent); kfree(opts.name); |
ddbcc7e8e Task Control Grou... |
1490 1491 1492 1493 1494 |
return ret; } static void cgroup_kill_sb(struct super_block *sb) { struct cgroupfs_root *root = sb->s_fs_info; |
bd89aabc6 Control groups: R... |
1495 |
struct cgroup *cgrp = &root->top_cgroup; |
ddbcc7e8e Task Control Grou... |
1496 |
int ret; |
71cbb949d cgroup: list_for_... |
1497 1498 |
struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; |
ddbcc7e8e Task Control Grou... |
1499 1500 1501 1502 |
BUG_ON(!root); BUG_ON(root->number_of_cgroups != 1); |
bd89aabc6 Control groups: R... |
1503 1504 |
BUG_ON(!list_empty(&cgrp->children)); BUG_ON(!list_empty(&cgrp->sibling)); |
ddbcc7e8e Task Control Grou... |
1505 1506 1507 1508 1509 1510 1511 |
mutex_lock(&cgroup_mutex); /* Rebind all subsystems back to the default hierarchy */ ret = rebind_subsystems(root, 0); /* Shouldn't be able to fail ... */ BUG_ON(ret); |
817929ec2 Task Control Grou... |
1512 1513 1514 1515 1516 |
/* * Release all the links from css_sets to this hierarchy's * root cgroup */ write_lock(&css_set_lock); |
71cbb949d cgroup: list_for_... |
1517 1518 1519 |
list_for_each_entry_safe(link, saved_link, &cgrp->css_sets, cgrp_link_list) { |
817929ec2 Task Control Grou... |
1520 |
list_del(&link->cg_link_list); |
bd89aabc6 Control groups: R... |
1521 |
list_del(&link->cgrp_link_list); |
817929ec2 Task Control Grou... |
1522 1523 1524 |
kfree(link); } write_unlock(&css_set_lock); |
839ec5452 cgroup: fix root_... |
1525 1526 1527 1528 |
if (!list_empty(&root->root_list)) { list_del(&root->root_list); root_count--; } |
e5f6a8609 cgroups: make roo... |
1529 |
|
ddbcc7e8e Task Control Grou... |
1530 |
mutex_unlock(&cgroup_mutex); |
ddbcc7e8e Task Control Grou... |
1531 |
kill_litter_super(sb); |
2c6ab6d20 cgroups: allow cg... |
1532 |
cgroup_drop_root(root); |
ddbcc7e8e Task Control Grou... |
1533 1534 1535 1536 1537 1538 1539 |
} static struct file_system_type cgroup_fs_type = { .name = "cgroup", .get_sb = cgroup_get_sb, .kill_sb = cgroup_kill_sb, }; |
676db4af0 cgroupfs: create ... |
1540 |
static struct kobject *cgroup_kobj; |
bd89aabc6 Control groups: R... |
1541 |
static inline struct cgroup *__d_cgrp(struct dentry *dentry) |
ddbcc7e8e Task Control Grou... |
1542 1543 1544 1545 1546 1547 1548 1549 |
{ return dentry->d_fsdata; } static inline struct cftype *__d_cft(struct dentry *dentry) { return dentry->d_fsdata; } |
a043e3b2c cgroup: fix comments |
1550 1551 1552 1553 1554 1555 |
/** * cgroup_path - generate the path of a cgroup * @cgrp: the cgroup in question * @buf: the buffer to write the path into * @buflen: the length of the buffer * |
a47295e6b cgroups: make cgr... |
1556 1557 1558 |
* Called with cgroup_mutex held or else with an RCU-protected cgroup * reference. Writes path of cgroup into buf. Returns 0 on success, * -errno on error. |
ddbcc7e8e Task Control Grou... |
1559 |
*/ |
bd89aabc6 Control groups: R... |
1560 |
int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) |
ddbcc7e8e Task Control Grou... |
1561 1562 |
{ char *start; |
9a9686b63 cgroup: Fix an RC... |
1563 1564 1565 |
struct dentry *dentry = rcu_dereference_check(cgrp->dentry, rcu_read_lock_held() || cgroup_lock_is_held()); |
ddbcc7e8e Task Control Grou... |
1566 |
|
a47295e6b cgroups: make cgr... |
1567 |
if (!dentry || cgrp == dummytop) { |
ddbcc7e8e Task Control Grou... |
1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 |
/* * Inactive subsystems have no dentry for their root * cgroup */ strcpy(buf, "/"); return 0; } start = buf + buflen; *--start = '\0'; for (;;) { |
a47295e6b cgroups: make cgr... |
1580 |
int len = dentry->d_name.len; |
9a9686b63 cgroup: Fix an RC... |
1581 |
|
ddbcc7e8e Task Control Grou... |
1582 1583 |
if ((start -= len) < buf) return -ENAMETOOLONG; |
9a9686b63 cgroup: Fix an RC... |
1584 |
memcpy(start, dentry->d_name.name, len); |
bd89aabc6 Control groups: R... |
1585 1586 |
cgrp = cgrp->parent; if (!cgrp) |
ddbcc7e8e Task Control Grou... |
1587 |
break; |
9a9686b63 cgroup: Fix an RC... |
1588 1589 1590 1591 |
dentry = rcu_dereference_check(cgrp->dentry, rcu_read_lock_held() || cgroup_lock_is_held()); |
bd89aabc6 Control groups: R... |
1592 |
if (!cgrp->parent) |
ddbcc7e8e Task Control Grou... |
1593 1594 1595 1596 1597 1598 1599 1600 |
continue; if (--start < buf) return -ENAMETOOLONG; *start = '/'; } memmove(buf, start, buf + buflen - start); return 0; } |
67523c48a cgroups: blkio su... |
1601 |
EXPORT_SYMBOL_GPL(cgroup_path); |
ddbcc7e8e Task Control Grou... |
1602 |
|
a043e3b2c cgroup: fix comments |
1603 1604 1605 1606 |
/** * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp' * @cgrp: the cgroup the task is attaching to * @tsk: the task to be attached |
bbcb81d09 Task Control Grou... |
1607 |
* |
a043e3b2c cgroup: fix comments |
1608 1609 |
* Call holding cgroup_mutex. May take task_lock of * the task 'tsk' during call. |
bbcb81d09 Task Control Grou... |
1610 |
*/ |
956db3ca0 hotplug cpu: move... |
1611 |
int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
bbcb81d09 Task Control Grou... |
1612 1613 |
{ int retval = 0; |
2468c7234 cgroup: introduce... |
1614 |
struct cgroup_subsys *ss, *failed_ss = NULL; |
bd89aabc6 Control groups: R... |
1615 |
struct cgroup *oldcgrp; |
77efecd9e cgroups: call fin... |
1616 |
struct css_set *cg; |
817929ec2 Task Control Grou... |
1617 |
struct css_set *newcg; |
bd89aabc6 Control groups: R... |
1618 |
struct cgroupfs_root *root = cgrp->root; |
bbcb81d09 Task Control Grou... |
1619 1620 |
/* Nothing to do if the task is already in that cgroup */ |
7717f7ba9 cgroups: add a ba... |
1621 |
oldcgrp = task_cgroup_from_root(tsk, root); |
bd89aabc6 Control groups: R... |
1622 |
if (cgrp == oldcgrp) |
bbcb81d09 Task Control Grou... |
1623 1624 1625 1626 |
return 0; for_each_subsys(root, ss) { if (ss->can_attach) { |
be367d099 cgroups: let ss->... |
1627 |
retval = ss->can_attach(ss, cgrp, tsk, false); |
2468c7234 cgroup: introduce... |
1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 |
if (retval) { /* * Remember on which subsystem the can_attach() * failed, so that we only call cancel_attach() * against the subsystems whose can_attach() * succeeded. (See below) */ failed_ss = ss; goto out; } |
bbcb81d09 Task Control Grou... |
1638 1639 |
} } |
77efecd9e cgroups: call fin... |
1640 1641 1642 1643 |
task_lock(tsk); cg = tsk->cgroups; get_css_set(cg); task_unlock(tsk); |
817929ec2 Task Control Grou... |
1644 1645 1646 1647 |
/* * Locate or allocate a new css_set for this task, * based on its final set of cgroups */ |
bd89aabc6 Control groups: R... |
1648 |
newcg = find_css_set(cg, cgrp); |
77efecd9e cgroups: call fin... |
1649 |
put_css_set(cg); |
2468c7234 cgroup: introduce... |
1650 1651 1652 1653 |
if (!newcg) { retval = -ENOMEM; goto out; } |
817929ec2 Task Control Grou... |
1654 |
|
bbcb81d09 Task Control Grou... |
1655 1656 1657 |
task_lock(tsk); if (tsk->flags & PF_EXITING) { task_unlock(tsk); |
817929ec2 Task Control Grou... |
1658 |
put_css_set(newcg); |
2468c7234 cgroup: introduce... |
1659 1660 |
retval = -ESRCH; goto out; |
bbcb81d09 Task Control Grou... |
1661 |
} |
817929ec2 Task Control Grou... |
1662 |
rcu_assign_pointer(tsk->cgroups, newcg); |
bbcb81d09 Task Control Grou... |
1663 |
task_unlock(tsk); |
817929ec2 Task Control Grou... |
1664 1665 1666 1667 1668 1669 1670 |
/* Update the css_set linked lists if we're using them */ write_lock(&css_set_lock); if (!list_empty(&tsk->cg_list)) { list_del(&tsk->cg_list); list_add(&tsk->cg_list, &newcg->tasks); } write_unlock(&css_set_lock); |
bbcb81d09 Task Control Grou... |
1671 |
for_each_subsys(root, ss) { |
e18f6318e cgroup brace codi... |
1672 |
if (ss->attach) |
be367d099 cgroups: let ss->... |
1673 |
ss->attach(ss, cgrp, oldcgrp, tsk, false); |
bbcb81d09 Task Control Grou... |
1674 |
} |
bd89aabc6 Control groups: R... |
1675 |
set_bit(CGRP_RELEASABLE, &oldcgrp->flags); |
bbcb81d09 Task Control Grou... |
1676 |
synchronize_rcu(); |
817929ec2 Task Control Grou... |
1677 |
put_css_set(cg); |
ec64f5154 cgroup: fix frequ... |
1678 1679 1680 1681 1682 |
/* * wake up rmdir() waiter. the rmdir should fail since the cgroup * is no longer empty. */ |
887032670 cgroup avoid perm... |
1683 |
cgroup_wakeup_rmdir_waiter(cgrp); |
2468c7234 cgroup: introduce... |
1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 |
out: if (retval) { for_each_subsys(root, ss) { if (ss == failed_ss) /* * This subsystem was the one that failed the * can_attach() check earlier, so we don't need * to call cancel_attach() against it or any * remaining subsystems. */ break; if (ss->cancel_attach) ss->cancel_attach(ss, cgrp, tsk, false); } } return retval; |
bbcb81d09 Task Control Grou... |
1700 |
} |
d7926ee38 cgroups: Add an A... |
1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 |
/** * cgroup_attach_task_current_cg - attach task 'tsk' to current task's cgroup * @tsk: the task to be attached */ int cgroup_attach_task_current_cg(struct task_struct *tsk) { struct cgroupfs_root *root; struct cgroup *cur_cg; int retval = 0; cgroup_lock(); for_each_active_root(root) { cur_cg = task_cgroup_from_root(current, root); retval = cgroup_attach_task(cur_cg, tsk); if (retval) break; } cgroup_unlock(); return retval; } EXPORT_SYMBOL_GPL(cgroup_attach_task_current_cg); |
bbcb81d09 Task Control Grou... |
1723 |
/* |
af351026a cgroup files: tur... |
1724 1725 |
* Attach task with pid 'pid' to cgroup 'cgrp'. Call with cgroup_mutex * held. May take task_lock of task |
bbcb81d09 Task Control Grou... |
1726 |
*/ |
af351026a cgroup files: tur... |
1727 |
static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) |
bbcb81d09 Task Control Grou... |
1728 |
{ |
bbcb81d09 Task Control Grou... |
1729 |
struct task_struct *tsk; |
c69e8d9c0 CRED: Use RCU to ... |
1730 |
const struct cred *cred = current_cred(), *tcred; |
bbcb81d09 Task Control Grou... |
1731 |
int ret; |
bbcb81d09 Task Control Grou... |
1732 1733 |
if (pid) { rcu_read_lock(); |
73507f335 Handle pid namesp... |
1734 |
tsk = find_task_by_vpid(pid); |
bbcb81d09 Task Control Grou... |
1735 1736 1737 1738 |
if (!tsk || tsk->flags & PF_EXITING) { rcu_read_unlock(); return -ESRCH; } |
bbcb81d09 Task Control Grou... |
1739 |
|
c69e8d9c0 CRED: Use RCU to ... |
1740 1741 1742 1743 1744 |
tcred = __task_cred(tsk); if (cred->euid && cred->euid != tcred->uid && cred->euid != tcred->suid) { rcu_read_unlock(); |
bbcb81d09 Task Control Grou... |
1745 1746 |
return -EACCES; } |
c69e8d9c0 CRED: Use RCU to ... |
1747 1748 |
get_task_struct(tsk); rcu_read_unlock(); |
bbcb81d09 Task Control Grou... |
1749 1750 1751 1752 |
} else { tsk = current; get_task_struct(tsk); } |
956db3ca0 hotplug cpu: move... |
1753 |
ret = cgroup_attach_task(cgrp, tsk); |
bbcb81d09 Task Control Grou... |
1754 1755 1756 |
put_task_struct(tsk); return ret; } |
af351026a cgroup files: tur... |
1757 1758 1759 1760 1761 1762 1763 1764 1765 |
static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid) { int ret; if (!cgroup_lock_live_group(cgrp)) return -ENODEV; ret = attach_task_by_pid(cgrp, pid); cgroup_unlock(); return ret; } |
e788e066c cgroup files: mov... |
1766 1767 1768 1769 |
/** * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. * @cgrp: the cgroup to be checked for liveness * |
84eea8428 cgroups: misc cle... |
1770 1771 |
* On success, returns true; the lock should be later released with * cgroup_unlock(). On failure returns false with no lock held. |
e788e066c cgroup files: mov... |
1772 |
*/ |
84eea8428 cgroups: misc cle... |
1773 |
bool cgroup_lock_live_group(struct cgroup *cgrp) |
e788e066c cgroup files: mov... |
1774 1775 1776 1777 1778 1779 1780 1781 |
{ mutex_lock(&cgroup_mutex); if (cgroup_is_removed(cgrp)) { mutex_unlock(&cgroup_mutex); return false; } return true; } |
67523c48a cgroups: blkio su... |
1782 |
EXPORT_SYMBOL_GPL(cgroup_lock_live_group); |
e788e066c cgroup files: mov... |
1783 1784 1785 1786 1787 1788 1789 1790 |
static int cgroup_release_agent_write(struct cgroup *cgrp, struct cftype *cft, const char *buffer) { BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX); if (!cgroup_lock_live_group(cgrp)) return -ENODEV; strcpy(cgrp->root->release_agent_path, buffer); |
84eea8428 cgroups: misc cle... |
1791 |
cgroup_unlock(); |
e788e066c cgroup files: mov... |
1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 |
return 0; } static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft, struct seq_file *seq) { if (!cgroup_lock_live_group(cgrp)) return -ENODEV; seq_puts(seq, cgrp->root->release_agent_path); seq_putc(seq, ' '); |
84eea8428 cgroups: misc cle... |
1803 |
cgroup_unlock(); |
e788e066c cgroup files: mov... |
1804 1805 |
return 0; } |
84eea8428 cgroups: misc cle... |
1806 1807 |
/* A buffer size big enough for numbers or short strings */ #define CGROUP_LOCAL_BUFFER_SIZE 64 |
e73d2c61d CGroups _s64 file... |
1808 |
static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft, |
f4c753b7e CGroup API files:... |
1809 1810 1811 |
struct file *file, const char __user *userbuf, size_t nbytes, loff_t *unused_ppos) |
355e0c48b Add cgroup write_... |
1812 |
{ |
84eea8428 cgroups: misc cle... |
1813 |
char buffer[CGROUP_LOCAL_BUFFER_SIZE]; |
355e0c48b Add cgroup write_... |
1814 |
int retval = 0; |
355e0c48b Add cgroup write_... |
1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 |
char *end; if (!nbytes) return -EINVAL; if (nbytes >= sizeof(buffer)) return -E2BIG; if (copy_from_user(buffer, userbuf, nbytes)) return -EFAULT; buffer[nbytes] = 0; /* nul-terminate */ |
e73d2c61d CGroups _s64 file... |
1825 |
if (cft->write_u64) { |
478988d3b cgroup: fix strst... |
1826 |
u64 val = simple_strtoull(strstrip(buffer), &end, 0); |
e73d2c61d CGroups _s64 file... |
1827 1828 1829 1830 |
if (*end) return -EINVAL; retval = cft->write_u64(cgrp, cft, val); } else { |
478988d3b cgroup: fix strst... |
1831 |
s64 val = simple_strtoll(strstrip(buffer), &end, 0); |
e73d2c61d CGroups _s64 file... |
1832 1833 1834 1835 |
if (*end) return -EINVAL; retval = cft->write_s64(cgrp, cft, val); } |
355e0c48b Add cgroup write_... |
1836 1837 1838 1839 |
if (!retval) retval = nbytes; return retval; } |
db3b14978 cgroup files: add... |
1840 1841 1842 1843 1844 |
static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft, struct file *file, const char __user *userbuf, size_t nbytes, loff_t *unused_ppos) { |
84eea8428 cgroups: misc cle... |
1845 |
char local_buffer[CGROUP_LOCAL_BUFFER_SIZE]; |
db3b14978 cgroup files: add... |
1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 |
int retval = 0; size_t max_bytes = cft->max_write_len; char *buffer = local_buffer; if (!max_bytes) max_bytes = sizeof(local_buffer) - 1; if (nbytes >= max_bytes) return -E2BIG; /* Allocate a dynamic buffer if we need one */ if (nbytes >= sizeof(local_buffer)) { buffer = kmalloc(nbytes + 1, GFP_KERNEL); if (buffer == NULL) return -ENOMEM; } |
5a3eb9f6b cgroup: fix possi... |
1860 1861 1862 1863 |
if (nbytes && copy_from_user(buffer, userbuf, nbytes)) { retval = -EFAULT; goto out; } |
db3b14978 cgroup files: add... |
1864 1865 |
buffer[nbytes] = 0; /* nul-terminate */ |
478988d3b cgroup: fix strst... |
1866 |
retval = cft->write_string(cgrp, cft, strstrip(buffer)); |
db3b14978 cgroup files: add... |
1867 1868 |
if (!retval) retval = nbytes; |
5a3eb9f6b cgroup: fix possi... |
1869 |
out: |
db3b14978 cgroup files: add... |
1870 1871 1872 1873 |
if (buffer != local_buffer) kfree(buffer); return retval; } |
ddbcc7e8e Task Control Grou... |
1874 1875 1876 1877 |
static ssize_t cgroup_file_write(struct file *file, const char __user *buf, size_t nbytes, loff_t *ppos) { struct cftype *cft = __d_cft(file->f_dentry); |
bd89aabc6 Control groups: R... |
1878 |
struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); |
ddbcc7e8e Task Control Grou... |
1879 |
|
75139b827 cgroups: remove s... |
1880 |
if (cgroup_is_removed(cgrp)) |
ddbcc7e8e Task Control Grou... |
1881 |
return -ENODEV; |
355e0c48b Add cgroup write_... |
1882 |
if (cft->write) |
bd89aabc6 Control groups: R... |
1883 |
return cft->write(cgrp, cft, file, buf, nbytes, ppos); |
e73d2c61d CGroups _s64 file... |
1884 1885 |
if (cft->write_u64 || cft->write_s64) return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos); |
db3b14978 cgroup files: add... |
1886 1887 |
if (cft->write_string) return cgroup_write_string(cgrp, cft, file, buf, nbytes, ppos); |
d447ea2f3 cgroups: add the ... |
1888 1889 1890 1891 |
if (cft->trigger) { int ret = cft->trigger(cgrp, (unsigned int)cft->private); return ret ? ret : nbytes; } |
355e0c48b Add cgroup write_... |
1892 |
return -EINVAL; |
ddbcc7e8e Task Control Grou... |
1893 |
} |
f4c753b7e CGroup API files:... |
1894 1895 1896 1897 |
static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft, struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) |
ddbcc7e8e Task Control Grou... |
1898 |
{ |
84eea8428 cgroups: misc cle... |
1899 |
char tmp[CGROUP_LOCAL_BUFFER_SIZE]; |
f4c753b7e CGroup API files:... |
1900 |
u64 val = cft->read_u64(cgrp, cft); |
ddbcc7e8e Task Control Grou... |
1901 1902 1903 1904 1905 |
int len = sprintf(tmp, "%llu ", (unsigned long long) val); return simple_read_from_buffer(buf, nbytes, ppos, tmp, len); } |
e73d2c61d CGroups _s64 file... |
1906 1907 1908 1909 1910 |
static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft, struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { |
84eea8428 cgroups: misc cle... |
1911 |
char tmp[CGROUP_LOCAL_BUFFER_SIZE]; |
e73d2c61d CGroups _s64 file... |
1912 1913 1914 1915 1916 1917 |
s64 val = cft->read_s64(cgrp, cft); int len = sprintf(tmp, "%lld ", (long long) val); return simple_read_from_buffer(buf, nbytes, ppos, tmp, len); } |
ddbcc7e8e Task Control Grou... |
1918 1919 1920 1921 |
static ssize_t cgroup_file_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { struct cftype *cft = __d_cft(file->f_dentry); |
bd89aabc6 Control groups: R... |
1922 |
struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); |
ddbcc7e8e Task Control Grou... |
1923 |
|
75139b827 cgroups: remove s... |
1924 |
if (cgroup_is_removed(cgrp)) |
ddbcc7e8e Task Control Grou... |
1925 1926 1927 |
return -ENODEV; if (cft->read) |
bd89aabc6 Control groups: R... |
1928 |
return cft->read(cgrp, cft, file, buf, nbytes, ppos); |
f4c753b7e CGroup API files:... |
1929 1930 |
if (cft->read_u64) return cgroup_read_u64(cgrp, cft, file, buf, nbytes, ppos); |
e73d2c61d CGroups _s64 file... |
1931 1932 |
if (cft->read_s64) return cgroup_read_s64(cgrp, cft, file, buf, nbytes, ppos); |
ddbcc7e8e Task Control Grou... |
1933 1934 |
return -EINVAL; } |
917965696 CGroup API files:... |
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 |
/* * seqfile ops/methods for returning structured data. Currently just * supports string->u64 maps, but can be extended in future. */ struct cgroup_seqfile_state { struct cftype *cft; struct cgroup *cgroup; }; static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value) { struct seq_file *sf = cb->state; return seq_printf(sf, "%s %llu ", key, (unsigned long long)value); } static int cgroup_seqfile_show(struct seq_file *m, void *arg) { struct cgroup_seqfile_state *state = m->private; struct cftype *cft = state->cft; |
29486df32 cgroups: introduc... |
1956 1957 1958 1959 1960 1961 1962 1963 |
if (cft->read_map) { struct cgroup_map_cb cb = { .fill = cgroup_map_add, .state = m, }; return cft->read_map(state->cgroup, cft, &cb); } return cft->read_seq_string(state->cgroup, cft, m); |
917965696 CGroup API files:... |
1964 |
} |
96930a636 make cgroup_seqfi... |
1965 |
static int cgroup_seqfile_release(struct inode *inode, struct file *file) |
917965696 CGroup API files:... |
1966 1967 1968 1969 1970 |
{ struct seq_file *seq = file->private_data; kfree(seq->private); return single_release(inode, file); } |
828c09509 const: constify r... |
1971 |
static const struct file_operations cgroup_seqfile_operations = { |
917965696 CGroup API files:... |
1972 |
.read = seq_read, |
e788e066c cgroup files: mov... |
1973 |
.write = cgroup_file_write, |
917965696 CGroup API files:... |
1974 1975 1976 |
.llseek = seq_lseek, .release = cgroup_seqfile_release, }; |
ddbcc7e8e Task Control Grou... |
1977 1978 1979 1980 1981 1982 1983 1984 |
static int cgroup_file_open(struct inode *inode, struct file *file) { int err; struct cftype *cft; err = generic_file_open(inode, file); if (err) return err; |
ddbcc7e8e Task Control Grou... |
1985 |
cft = __d_cft(file->f_dentry); |
75139b827 cgroups: remove s... |
1986 |
|
29486df32 cgroups: introduc... |
1987 |
if (cft->read_map || cft->read_seq_string) { |
917965696 CGroup API files:... |
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 |
struct cgroup_seqfile_state *state = kzalloc(sizeof(*state), GFP_USER); if (!state) return -ENOMEM; state->cft = cft; state->cgroup = __d_cgrp(file->f_dentry->d_parent); file->f_op = &cgroup_seqfile_operations; err = single_open(file, cgroup_seqfile_show, state); if (err < 0) kfree(state); } else if (cft->open) |
ddbcc7e8e Task Control Grou... |
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 |
err = cft->open(inode, file); else err = 0; return err; } static int cgroup_file_release(struct inode *inode, struct file *file) { struct cftype *cft = __d_cft(file->f_dentry); if (cft->release) return cft->release(inode, file); return 0; } /* * cgroup_rename - Only allow simple rename of directories in place. */ static int cgroup_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { if (!S_ISDIR(old_dentry->d_inode->i_mode)) return -ENOTDIR; if (new_dentry->d_inode) return -EEXIST; if (old_dir != new_dir) return -EIO; return simple_rename(old_dir, old_dentry, new_dir, new_dentry); } |
828c09509 const: constify r... |
2028 |
static const struct file_operations cgroup_file_operations = { |
ddbcc7e8e Task Control Grou... |
2029 2030 2031 2032 2033 2034 |
.read = cgroup_file_read, .write = cgroup_file_write, .llseek = generic_file_llseek, .open = cgroup_file_open, .release = cgroup_file_release, }; |
6e1d5dcc2 const: mark remai... |
2035 |
static const struct inode_operations cgroup_dir_inode_operations = { |
ddbcc7e8e Task Control Grou... |
2036 2037 2038 2039 2040 |
.lookup = simple_lookup, .mkdir = cgroup_mkdir, .rmdir = cgroup_rmdir, .rename = cgroup_rename, }; |
0dea11687 cgroup: implement... |
2041 2042 2043 2044 2045 2046 2047 2048 2049 |
/* * Check if a file is a control file */ static inline struct cftype *__file_cft(struct file *file) { if (file->f_dentry->d_inode->i_fop != &cgroup_file_operations) return ERR_PTR(-EINVAL); return __d_cft(file->f_dentry); } |
099fca322 cgroups: show cor... |
2050 |
static int cgroup_create_file(struct dentry *dentry, mode_t mode, |
ddbcc7e8e Task Control Grou... |
2051 2052 |
struct super_block *sb) { |
3ba13d179 constify dentry_o... |
2053 |
static const struct dentry_operations cgroup_dops = { |
ddbcc7e8e Task Control Grou... |
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 |
.d_iput = cgroup_diput, }; struct inode *inode; if (!dentry) return -ENOENT; if (dentry->d_inode) return -EEXIST; inode = cgroup_new_inode(mode, sb); if (!inode) return -ENOMEM; if (S_ISDIR(mode)) { inode->i_op = &cgroup_dir_inode_operations; inode->i_fop = &simple_dir_operations; /* start off with i_nlink == 2 (for "." entry) */ inc_nlink(inode); /* start with the directory inode held, so that we can * populate it without racing with another mkdir */ |
817929ec2 Task Control Grou... |
2077 |
mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); |
ddbcc7e8e Task Control Grou... |
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 |
} else if (S_ISREG(mode)) { inode->i_size = 0; inode->i_fop = &cgroup_file_operations; } dentry->d_op = &cgroup_dops; d_instantiate(dentry, inode); dget(dentry); /* Extra count - pin the dentry in core */ return 0; } /* |
a043e3b2c cgroup: fix comments |
2089 2090 2091 2092 2093 |
* cgroup_create_dir - create a directory for an object. * @cgrp: the cgroup we create the directory for. It must have a valid * ->parent field. And we are going to fill its ->dentry field. * @dentry: dentry of the new cgroup * @mode: mode to set on new directory. |
ddbcc7e8e Task Control Grou... |
2094 |
*/ |
bd89aabc6 Control groups: R... |
2095 |
static int cgroup_create_dir(struct cgroup *cgrp, struct dentry *dentry, |
099fca322 cgroups: show cor... |
2096 |
mode_t mode) |
ddbcc7e8e Task Control Grou... |
2097 2098 2099 |
{ struct dentry *parent; int error = 0; |
bd89aabc6 Control groups: R... |
2100 2101 |
parent = cgrp->parent->dentry; error = cgroup_create_file(dentry, S_IFDIR | mode, cgrp->root->sb); |
ddbcc7e8e Task Control Grou... |
2102 |
if (!error) { |
bd89aabc6 Control groups: R... |
2103 |
dentry->d_fsdata = cgrp; |
ddbcc7e8e Task Control Grou... |
2104 |
inc_nlink(parent->d_inode); |
a47295e6b cgroups: make cgr... |
2105 |
rcu_assign_pointer(cgrp->dentry, dentry); |
ddbcc7e8e Task Control Grou... |
2106 2107 2108 2109 2110 2111 |
dget(dentry); } dput(dentry); return error; } |
099fca322 cgroups: show cor... |
2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 |
/** * cgroup_file_mode - deduce file mode of a control file * @cft: the control file in question * * returns cft->mode if ->mode is not 0 * returns S_IRUGO|S_IWUSR if it has both a read and a write handler * returns S_IRUGO if it has only a read handler * returns S_IWUSR if it has only a write hander */ static mode_t cgroup_file_mode(const struct cftype *cft) { mode_t mode = 0; if (cft->mode) return cft->mode; if (cft->read || cft->read_u64 || cft->read_s64 || cft->read_map || cft->read_seq_string) mode |= S_IRUGO; if (cft->write || cft->write_u64 || cft->write_s64 || cft->write_string || cft->trigger) mode |= S_IWUSR; return mode; } |
bd89aabc6 Control groups: R... |
2138 |
int cgroup_add_file(struct cgroup *cgrp, |
ddbcc7e8e Task Control Grou... |
2139 2140 2141 |
struct cgroup_subsys *subsys, const struct cftype *cft) { |
bd89aabc6 Control groups: R... |
2142 |
struct dentry *dir = cgrp->dentry; |
ddbcc7e8e Task Control Grou... |
2143 2144 |
struct dentry *dentry; int error; |
099fca322 cgroups: show cor... |
2145 |
mode_t mode; |
ddbcc7e8e Task Control Grou... |
2146 2147 |
char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 }; |
bd89aabc6 Control groups: R... |
2148 |
if (subsys && !test_bit(ROOT_NOPREFIX, &cgrp->root->flags)) { |
ddbcc7e8e Task Control Grou... |
2149 2150 2151 2152 2153 2154 2155 |
strcpy(name, subsys->name); strcat(name, "."); } strcat(name, cft->name); BUG_ON(!mutex_is_locked(&dir->d_inode->i_mutex)); dentry = lookup_one_len(name, dir, strlen(name)); if (!IS_ERR(dentry)) { |
099fca322 cgroups: show cor... |
2156 2157 |
mode = cgroup_file_mode(cft); error = cgroup_create_file(dentry, mode | S_IFREG, |
bd89aabc6 Control groups: R... |
2158 |
cgrp->root->sb); |
ddbcc7e8e Task Control Grou... |
2159 2160 2161 2162 2163 2164 2165 |
if (!error) dentry->d_fsdata = (void *)cft; dput(dentry); } else error = PTR_ERR(dentry); return error; } |
e6a1105ba cgroups: subsyste... |
2166 |
EXPORT_SYMBOL_GPL(cgroup_add_file); |
ddbcc7e8e Task Control Grou... |
2167 |
|
bd89aabc6 Control groups: R... |
2168 |
int cgroup_add_files(struct cgroup *cgrp, |
ddbcc7e8e Task Control Grou... |
2169 2170 2171 2172 2173 2174 |
struct cgroup_subsys *subsys, const struct cftype cft[], int count) { int i, err; for (i = 0; i < count; i++) { |
bd89aabc6 Control groups: R... |
2175 |
err = cgroup_add_file(cgrp, subsys, &cft[i]); |
ddbcc7e8e Task Control Grou... |
2176 2177 2178 2179 2180 |
if (err) return err; } return 0; } |
e6a1105ba cgroups: subsyste... |
2181 |
EXPORT_SYMBOL_GPL(cgroup_add_files); |
ddbcc7e8e Task Control Grou... |
2182 |
|
a043e3b2c cgroup: fix comments |
2183 2184 2185 2186 2187 2188 |
/** * cgroup_task_count - count the number of tasks in a cgroup. * @cgrp: the cgroup in question * * Return the number of tasks in the cgroup. */ |
bd89aabc6 Control groups: R... |
2189 |
int cgroup_task_count(const struct cgroup *cgrp) |
bbcb81d09 Task Control Grou... |
2190 2191 |
{ int count = 0; |
71cbb949d cgroup: list_for_... |
2192 |
struct cg_cgroup_link *link; |
817929ec2 Task Control Grou... |
2193 2194 |
read_lock(&css_set_lock); |
71cbb949d cgroup: list_for_... |
2195 |
list_for_each_entry(link, &cgrp->css_sets, cgrp_link_list) { |
146aa1bd0 cgroups: fix prob... |
2196 |
count += atomic_read(&link->cg->refcount); |
817929ec2 Task Control Grou... |
2197 2198 |
} read_unlock(&css_set_lock); |
bbcb81d09 Task Control Grou... |
2199 2200 2201 2202 |
return count; } /* |
817929ec2 Task Control Grou... |
2203 2204 2205 |
* Advance a list_head iterator. The iterator should be positioned at * the start of a css_set */ |
bd89aabc6 Control groups: R... |
2206 |
static void cgroup_advance_iter(struct cgroup *cgrp, |
7717f7ba9 cgroups: add a ba... |
2207 |
struct cgroup_iter *it) |
817929ec2 Task Control Grou... |
2208 2209 2210 2211 2212 2213 2214 2215 |
{ struct list_head *l = it->cg_link; struct cg_cgroup_link *link; struct css_set *cg; /* Advance to the next non-empty css_set */ do { l = l->next; |
bd89aabc6 Control groups: R... |
2216 |
if (l == &cgrp->css_sets) { |
817929ec2 Task Control Grou... |
2217 2218 2219 |
it->cg_link = NULL; return; } |
bd89aabc6 Control groups: R... |
2220 |
link = list_entry(l, struct cg_cgroup_link, cgrp_link_list); |
817929ec2 Task Control Grou... |
2221 2222 2223 2224 2225 |
cg = link->cg; } while (list_empty(&cg->tasks)); it->cg_link = l; it->task = cg->tasks.next; } |
31a7df01f cgroups: mechanis... |
2226 2227 2228 2229 2230 2231 2232 2233 2234 |
/* * To reduce the fork() overhead for systems that are not actually * using their cgroups capability, we don't maintain the lists running * through each css_set to its tasks until we see the list actually * used - in other words after the first call to cgroup_iter_start(). * * The tasklist_lock is not held here, as do_each_thread() and * while_each_thread() are protected by RCU. */ |
3df91fe30 make cgroup_enabl... |
2235 |
static void cgroup_enable_task_cg_lists(void) |
31a7df01f cgroups: mechanis... |
2236 2237 2238 2239 2240 2241 |
{ struct task_struct *p, *g; write_lock(&css_set_lock); use_task_css_set_links = 1; do_each_thread(g, p) { task_lock(p); |
0e04388f0 cgroup: fix a rac... |
2242 2243 2244 2245 2246 2247 |
/* * We should check if the process is exiting, otherwise * it will race with cgroup_exit() in that the list * entry won't be deleted though the process has exited. */ if (!(p->flags & PF_EXITING) && list_empty(&p->cg_list)) |
31a7df01f cgroups: mechanis... |
2248 2249 2250 2251 2252 |
list_add(&p->cg_list, &p->cgroups->tasks); task_unlock(p); } while_each_thread(g, p); write_unlock(&css_set_lock); } |
bd89aabc6 Control groups: R... |
2253 |
void cgroup_iter_start(struct cgroup *cgrp, struct cgroup_iter *it) |
817929ec2 Task Control Grou... |
2254 2255 2256 2257 2258 2259 |
{ /* * The first time anyone tries to iterate across a cgroup, * we need to enable the list linking each css_set to its * tasks, and fix up all existing tasks. */ |
31a7df01f cgroups: mechanis... |
2260 2261 |
if (!use_task_css_set_links) cgroup_enable_task_cg_lists(); |
817929ec2 Task Control Grou... |
2262 |
read_lock(&css_set_lock); |
bd89aabc6 Control groups: R... |
2263 2264 |
it->cg_link = &cgrp->css_sets; cgroup_advance_iter(cgrp, it); |
817929ec2 Task Control Grou... |
2265 |
} |
bd89aabc6 Control groups: R... |
2266 |
struct task_struct *cgroup_iter_next(struct cgroup *cgrp, |
817929ec2 Task Control Grou... |
2267 2268 2269 2270 |
struct cgroup_iter *it) { struct task_struct *res; struct list_head *l = it->task; |
2019f634c cgroups: fix cgro... |
2271 |
struct cg_cgroup_link *link; |
817929ec2 Task Control Grou... |
2272 2273 2274 2275 2276 2277 2278 |
/* If the iterator cg is NULL, we have no tasks */ if (!it->cg_link) return NULL; res = list_entry(l, struct task_struct, cg_list); /* Advance iterator to find next entry */ l = l->next; |
2019f634c cgroups: fix cgro... |
2279 2280 |
link = list_entry(it->cg_link, struct cg_cgroup_link, cgrp_link_list); if (l == &link->cg->tasks) { |
817929ec2 Task Control Grou... |
2281 2282 |
/* We reached the end of this task list - move on to * the next cg_cgroup_link */ |
bd89aabc6 Control groups: R... |
2283 |
cgroup_advance_iter(cgrp, it); |
817929ec2 Task Control Grou... |
2284 2285 2286 2287 2288 |
} else { it->task = l; } return res; } |
bd89aabc6 Control groups: R... |
2289 |
void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it) |
817929ec2 Task Control Grou... |
2290 2291 2292 |
{ read_unlock(&css_set_lock); } |
31a7df01f cgroups: mechanis... |
2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 |
static inline int started_after_time(struct task_struct *t1, struct timespec *time, struct task_struct *t2) { int start_diff = timespec_compare(&t1->start_time, time); if (start_diff > 0) { return 1; } else if (start_diff < 0) { return 0; } else { /* * Arbitrarily, if two processes started at the same * time, we'll say that the lower pointer value * started first. Note that t2 may have exited by now * so this may not be a valid pointer any longer, but * that's fine - it still serves to distinguish * between two tasks started (effectively) simultaneously. */ return t1 > t2; } } /* * This function is a callback from heap_insert() and is used to order * the heap. * In this case we order the heap in descending task start time. */ static inline int started_after(void *p1, void *p2) { struct task_struct *t1 = p1; struct task_struct *t2 = p2; return started_after_time(t1, &t2->start_time, t2); } /** * cgroup_scan_tasks - iterate though all the tasks in a cgroup * @scan: struct cgroup_scanner containing arguments for the scan * * Arguments include pointers to callback functions test_task() and * process_task(). * Iterate through all the tasks in a cgroup, calling test_task() for each, * and if it returns true, call process_task() for it also. * The test_task pointer may be NULL, meaning always true (select all tasks). * Effectively duplicates cgroup_iter_{start,next,end}() * but does not lock css_set_lock for the call to process_task(). * The struct cgroup_scanner may be embedded in any structure of the caller's * creation. * It is guaranteed that process_task() will act on every task that * is a member of the cgroup for the duration of this call. This * function may or may not call process_task() for tasks that exit * or move to a different cgroup during the call, or are forked or * move into the cgroup during the call. * * Note that test_task() may be called with locks held, and may in some * situations be called multiple times for the same task, so it should * be cheap. * If the heap pointer in the struct cgroup_scanner is non-NULL, a heap has been * pre-allocated and will be used for heap operations (and its "gt" member will * be overwritten), else a temporary heap will be used (allocation of which * may cause this function to fail). */ int cgroup_scan_tasks(struct cgroup_scanner *scan) { int retval, i; struct cgroup_iter it; struct task_struct *p, *dropped; /* Never dereference latest_task, since it's not refcounted */ struct task_struct *latest_task = NULL; struct ptr_heap tmp_heap; struct ptr_heap *heap; struct timespec latest_time = { 0, 0 }; if (scan->heap) { /* The caller supplied our heap and pre-allocated its memory */ heap = scan->heap; heap->gt = &started_after; } else { /* We need to allocate our own heap memory */ heap = &tmp_heap; retval = heap_init(heap, PAGE_SIZE, GFP_KERNEL, &started_after); if (retval) /* cannot allocate the heap */ return retval; } again: /* * Scan tasks in the cgroup, using the scanner's "test_task" callback * to determine which are of interest, and using the scanner's * "process_task" callback to process any of them that need an update. * Since we don't want to hold any locks during the task updates, * gather tasks to be processed in a heap structure. * The heap is sorted by descending task start time. * If the statically-sized heap fills up, we overflow tasks that * started later, and in future iterations only consider tasks that * started after the latest task in the previous pass. This * guarantees forward progress and that we don't miss any tasks. */ heap->size = 0; cgroup_iter_start(scan->cg, &it); while ((p = cgroup_iter_next(scan->cg, &it))) { /* * Only affect tasks that qualify per the caller's callback, * if he provided one */ if (scan->test_task && !scan->test_task(p, scan)) continue; /* * Only process tasks that started after the last task * we processed */ if (!started_after_time(p, &latest_time, latest_task)) continue; dropped = heap_insert(heap, p); if (dropped == NULL) { /* * The new task was inserted; the heap wasn't * previously full */ get_task_struct(p); } else if (dropped != p) { /* * The new task was inserted, and pushed out a * different task */ get_task_struct(p); put_task_struct(dropped); } /* * Else the new task was newer than anything already in * the heap and wasn't inserted */ } cgroup_iter_end(scan->cg, &it); if (heap->size) { for (i = 0; i < heap->size; i++) { |
4fe91d518 cgroup: fix spars... |
2430 |
struct task_struct *q = heap->ptrs[i]; |
31a7df01f cgroups: mechanis... |
2431 |
if (i == 0) { |
4fe91d518 cgroup: fix spars... |
2432 2433 |
latest_time = q->start_time; latest_task = q; |
31a7df01f cgroups: mechanis... |
2434 2435 |
} /* Process the task per the caller's callback */ |
4fe91d518 cgroup: fix spars... |
2436 2437 |
scan->process_task(q, scan); put_task_struct(q); |
31a7df01f cgroups: mechanis... |
2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 |
} /* * If we had to process any tasks at all, scan again * in case some of them were in the middle of forking * children that didn't get processed. * Not the most efficient way to do it, but it avoids * having to take callback_mutex in the fork path */ goto again; } if (heap == &tmp_heap) heap_free(&tmp_heap); return 0; } |
817929ec2 Task Control Grou... |
2452 |
/* |
102a775e3 cgroups: add a re... |
2453 |
* Stuff for reading the 'tasks'/'procs' files. |
bbcb81d09 Task Control Grou... |
2454 2455 2456 2457 2458 2459 |
* * 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. * |
bbcb81d09 Task Control Grou... |
2460 |
*/ |
bbcb81d09 Task Control Grou... |
2461 2462 |
/* |
d1d9fd330 cgroups: use vmal... |
2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 |
* 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) { if (is_vmalloc_addr(p)) vfree(p); else kfree(p); } static void *pidlist_resize(void *p, int newcount) { void *newlist; /* note: if new alloc fails, old p will still be valid either way */ if (is_vmalloc_addr(p)) { newlist = vmalloc(newcount * sizeof(pid_t)); if (!newlist) return NULL; memcpy(newlist, p, newcount * sizeof(pid_t)); vfree(p); } else { newlist = krealloc(p, newcount * sizeof(pid_t), GFP_KERNEL); } return newlist; } /* |
102a775e3 cgroups: add a re... |
2499 2500 2501 2502 |
* pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries * If the new stripped list is sufficiently smaller and there's enough memory * to allocate a new buffer, will let go of the unneeded memory. Returns the * number of unique elements. |
bbcb81d09 Task Control Grou... |
2503 |
*/ |
102a775e3 cgroups: add a re... |
2504 2505 2506 |
/* is the size difference enough that we should re-allocate the array? */ #define PIDLIST_REALLOC_DIFFERENCE(old, new) ((old) - PAGE_SIZE >= (new)) static int pidlist_uniq(pid_t **p, int length) |
bbcb81d09 Task Control Grou... |
2507 |
{ |
102a775e3 cgroups: add a re... |
2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 |
int src, dest = 1; pid_t *list = *p; pid_t *newlist; /* * 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: /* * if the length difference is large enough, we want to allocate a * smaller buffer to save memory. if this fails due to out of memory, * we'll just stay with what we've got. */ if (PIDLIST_REALLOC_DIFFERENCE(length, dest)) { |
d1d9fd330 cgroups: use vmal... |
2537 |
newlist = pidlist_resize(list, dest); |
102a775e3 cgroups: add a re... |
2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 |
if (newlist) *p = newlist; } return dest; } static int cmppid(const void *a, const void *b) { return *(pid_t *)a - *(pid_t *)b; } /* |
72a8cb30d cgroups: ensure c... |
2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 |
* 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(struct cgroup *cgrp, enum cgroup_filetype type) { struct cgroup_pidlist *l; /* don't need task_nsproxy() if we're looking at ourself */ |
b70cc5fdb cgroups: clean up... |
2560 |
struct pid_namespace *ns = current->nsproxy->pid_ns; |
72a8cb30d cgroups: ensure c... |
2561 2562 2563 2564 2565 2566 2567 2568 2569 |
/* * We can't drop the pidlist_mutex before taking the l->mutex in case * the last ref-holder is trying to remove l from the list at the same * time. Holding the pidlist_mutex precludes somebody taking whichever * list we find out from under us - compare release_pid_array(). */ mutex_lock(&cgrp->pidlist_mutex); list_for_each_entry(l, &cgrp->pidlists, links) { if (l->key.type == type && l->key.ns == ns) { |
72a8cb30d cgroups: ensure c... |
2570 2571 2572 |
/* make sure l doesn't vanish out from under us */ down_write(&l->mutex); mutex_unlock(&cgrp->pidlist_mutex); |
72a8cb30d cgroups: ensure c... |
2573 2574 2575 2576 2577 2578 2579 |
return l; } } /* entry not found; create a new one */ l = kmalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL); if (!l) { mutex_unlock(&cgrp->pidlist_mutex); |
72a8cb30d cgroups: ensure c... |
2580 2581 2582 2583 2584 |
return l; } init_rwsem(&l->mutex); down_write(&l->mutex); l->key.type = type; |
b70cc5fdb cgroups: clean up... |
2585 |
l->key.ns = get_pid_ns(ns); |
72a8cb30d cgroups: ensure c... |
2586 2587 2588 2589 2590 2591 2592 2593 2594 |
l->use_count = 0; /* don't increment here */ l->list = NULL; l->owner = cgrp; list_add(&l->links, &cgrp->pidlists); mutex_unlock(&cgrp->pidlist_mutex); return l; } /* |
102a775e3 cgroups: add a re... |
2595 2596 |
* Load a cgroup's pidarray with either procs' tgids or tasks' pids */ |
72a8cb30d cgroups: ensure c... |
2597 2598 |
static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, struct cgroup_pidlist **lp) |
102a775e3 cgroups: add a re... |
2599 2600 2601 2602 |
{ pid_t *array; int length; int pid, n = 0; /* used for populating the array */ |
817929ec2 Task Control Grou... |
2603 2604 |
struct cgroup_iter it; struct task_struct *tsk; |
102a775e3 cgroups: add a re... |
2605 2606 2607 2608 2609 2610 2611 2612 2613 |
struct cgroup_pidlist *l; /* * 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); |
d1d9fd330 cgroups: use vmal... |
2614 |
array = pidlist_allocate(length); |
102a775e3 cgroups: add a re... |
2615 2616 2617 |
if (!array) return -ENOMEM; /* now, populate the array */ |
bd89aabc6 Control groups: R... |
2618 2619 |
cgroup_iter_start(cgrp, &it); while ((tsk = cgroup_iter_next(cgrp, &it))) { |
102a775e3 cgroups: add a re... |
2620 |
if (unlikely(n == length)) |
817929ec2 Task Control Grou... |
2621 |
break; |
102a775e3 cgroups: add a re... |
2622 |
/* get tgid or pid for procs or tasks file respectively */ |
72a8cb30d cgroups: ensure c... |
2623 2624 2625 2626 |
if (type == CGROUP_FILE_PROCS) pid = task_tgid_vnr(tsk); else pid = task_pid_vnr(tsk); |
102a775e3 cgroups: add a re... |
2627 2628 |
if (pid > 0) /* make sure to only use valid results */ array[n++] = pid; |
817929ec2 Task Control Grou... |
2629 |
} |
bd89aabc6 Control groups: R... |
2630 |
cgroup_iter_end(cgrp, &it); |
102a775e3 cgroups: add a re... |
2631 2632 2633 |
length = n; /* now sort & (if procs) strip out duplicates */ sort(array, length, sizeof(pid_t), cmppid, NULL); |
72a8cb30d cgroups: ensure c... |
2634 |
if (type == CGROUP_FILE_PROCS) |
102a775e3 cgroups: add a re... |
2635 |
length = pidlist_uniq(&array, length); |
72a8cb30d cgroups: ensure c... |
2636 2637 |
l = cgroup_pidlist_find(cgrp, type); if (!l) { |
d1d9fd330 cgroups: use vmal... |
2638 |
pidlist_free(array); |
72a8cb30d cgroups: ensure c... |
2639 |
return -ENOMEM; |
102a775e3 cgroups: add a re... |
2640 |
} |
72a8cb30d cgroups: ensure c... |
2641 |
/* store array, freeing old if necessary - lock already held */ |
d1d9fd330 cgroups: use vmal... |
2642 |
pidlist_free(l->list); |
102a775e3 cgroups: add a re... |
2643 2644 2645 2646 |
l->list = array; l->length = length; l->use_count++; up_write(&l->mutex); |
72a8cb30d cgroups: ensure c... |
2647 |
*lp = l; |
102a775e3 cgroups: add a re... |
2648 |
return 0; |
bbcb81d09 Task Control Grou... |
2649 |
} |
846c7bb05 Add cgroupstats |
2650 |
/** |
a043e3b2c cgroup: fix comments |
2651 |
* cgroupstats_build - build and fill cgroupstats |
846c7bb05 Add cgroupstats |
2652 2653 2654 |
* @stats: cgroupstats to fill information into * @dentry: A dentry entry belonging to the cgroup for which stats have * been requested. |
a043e3b2c cgroup: fix comments |
2655 2656 2657 |
* * Build and fill cgroupstats so that taskstats can export it to user * space. |
846c7bb05 Add cgroupstats |
2658 2659 2660 2661 |
*/ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) { int ret = -EINVAL; |
bd89aabc6 Control groups: R... |
2662 |
struct cgroup *cgrp; |
846c7bb05 Add cgroupstats |
2663 2664 |
struct cgroup_iter it; struct task_struct *tsk; |
33d283bef cgroups: fix a se... |
2665 |
|
846c7bb05 Add cgroupstats |
2666 |
/* |
33d283bef cgroups: fix a se... |
2667 2668 |
* Validate dentry by checking the superblock operations, * and make sure it's a directory. |
846c7bb05 Add cgroupstats |
2669 |
*/ |
33d283bef cgroups: fix a se... |
2670 2671 |
if (dentry->d_sb->s_op != &cgroup_ops || !S_ISDIR(dentry->d_inode->i_mode)) |
846c7bb05 Add cgroupstats |
2672 2673 2674 |
goto err; ret = 0; |
bd89aabc6 Control groups: R... |
2675 |
cgrp = dentry->d_fsdata; |
846c7bb05 Add cgroupstats |
2676 |
|
bd89aabc6 Control groups: R... |
2677 2678 |
cgroup_iter_start(cgrp, &it); while ((tsk = cgroup_iter_next(cgrp, &it))) { |
846c7bb05 Add cgroupstats |
2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 |
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; } } |
bd89aabc6 Control groups: R... |
2698 |
cgroup_iter_end(cgrp, &it); |
846c7bb05 Add cgroupstats |
2699 |
|
846c7bb05 Add cgroupstats |
2700 2701 2702 |
err: return ret; } |
8f3ff2086 cgroups: revert "... |
2703 |
|
bbcb81d09 Task Control Grou... |
2704 |
/* |
102a775e3 cgroups: add a re... |
2705 |
* seq_file methods for the tasks/procs files. The seq_file position is the |
cc31edcee cgroups: convert ... |
2706 |
* next pid to display; the seq_file iterator is a pointer to the pid |
102a775e3 cgroups: add a re... |
2707 |
* in the cgroup->l->list array. |
bbcb81d09 Task Control Grou... |
2708 |
*/ |
cc31edcee cgroups: convert ... |
2709 |
|
102a775e3 cgroups: add a re... |
2710 |
static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos) |
bbcb81d09 Task Control Grou... |
2711 |
{ |
cc31edcee cgroups: convert ... |
2712 2713 2714 2715 2716 2717 |
/* * 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 */ |
102a775e3 cgroups: add a re... |
2718 |
struct cgroup_pidlist *l = s->private; |
cc31edcee cgroups: convert ... |
2719 2720 |
int index = 0, pid = *pos; int *iter; |
102a775e3 cgroups: add a re... |
2721 |
down_read(&l->mutex); |
cc31edcee cgroups: convert ... |
2722 |
if (pid) { |
102a775e3 cgroups: add a re... |
2723 |
int end = l->length; |
207777664 cgroup: remove un... |
2724 |
|
cc31edcee cgroups: convert ... |
2725 2726 |
while (index < end) { int mid = (index + end) / 2; |
102a775e3 cgroups: add a re... |
2727 |
if (l->list[mid] == pid) { |
cc31edcee cgroups: convert ... |
2728 2729 |
index = mid; break; |
102a775e3 cgroups: add a re... |
2730 |
} else if (l->list[mid] <= pid) |
cc31edcee cgroups: convert ... |
2731 2732 2733 2734 2735 2736 |
index = mid + 1; else end = mid; } } /* If we're off the end of the array, we're done */ |
102a775e3 cgroups: add a re... |
2737 |
if (index >= l->length) |
cc31edcee cgroups: convert ... |
2738 2739 |
return NULL; /* Update the abstract position to be the actual pid that we found */ |
102a775e3 cgroups: add a re... |
2740 |
iter = l->list + index; |
cc31edcee cgroups: convert ... |
2741 2742 2743 |
*pos = *iter; return iter; } |
102a775e3 cgroups: add a re... |
2744 |
static void cgroup_pidlist_stop(struct seq_file *s, void *v) |
cc31edcee cgroups: convert ... |
2745 |
{ |
102a775e3 cgroups: add a re... |
2746 2747 |
struct cgroup_pidlist *l = s->private; up_read(&l->mutex); |
cc31edcee cgroups: convert ... |
2748 |
} |
102a775e3 cgroups: add a re... |
2749 |
static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos) |
cc31edcee cgroups: convert ... |
2750 |
{ |
102a775e3 cgroups: add a re... |
2751 2752 2753 |
struct cgroup_pidlist *l = s->private; pid_t *p = v; pid_t *end = l->list + l->length; |
cc31edcee cgroups: convert ... |
2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 |
/* * 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; } } |
102a775e3 cgroups: add a re... |
2766 |
static int cgroup_pidlist_show(struct seq_file *s, void *v) |
cc31edcee cgroups: convert ... |
2767 2768 2769 2770 |
{ return seq_printf(s, "%d ", *(int *)v); } |
bbcb81d09 Task Control Grou... |
2771 |
|
102a775e3 cgroups: add a re... |
2772 2773 2774 2775 2776 2777 2778 2779 2780 |
/* * seq_operations functions for iterating on pidlists through seq_file - * independent of whether it's tasks or procs */ static const struct seq_operations cgroup_pidlist_seq_operations = { .start = cgroup_pidlist_start, .stop = cgroup_pidlist_stop, .next = cgroup_pidlist_next, .show = cgroup_pidlist_show, |
cc31edcee cgroups: convert ... |
2781 |
}; |
102a775e3 cgroups: add a re... |
2782 |
static void cgroup_release_pid_array(struct cgroup_pidlist *l) |
cc31edcee cgroups: convert ... |
2783 |
{ |
72a8cb30d cgroups: ensure c... |
2784 2785 2786 2787 2788 2789 2790 |
/* * the case where we're the last user of this particular pidlist will * have us remove it from the cgroup's list, which entails taking the * mutex. since in pidlist_find the pidlist->lock depends on cgroup-> * pidlist_mutex, we have to take pidlist_mutex first. */ mutex_lock(&l->owner->pidlist_mutex); |
102a775e3 cgroups: add a re... |
2791 2792 2793 |
down_write(&l->mutex); BUG_ON(!l->use_count); if (!--l->use_count) { |
72a8cb30d cgroups: ensure c... |
2794 2795 2796 |
/* we're the last user if refcount is 0; remove and free */ list_del(&l->links); mutex_unlock(&l->owner->pidlist_mutex); |
d1d9fd330 cgroups: use vmal... |
2797 |
pidlist_free(l->list); |
72a8cb30d cgroups: ensure c... |
2798 2799 2800 2801 |
put_pid_ns(l->key.ns); up_write(&l->mutex); kfree(l); return; |
cc31edcee cgroups: convert ... |
2802 |
} |
72a8cb30d cgroups: ensure c... |
2803 |
mutex_unlock(&l->owner->pidlist_mutex); |
102a775e3 cgroups: add a re... |
2804 |
up_write(&l->mutex); |
bbcb81d09 Task Control Grou... |
2805 |
} |
102a775e3 cgroups: add a re... |
2806 |
static int cgroup_pidlist_release(struct inode *inode, struct file *file) |
cc31edcee cgroups: convert ... |
2807 |
{ |
102a775e3 cgroups: add a re... |
2808 |
struct cgroup_pidlist *l; |
cc31edcee cgroups: convert ... |
2809 2810 |
if (!(file->f_mode & FMODE_READ)) return 0; |
102a775e3 cgroups: add a re... |
2811 2812 2813 2814 2815 2816 |
/* * the seq_file will only be initialized if the file was opened for * reading; hence we check if it's not null only in that case. */ l = ((struct seq_file *)file->private_data)->private; cgroup_release_pid_array(l); |
cc31edcee cgroups: convert ... |
2817 2818 |
return seq_release(inode, file); } |
102a775e3 cgroups: add a re... |
2819 |
static const struct file_operations cgroup_pidlist_operations = { |
cc31edcee cgroups: convert ... |
2820 2821 2822 |
.read = seq_read, .llseek = seq_lseek, .write = cgroup_file_write, |
102a775e3 cgroups: add a re... |
2823 |
.release = cgroup_pidlist_release, |
cc31edcee cgroups: convert ... |
2824 |
}; |
bbcb81d09 Task Control Grou... |
2825 |
/* |
102a775e3 cgroups: add a re... |
2826 2827 2828 |
* The following functions handle opens on a file that displays a pidlist * (tasks or procs). Prepare an array of the process/thread IDs of whoever's * in the cgroup. |
bbcb81d09 Task Control Grou... |
2829 |
*/ |
102a775e3 cgroups: add a re... |
2830 |
/* helper function for the two below it */ |
72a8cb30d cgroups: ensure c... |
2831 |
static int cgroup_pidlist_open(struct file *file, enum cgroup_filetype type) |
bbcb81d09 Task Control Grou... |
2832 |
{ |
bd89aabc6 Control groups: R... |
2833 |
struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); |
72a8cb30d cgroups: ensure c... |
2834 |
struct cgroup_pidlist *l; |
cc31edcee cgroups: convert ... |
2835 |
int retval; |
bbcb81d09 Task Control Grou... |
2836 |
|
cc31edcee cgroups: convert ... |
2837 |
/* Nothing to do for write-only files */ |
bbcb81d09 Task Control Grou... |
2838 2839 |
if (!(file->f_mode & FMODE_READ)) return 0; |
102a775e3 cgroups: add a re... |
2840 |
/* have the array populated */ |
72a8cb30d cgroups: ensure c... |
2841 |
retval = pidlist_array_load(cgrp, type, &l); |
102a775e3 cgroups: add a re... |
2842 2843 2844 2845 |
if (retval) return retval; /* configure file information */ file->f_op = &cgroup_pidlist_operations; |
cc31edcee cgroups: convert ... |
2846 |
|
102a775e3 cgroups: add a re... |
2847 |
retval = seq_open(file, &cgroup_pidlist_seq_operations); |
cc31edcee cgroups: convert ... |
2848 |
if (retval) { |
102a775e3 cgroups: add a re... |
2849 |
cgroup_release_pid_array(l); |
cc31edcee cgroups: convert ... |
2850 |
return retval; |
bbcb81d09 Task Control Grou... |
2851 |
} |
102a775e3 cgroups: add a re... |
2852 |
((struct seq_file *)file->private_data)->private = l; |
bbcb81d09 Task Control Grou... |
2853 2854 |
return 0; } |
102a775e3 cgroups: add a re... |
2855 2856 |
static int cgroup_tasks_open(struct inode *unused, struct file *file) { |
72a8cb30d cgroups: ensure c... |
2857 |
return cgroup_pidlist_open(file, CGROUP_FILE_TASKS); |
102a775e3 cgroups: add a re... |
2858 2859 2860 |
} static int cgroup_procs_open(struct inode *unused, struct file *file) { |
72a8cb30d cgroups: ensure c... |
2861 |
return cgroup_pidlist_open(file, CGROUP_FILE_PROCS); |
102a775e3 cgroups: add a re... |
2862 |
} |
bbcb81d09 Task Control Grou... |
2863 |
|
bd89aabc6 Control groups: R... |
2864 |
static u64 cgroup_read_notify_on_release(struct cgroup *cgrp, |
81a6a5cdd Task Control Grou... |
2865 2866 |
struct cftype *cft) { |
bd89aabc6 Control groups: R... |
2867 |
return notify_on_release(cgrp); |
81a6a5cdd Task Control Grou... |
2868 |
} |
6379c1061 cgroup files: mov... |
2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 |
static int cgroup_write_notify_on_release(struct cgroup *cgrp, struct cftype *cft, u64 val) { clear_bit(CGRP_RELEASABLE, &cgrp->flags); if (val) set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); else clear_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); return 0; } |
bbcb81d09 Task Control Grou... |
2880 |
/* |
0dea11687 cgroup: implement... |
2881 2882 2883 2884 2885 2886 2887 2888 2889 |
* Unregister event and free resources. * * Gets called from workqueue. */ static void cgroup_event_remove(struct work_struct *work) { struct cgroup_event *event = container_of(work, struct cgroup_event, remove); struct cgroup *cgrp = event->cgrp; |
0dea11687 cgroup: implement... |
2890 2891 2892 |
event->cft->unregister_event(cgrp, event->cft, event->eventfd); eventfd_ctx_put(event->eventfd); |
0dea11687 cgroup: implement... |
2893 |
kfree(event); |
a0a4db548 cgroups: remove e... |
2894 |
dput(cgrp->dentry); |
0dea11687 cgroup: implement... |
2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 |
} /* * Gets called on POLLHUP on eventfd when user closes it. * * Called with wqh->lock held and interrupts disabled. */ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode, int sync, void *key) { struct cgroup_event *event = container_of(wait, struct cgroup_event, wait); struct cgroup *cgrp = event->cgrp; unsigned long flags = (unsigned long)key; if (flags & POLLHUP) { |
a93d2f174 sched, wait: Use ... |
2911 |
__remove_wait_queue(event->wqh, &event->wait); |
0dea11687 cgroup: implement... |
2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 |
spin_lock(&cgrp->event_list_lock); list_del(&event->list); spin_unlock(&cgrp->event_list_lock); /* * We are in atomic context, but cgroup_event_remove() may * sleep, so we have to call it in workqueue. */ schedule_work(&event->remove); } return 0; } static void cgroup_event_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt) { struct cgroup_event *event = container_of(pt, struct cgroup_event, pt); event->wqh = wqh; add_wait_queue(wqh, &event->wait); } /* * Parse input and register new cgroup event handler. * * Input must be in format '<event_fd> <control_fd> <args>'. * Interpretation of args is defined by control file implementation. */ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft, const char *buffer) { struct cgroup_event *event = NULL; unsigned int efd, cfd; struct file *efile = NULL; struct file *cfile = NULL; char *endp; int ret; efd = simple_strtoul(buffer, &endp, 10); if (*endp != ' ') return -EINVAL; buffer = endp + 1; cfd = simple_strtoul(buffer, &endp, 10); if ((*endp != ' ') && (*endp != '\0')) return -EINVAL; buffer = endp + 1; event = kzalloc(sizeof(*event), GFP_KERNEL); if (!event) return -ENOMEM; event->cgrp = cgrp; INIT_LIST_HEAD(&event->list); init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc); init_waitqueue_func_entry(&event->wait, cgroup_event_wake); INIT_WORK(&event->remove, cgroup_event_remove); efile = eventfd_fget(efd); if (IS_ERR(efile)) { ret = PTR_ERR(efile); goto fail; } event->eventfd = eventfd_ctx_fileget(efile); if (IS_ERR(event->eventfd)) { ret = PTR_ERR(event->eventfd); goto fail; } cfile = fget(cfd); if (!cfile) { ret = -EBADF; goto fail; } /* the process need read permission on control file */ ret = file_permission(cfile, MAY_READ); if (ret < 0) goto fail; event->cft = __file_cft(cfile); if (IS_ERR(event->cft)) { ret = PTR_ERR(event->cft); goto fail; } if (!event->cft->register_event || !event->cft->unregister_event) { ret = -EINVAL; goto fail; } ret = event->cft->register_event(cgrp, event->cft, event->eventfd, buffer); if (ret) goto fail; if (efile->f_op->poll(efile, &event->pt) & POLLHUP) { event->cft->unregister_event(cgrp, event->cft, event->eventfd); ret = 0; goto fail; } |
a0a4db548 cgroups: remove e... |
3014 3015 3016 3017 3018 3019 |
/* * Events should be removed after rmdir of cgroup directory, but before * destroying subsystem state objects. Let's take reference to cgroup * directory dentry to do that. */ dget(cgrp->dentry); |
0dea11687 cgroup: implement... |
3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 |
spin_lock(&cgrp->event_list_lock); list_add(&event->list, &cgrp->event_list); spin_unlock(&cgrp->event_list_lock); fput(cfile); fput(efile); return 0; fail: if (cfile) fput(cfile); if (event && event->eventfd && !IS_ERR(event->eventfd)) eventfd_ctx_put(event->eventfd); if (!IS_ERR_OR_NULL(efile)) fput(efile); kfree(event); return ret; } /* |
bbcb81d09 Task Control Grou... |
3045 3046 |
* for the common functions, 'private' gives the type of file */ |
102a775e3 cgroups: add a re... |
3047 3048 |
/* for hysterical raisins, we can't put this on the older files */ #define CGROUP_FILE_GENERIC_PREFIX "cgroup." |
81a6a5cdd Task Control Grou... |
3049 3050 3051 3052 |
static struct cftype files[] = { { .name = "tasks", .open = cgroup_tasks_open, |
af351026a cgroup files: tur... |
3053 |
.write_u64 = cgroup_tasks_write, |
102a775e3 cgroups: add a re... |
3054 |
.release = cgroup_pidlist_release, |
099fca322 cgroups: show cor... |
3055 |
.mode = S_IRUGO | S_IWUSR, |
81a6a5cdd Task Control Grou... |
3056 |
}, |
102a775e3 cgroups: add a re... |
3057 3058 3059 3060 3061 3062 3063 |
{ .name = CGROUP_FILE_GENERIC_PREFIX "procs", .open = cgroup_procs_open, /* .write_u64 = cgroup_procs_write, TODO */ .release = cgroup_pidlist_release, .mode = S_IRUGO, }, |
81a6a5cdd Task Control Grou... |
3064 3065 |
{ .name = "notify_on_release", |
f4c753b7e CGroup API files:... |
3066 |
.read_u64 = cgroup_read_notify_on_release, |
6379c1061 cgroup files: mov... |
3067 |
.write_u64 = cgroup_write_notify_on_release, |
81a6a5cdd Task Control Grou... |
3068 |
}, |
0dea11687 cgroup: implement... |
3069 3070 3071 3072 3073 |
{ .name = CGROUP_FILE_GENERIC_PREFIX "event_control", .write_string = cgroup_write_event_control, .mode = S_IWUGO, }, |
81a6a5cdd Task Control Grou... |
3074 3075 3076 3077 |
}; static struct cftype cft_release_agent = { .name = "release_agent", |
e788e066c cgroup files: mov... |
3078 3079 3080 |
.read_seq_string = cgroup_release_agent_show, .write_string = cgroup_release_agent_write, .max_write_len = PATH_MAX, |
bbcb81d09 Task Control Grou... |
3081 |
}; |
bd89aabc6 Control groups: R... |
3082 |
static int cgroup_populate_dir(struct cgroup *cgrp) |
ddbcc7e8e Task Control Grou... |
3083 3084 3085 3086 3087 |
{ int err; struct cgroup_subsys *ss; /* First clear out any existing files */ |
bd89aabc6 Control groups: R... |
3088 |
cgroup_clear_directory(cgrp->dentry); |
ddbcc7e8e Task Control Grou... |
3089 |
|
bd89aabc6 Control groups: R... |
3090 |
err = cgroup_add_files(cgrp, NULL, files, ARRAY_SIZE(files)); |
bbcb81d09 Task Control Grou... |
3091 3092 |
if (err < 0) return err; |
bd89aabc6 Control groups: R... |
3093 3094 |
if (cgrp == cgrp->top_cgroup) { if ((err = cgroup_add_file(cgrp, NULL, &cft_release_agent)) < 0) |
81a6a5cdd Task Control Grou... |
3095 3096 |
return err; } |
bd89aabc6 Control groups: R... |
3097 3098 |
for_each_subsys(cgrp->root, ss) { if (ss->populate && (err = ss->populate(ss, cgrp)) < 0) |
ddbcc7e8e Task Control Grou... |
3099 3100 |
return err; } |
38460b48d cgroup: CSS ID su... |
3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 |
/* This cgroup is ready now */ for_each_subsys(cgrp->root, ss) { struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id]; /* * Update id->css pointer and make this css visible from * CSS ID functions. This pointer will be dereferened * from RCU-read-side without locks. */ if (css->id) rcu_assign_pointer(css->id->css, css); } |
ddbcc7e8e Task Control Grou... |
3112 3113 3114 3115 3116 3117 |
return 0; } static void init_cgroup_css(struct cgroup_subsys_state *css, struct cgroup_subsys *ss, |
bd89aabc6 Control groups: R... |
3118 |
struct cgroup *cgrp) |
ddbcc7e8e Task Control Grou... |
3119 |
{ |
bd89aabc6 Control groups: R... |
3120 |
css->cgroup = cgrp; |
e7c5ec919 cgroups: add css_... |
3121 |
atomic_set(&css->refcnt, 1); |
ddbcc7e8e Task Control Grou... |
3122 |
css->flags = 0; |
38460b48d cgroup: CSS ID su... |
3123 |
css->id = NULL; |
bd89aabc6 Control groups: R... |
3124 |
if (cgrp == dummytop) |
ddbcc7e8e Task Control Grou... |
3125 |
set_bit(CSS_ROOT, &css->flags); |
bd89aabc6 Control groups: R... |
3126 3127 |
BUG_ON(cgrp->subsys[ss->subsys_id]); cgrp->subsys[ss->subsys_id] = css; |
ddbcc7e8e Task Control Grou... |
3128 |
} |
999cd8a45 cgroups: add a pe... |
3129 3130 3131 3132 |
static void cgroup_lock_hierarchy(struct cgroupfs_root *root) { /* We need to take each hierarchy_mutex in a consistent order */ int i; |
aae8aab40 cgroups: revamp s... |
3133 3134 3135 3136 |
/* * No worry about a race with rebind_subsystems that might mess up the * locking order, since both parties are under cgroup_mutex. */ |
999cd8a45 cgroups: add a pe... |
3137 3138 |
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; |
aae8aab40 cgroups: revamp s... |
3139 3140 |
if (ss == NULL) continue; |
999cd8a45 cgroups: add a pe... |
3141 |
if (ss->root == root) |
cfebe563b cgroups: fix lock... |
3142 |
mutex_lock(&ss->hierarchy_mutex); |
999cd8a45 cgroups: add a pe... |
3143 3144 3145 3146 3147 3148 3149 3150 3151 |
} } static void cgroup_unlock_hierarchy(struct cgroupfs_root *root) { int i; for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; |
aae8aab40 cgroups: revamp s... |
3152 3153 |
if (ss == NULL) continue; |
999cd8a45 cgroups: add a pe... |
3154 3155 3156 3157 |
if (ss->root == root) mutex_unlock(&ss->hierarchy_mutex); } } |
ddbcc7e8e Task Control Grou... |
3158 |
/* |
a043e3b2c cgroup: fix comments |
3159 3160 3161 3162 |
* cgroup_create - create a cgroup * @parent: cgroup that will be parent of the new cgroup * @dentry: dentry of the new cgroup * @mode: mode to set on new inode |
ddbcc7e8e Task Control Grou... |
3163 |
* |
a043e3b2c cgroup: fix comments |
3164 |
* Must be called with the mutex on the parent inode held |
ddbcc7e8e Task Control Grou... |
3165 |
*/ |
ddbcc7e8e Task Control Grou... |
3166 |
static long cgroup_create(struct cgroup *parent, struct dentry *dentry, |
099fca322 cgroups: show cor... |
3167 |
mode_t mode) |
ddbcc7e8e Task Control Grou... |
3168 |
{ |
bd89aabc6 Control groups: R... |
3169 |
struct cgroup *cgrp; |
ddbcc7e8e Task Control Grou... |
3170 3171 3172 3173 |
struct cgroupfs_root *root = parent->root; int err = 0; struct cgroup_subsys *ss; struct super_block *sb = root->sb; |
bd89aabc6 Control groups: R... |
3174 3175 |
cgrp = kzalloc(sizeof(*cgrp), GFP_KERNEL); if (!cgrp) |
ddbcc7e8e Task Control Grou... |
3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 |
return -ENOMEM; /* Grab a reference on the superblock so the hierarchy doesn't * get deleted on unmount if there are child cgroups. This * can be done outside cgroup_mutex, since the sb can't * disappear while someone has an open control file on the * fs */ atomic_inc(&sb->s_active); mutex_lock(&cgroup_mutex); |
cc31edcee cgroups: convert ... |
3186 |
init_cgroup_housekeeping(cgrp); |
ddbcc7e8e Task Control Grou... |
3187 |
|
bd89aabc6 Control groups: R... |
3188 3189 3190 |
cgrp->parent = parent; cgrp->root = parent->root; cgrp->top_cgroup = parent->top_cgroup; |
ddbcc7e8e Task Control Grou... |
3191 |
|
b6abdb0e6 cgroup: fix defau... |
3192 3193 |
if (notify_on_release(parent)) set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); |
ddbcc7e8e Task Control Grou... |
3194 |
for_each_subsys(root, ss) { |
bd89aabc6 Control groups: R... |
3195 |
struct cgroup_subsys_state *css = ss->create(ss, cgrp); |
4528fd059 cgroups: fix to r... |
3196 |
|
ddbcc7e8e Task Control Grou... |
3197 3198 3199 3200 |
if (IS_ERR(css)) { err = PTR_ERR(css); goto err_destroy; } |
bd89aabc6 Control groups: R... |
3201 |
init_cgroup_css(css, ss, cgrp); |
4528fd059 cgroups: fix to r... |
3202 3203 3204 |
if (ss->use_id) { err = alloc_css_id(ss, parent, cgrp); if (err) |
38460b48d cgroup: CSS ID su... |
3205 |
goto err_destroy; |
4528fd059 cgroups: fix to r... |
3206 |
} |
38460b48d cgroup: CSS ID su... |
3207 |
/* At error, ->destroy() callback has to free assigned ID. */ |
ddbcc7e8e Task Control Grou... |
3208 |
} |
999cd8a45 cgroups: add a pe... |
3209 |
cgroup_lock_hierarchy(root); |
bd89aabc6 Control groups: R... |
3210 |
list_add(&cgrp->sibling, &cgrp->parent->children); |
999cd8a45 cgroups: add a pe... |
3211 |
cgroup_unlock_hierarchy(root); |
ddbcc7e8e Task Control Grou... |
3212 |
root->number_of_cgroups++; |
bd89aabc6 Control groups: R... |
3213 |
err = cgroup_create_dir(cgrp, dentry, mode); |
ddbcc7e8e Task Control Grou... |
3214 3215 3216 3217 |
if (err < 0) goto err_remove; /* The cgroup directory was pre-locked for us */ |
bd89aabc6 Control groups: R... |
3218 |
BUG_ON(!mutex_is_locked(&cgrp->dentry->d_inode->i_mutex)); |
ddbcc7e8e Task Control Grou... |
3219 |
|
bd89aabc6 Control groups: R... |
3220 |
err = cgroup_populate_dir(cgrp); |
ddbcc7e8e Task Control Grou... |
3221 3222 3223 |
/* If err < 0, we have a half-filled directory - oh well ;) */ mutex_unlock(&cgroup_mutex); |
bd89aabc6 Control groups: R... |
3224 |
mutex_unlock(&cgrp->dentry->d_inode->i_mutex); |
ddbcc7e8e Task Control Grou... |
3225 3226 3227 3228 |
return 0; err_remove: |
baef99a08 cgroups: use hier... |
3229 |
cgroup_lock_hierarchy(root); |
bd89aabc6 Control groups: R... |
3230 |
list_del(&cgrp->sibling); |
baef99a08 cgroups: use hier... |
3231 |
cgroup_unlock_hierarchy(root); |
ddbcc7e8e Task Control Grou... |
3232 3233 3234 3235 3236 |
root->number_of_cgroups--; err_destroy: for_each_subsys(root, ss) { |
bd89aabc6 Control groups: R... |
3237 3238 |
if (cgrp->subsys[ss->subsys_id]) ss->destroy(ss, cgrp); |
ddbcc7e8e Task Control Grou... |
3239 3240 3241 3242 3243 3244 |
} mutex_unlock(&cgroup_mutex); /* Release the reference count that we took on the superblock */ deactivate_super(sb); |
bd89aabc6 Control groups: R... |
3245 |
kfree(cgrp); |
ddbcc7e8e Task Control Grou... |
3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 |
return err; } static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode) { struct cgroup *c_parent = dentry->d_parent->d_fsdata; /* the vfs holds inode->i_mutex already */ return cgroup_create(c_parent, dentry, mode | S_IFDIR); } |
55b6fd016 cgroup: uninline ... |
3256 |
static int cgroup_has_css_refs(struct cgroup *cgrp) |
81a6a5cdd Task Control Grou... |
3257 3258 3259 |
{ /* Check the reference count on each subsystem. Since we * already established that there are no tasks in the |
e7c5ec919 cgroups: add css_... |
3260 |
* cgroup, if the css refcount is also 1, then there should |
81a6a5cdd Task Control Grou... |
3261 3262 3263 3264 3265 3266 3267 |
* 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; |
aae8aab40 cgroups: revamp s... |
3268 3269 3270 3271 3272 |
/* * We won't need to lock the subsys array, because the subsystems * we're concerned about aren't going anywhere since our cgroup root * has a reference on them. */ |
81a6a5cdd Task Control Grou... |
3273 3274 3275 |
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; struct cgroup_subsys_state *css; |
aae8aab40 cgroups: revamp s... |
3276 3277 |
/* Skip subsystems not present or not in this hierarchy */ if (ss == NULL || ss->root != cgrp->root) |
81a6a5cdd Task Control Grou... |
3278 |
continue; |
bd89aabc6 Control groups: R... |
3279 |
css = cgrp->subsys[ss->subsys_id]; |
81a6a5cdd Task Control Grou... |
3280 3281 3282 3283 3284 3285 |
/* 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. */ |
e7c5ec919 cgroups: add css_... |
3286 |
if (css && (atomic_read(&css->refcnt) > 1)) |
81a6a5cdd Task Control Grou... |
3287 |
return 1; |
81a6a5cdd Task Control Grou... |
3288 3289 3290 |
} return 0; } |
e7c5ec919 cgroups: add css_... |
3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 |
/* * Atomically mark all (or else none) of the cgroup's CSS objects as * CSS_REMOVED. Return true on success, or false if the cgroup has * busy subsystems. Call with cgroup_mutex held */ static int cgroup_clear_css_refs(struct cgroup *cgrp) { struct cgroup_subsys *ss; unsigned long flags; bool failed = false; local_irq_save(flags); for_each_subsys(cgrp->root, ss) { struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id]; int refcnt; |
804b3c28a cgroups: add cpu_... |
3306 |
while (1) { |
e7c5ec919 cgroups: add css_... |
3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 |
/* We can only remove a CSS with a refcnt==1 */ refcnt = atomic_read(&css->refcnt); if (refcnt > 1) { failed = true; goto done; } BUG_ON(!refcnt); /* * Drop the refcnt to 0 while we check other * subsystems. This will cause any racing * css_tryget() to spin until we set the * CSS_REMOVED bits or abort */ |
804b3c28a cgroups: add cpu_... |
3320 3321 3322 3323 |
if (atomic_cmpxchg(&css->refcnt, refcnt, 0) == refcnt) break; cpu_relax(); } |
e7c5ec919 cgroups: add css_... |
3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 |
} done: for_each_subsys(cgrp->root, ss) { struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id]; if (failed) { /* * Restore old refcnt if we previously managed * to clear it from 1 to 0 */ if (!atomic_read(&css->refcnt)) atomic_set(&css->refcnt, 1); } else { /* Commit the fact that the CSS is removed */ set_bit(CSS_REMOVED, &css->flags); } } local_irq_restore(flags); return !failed; } |
ddbcc7e8e Task Control Grou... |
3343 3344 |
static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry) { |
bd89aabc6 Control groups: R... |
3345 |
struct cgroup *cgrp = dentry->d_fsdata; |
ddbcc7e8e Task Control Grou... |
3346 3347 |
struct dentry *d; struct cgroup *parent; |
ec64f5154 cgroup: fix frequ... |
3348 |
DEFINE_WAIT(wait); |
4ab78683c cgroups: fix race... |
3349 |
struct cgroup_event *event, *tmp; |
ec64f5154 cgroup: fix frequ... |
3350 |
int ret; |
ddbcc7e8e Task Control Grou... |
3351 3352 |
/* the vfs holds both inode->i_mutex already */ |
ec64f5154 cgroup: fix frequ... |
3353 |
again: |
ddbcc7e8e Task Control Grou... |
3354 |
mutex_lock(&cgroup_mutex); |
bd89aabc6 Control groups: R... |
3355 |
if (atomic_read(&cgrp->count) != 0) { |
ddbcc7e8e Task Control Grou... |
3356 3357 3358 |
mutex_unlock(&cgroup_mutex); return -EBUSY; } |
bd89aabc6 Control groups: R... |
3359 |
if (!list_empty(&cgrp->children)) { |
ddbcc7e8e Task Control Grou... |
3360 3361 3362 |
mutex_unlock(&cgroup_mutex); return -EBUSY; } |
3fa59dfbc cgroup: fix poten... |
3363 |
mutex_unlock(&cgroup_mutex); |
a043e3b2c cgroup: fix comments |
3364 |
|
4fca88c87 memory cgroup enh... |
3365 |
/* |
887032670 cgroup avoid perm... |
3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 |
* In general, subsystem has no css->refcnt after pre_destroy(). But * in racy cases, subsystem may have to get css->refcnt after * pre_destroy() and it makes rmdir return with -EBUSY. This sometimes * make rmdir return -EBUSY too often. To avoid that, we use waitqueue * for cgroup's rmdir. CGRP_WAIT_ON_RMDIR is for synchronizing rmdir * and subsystem's reference count handling. Please see css_get/put * and css_tryget() and cgroup_wakeup_rmdir_waiter() implementation. */ set_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags); /* |
a043e3b2c cgroup: fix comments |
3377 3378 |
* Call pre_destroy handlers of subsys. Notify subsystems * that rmdir() request comes. |
4fca88c87 memory cgroup enh... |
3379 |
*/ |
ec64f5154 cgroup: fix frequ... |
3380 |
ret = cgroup_call_pre_destroy(cgrp); |
887032670 cgroup avoid perm... |
3381 3382 |
if (ret) { clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags); |
ec64f5154 cgroup: fix frequ... |
3383 |
return ret; |
887032670 cgroup avoid perm... |
3384 |
} |
ddbcc7e8e Task Control Grou... |
3385 |
|
3fa59dfbc cgroup: fix poten... |
3386 3387 |
mutex_lock(&cgroup_mutex); parent = cgrp->parent; |
ec64f5154 cgroup: fix frequ... |
3388 |
if (atomic_read(&cgrp->count) || !list_empty(&cgrp->children)) { |
887032670 cgroup avoid perm... |
3389 |
clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags); |
ddbcc7e8e Task Control Grou... |
3390 3391 3392 |
mutex_unlock(&cgroup_mutex); return -EBUSY; } |
ec64f5154 cgroup: fix frequ... |
3393 |
prepare_to_wait(&cgroup_rmdir_waitq, &wait, TASK_INTERRUPTIBLE); |
ec64f5154 cgroup: fix frequ... |
3394 3395 |
if (!cgroup_clear_css_refs(cgrp)) { mutex_unlock(&cgroup_mutex); |
887032670 cgroup avoid perm... |
3396 3397 3398 3399 3400 3401 |
/* * Because someone may call cgroup_wakeup_rmdir_waiter() before * prepare_to_wait(), we need to check this flag. */ if (test_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags)) schedule(); |
ec64f5154 cgroup: fix frequ... |
3402 3403 3404 3405 3406 3407 3408 3409 3410 |
finish_wait(&cgroup_rmdir_waitq, &wait); clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags); if (signal_pending(current)) return -EINTR; goto again; } /* NO css_tryget() can success after here. */ finish_wait(&cgroup_rmdir_waitq, &wait); clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags); |
ddbcc7e8e Task Control Grou... |
3411 |
|
81a6a5cdd Task Control Grou... |
3412 |
spin_lock(&release_list_lock); |
bd89aabc6 Control groups: R... |
3413 3414 3415 |
set_bit(CGRP_REMOVED, &cgrp->flags); if (!list_empty(&cgrp->release_list)) list_del(&cgrp->release_list); |
81a6a5cdd Task Control Grou... |
3416 |
spin_unlock(&release_list_lock); |
999cd8a45 cgroups: add a pe... |
3417 3418 3419 |
cgroup_lock_hierarchy(cgrp->root); /* delete this cgroup from parent->children */ |
bd89aabc6 Control groups: R... |
3420 |
list_del(&cgrp->sibling); |
999cd8a45 cgroups: add a pe... |
3421 |
cgroup_unlock_hierarchy(cgrp->root); |
bd89aabc6 Control groups: R... |
3422 3423 |
spin_lock(&cgrp->dentry->d_lock); d = dget(cgrp->dentry); |
ddbcc7e8e Task Control Grou... |
3424 3425 3426 3427 |
spin_unlock(&d->d_lock); cgroup_d_remove_dir(d); dput(d); |
ddbcc7e8e Task Control Grou... |
3428 |
|
bd89aabc6 Control groups: R... |
3429 |
set_bit(CGRP_RELEASABLE, &parent->flags); |
81a6a5cdd Task Control Grou... |
3430 |
check_for_release(parent); |
4ab78683c cgroups: fix race... |
3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 |
/* * Unregister events and notify userspace. * Notify userspace about cgroup removing only after rmdir of cgroup * directory to avoid race between userspace and kernelspace */ spin_lock(&cgrp->event_list_lock); list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) { list_del(&event->list); remove_wait_queue(event->wqh, &event->wait); eventfd_signal(event->eventfd, 1); schedule_work(&event->remove); } spin_unlock(&cgrp->event_list_lock); |
ddbcc7e8e Task Control Grou... |
3444 |
mutex_unlock(&cgroup_mutex); |
ddbcc7e8e Task Control Grou... |
3445 3446 |
return 0; } |
06a119204 cgroup: annotate ... |
3447 |
static void __init cgroup_init_subsys(struct cgroup_subsys *ss) |
ddbcc7e8e Task Control Grou... |
3448 |
{ |
ddbcc7e8e Task Control Grou... |
3449 |
struct cgroup_subsys_state *css; |
cfe36bde5 Improve cgroup pr... |
3450 3451 3452 |
printk(KERN_INFO "Initializing cgroup subsys %s ", ss->name); |
ddbcc7e8e Task Control Grou... |
3453 3454 |
/* Create the top cgroup state for this subsystem */ |
33a68ac1c cgroups: add inac... |
3455 |
list_add(&ss->sibling, &rootnode.subsys_list); |
ddbcc7e8e Task Control Grou... |
3456 3457 3458 3459 3460 |
ss->root = &rootnode; css = ss->create(ss, dummytop); /* We don't handle early failures gracefully */ BUG_ON(IS_ERR(css)); init_cgroup_css(css, ss, dummytop); |
e8d55fdeb cgroups: simplify... |
3461 |
/* Update the init_css_set to contain a subsys |
817929ec2 Task Control Grou... |
3462 |
* pointer to this state - since the subsystem is |
e8d55fdeb cgroups: simplify... |
3463 3464 3465 |
* newly registered, all tasks and hence the * init_css_set is in the subsystem's top cgroup. */ init_css_set.subsys[ss->subsys_id] = dummytop->subsys[ss->subsys_id]; |
ddbcc7e8e Task Control Grou... |
3466 3467 |
need_forkexit_callback |= ss->fork || ss->exit; |
e8d55fdeb cgroups: simplify... |
3468 3469 3470 3471 |
/* At system boot, before all subsystems have been * registered, no tasks have been forked, so we don't * need to invoke fork callbacks here. */ BUG_ON(!list_empty(&init_task.tasks)); |
999cd8a45 cgroups: add a pe... |
3472 |
mutex_init(&ss->hierarchy_mutex); |
cfebe563b cgroups: fix lock... |
3473 |
lockdep_set_class(&ss->hierarchy_mutex, &ss->subsys_key); |
ddbcc7e8e Task Control Grou... |
3474 |
ss->active = 1; |
e6a1105ba cgroups: subsyste... |
3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 |
/* this function shouldn't be used with modular subsystems, since they * need to register a subsys_id, among other things */ BUG_ON(ss->module); } /** * cgroup_load_subsys: load and register a modular subsystem at runtime * @ss: the subsystem to load * * This function should be called in a modular subsystem's initcall. If the |
883931612 Fix typos in comm... |
3486 |
* subsystem is built as a module, it will be assigned a new subsys_id and set |
e6a1105ba cgroups: subsyste... |
3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 |
* up for use. If the subsystem is built-in anyway, work is delegated to the * simpler cgroup_init_subsys. */ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss) { int i; struct cgroup_subsys_state *css; /* check name and function validity */ if (ss->name == NULL || strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN || ss->create == NULL || ss->destroy == NULL) return -EINVAL; /* * we don't support callbacks in modular subsystems. this check is * before the ss->module check for consistency; a subsystem that could * be a module should still have no callbacks even if the user isn't * compiling it as one. */ if (ss->fork || ss->exit) return -EINVAL; /* * an optionally modular subsystem is built-in: we want to do nothing, * since cgroup_init_subsys will have already taken care of it. */ if (ss->module == NULL) { /* a few sanity checks */ BUG_ON(ss->subsys_id >= CGROUP_BUILTIN_SUBSYS_COUNT); BUG_ON(subsys[ss->subsys_id] != ss); return 0; } /* * need to register a subsys id before anything else - for example, * init_cgroup_css needs it. */ mutex_lock(&cgroup_mutex); /* find the first empty slot in the array */ for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) { if (subsys[i] == NULL) break; } if (i == CGROUP_SUBSYS_COUNT) { /* maximum number of subsystems already registered! */ mutex_unlock(&cgroup_mutex); return -EBUSY; } /* assign ourselves the subsys_id */ ss->subsys_id = i; subsys[i] = ss; /* * no ss->create seems to need anything important in the ss struct, so * this can happen first (i.e. before the rootnode attachment). */ css = ss->create(ss, dummytop); if (IS_ERR(css)) { /* failure case - need to deassign the subsys[] slot. */ subsys[i] = NULL; mutex_unlock(&cgroup_mutex); return PTR_ERR(css); } list_add(&ss->sibling, &rootnode.subsys_list); ss->root = &rootnode; /* our new subsystem will be attached to the dummy hierarchy. */ init_cgroup_css(css, ss, dummytop); /* init_idr must be after init_cgroup_css because it sets css->id. */ if (ss->use_id) { int ret = cgroup_init_idr(ss, css); if (ret) { dummytop->subsys[ss->subsys_id] = NULL; ss->destroy(ss, dummytop); subsys[i] = NULL; mutex_unlock(&cgroup_mutex); return ret; } } /* * Now we need to entangle the css into the existing css_sets. unlike * in cgroup_init_subsys, there are now multiple css_sets, so each one * will need a new pointer to it; done by iterating the css_set_table. * furthermore, modifying the existing css_sets will corrupt the hash * table state, so each changed css_set will need its hash recomputed. * this is all done under the css_set_lock. */ write_lock(&css_set_lock); for (i = 0; i < CSS_SET_TABLE_SIZE; i++) { struct css_set *cg; struct hlist_node *node, *tmp; struct hlist_head *bucket = &css_set_table[i], *new_bucket; hlist_for_each_entry_safe(cg, node, tmp, bucket, hlist) { /* skip entries that we already rehashed */ if (cg->subsys[ss->subsys_id]) continue; /* remove existing entry */ hlist_del(&cg->hlist); /* set new value */ cg->subsys[ss->subsys_id] = css; /* recompute hash and restore entry */ new_bucket = css_set_hash(cg->subsys); hlist_add_head(&cg->hlist, new_bucket); } } write_unlock(&css_set_lock); mutex_init(&ss->hierarchy_mutex); lockdep_set_class(&ss->hierarchy_mutex, &ss->subsys_key); ss->active = 1; |
e6a1105ba cgroups: subsyste... |
3600 3601 3602 |
/* success! */ mutex_unlock(&cgroup_mutex); return 0; |
ddbcc7e8e Task Control Grou... |
3603 |
} |
e6a1105ba cgroups: subsyste... |
3604 |
EXPORT_SYMBOL_GPL(cgroup_load_subsys); |
ddbcc7e8e Task Control Grou... |
3605 3606 |
/** |
cf5d5941f cgroups: subsyste... |
3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 |
* cgroup_unload_subsys: unload a modular subsystem * @ss: the subsystem to unload * * This function should be called in a modular subsystem's exitcall. When this * function is invoked, the refcount on the subsystem's module will be 0, so * the subsystem will not be attached to any hierarchy. */ void cgroup_unload_subsys(struct cgroup_subsys *ss) { struct cg_cgroup_link *link; struct hlist_head *hhead; BUG_ON(ss->module == NULL); /* * we shouldn't be called if the subsystem is in use, and the use of * try_module_get in parse_cgroupfs_options should ensure that it * doesn't start being used while we're killing it off. */ BUG_ON(ss->root != &rootnode); mutex_lock(&cgroup_mutex); /* deassign the subsys_id */ BUG_ON(ss->subsys_id < CGROUP_BUILTIN_SUBSYS_COUNT); subsys[ss->subsys_id] = NULL; /* remove subsystem from rootnode's list of subsystems */ list_del(&ss->sibling); /* * disentangle the css from all css_sets attached to the dummytop. as * in loading, we need to pay our respects to the hashtable gods. */ write_lock(&css_set_lock); list_for_each_entry(link, &dummytop->css_sets, cgrp_link_list) { struct css_set *cg = link->cg; hlist_del(&cg->hlist); BUG_ON(!cg->subsys[ss->subsys_id]); cg->subsys[ss->subsys_id] = NULL; hhead = css_set_hash(cg->subsys); hlist_add_head(&cg->hlist, hhead); } write_unlock(&css_set_lock); /* * remove subsystem's css from the dummytop and free it - need to free * before marking as null because ss->destroy needs the cgrp->subsys * pointer to find their state. note that this also takes care of * freeing the css_id. */ ss->destroy(ss, dummytop); dummytop->subsys[ss->subsys_id] = NULL; mutex_unlock(&cgroup_mutex); } EXPORT_SYMBOL_GPL(cgroup_unload_subsys); /** |
a043e3b2c cgroup: fix comments |
3666 3667 3668 3669 |
* cgroup_init_early - cgroup initialization at system boot * * Initialize cgroups at system boot, and initialize any * subsystems that request early init. |
ddbcc7e8e Task Control Grou... |
3670 3671 3672 3673 |
*/ int __init cgroup_init_early(void) { int i; |
146aa1bd0 cgroups: fix prob... |
3674 |
atomic_set(&init_css_set.refcount, 1); |
817929ec2 Task Control Grou... |
3675 3676 |
INIT_LIST_HEAD(&init_css_set.cg_links); INIT_LIST_HEAD(&init_css_set.tasks); |
472b1053f cgroups: use a ha... |
3677 |
INIT_HLIST_NODE(&init_css_set.hlist); |
817929ec2 Task Control Grou... |
3678 |
css_set_count = 1; |
ddbcc7e8e Task Control Grou... |
3679 |
init_cgroup_root(&rootnode); |
817929ec2 Task Control Grou... |
3680 3681 3682 3683 |
root_count = 1; init_task.cgroups = &init_css_set; init_css_set_link.cg = &init_css_set; |
7717f7ba9 cgroups: add a ba... |
3684 |
init_css_set_link.cgrp = dummytop; |
bd89aabc6 Control groups: R... |
3685 |
list_add(&init_css_set_link.cgrp_link_list, |
817929ec2 Task Control Grou... |
3686 3687 3688 |
&rootnode.top_cgroup.css_sets); list_add(&init_css_set_link.cg_link_list, &init_css_set.cg_links); |
ddbcc7e8e Task Control Grou... |
3689 |
|
472b1053f cgroups: use a ha... |
3690 3691 |
for (i = 0; i < CSS_SET_TABLE_SIZE; i++) INIT_HLIST_HEAD(&css_set_table[i]); |
aae8aab40 cgroups: revamp s... |
3692 3693 |
/* at bootup time, we don't worry about modular subsystems */ for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { |
ddbcc7e8e Task Control Grou... |
3694 3695 3696 3697 3698 3699 3700 |
struct cgroup_subsys *ss = subsys[i]; BUG_ON(!ss->name); BUG_ON(strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN); BUG_ON(!ss->create); BUG_ON(!ss->destroy); if (ss->subsys_id != i) { |
cfe36bde5 Improve cgroup pr... |
3701 3702 |
printk(KERN_ERR "cgroup: Subsys %s id == %d ", |
ddbcc7e8e Task Control Grou... |
3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 |
ss->name, ss->subsys_id); BUG(); } if (ss->early_init) cgroup_init_subsys(ss); } return 0; } /** |
a043e3b2c cgroup: fix comments |
3714 3715 3716 3717 |
* cgroup_init - cgroup initialization * * Register cgroup filesystem and /proc file, and initialize * any subsystems that didn't request early init. |
ddbcc7e8e Task Control Grou... |
3718 3719 3720 3721 3722 |
*/ int __init cgroup_init(void) { int err; int i; |
472b1053f cgroups: use a ha... |
3723 |
struct hlist_head *hhead; |
a424316ca Task Control Grou... |
3724 3725 3726 3727 |
err = bdi_init(&cgroup_backing_dev_info); if (err) return err; |
ddbcc7e8e Task Control Grou... |
3728 |
|
aae8aab40 cgroups: revamp s... |
3729 3730 |
/* at bootup time, we don't worry about modular subsystems */ for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { |
ddbcc7e8e Task Control Grou... |
3731 3732 3733 |
struct cgroup_subsys *ss = subsys[i]; if (!ss->early_init) cgroup_init_subsys(ss); |
38460b48d cgroup: CSS ID su... |
3734 |
if (ss->use_id) |
e6a1105ba cgroups: subsyste... |
3735 |
cgroup_init_idr(ss, init_css_set.subsys[ss->subsys_id]); |
ddbcc7e8e Task Control Grou... |
3736 |
} |
472b1053f cgroups: use a ha... |
3737 3738 3739 |
/* Add init_css_set to the hash table */ hhead = css_set_hash(init_css_set.subsys); hlist_add_head(&init_css_set.hlist, hhead); |
2c6ab6d20 cgroups: allow cg... |
3740 |
BUG_ON(!init_root_id(&rootnode)); |
676db4af0 cgroupfs: create ... |
3741 3742 3743 3744 3745 3746 |
cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj); if (!cgroup_kobj) { err = -ENOMEM; goto out; } |
ddbcc7e8e Task Control Grou... |
3747 |
err = register_filesystem(&cgroup_fs_type); |
676db4af0 cgroupfs: create ... |
3748 3749 |
if (err < 0) { kobject_put(cgroup_kobj); |
ddbcc7e8e Task Control Grou... |
3750 |
goto out; |
676db4af0 cgroupfs: create ... |
3751 |
} |
ddbcc7e8e Task Control Grou... |
3752 |
|
46ae220be cgroup: switch to... |
3753 |
proc_create("cgroups", 0, NULL, &proc_cgroupstats_operations); |
a424316ca Task Control Grou... |
3754 |
|
ddbcc7e8e Task Control Grou... |
3755 |
out: |
a424316ca Task Control Grou... |
3756 3757 |
if (err) bdi_destroy(&cgroup_backing_dev_info); |
ddbcc7e8e Task Control Grou... |
3758 3759 |
return err; } |
b4f48b636 Task Control Grou... |
3760 |
|
a424316ca Task Control Grou... |
3761 3762 3763 3764 3765 3766 |
/* * proc_cgroup_show() * - Print task's cgroup paths into seq_file, one line for each hierarchy * - Used for /proc/<pid>/cgroup. * - No need to task_lock(tsk) on this tsk->cgroup reference, as it * doesn't really matter if tsk->cgroup changes after we read it, |
956db3ca0 hotplug cpu: move... |
3767 |
* and we take cgroup_mutex, keeping cgroup_attach_task() from changing it |
a424316ca Task Control Grou... |
3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 |
* anyway. No need to check that tsk->cgroup != NULL, thanks to * the_top_cgroup_hack in cgroup_exit(), which sets an exiting tasks * cgroup to top_cgroup. */ /* TODO: Use a proper seq_file iterator */ static int proc_cgroup_show(struct seq_file *m, void *v) { struct pid *pid; struct task_struct *tsk; char *buf; int retval; struct cgroupfs_root *root; retval = -ENOMEM; buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!buf) goto out; retval = -ESRCH; pid = m->private; tsk = get_pid_task(pid, PIDTYPE_PID); if (!tsk) goto out_free; retval = 0; mutex_lock(&cgroup_mutex); |
e5f6a8609 cgroups: make roo... |
3796 |
for_each_active_root(root) { |
a424316ca Task Control Grou... |
3797 |
struct cgroup_subsys *ss; |
bd89aabc6 Control groups: R... |
3798 |
struct cgroup *cgrp; |
a424316ca Task Control Grou... |
3799 |
int count = 0; |
2c6ab6d20 cgroups: allow cg... |
3800 |
seq_printf(m, "%d:", root->hierarchy_id); |
a424316ca Task Control Grou... |
3801 3802 |
for_each_subsys(root, ss) seq_printf(m, "%s%s", count++ ? "," : "", ss->name); |
c6d57f331 cgroups: support ... |
3803 3804 3805 |
if (strlen(root->name)) seq_printf(m, "%sname=%s", count ? "," : "", root->name); |
a424316ca Task Control Grou... |
3806 |
seq_putc(m, ':'); |
7717f7ba9 cgroups: add a ba... |
3807 |
cgrp = task_cgroup_from_root(tsk, root); |
bd89aabc6 Control groups: R... |
3808 |
retval = cgroup_path(cgrp, buf, PAGE_SIZE); |
a424316ca Task Control Grou... |
3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 |
if (retval < 0) goto out_unlock; seq_puts(m, buf); seq_putc(m, ' '); } out_unlock: mutex_unlock(&cgroup_mutex); put_task_struct(tsk); out_free: kfree(buf); out: return retval; } static int cgroup_open(struct inode *inode, struct file *file) { struct pid *pid = PROC_I(inode)->pid; return single_open(file, proc_cgroup_show, pid); } |
828c09509 const: constify r... |
3830 |
const struct file_operations proc_cgroup_operations = { |
a424316ca Task Control Grou... |
3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 |
.open = cgroup_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; /* Display information about each subsystem and each hierarchy */ static int proc_cgroupstats_show(struct seq_file *m, void *v) { int i; |
a424316ca Task Control Grou... |
3841 |
|
8bab8dded cgroups: add cgro... |
3842 3843 |
seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled "); |
aae8aab40 cgroups: revamp s... |
3844 3845 3846 3847 3848 |
/* * 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. */ |
a424316ca Task Control Grou... |
3849 |
mutex_lock(&cgroup_mutex); |
a424316ca Task Control Grou... |
3850 3851 |
for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; |
aae8aab40 cgroups: revamp s... |
3852 3853 |
if (ss == NULL) continue; |
2c6ab6d20 cgroups: allow cg... |
3854 3855 3856 |
seq_printf(m, "%s\t%d\t%d\t%d ", ss->name, ss->root->hierarchy_id, |
8bab8dded cgroups: add cgro... |
3857 |
ss->root->number_of_cgroups, !ss->disabled); |
a424316ca Task Control Grou... |
3858 3859 3860 3861 3862 3863 3864 |
} mutex_unlock(&cgroup_mutex); return 0; } static int cgroupstats_open(struct inode *inode, struct file *file) { |
9dce07f1a NULL noise: fs/*,... |
3865 |
return single_open(file, proc_cgroupstats_show, NULL); |
a424316ca Task Control Grou... |
3866 |
} |
828c09509 const: constify r... |
3867 |
static const struct file_operations proc_cgroupstats_operations = { |
a424316ca Task Control Grou... |
3868 3869 3870 3871 3872 |
.open = cgroupstats_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; |
b4f48b636 Task Control Grou... |
3873 3874 |
/** * cgroup_fork - attach newly forked task to its parents cgroup. |
a043e3b2c cgroup: fix comments |
3875 |
* @child: pointer to task_struct of forking parent process. |
b4f48b636 Task Control Grou... |
3876 3877 3878 3879 3880 3881 |
* * Description: A task inherits its parent's cgroup at fork(). * * A pointer to the shared css_set was automatically copied in * fork.c by dup_task_struct(). However, we ignore that copy, since * it was not made under the protection of RCU or cgroup_mutex, so |
956db3ca0 hotplug cpu: move... |
3882 |
* might no longer be a valid cgroup pointer. cgroup_attach_task() might |
817929ec2 Task Control Grou... |
3883 3884 |
* have already changed current->cgroups, allowing the previously * referenced cgroup group to be removed and freed. |
b4f48b636 Task Control Grou... |
3885 3886 3887 3888 3889 3890 |
* * At the point that cgroup_fork() is called, 'current' is the parent * task, and the passed argument 'child' points to the child task. */ void cgroup_fork(struct task_struct *child) { |
817929ec2 Task Control Grou... |
3891 3892 3893 3894 3895 |
task_lock(current); child->cgroups = current->cgroups; get_css_set(child->cgroups); task_unlock(current); INIT_LIST_HEAD(&child->cg_list); |
b4f48b636 Task Control Grou... |
3896 3897 3898 |
} /** |
a043e3b2c cgroup: fix comments |
3899 3900 3901 3902 3903 3904 |
* cgroup_fork_callbacks - run fork callbacks * @child: the new task * * Called on a new task very soon before adding it to the * tasklist. No need to take any locks since no-one can * be operating on this task. |
b4f48b636 Task Control Grou... |
3905 3906 3907 3908 3909 |
*/ void cgroup_fork_callbacks(struct task_struct *child) { if (need_forkexit_callback) { int i; |
aae8aab40 cgroups: revamp s... |
3910 3911 3912 3913 3914 3915 |
/* * forkexit callbacks are only supported for builtin * subsystems, and the builtin section of the subsys array is * immutable, so we don't need to lock the subsys array here. */ for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { |
b4f48b636 Task Control Grou... |
3916 3917 3918 3919 3920 3921 3922 3923 |
struct cgroup_subsys *ss = subsys[i]; if (ss->fork) ss->fork(ss, child); } } } /** |
a043e3b2c cgroup: fix comments |
3924 3925 3926 3927 3928 3929 3930 3931 |
* cgroup_post_fork - called on a new task after adding it to the task list * @child: the task in question * * Adds the task to the list running through its css_set if necessary. * Has to be after the task is visible on the task list in case we race * with the first call to cgroup_iter_start() - to guarantee that the * new task ends up on its list. */ |
817929ec2 Task Control Grou... |
3932 3933 3934 3935 |
void cgroup_post_fork(struct task_struct *child) { if (use_task_css_set_links) { write_lock(&css_set_lock); |
b12b533fa cgroups: add lock... |
3936 |
task_lock(child); |
817929ec2 Task Control Grou... |
3937 3938 |
if (list_empty(&child->cg_list)) list_add(&child->cg_list, &child->cgroups->tasks); |
b12b533fa cgroups: add lock... |
3939 |
task_unlock(child); |
817929ec2 Task Control Grou... |
3940 3941 3942 3943 |
write_unlock(&css_set_lock); } } /** |
b4f48b636 Task Control Grou... |
3944 3945 |
* cgroup_exit - detach cgroup from exiting task * @tsk: pointer to task_struct of exiting process |
a043e3b2c cgroup: fix comments |
3946 |
* @run_callback: run exit callbacks? |
b4f48b636 Task Control Grou... |
3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 |
* * Description: Detach cgroup from @tsk and release it. * * Note that cgroups marked notify_on_release force every task in * them to take the global cgroup_mutex mutex when exiting. * This could impact scaling on very large systems. Be reluctant to * use notify_on_release cgroups where very high task exit scaling * is required on large systems. * * the_top_cgroup_hack: * * Set the exiting tasks cgroup to the root cgroup (top_cgroup). * * We call cgroup_exit() while the task is still competent to * handle notify_on_release(), then leave the task attached to the * root cgroup in each hierarchy for the remainder of its exit. * * To do this properly, we would increment the reference count on * top_cgroup, and near the very end of the kernel/exit.c do_exit() * code we would add a second cgroup function call, to drop that * reference. This would just create an unnecessary hot spot on * the top_cgroup reference count, to no avail. * * Normally, holding a reference to a cgroup without bumping its * count is unsafe. The cgroup could go away, or someone could * attach us to a different cgroup, decrementing the count on * the first cgroup that we never incremented. But in this case, * top_cgroup isn't going away, and either task has PF_EXITING set, |
956db3ca0 hotplug cpu: move... |
3975 3976 |
* which wards off any cgroup_attach_task() attempts, or task is a failed * fork, never visible to cgroup_attach_task. |
b4f48b636 Task Control Grou... |
3977 3978 3979 3980 |
*/ void cgroup_exit(struct task_struct *tsk, int run_callbacks) { int i; |
817929ec2 Task Control Grou... |
3981 |
struct css_set *cg; |
b4f48b636 Task Control Grou... |
3982 3983 |
if (run_callbacks && need_forkexit_callback) { |
aae8aab40 cgroups: revamp s... |
3984 3985 3986 3987 3988 |
/* * modular subsystems can't use callbacks, so no need to lock * the subsys array */ for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { |
b4f48b636 Task Control Grou... |
3989 3990 3991 3992 3993 |
struct cgroup_subsys *ss = subsys[i]; if (ss->exit) ss->exit(ss, tsk); } } |
817929ec2 Task Control Grou... |
3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 |
/* * Unlink from the css_set task list if necessary. * Optimistically check cg_list before taking * css_set_lock */ if (!list_empty(&tsk->cg_list)) { write_lock(&css_set_lock); if (!list_empty(&tsk->cg_list)) list_del(&tsk->cg_list); write_unlock(&css_set_lock); } |
b4f48b636 Task Control Grou... |
4006 4007 |
/* Reassign the task to the init_css_set. */ task_lock(tsk); |
817929ec2 Task Control Grou... |
4008 4009 |
cg = tsk->cgroups; tsk->cgroups = &init_css_set; |
b4f48b636 Task Control Grou... |
4010 |
task_unlock(tsk); |
817929ec2 Task Control Grou... |
4011 |
if (cg) |
81a6a5cdd Task Control Grou... |
4012 |
put_css_set_taskexit(cg); |
b4f48b636 Task Control Grou... |
4013 |
} |
697f41610 Task Control Grou... |
4014 4015 |
/** |
a043e3b2c cgroup: fix comments |
4016 4017 4018 |
* cgroup_clone - clone the cgroup the given subsystem is attached to * @tsk: the task to be moved * @subsys: the given subsystem |
e885dcde7 cgroup_clone: use... |
4019 |
* @nodename: the name for the new cgroup |
a043e3b2c cgroup: fix comments |
4020 4021 4022 4023 |
* * Duplicate the current cgroup in the hierarchy that the given * subsystem is attached to, and move this task into the new * child. |
697f41610 Task Control Grou... |
4024 |
*/ |
e885dcde7 cgroup_clone: use... |
4025 4026 |
int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys, char *nodename) |
697f41610 Task Control Grou... |
4027 4028 4029 |
{ struct dentry *dentry; int ret = 0; |
697f41610 Task Control Grou... |
4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 |
struct cgroup *parent, *child; struct inode *inode; struct css_set *cg; struct cgroupfs_root *root; struct cgroup_subsys *ss; /* We shouldn't be called by an unregistered subsystem */ BUG_ON(!subsys->active); /* First figure out what hierarchy and cgroup we're dealing * with, and pin them so we can drop cgroup_mutex */ mutex_lock(&cgroup_mutex); again: root = subsys->root; if (root == &rootnode) { |
697f41610 Task Control Grou... |
4045 4046 4047 |
mutex_unlock(&cgroup_mutex); return 0; } |
697f41610 Task Control Grou... |
4048 |
|
697f41610 Task Control Grou... |
4049 |
/* Pin the hierarchy */ |
1404f0656 cgroups: fix lock... |
4050 |
if (!atomic_inc_not_zero(&root->sb->s_active)) { |
7b574b7b0 cgroups: fix a ra... |
4051 4052 4053 4054 |
/* We race with the final deactivate_super() */ mutex_unlock(&cgroup_mutex); return 0; } |
697f41610 Task Control Grou... |
4055 |
|
817929ec2 Task Control Grou... |
4056 |
/* Keep the cgroup alive */ |
1404f0656 cgroups: fix lock... |
4057 4058 4059 |
task_lock(tsk); parent = task_cgroup(tsk, subsys->subsys_id); cg = tsk->cgroups; |
817929ec2 Task Control Grou... |
4060 |
get_css_set(cg); |
104cbd553 cgroups: use task... |
4061 |
task_unlock(tsk); |
1404f0656 cgroups: fix lock... |
4062 |
|
697f41610 Task Control Grou... |
4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 |
mutex_unlock(&cgroup_mutex); /* Now do the VFS work to create a cgroup */ inode = parent->dentry->d_inode; /* Hold the parent directory mutex across this operation to * stop anyone else deleting the new cgroup */ mutex_lock(&inode->i_mutex); dentry = lookup_one_len(nodename, parent->dentry, strlen(nodename)); if (IS_ERR(dentry)) { printk(KERN_INFO |
cfe36bde5 Improve cgroup pr... |
4074 4075 |
"cgroup: Couldn't allocate dentry for %s: %ld ", nodename, |
697f41610 Task Control Grou... |
4076 4077 4078 4079 4080 4081 |
PTR_ERR(dentry)); ret = PTR_ERR(dentry); goto out_release; } /* Create the cgroup directory, which also creates the cgroup */ |
75139b827 cgroups: remove s... |
4082 |
ret = vfs_mkdir(inode, dentry, 0755); |
bd89aabc6 Control groups: R... |
4083 |
child = __d_cgrp(dentry); |
697f41610 Task Control Grou... |
4084 4085 4086 4087 4088 4089 4090 4091 |
dput(dentry); if (ret) { printk(KERN_INFO "Failed to create cgroup %s: %d ", nodename, ret); goto out_release; } |
697f41610 Task Control Grou... |
4092 4093 4094 4095 4096 4097 4098 4099 |
/* The cgroup now exists. Retake cgroup_mutex and check * that we're still in the same state that we thought we * were. */ mutex_lock(&cgroup_mutex); if ((root != subsys->root) || (parent != task_cgroup(tsk, subsys->subsys_id))) { /* Aargh, we raced ... */ mutex_unlock(&inode->i_mutex); |
817929ec2 Task Control Grou... |
4100 |
put_css_set(cg); |
697f41610 Task Control Grou... |
4101 |
|
1404f0656 cgroups: fix lock... |
4102 |
deactivate_super(root->sb); |
697f41610 Task Control Grou... |
4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 |
/* The cgroup is still accessible in the VFS, but * we're not going to try to rmdir() it at this * point. */ printk(KERN_INFO "Race in cgroup_clone() - leaking cgroup %s ", nodename); goto again; } /* do any required auto-setup */ for_each_subsys(root, ss) { if (ss->post_clone) ss->post_clone(ss, child); } /* All seems fine. Finish by moving the task into the new cgroup */ |
956db3ca0 hotplug cpu: move... |
4120 |
ret = cgroup_attach_task(child, tsk); |
697f41610 Task Control Grou... |
4121 4122 4123 4124 |
mutex_unlock(&cgroup_mutex); out_release: mutex_unlock(&inode->i_mutex); |
81a6a5cdd Task Control Grou... |
4125 4126 |
mutex_lock(&cgroup_mutex); |
817929ec2 Task Control Grou... |
4127 |
put_css_set(cg); |
81a6a5cdd Task Control Grou... |
4128 |
mutex_unlock(&cgroup_mutex); |
1404f0656 cgroups: fix lock... |
4129 |
deactivate_super(root->sb); |
697f41610 Task Control Grou... |
4130 4131 |
return ret; } |
a043e3b2c cgroup: fix comments |
4132 |
/** |
313e924c0 cgroups: relax ns... |
4133 |
* cgroup_is_descendant - see if @cgrp is a descendant of @task's cgrp |
a043e3b2c cgroup: fix comments |
4134 |
* @cgrp: the cgroup in question |
313e924c0 cgroups: relax ns... |
4135 |
* @task: the task in question |
a043e3b2c cgroup: fix comments |
4136 |
* |
313e924c0 cgroups: relax ns... |
4137 4138 |
* See if @cgrp is a descendant of @task's cgroup in the appropriate * hierarchy. |
697f41610 Task Control Grou... |
4139 4140 4141 4142 4143 4144 |
* * If we are sending in dummytop, then presumably we are creating * the top cgroup in the subsystem. * * Called only by the ns (nsproxy) cgroup. */ |
313e924c0 cgroups: relax ns... |
4145 |
int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task) |
697f41610 Task Control Grou... |
4146 4147 4148 |
{ int ret; struct cgroup *target; |
697f41610 Task Control Grou... |
4149 |
|
bd89aabc6 Control groups: R... |
4150 |
if (cgrp == dummytop) |
697f41610 Task Control Grou... |
4151 |
return 1; |
7717f7ba9 cgroups: add a ba... |
4152 |
target = task_cgroup_from_root(task, cgrp->root); |
bd89aabc6 Control groups: R... |
4153 4154 4155 |
while (cgrp != target && cgrp!= cgrp->top_cgroup) cgrp = cgrp->parent; ret = (cgrp == target); |
697f41610 Task Control Grou... |
4156 4157 |
return ret; } |
81a6a5cdd Task Control Grou... |
4158 |
|
bd89aabc6 Control groups: R... |
4159 |
static void check_for_release(struct cgroup *cgrp) |
81a6a5cdd Task Control Grou... |
4160 4161 4162 |
{ /* All of these checks rely on RCU to keep the cgroup * structure alive */ |
bd89aabc6 Control groups: R... |
4163 4164 |
if (cgroup_is_releasable(cgrp) && !atomic_read(&cgrp->count) && list_empty(&cgrp->children) && !cgroup_has_css_refs(cgrp)) { |
81a6a5cdd Task Control Grou... |
4165 4166 4167 4168 4169 |
/* 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); |
bd89aabc6 Control groups: R... |
4170 4171 4172 |
if (!cgroup_is_removed(cgrp) && list_empty(&cgrp->release_list)) { list_add(&cgrp->release_list, &release_list); |
81a6a5cdd Task Control Grou... |
4173 4174 4175 4176 4177 4178 4179 |
need_schedule_work = 1; } spin_unlock(&release_list_lock); if (need_schedule_work) schedule_work(&release_agent_work); } } |
d7b9fff71 cgroup: introduce... |
4180 4181 |
/* Caller must verify that the css is not for root cgroup */ void __css_put(struct cgroup_subsys_state *css, int count) |
81a6a5cdd Task Control Grou... |
4182 |
{ |
bd89aabc6 Control groups: R... |
4183 |
struct cgroup *cgrp = css->cgroup; |
3dece8347 cgroup: catch bad... |
4184 |
int val; |
81a6a5cdd Task Control Grou... |
4185 |
rcu_read_lock(); |
d7b9fff71 cgroup: introduce... |
4186 |
val = atomic_sub_return(count, &css->refcnt); |
3dece8347 cgroup: catch bad... |
4187 |
if (val == 1) { |
ec64f5154 cgroup: fix frequ... |
4188 4189 4190 4191 |
if (notify_on_release(cgrp)) { set_bit(CGRP_RELEASABLE, &cgrp->flags); check_for_release(cgrp); } |
887032670 cgroup avoid perm... |
4192 |
cgroup_wakeup_rmdir_waiter(cgrp); |
81a6a5cdd Task Control Grou... |
4193 4194 |
} rcu_read_unlock(); |
3dece8347 cgroup: catch bad... |
4195 |
WARN_ON_ONCE(val < 1); |
81a6a5cdd Task Control Grou... |
4196 |
} |
67523c48a cgroups: blkio su... |
4197 |
EXPORT_SYMBOL_GPL(__css_put); |
81a6a5cdd Task Control Grou... |
4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 |
/* * 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. |
81a6a5cdd Task Control Grou... |
4221 |
*/ |
81a6a5cdd Task Control Grou... |
4222 4223 4224 4225 4226 4227 4228 4229 |
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; |
e788e066c cgroup files: mov... |
4230 |
char *pathbuf = NULL, *agentbuf = NULL; |
bd89aabc6 Control groups: R... |
4231 |
struct cgroup *cgrp = list_entry(release_list.next, |
81a6a5cdd Task Control Grou... |
4232 4233 |
struct cgroup, release_list); |
bd89aabc6 Control groups: R... |
4234 |
list_del_init(&cgrp->release_list); |
81a6a5cdd Task Control Grou... |
4235 4236 |
spin_unlock(&release_list_lock); pathbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
e788e066c cgroup files: mov... |
4237 4238 4239 4240 4241 4242 4243 |
if (!pathbuf) goto continue_free; if (cgroup_path(cgrp, pathbuf, PAGE_SIZE) < 0) goto continue_free; agentbuf = kstrdup(cgrp->root->release_agent_path, GFP_KERNEL); if (!agentbuf) goto continue_free; |
81a6a5cdd Task Control Grou... |
4244 4245 |
i = 0; |
e788e066c cgroup files: mov... |
4246 4247 |
argv[i++] = agentbuf; argv[i++] = pathbuf; |
81a6a5cdd Task Control Grou... |
4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 |
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); |
81a6a5cdd Task Control Grou... |
4261 |
mutex_lock(&cgroup_mutex); |
e788e066c cgroup files: mov... |
4262 4263 4264 |
continue_free: kfree(pathbuf); kfree(agentbuf); |
81a6a5cdd Task Control Grou... |
4265 4266 4267 4268 4269 |
spin_lock(&release_list_lock); } spin_unlock(&release_list_lock); mutex_unlock(&cgroup_mutex); } |
8bab8dded cgroups: add cgro... |
4270 4271 4272 4273 4274 4275 4276 4277 4278 |
static int __init cgroup_disable(char *str) { int i; char *token; while ((token = strsep(&str, ",")) != NULL) { if (!*token) continue; |
aae8aab40 cgroups: revamp s... |
4279 4280 4281 4282 4283 |
/* * cgroup_disable, being at boot time, can't know about module * subsystems, so we don't worry about them. */ for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { |
8bab8dded cgroups: add cgro... |
4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 |
struct cgroup_subsys *ss = subsys[i]; if (!strcmp(token, ss->name)) { ss->disabled = 1; printk(KERN_INFO "Disabling %s control group" " subsystem ", ss->name); break; } } } return 1; } __setup("cgroup_disable=", cgroup_disable); |
38460b48d cgroup: CSS ID su... |
4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 |
/* * Functons for CSS ID. */ /* *To get ID other than 0, this should be called when !cgroup_is_removed(). */ unsigned short css_id(struct cgroup_subsys_state *css) { |
7f0f15464 memcg: fix css_id... |
4308 4309 4310 4311 4312 4313 4314 4315 4316 |
struct css_id *cssid; /* * This css_id() can return correct value when somone has refcnt * on this or this is under rcu_read_lock(). Once css->id is allocated, * it's unchanged until freed. */ cssid = rcu_dereference_check(css->id, rcu_read_lock_held() || atomic_read(&css->refcnt)); |
38460b48d cgroup: CSS ID su... |
4317 4318 4319 4320 4321 |
if (cssid) return cssid->id; return 0; } |
67523c48a cgroups: blkio su... |
4322 |
EXPORT_SYMBOL_GPL(css_id); |
38460b48d cgroup: CSS ID su... |
4323 4324 4325 |
unsigned short css_depth(struct cgroup_subsys_state *css) { |
7f0f15464 memcg: fix css_id... |
4326 4327 4328 4329 |
struct css_id *cssid; cssid = rcu_dereference_check(css->id, rcu_read_lock_held() || atomic_read(&css->refcnt)); |
38460b48d cgroup: CSS ID su... |
4330 4331 4332 4333 4334 |
if (cssid) return cssid->depth; return 0; } |
67523c48a cgroups: blkio su... |
4335 |
EXPORT_SYMBOL_GPL(css_depth); |
38460b48d cgroup: CSS ID su... |
4336 |
|
747388d78 memcg: fix css_is... |
4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 |
/** * css_is_ancestor - test "root" css is an ancestor of "child" * @child: the css to be tested. * @root: the css supporsed to be an ancestor of the child. * * Returns true if "root" is an ancestor of "child" in its hierarchy. Because * this function reads css->id, this use rcu_dereference() and rcu_read_lock(). * But, considering usual usage, the csses should be valid objects after test. * Assuming that the caller will do some action to the child if this returns * returns true, the caller must take "child";s reference count. * If "child" is valid object and this returns true, "root" is valid, too. */ |
38460b48d cgroup: CSS ID su... |
4349 |
bool css_is_ancestor(struct cgroup_subsys_state *child, |
0b7f569e4 memcg: fix OOM ki... |
4350 |
const struct cgroup_subsys_state *root) |
38460b48d cgroup: CSS ID su... |
4351 |
{ |
747388d78 memcg: fix css_is... |
4352 4353 4354 |
struct css_id *child_id; struct css_id *root_id; bool ret = true; |
38460b48d cgroup: CSS ID su... |
4355 |
|
747388d78 memcg: fix css_is... |
4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 |
rcu_read_lock(); child_id = rcu_dereference(child->id); root_id = rcu_dereference(root->id); if (!child_id || !root_id || (child_id->depth < root_id->depth) || (child_id->stack[root_id->depth] != root_id->id)) ret = false; rcu_read_unlock(); return ret; |
38460b48d cgroup: CSS ID su... |
4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 |
} static void __free_css_id_cb(struct rcu_head *head) { struct css_id *id; id = container_of(head, struct css_id, rcu_head); kfree(id); } void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css) { struct css_id *id = css->id; /* When this is called before css_id initialization, id can be NULL */ if (!id) return; BUG_ON(!ss->use_id); rcu_assign_pointer(id->css, NULL); rcu_assign_pointer(css->id, NULL); spin_lock(&ss->id_lock); idr_remove(&ss->idr, id->id); spin_unlock(&ss->id_lock); call_rcu(&id->rcu_head, __free_css_id_cb); } |
67523c48a cgroups: blkio su... |
4392 |
EXPORT_SYMBOL_GPL(free_css_id); |
38460b48d cgroup: CSS ID su... |
4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 |
/* * This is called by init or create(). Then, calls to this function are * always serialized (By cgroup_mutex() at create()). */ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth) { struct css_id *newid; int myid, error, size; BUG_ON(!ss->use_id); size = sizeof(*newid) + sizeof(unsigned short) * (depth + 1); newid = kzalloc(size, GFP_KERNEL); if (!newid) return ERR_PTR(-ENOMEM); /* get id */ if (unlikely(!idr_pre_get(&ss->idr, GFP_KERNEL))) { error = -ENOMEM; goto err_out; } spin_lock(&ss->id_lock); /* Don't use 0. allocates an ID of 1-65535 */ error = idr_get_new_above(&ss->idr, newid, 1, &myid); spin_unlock(&ss->id_lock); /* Returns error when there are no free spaces for new ID.*/ if (error) { error = -ENOSPC; goto err_out; } if (myid > CSS_ID_MAX) goto remove_idr; newid->id = myid; newid->depth = depth; return newid; remove_idr: error = -ENOSPC; spin_lock(&ss->id_lock); idr_remove(&ss->idr, myid); spin_unlock(&ss->id_lock); err_out: kfree(newid); return ERR_PTR(error); } |
e6a1105ba cgroups: subsyste... |
4441 4442 |
static int __init_or_module cgroup_init_idr(struct cgroup_subsys *ss, struct cgroup_subsys_state *rootcss) |
38460b48d cgroup: CSS ID su... |
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{ struct css_id *newid; |
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spin_lock_init(&ss->id_lock); idr_init(&ss->idr); |
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newid = get_new_cssid(ss, 0); if (IS_ERR(newid)) return PTR_ERR(newid); newid->stack[0] = newid->id; newid->css = rootcss; rootcss->id = newid; return 0; } static int alloc_css_id(struct cgroup_subsys *ss, struct cgroup *parent, struct cgroup *child) { int subsys_id, i, depth = 0; struct cgroup_subsys_state *parent_css, *child_css; |
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struct css_id *child_id, *parent_id; |
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subsys_id = ss->subsys_id; parent_css = parent->subsys[subsys_id]; child_css = child->subsys[subsys_id]; |
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parent_id = parent_css->id; |
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depth = parent_id->depth + 1; |
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child_id = get_new_cssid(ss, depth); if (IS_ERR(child_id)) return PTR_ERR(child_id); for (i = 0; i < depth; i++) child_id->stack[i] = parent_id->stack[i]; child_id->stack[depth] = child_id->id; /* * child_id->css pointer will be set after this cgroup is available * see cgroup_populate_dir() */ rcu_assign_pointer(child_css->id, child_id); return 0; } /** * css_lookup - lookup css by id * @ss: cgroup subsys to be looked into. * @id: the id * * Returns pointer to cgroup_subsys_state if there is valid one with id. * NULL if not. Should be called under rcu_read_lock() */ struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id) { struct css_id *cssid = NULL; BUG_ON(!ss->use_id); cssid = idr_find(&ss->idr, id); if (unlikely(!cssid)) return NULL; return rcu_dereference(cssid->css); } |
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EXPORT_SYMBOL_GPL(css_lookup); |
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/** * css_get_next - lookup next cgroup under specified hierarchy. * @ss: pointer to subsystem * @id: current position of iteration. * @root: pointer to css. search tree under this. * @foundid: position of found object. * * Search next css under the specified hierarchy of rootid. Calling under * rcu_read_lock() is necessary. Returns NULL if it reaches the end. */ struct cgroup_subsys_state * css_get_next(struct cgroup_subsys *ss, int id, struct cgroup_subsys_state *root, int *foundid) { struct cgroup_subsys_state *ret = NULL; struct css_id *tmp; int tmpid; int rootid = css_id(root); int depth = css_depth(root); if (!rootid) return NULL; BUG_ON(!ss->use_id); /* fill start point for scan */ tmpid = id; while (1) { /* * scan next entry from bitmap(tree), tmpid is updated after * idr_get_next(). */ spin_lock(&ss->id_lock); tmp = idr_get_next(&ss->idr, &tmpid); spin_unlock(&ss->id_lock); if (!tmp) break; if (tmp->depth >= depth && tmp->stack[depth] == rootid) { ret = rcu_dereference(tmp->css); if (ret) { *foundid = tmpid; break; } } /* continue to scan from next id */ tmpid = tmpid + 1; } return ret; } |
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#ifdef CONFIG_CGROUP_DEBUG static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss, struct cgroup *cont) { struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL); if (!css) return ERR_PTR(-ENOMEM); return css; } static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont) { kfree(cont->subsys[debug_subsys_id]); } static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft) { return atomic_read(&cont->count); } static u64 debug_taskcount_read(struct cgroup *cont, struct cftype *cft) { return cgroup_task_count(cont); } static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft) { return (u64)(unsigned long)current->cgroups; } static u64 current_css_set_refcount_read(struct cgroup *cont, struct cftype *cft) { u64 count; rcu_read_lock(); count = atomic_read(¤t->cgroups->refcount); rcu_read_unlock(); return count; } |
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static int current_css_set_cg_links_read(struct cgroup *cont, struct cftype *cft, struct seq_file *seq) { struct cg_cgroup_link *link; struct css_set *cg; read_lock(&css_set_lock); rcu_read_lock(); cg = rcu_dereference(current->cgroups); list_for_each_entry(link, &cg->cg_links, cg_link_list) { struct cgroup *c = link->cgrp; const char *name; if (c->dentry) name = c->dentry->d_name.name; else name = "?"; |
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seq_printf(seq, "Root %d group %s ", c->root->hierarchy_id, name); |
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} rcu_read_unlock(); read_unlock(&css_set_lock); return 0; } #define MAX_TASKS_SHOWN_PER_CSS 25 static int cgroup_css_links_read(struct cgroup *cont, struct cftype *cft, struct seq_file *seq) { struct cg_cgroup_link *link; read_lock(&css_set_lock); list_for_each_entry(link, &cont->css_sets, cgrp_link_list) { struct css_set *cg = link->cg; struct task_struct *task; int count = 0; seq_printf(seq, "css_set %p ", cg); list_for_each_entry(task, &cg->tasks, cg_list) { if (count++ > MAX_TASKS_SHOWN_PER_CSS) { seq_puts(seq, " ... "); break; } else { seq_printf(seq, " task %d ", task_pid_vnr(task)); } } } read_unlock(&css_set_lock); return 0; } |
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static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft) { return test_bit(CGRP_RELEASABLE, &cgrp->flags); } static struct cftype debug_files[] = { { .name = "cgroup_refcount", .read_u64 = cgroup_refcount_read, }, { .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, }, { |
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.name = "current_css_set_cg_links", .read_seq_string = current_css_set_cg_links_read, }, { .name = "cgroup_css_links", .read_seq_string = cgroup_css_links_read, }, { |
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.name = "releasable", .read_u64 = releasable_read, }, }; static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont) { return cgroup_add_files(cont, ss, debug_files, ARRAY_SIZE(debug_files)); } struct cgroup_subsys debug_subsys = { .name = "debug", .create = debug_create, .destroy = debug_destroy, .populate = debug_populate, .subsys_id = debug_subsys_id, }; #endif /* CONFIG_CGROUP_DEBUG */ |