From 65dff759d2948cf18e2029fc5c0c595b8b7da3a5 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 1 Mar 2013 15:01:56 +0800 Subject: cgroup: fix cgroup_path() vs rename() race rename() will change dentry->d_name. The result of this race can be worse than seeing partially rewritten name, but we might access a stale pointer because rename() will re-allocate memory to hold a longer name. As accessing dentry->name must be protected by dentry->d_lock or parent inode's i_mutex, while on the other hand cgroup-path() can be called with some irq-safe spinlocks held, we can't generate cgroup path using dentry->d_name. Alternatively we make a copy of dentry->d_name and save it in cgrp->name when a cgroup is created, and update cgrp->name at rename(). v5: use flexible array instead of zero-size array. v4: - allocate root_cgroup_name and all root_cgroup->name points to it. - add cgroup_name() wrapper. v3: use kfree_rcu() instead of synchronize_rcu() in user-visible path. v2: make cgrp->name RCU safe. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 900af5964f55..75c6ec1ba1ba 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -150,6 +150,11 @@ enum { CGRP_CPUSET_CLONE_CHILDREN, }; +struct cgroup_name { + struct rcu_head rcu_head; + char name[]; +}; + struct cgroup { unsigned long flags; /* "unsigned long" so bitops work */ @@ -172,6 +177,19 @@ struct cgroup { struct cgroup *parent; /* my parent */ struct dentry *dentry; /* cgroup fs entry, RCU protected */ + /* + * This is a copy of dentry->d_name, and it's needed because + * we can't use dentry->d_name in cgroup_path(). + * + * You must acquire rcu_read_lock() to access cgrp->name, and + * the only place that can change it is rename(), which is + * protected by parent dir's i_mutex. + * + * Normally you should use cgroup_name() wrapper rather than + * access it directly. + */ + struct cgroup_name __rcu *name; + /* Private pointers for each registered subsystem */ struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; @@ -404,6 +422,12 @@ struct cgroup_scanner { void *data; }; +/* Caller should hold rcu_read_lock() */ +static inline const char *cgroup_name(const struct cgroup *cgrp) +{ + return rcu_dereference(cgrp->name)->name; +} + int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); int cgroup_rm_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); -- cgit v1.2.3 From 7d8e0bf56a66bab08d2f316dd87e56c08cecb899 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 5 Mar 2013 10:57:03 +0800 Subject: cgroup: avoid accessing modular cgroup subsys structure without locking subsys[i] is set to NULL in cgroup_unload_subsys() at modular unload, and that's protected by cgroup_mutex, and then the memory *subsys[i] resides will be freed. So this is unsafe without any locking: if (!ss || ss->module) ... v2: - add a comment for enum cgroup_subsys_id - simplify the comment in cgroup_exit() Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 17 ++++++++++++++--- kernel/cgroup.c | 28 ++++++++++++++-------------- 2 files changed, 28 insertions(+), 17 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 75c6ec1ba1ba..5f76829dd75e 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -44,14 +44,25 @@ extern void cgroup_unload_subsys(struct cgroup_subsys *ss); extern const struct file_operations proc_cgroup_operations; -/* Define the enumeration of all builtin cgroup subsystems */ +/* + * Define the enumeration of all cgroup subsystems. + * + * We define ids for builtin subsystems and then modular ones. + */ #define SUBSYS(_x) _x ## _subsys_id, -#define IS_SUBSYS_ENABLED(option) IS_ENABLED(option) enum cgroup_subsys_id { +#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option) +#include +#undef IS_SUBSYS_ENABLED + CGROUP_BUILTIN_SUBSYS_COUNT, + + __CGROUP_SUBSYS_TEMP_PLACEHOLDER = CGROUP_BUILTIN_SUBSYS_COUNT - 1, + +#define IS_SUBSYS_ENABLED(option) IS_MODULE(option) #include +#undef IS_SUBSYS_ENABLED CGROUP_SUBSYS_COUNT, }; -#undef IS_SUBSYS_ENABLED #undef SUBSYS /* Per-subsystem/per-cgroup state maintained by the system. */ diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 9df799d5d31c..7a6c4c72ca55 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4940,17 +4940,17 @@ void cgroup_post_fork(struct task_struct *child) * and addition to css_set. */ if (need_forkexit_callback) { - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { + /* + * fork/exit callbacks are supported only for builtin + * subsystems, and the builtin section of the subsys + * array is immutable, so we don't need to lock the + * subsys array here. On the other hand, modular section + * of the array can be freed at module unload, so we + * can't touch that. + */ + for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; - /* - * fork/exit callbacks are supported only for - * builtin subsystems and we don't need further - * synchronization as they never go away. - */ - if (!ss || ss->module) - continue; - if (ss->fork) ss->fork(child); } @@ -5015,13 +5015,13 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) tsk->cgroups = &init_css_set; if (run_callbacks && need_forkexit_callback) { - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { + /* + * fork/exit callbacks are supported only for builtin + * subsystems, see cgroup_post_fork() for details. + */ + for (i = 0; i < CGROUP_BUILTIN_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; - /* modular subsystems can't use callbacks */ - if (!ss || ss->module) - continue; - if (ss->exit) { struct cgroup *old_cgrp = rcu_dereference_raw(cg->subsys[i])->cgroup; -- cgit v1.2.3 From e7b2dcc52b0e2d598a469f01cc460ccdde6869f2 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 12 Mar 2013 15:35:58 -0700 Subject: cgroup: remove cgroup_is_descendant() It was used by ns cgroup, and ns cgroup was removed long ago. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 3 --- kernel/cgroup.c | 28 ---------------------------- 2 files changed, 31 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 5f76829dd75e..7e818a3ef60a 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -448,9 +448,6 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen); int cgroup_task_count(const struct cgroup *cgrp); -/* Return true if cgrp is a descendant of the task's cgroup */ -int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task); - /* * Control Group taskset, used to pass around set of tasks to cgroup_subsys * methods. diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7a6c4c72ca55..f51443fd5f71 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -5035,34 +5035,6 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) put_css_set_taskexit(cg); } -/** - * cgroup_is_descendant - see if @cgrp is a descendant of @task's cgrp - * @cgrp: the cgroup in question - * @task: the task in question - * - * See if @cgrp is a descendant of @task's cgroup in the appropriate - * hierarchy. - * - * If we are sending in dummytop, then presumably we are creating - * the top cgroup in the subsystem. - * - * Called only by the ns (nsproxy) cgroup. - */ -int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task) -{ - int ret; - struct cgroup *target; - - if (cgrp == dummytop) - return 1; - - target = task_cgroup_from_root(task, cgrp->root); - while (cgrp != target && cgrp!= cgrp->top_cgroup) - cgrp = cgrp->parent; - ret = (cgrp == target); - return ret; -} - static void check_for_release(struct cgroup *cgrp) { /* All of these checks rely on RCU to keep the cgroup -- cgit v1.2.3 From 081aa458c38ba576bdd4265fc807fa95b48b9e79 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 13 Mar 2013 09:17:09 +0800 Subject: cgroup: consolidate cgroup_attach_task() and cgroup_attach_proc() These two functions share most of the code. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 3 +- kernel/cgroup.c | 109 +++++++++---------------------------------------- kernel/cpuset.c | 2 +- 3 files changed, 23 insertions(+), 91 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 7e818a3ef60a..01c48c6806d6 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -693,7 +693,8 @@ struct task_struct *cgroup_iter_next(struct cgroup *cgrp, struct cgroup_iter *it); void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it); int cgroup_scan_tasks(struct cgroup_scanner *scan); -int cgroup_attach_task(struct cgroup *, struct task_struct *); +int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, + bool threadgroup); int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); /* diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 54689fc008f6..04fa2abf94b2 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -59,7 +59,7 @@ #include /* TODO: replace with more sophisticated array */ #include #include -#include /* used in cgroup_attach_proc */ +#include /* used in cgroup_attach_task */ #include #include @@ -1943,82 +1943,6 @@ static void cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp, put_css_set(oldcg); } -/** - * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp' - * @cgrp: the cgroup the task is attaching to - * @tsk: the task to be attached - * - * Call with cgroup_mutex and threadgroup locked. May take task_lock of - * @tsk during call. - */ -int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) -{ - int retval = 0; - struct cgroup_subsys *ss, *failed_ss = NULL; - struct cgroup *oldcgrp; - struct cgroupfs_root *root = cgrp->root; - struct cgroup_taskset tset = { }; - struct css_set *newcg; - - /* @tsk either already exited or can't exit until the end */ - if (tsk->flags & PF_EXITING) - return -ESRCH; - - /* Nothing to do if the task is already in that cgroup */ - oldcgrp = task_cgroup_from_root(tsk, root); - if (cgrp == oldcgrp) - return 0; - - tset.single.task = tsk; - tset.single.cgrp = oldcgrp; - - for_each_subsys(root, ss) { - if (ss->can_attach) { - retval = ss->can_attach(cgrp, &tset); - 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; - } - } - } - - newcg = find_css_set(tsk->cgroups, cgrp); - if (!newcg) { - retval = -ENOMEM; - goto out; - } - - cgroup_task_migrate(cgrp, oldcgrp, tsk, newcg); - - for_each_subsys(root, ss) { - if (ss->attach) - ss->attach(cgrp, &tset); - } - -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(cgrp, &tset); - } - } - return retval; -} - /** * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from' * @from: attach to all cgroups of a given task @@ -2033,7 +1957,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) for_each_active_root(root) { struct cgroup *from_cg = task_cgroup_from_root(from, root); - retval = cgroup_attach_task(from_cg, tsk); + retval = cgroup_attach_task(from_cg, tsk, false); if (retval) break; } @@ -2044,21 +1968,22 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) EXPORT_SYMBOL_GPL(cgroup_attach_task_all); /** - * cgroup_attach_proc - attach all threads in a threadgroup to a cgroup + * cgroup_attach_task - attach a task or a whole threadgroup to a cgroup * @cgrp: the cgroup to attach to - * @leader: the threadgroup leader task_struct of the group to be attached + * @tsk: the task or the leader of the threadgroup to be attached + * @threadgroup: attach the whole threadgroup? * * Call holding cgroup_mutex and the group_rwsem of the leader. Will take - * task_lock of each thread in leader's threadgroup individually in turn. + * task_lock of @tsk or each thread in the threadgroup individually in turn. */ -static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) +int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, + bool threadgroup) { int retval, i, group_size; struct cgroup_subsys *ss, *failed_ss = NULL; - /* guaranteed to be initialized later, but the compiler needs this */ struct cgroupfs_root *root = cgrp->root; /* threadgroup list cursor and array */ - struct task_struct *tsk; + struct task_struct *leader = tsk; struct task_and_cgroup *tc; struct flex_array *group; struct cgroup_taskset tset = { }; @@ -2070,7 +1995,10 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) * group - group_rwsem prevents new threads from appearing, and if * threads exit, this will just be an over-estimate. */ - group_size = get_nr_threads(leader); + if (threadgroup) + group_size = get_nr_threads(tsk); + else + group_size = 1; /* flex_array supports very large thread-groups better than kmalloc. */ group = flex_array_alloc(sizeof(*tc), group_size, GFP_KERNEL); if (!group) @@ -2080,7 +2008,6 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) if (retval) goto out_free_group_list; - tsk = leader; i = 0; /* * Prevent freeing of tasks while we take a snapshot. Tasks that are @@ -2109,6 +2036,9 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) retval = flex_array_put(group, i, &ent, GFP_ATOMIC); BUG_ON(retval != 0); i++; + + if (!threadgroup) + break; } while_each_thread(leader, tsk); rcu_read_unlock(); /* remember the number of threads in the array for later. */ @@ -2262,9 +2192,10 @@ retry_find_task: put_task_struct(tsk); goto retry_find_task; } - ret = cgroup_attach_proc(cgrp, tsk); - } else - ret = cgroup_attach_task(cgrp, tsk); + } + + ret = cgroup_attach_task(cgrp, tsk, threadgroup); + threadgroup_unlock(tsk); put_task_struct(tsk); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index efbfca7a33e4..98d458aad789 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2008,7 +2008,7 @@ static void cpuset_do_move_task(struct task_struct *tsk, struct cgroup *new_cgroup = scan->data; cgroup_lock(); - cgroup_attach_task(new_cgroup, tsk); + cgroup_attach_task(new_cgroup, tsk, false); cgroup_unlock(); } -- cgit v1.2.3 From 8cc9934520e7f752fe45d5199664d741ba24a932 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 7 Apr 2013 09:29:50 -0700 Subject: cgroup, cpuset: replace move_member_tasks_to_cpuset() with cgroup_transfer_tasks() When a cpuset becomes empty (no CPU or memory), its tasks are transferred with the nearest ancestor with execution resources. This is implemented using cgroup_scan_tasks() with a callback which grabs cgroup_mutex and invokes cgroup_attach_task() on each task. Both cgroup_mutex and cgroup_attach_task() are scheduled to be unexported. Implement cgroup_transfer_tasks() in cgroup proper which is essentially the same as move_member_tasks_to_cpuset() except that it takes cgroups instead of cpusets and @to comes before @from like normal functions with those arguments, and replace move_member_tasks_to_cpuset() with it. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- include/linux/cgroup.h | 1 + kernel/cgroup.c | 28 +++++++++++++++++++++++++++ kernel/cpuset.c | 51 ++++++-------------------------------------------- 3 files changed, 35 insertions(+), 45 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 01c48c6806d6..f8eb01d75ddc 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -696,6 +696,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan); int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, bool threadgroup); int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); +int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); /* * CSS ID is ID for cgroup_subsys_state structs under subsys. This only works diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 4aee5bdd66c8..147d7ccb3b0b 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3269,6 +3269,34 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) return 0; } +static void cgroup_transfer_one_task(struct task_struct *task, + struct cgroup_scanner *scan) +{ + struct cgroup *new_cgroup = scan->data; + + cgroup_lock(); + cgroup_attach_task(new_cgroup, task, false); + cgroup_unlock(); +} + +/** + * cgroup_trasnsfer_tasks - move tasks from one cgroup to another + * @to: cgroup to which the tasks will be moved + * @from: cgroup in which the tasks currently reside + */ +int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) +{ + struct cgroup_scanner scan; + + scan.cg = from; + scan.test_task = NULL; /* select all tasks in cgroup */ + scan.process_task = cgroup_transfer_one_task; + scan.heap = NULL; + scan.data = to; + + return cgroup_scan_tasks(&scan); +} + /* * Stuff for reading the 'tasks'/'procs' files. * diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 98d458aad789..866d78ee7930 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1994,50 +1994,6 @@ int __init cpuset_init(void) return 0; } -/** - * cpuset_do_move_task - move a given task to another cpuset - * @tsk: pointer to task_struct the task to move - * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner - * - * Called by cgroup_scan_tasks() for each task in a cgroup. - * Return nonzero to stop the walk through the tasks. - */ -static void cpuset_do_move_task(struct task_struct *tsk, - struct cgroup_scanner *scan) -{ - struct cgroup *new_cgroup = scan->data; - - cgroup_lock(); - cgroup_attach_task(new_cgroup, tsk, false); - cgroup_unlock(); -} - -/** - * move_member_tasks_to_cpuset - move tasks from one cpuset to another - * @from: cpuset in which the tasks currently reside - * @to: cpuset to which the tasks will be moved - * - * Called with cpuset_mutex held - * callback_mutex must not be held, as cpuset_attach() will take it. - * - * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, - * calling callback functions for each. - */ -static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to) -{ - struct cgroup_scanner scan; - - scan.cg = from->css.cgroup; - scan.test_task = NULL; /* select all tasks in cgroup */ - scan.process_task = cpuset_do_move_task; - scan.heap = NULL; - scan.data = to->css.cgroup; - - if (cgroup_scan_tasks(&scan)) - printk(KERN_ERR "move_member_tasks_to_cpuset: " - "cgroup_scan_tasks failed\n"); -} - /* * If CPU and/or memory hotplug handlers, below, unplug any CPUs * or memory nodes, we need to walk over the cpuset hierarchy, @@ -2058,7 +2014,12 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs) nodes_empty(parent->mems_allowed)) parent = parent_cs(parent); - move_member_tasks_to_cpuset(cs, parent); + if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) { + rcu_read_lock(); + printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset %s\n", + cgroup_name(cs->css.cgroup)); + rcu_read_unlock(); + } } /** -- cgit v1.2.3 From b9777cf8d7c7854c3c38bd6621d993b85c2afcdf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 7 Apr 2013 09:29:51 -0700 Subject: cgroup: unexport locking interface and cgroup_attach_task() Now that all external cgroup_lock() users are gone, we can finally unexport the locking interface and prevent future abuse of cgroup_mutex. Make cgroup_[un]lock() and cgroup_lock_live_group() static. Also, cgroup_attach_task() doesn't have any user left and can't be used without locking interface anyway. Make it static too. Signed-off-by: Tejun Heo Acked-by: Li Zefan --- include/linux/cgroup.h | 5 ----- kernel/cgroup.c | 9 +++------ 2 files changed, 3 insertions(+), 11 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index f8eb01d75ddc..63deb70f3149 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -30,10 +30,7 @@ struct css_id; extern int cgroup_init_early(void); extern int cgroup_init(void); -extern void cgroup_lock(void); extern int cgroup_lock_is_held(void); -extern bool cgroup_lock_live_group(struct cgroup *cgrp); -extern void cgroup_unlock(void); extern void cgroup_fork(struct task_struct *p); extern void cgroup_post_fork(struct task_struct *p); extern void cgroup_exit(struct task_struct *p, int run_callbacks); @@ -693,8 +690,6 @@ struct task_struct *cgroup_iter_next(struct cgroup *cgrp, struct cgroup_iter *it); void cgroup_iter_end(struct cgroup *cgrp, struct cgroup_iter *it); int cgroup_scan_tasks(struct cgroup_scanner *scan); -int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, - bool threadgroup); int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ae7617095dec..32ca0304452f 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -336,7 +336,7 @@ static inline struct cftype *__d_cft(struct dentry *dentry) * On success, returns true; the lock should be later released with * cgroup_unlock(). On failure returns false with no lock held. */ -bool cgroup_lock_live_group(struct cgroup *cgrp) +static bool cgroup_lock_live_group(struct cgroup *cgrp) { mutex_lock(&cgroup_mutex); if (cgroup_is_removed(cgrp)) { @@ -345,7 +345,6 @@ bool cgroup_lock_live_group(struct cgroup *cgrp) } return true; } -EXPORT_SYMBOL_GPL(cgroup_lock_live_group); /* the list of cgroups eligible for automatic release. Protected by * release_list_lock */ @@ -824,22 +823,20 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task, * cgroup_lock - lock out any changes to cgroup structures * */ -void cgroup_lock(void) +static void cgroup_lock(void) { mutex_lock(&cgroup_mutex); } -EXPORT_SYMBOL_GPL(cgroup_lock); /** * cgroup_unlock - release lock on cgroup changes * * Undo the lock taken in a previous cgroup_lock() call. */ -void cgroup_unlock(void) +static void cgroup_unlock(void) { mutex_unlock(&cgroup_mutex); } -EXPORT_SYMBOL_GPL(cgroup_unlock); /* * A couple of forward declarations required, due to cyclic reference loop: -- cgit v1.2.3 From 2219449a65ace0290cd9c2260ff337e326b8be8a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 7 Apr 2013 09:29:51 -0700 Subject: cgroup: remove cgroup_lock_is_held() We don't want controllers to assume that the information is officially available and do funky things with it. The only user is task_subsys_state_check() which uses it to verify RCU access context. We can move cgroup_lock_is_held() inside CONFIG_PROVE_RCU but that doesn't add meaningful protection compared to conditionally exposing cgroup_mutex. Remove cgroup_lock_is_held(), export cgroup_mutex iff CONFIG_PROVE_RCU and use lockdep_is_held() directly on the mutex in task_subsys_state_check(). While at it, add parentheses around macro arguments in task_subsys_state_check(). Signed-off-by: Tejun Heo Acked-by: Li Zefan --- include/linux/cgroup.h | 13 +++++++++---- kernel/cgroup.c | 20 ++++++-------------- 2 files changed, 15 insertions(+), 18 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 63deb70f3149..515927eebb37 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -30,7 +30,6 @@ struct css_id; extern int cgroup_init_early(void); extern int cgroup_init(void); -extern int cgroup_lock_is_held(void); extern void cgroup_fork(struct task_struct *p); extern void cgroup_post_fork(struct task_struct *p); extern void cgroup_exit(struct task_struct *p, int run_callbacks); @@ -552,10 +551,16 @@ static inline struct cgroup_subsys_state *cgroup_subsys_state( * rcu_dereference_check() conditions, such as locks used during the * cgroup_subsys::attach() methods. */ +#ifdef CONFIG_PROVE_RCU +extern struct mutex cgroup_mutex; #define task_subsys_state_check(task, subsys_id, __c) \ - rcu_dereference_check(task->cgroups->subsys[subsys_id], \ - lockdep_is_held(&task->alloc_lock) || \ - cgroup_lock_is_held() || (__c)) + rcu_dereference_check((task)->cgroups->subsys[(subsys_id)], \ + lockdep_is_held(&(task)->alloc_lock) || \ + lockdep_is_held(&cgroup_mutex) || (__c)) +#else +#define task_subsys_state_check(task, subsys_id, __c) \ + rcu_dereference((task)->cgroups->subsys[(subsys_id)]) +#endif static inline struct cgroup_subsys_state * task_subsys_state(struct task_struct *task, int subsys_id) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 1a65958c1a0b..ba3e24a76dae 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -83,7 +83,13 @@ * B happens only through cgroup_show_options() and using cgroup_root_mutex * breaks it. */ +#ifdef CONFIG_PROVE_RCU +DEFINE_MUTEX(cgroup_mutex); +EXPORT_SYMBOL_GPL(cgroup_mutex); /* only for task_subsys_state_check() */ +#else static DEFINE_MUTEX(cgroup_mutex); +#endif + static DEFINE_MUTEX(cgroup_root_mutex); /* @@ -251,20 +257,6 @@ static int cgroup_destroy_locked(struct cgroup *cgrp); static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, struct cftype cfts[], bool is_add); -#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); - static int css_unbias_refcnt(int refcnt) { return refcnt >= 0 ? refcnt : refcnt - CSS_DEACT_BIAS; -- cgit v1.2.3 From 479f614110b889d5783acdaec865ede3cdb96b97 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 29 Mar 2013 14:44:42 +0800 Subject: cgroup: Kill subsys.active flag The only user was cpuacct. Acked-by: Tejun Heo Signed-off-by: Li Zefan Acked-by: Peter Zijlstra Link: http://lkml.kernel.org/r/5155385A.4040207@huawei.com Signed-off-by: Ingo Molnar --- include/linux/cgroup.h | 1 - kernel/cgroup.c | 3 --- 2 files changed, 4 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 900af5964f55..95c02c0e35b3 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -458,7 +458,6 @@ struct cgroup_subsys { void (*bind)(struct cgroup *root); int subsys_id; - int active; int disabled; int early_init; /* diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a32f9432666c..5c462813722d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4468,7 +4468,6 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) * need to invoke fork callbacks here. */ BUG_ON(!list_empty(&init_task.tasks)); - ss->active = 1; BUG_ON(online_css(ss, dummytop)); mutex_unlock(&cgroup_mutex); @@ -4573,7 +4572,6 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss) } write_unlock(&css_set_lock); - ss->active = 1; ret = online_css(ss, dummytop); if (ret) goto err_unload; @@ -4614,7 +4612,6 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss) mutex_lock(&cgroup_mutex); offline_css(ss, dummytop); - ss->active = 0; if (ss->use_id) idr_destroy(&ss->idr); -- cgit v1.2.3 From 84cfb6ab484b442d5115eb3baf9db7d74a3ea626 Mon Sep 17 00:00:00 2001 From: Rami Rosen Date: Wed, 10 Apr 2013 14:41:17 +0300 Subject: cgroup: remove bind() method from cgroup_subsys. The bind() method of cgroup_subsys is not used in any of the controllers (cpuset, freezer, blkio, net_cls, memcg, net_prio, devices, perf, hugetlb, cpu and cpuacct) tj: Removed the entry on ->bind() from Documentation/cgroups/cgroups.txt. Also updated a couple paragraphs which were suggesting that dynamic re-binding may be implemented. It's not gonna. Signed-off-by: Rami Rosen Signed-off-by: Tejun Heo --- Documentation/cgroups/cgroups.txt | 20 +++++--------------- include/linux/cgroup.h | 2 -- kernel/cgroup.c | 4 ---- 3 files changed, 5 insertions(+), 21 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 638bf17ff869..2b51e12ce178 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -211,10 +211,9 @@ matches, and any of the requested subsystems are in use in an existing hierarchy, the mount will fail with -EBUSY. Otherwise, a new hierarchy is activated, associated with the requested subsystems. -It's not currently possible to bind a new subsystem to an active -cgroup hierarchy, or to unbind a subsystem from an active cgroup -hierarchy. This may be possible in future, but is fraught with nasty -error-recovery issues. +It's not possible to bind a new subsystem to an active cgroup +hierarchy, or to unbind a subsystem from an active cgroup +hierarchy. When a cgroup filesystem is unmounted, if there are any child cgroups created below the top-level cgroup, that hierarchy @@ -382,10 +381,8 @@ To Specify a hierarchy's release_agent: Note that specifying 'release_agent' more than once will return failure. -Note that changing the set of subsystems is currently only supported -when the hierarchy consists of a single (root) cgroup. Supporting -the ability to arbitrarily bind/unbind subsystems from an existing -cgroup hierarchy is intended to be implemented in the future. +Note that changing the set of subsystems is only supported when the +hierarchy consists of a single (root) cgroup. Then under /sys/fs/cgroup/rg1 you can find a tree that corresponds to the tree of the cgroups in the system. For instance, /sys/fs/cgroup/rg1 @@ -643,13 +640,6 @@ void exit(struct task_struct *task) Called during task exit. -void bind(struct cgroup *root) -(cgroup_mutex held by caller) - -Called when a cgroup subsystem is rebound to a different hierarchy -and root cgroup. Currently this will only involve movement between -the default hierarchy (which never has sub-cgroups) and a hierarchy -that is being created/destroyed (and hence has no sub-cgroups). 4. Extended attribute usage =========================== diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 515927eebb37..92acf8601ae0 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -483,8 +483,6 @@ struct cgroup_subsys { void (*fork)(struct task_struct *task); void (*exit)(struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *task); - void (*bind)(struct cgroup *root); - int subsys_id; int active; int disabled; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ba3e24a76dae..fd38e1cfacca 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1064,16 +1064,12 @@ static int rebind_subsystems(struct cgroupfs_root *root, cgrp->subsys[i]->cgroup = cgrp; list_move(&ss->sibling, &root->subsys_list); ss->root = root; - if (ss->bind) - ss->bind(cgrp); /* refcount was already taken, and we're keeping it */ } else if (bit & removed_mask) { /* We're removing this subsystem */ BUG_ON(ss == NULL); BUG_ON(cgrp->subsys[i] != dummytop->subsys[i]); BUG_ON(cgrp->subsys[i]->cgroup != cgrp); - if (ss->bind) - ss->bind(dummytop); dummytop->subsys[i]->cgroup = dummytop; cgrp->subsys[i] = NULL; subsys[i]->root = &rootnode; -- cgit v1.2.3 From 78574cf981cd3d9ae9f6adbd466a772310ec24ff Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 8 Apr 2013 19:00:38 -0700 Subject: cgroup: implement cgroup_is_descendant() A couple controllers want to determine whether two cgroups are in ancestor/descendant relationship. As it's more likely that the descendant is the primary subject of interest and there are other operations focusing on the descendants, let's ask is_descendent rather than is_ancestor. Implementation is trivial as the previous patch guarantees that all ancestors of a cgroup stay accessible as long as the cgroup is accessible. tj: Removed depth optimization, renamed from cgroup_is_ancestor(), rewrote descriptions. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 1 + kernel/cgroup.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 92acf8601ae0..a2b9d4b13369 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -439,6 +439,7 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); int cgroup_rm_cftypes(struct cgroup_subsys *ss, struct cftype *cfts); int cgroup_is_removed(const struct cgroup *cgrp); +bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor); int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 65b72d0367c5..7bf3ce09c50c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -276,6 +276,26 @@ inline int cgroup_is_removed(const struct cgroup *cgrp) return test_bit(CGRP_REMOVED, &cgrp->flags); } +/** + * cgroup_is_descendant - test ancestry + * @cgrp: the cgroup to be tested + * @ancestor: possible ancestor of @cgrp + * + * Test whether @cgrp is a descendant of @ancestor. It also returns %true + * if @cgrp == @ancestor. This function is safe to call as long as @cgrp + * and @ancestor are accessible. + */ +bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor) +{ + while (cgrp) { + if (cgrp == ancestor) + return true; + cgrp = cgrp->parent; + } + return false; +} +EXPORT_SYMBOL_GPL(cgroup_is_descendant); + /* bits in struct cgroupfs_root flags field */ enum { ROOT_NOPREFIX, /* mounted subsystems have no named prefix */ -- cgit v1.2.3 From 26d5bbe5ba2073fc7ef9e69a55543b2376f5bad0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 12 Apr 2013 10:29:04 -0700 Subject: Revert "cgroup: remove bind() method from cgroup_subsys." This reverts commit 84cfb6ab484b442d5115eb3baf9db7d74a3ea626. There are scheduled changes which make use of the removed callback. Signed-off-by: Tejun Heo Cc: Rami Rosen Cc: Li Zefan --- Documentation/cgroups/cgroups.txt | 20 +++++++++++++++----- include/linux/cgroup.h | 2 ++ kernel/cgroup.c | 4 ++++ 3 files changed, 21 insertions(+), 5 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 2b51e12ce178..638bf17ff869 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -211,9 +211,10 @@ matches, and any of the requested subsystems are in use in an existing hierarchy, the mount will fail with -EBUSY. Otherwise, a new hierarchy is activated, associated with the requested subsystems. -It's not possible to bind a new subsystem to an active cgroup -hierarchy, or to unbind a subsystem from an active cgroup -hierarchy. +It's not currently possible to bind a new subsystem to an active +cgroup hierarchy, or to unbind a subsystem from an active cgroup +hierarchy. This may be possible in future, but is fraught with nasty +error-recovery issues. When a cgroup filesystem is unmounted, if there are any child cgroups created below the top-level cgroup, that hierarchy @@ -381,8 +382,10 @@ To Specify a hierarchy's release_agent: Note that specifying 'release_agent' more than once will return failure. -Note that changing the set of subsystems is only supported when the -hierarchy consists of a single (root) cgroup. +Note that changing the set of subsystems is currently only supported +when the hierarchy consists of a single (root) cgroup. Supporting +the ability to arbitrarily bind/unbind subsystems from an existing +cgroup hierarchy is intended to be implemented in the future. Then under /sys/fs/cgroup/rg1 you can find a tree that corresponds to the tree of the cgroups in the system. For instance, /sys/fs/cgroup/rg1 @@ -640,6 +643,13 @@ void exit(struct task_struct *task) Called during task exit. +void bind(struct cgroup *root) +(cgroup_mutex held by caller) + +Called when a cgroup subsystem is rebound to a different hierarchy +and root cgroup. Currently this will only involve movement between +the default hierarchy (which never has sub-cgroups) and a hierarchy +that is being created/destroyed (and hence has no sub-cgroups). 4. Extended attribute usage =========================== diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index a2b9d4b13369..45aee0fc6b98 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -484,6 +484,8 @@ struct cgroup_subsys { void (*fork)(struct task_struct *task); void (*exit)(struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *task); + void (*bind)(struct cgroup *root); + int subsys_id; int active; int disabled; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7bf3ce09c50c..678a22c75fdb 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1091,12 +1091,16 @@ static int rebind_subsystems(struct cgroupfs_root *root, cgrp->subsys[i]->cgroup = cgrp; list_move(&ss->sibling, &root->subsys_list); ss->root = root; + if (ss->bind) + ss->bind(cgrp); /* refcount was already taken, and we're keeping it */ } else if (bit & removed_mask) { /* We're removing this subsystem */ BUG_ON(ss == NULL); BUG_ON(cgrp->subsys[i] != dummytop->subsys[i]); BUG_ON(cgrp->subsys[i]->cgroup != cgrp); + if (ss->bind) + ss->bind(dummytop); dummytop->subsys[i]->cgroup = dummytop; cgrp->subsys[i] = NULL; subsys[i]->root = &rootnode; -- cgit v1.2.3 From 25a7e6848db76e22677aff202d9c4ef3503be15b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 14 Apr 2013 20:15:25 -0700 Subject: move cgroupfs_root to include/linux/cgroup.h While controllers shouldn't be accessing cgroupfs_root directly, it being hidden inside kern/cgroup.c makes somethings pretty silly. This makes routing hierarchy-wide settings which need to be visible to controllers cumbersome. We're gonna add another hierarchy-wide setting which needs to be accessed from controllers. Move cgroupfs_root and its flags to the header file so that we can access root settings with inline helpers. Signed-off-by: Tejun Heo Acked-by: Serge E. Hallyn Acked-by: Li Zefan --- include/linux/cgroup.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/cgroup.c | 57 -------------------------------------------------- 2 files changed, 57 insertions(+), 57 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 45aee0fc6b98..b21881e1ea08 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -19,6 +19,7 @@ #include #include #include +#include #ifdef CONFIG_CGROUPS @@ -238,6 +239,62 @@ struct cgroup { struct simple_xattrs xattrs; }; +#define MAX_CGROUP_ROOT_NAMELEN 64 + +/* cgroupfs_root->flags */ +enum { + CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */ + CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */ +}; + +/* + * A cgroupfs_root represents the root of a cgroup hierarchy, and may be + * associated with a superblock to form an active hierarchy. This is + * internal to cgroup core. Don't access directly from controllers. + */ +struct cgroupfs_root { + struct super_block *sb; + + /* + * The bitmask of subsystems intended to be attached to this + * hierarchy + */ + unsigned long subsys_mask; + + /* Unique id for this hierarchy. */ + int hierarchy_id; + + /* The bitmask of subsystems currently attached to this hierarchy */ + unsigned long actual_subsys_mask; + + /* 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; + + /* A list running through the active hierarchies */ + struct list_head root_list; + + /* All cgroups on this root, cgroup_mutex protected */ + struct list_head allcg_list; + + /* Hierarchy-specific flags */ + unsigned long flags; + + /* IDs for cgroups in this hierarchy */ + struct ida cgroup_ida; + + /* The path to use for release notifications. */ + char release_agent_path[PATH_MAX]; + + /* The name for this hierarchy - may be empty */ + char name[MAX_CGROUP_ROOT_NAMELEN]; +}; + /* * A css_set is a structure holding pointers to a set of * cgroup_subsys_state objects. This saves space in the task struct diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 67428d84e38b..8b8eb7c168ff 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -30,7 +30,6 @@ #include #include #include -#include #include #include #include @@ -104,56 +103,6 @@ static struct cgroup_subsys *subsys[CGROUP_SUBSYS_COUNT] = { #include }; -#define MAX_CGROUP_ROOT_NAMELEN 64 - -/* - * 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_mask; - - /* Unique id for this hierarchy. */ - int hierarchy_id; - - /* The bitmask of subsystems currently attached to this hierarchy */ - unsigned long actual_subsys_mask; - - /* 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; - - /* A list running through the active hierarchies */ - struct list_head root_list; - - /* All cgroups on this root, cgroup_mutex protected */ - struct list_head allcg_list; - - /* Hierarchy-specific flags */ - unsigned long flags; - - /* IDs for cgroups in this hierarchy */ - struct ida cgroup_ida; - - /* The path to use for release notifications. */ - char release_agent_path[PATH_MAX]; - - /* The name for this hierarchy - may be empty */ - char name[MAX_CGROUP_ROOT_NAMELEN]; -}; - /* * The "rootnode" hierarchy is the "dummy hierarchy", reserved for the * subsystems that are otherwise unattached - it never has more than a @@ -296,12 +245,6 @@ bool cgroup_is_descendant(struct cgroup *cgrp, struct cgroup *ancestor) } EXPORT_SYMBOL_GPL(cgroup_is_descendant); -/* cgroupfs_root->flags */ -enum { - CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */ - CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */ -}; - static int cgroup_is_releasable(const struct cgroup *cgrp) { const int bits = -- cgit v1.2.3 From 873fe09ea5df6ccf6bb34811d8c9992aacb67598 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 14 Apr 2013 20:15:26 -0700 Subject: cgroup: introduce sane_behavior mount option It's a sad fact that at this point various cgroup controllers are carrying so many idiosyncrasies and pure insanities that it simply isn't possible to reach any sort of sane consistent behavior while maintaining staying fully compatible with what already has been exposed to userland. As we can't break exposed userland interface, transitioning to sane behaviors can only be done in steps while maintaining backwards compatibility. This patch introduces a new mount option - __DEVEL__sane_behavior - which disables crazy features and enforces consistent behaviors in cgroup core proper and various controllers. As exactly which behaviors it changes are still being determined, the mount option, at this point, is useful only for development of the new behaviors. As such, the mount option is prefixed with __DEVEL__ and generates a warning message when used. Eventually, once we get to the point where all controller's behaviors are consistent enough to implement unified hierarchy, the __DEVEL__ prefix will be dropped, and more importantly, unified-hierarchy will enforce sane_behavior by default. Maybe we'll able to completely drop the crazy stuff after a while, maybe not, but we at least have a strategy to move on to saner behaviors. This patch introduces the mount option and changes the following behaviors in cgroup core. * Mount options "noprefix" and "clone_children" are disallowed. Also, cgroupfs file cgroup.clone_children is not created. * When mounting an existing superblock, mount options should match. This is currently pretty crazy. If one mounts a cgroup, creates a subdirectory, unmounts it and then mount it again with different option, it looks like the new options are applied but they aren't. * Remount is disallowed. The behaviors changes are documented in the comment above CGRP_ROOT_SANE_BEHAVIOR enum and will be expanded as different controllers are converted and planned improvements progress. v2: Dropped unnecessary explicit file permission setting sane_behavior cftype entry as suggested by Li Zefan. Signed-off-by: Tejun Heo Acked-by: Serge E. Hallyn Acked-by: Li Zefan Cc: Michal Hocko Cc: Vivek Goyal --- include/linux/cgroup.h | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/cgroup.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b21881e1ea08..9c300ad9a911 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -156,6 +156,8 @@ enum { * specified at mount time and thus is implemented here. */ CGRP_CPUSET_CLONE_CHILDREN, + /* see the comment above CGRP_ROOT_SANE_BEHAVIOR for details */ + CGRP_SANE_BEHAVIOR, }; struct cgroup_name { @@ -243,6 +245,37 @@ struct cgroup { /* cgroupfs_root->flags */ enum { + /* + * Unfortunately, cgroup core and various controllers are riddled + * with idiosyncrasies and pointless options. The following flag, + * when set, will force sane behavior - some options are forced on, + * others are disallowed, and some controllers will change their + * hierarchical or other behaviors. + * + * The set of behaviors affected by this flag are still being + * determined and developed and the mount option for this flag is + * prefixed with __DEVEL__. The prefix will be dropped once we + * reach the point where all behaviors are compatible with the + * planned unified hierarchy, which will automatically turn on this + * flag. + * + * The followings are the behaviors currently affected this flag. + * + * - Mount options "noprefix" and "clone_children" are disallowed. + * Also, cgroupfs file cgroup.clone_children is not created. + * + * - When mounting an existing superblock, mount options should + * match. + * + * - Remount is disallowed. + * + * The followings are planned changes. + * + * - release_agent will be disallowed once replacement notification + * mechanism is implemented. + */ + CGRP_ROOT_SANE_BEHAVIOR = (1 << 0), + CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */ CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */ }; @@ -360,6 +393,7 @@ struct cgroup_map_cb { /* cftype->flags */ #define CFTYPE_ONLY_ON_ROOT (1U << 0) /* only create on root cg */ #define CFTYPE_NOT_ON_ROOT (1U << 1) /* don't create on root cg */ +#define CFTYPE_INSANE (1U << 2) /* don't create if sane_behavior */ #define MAX_CFTYPE_NAME 64 @@ -486,6 +520,15 @@ struct cgroup_scanner { void *data; }; +/* + * See the comment above CGRP_ROOT_SANE_BEHAVIOR for details. This + * function can be called as long as @cgrp is accessible. + */ +static inline bool cgroup_sane_behavior(const struct cgroup *cgrp) +{ + return cgrp->root->flags & CGRP_ROOT_SANE_BEHAVIOR; +} + /* Caller should hold rcu_read_lock() */ static inline const char *cgroup_name(const struct cgroup *cgrp) { diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8b8eb7c168ff..67804590d4b0 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1080,6 +1080,8 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry) mutex_lock(&cgroup_root_mutex); for_each_subsys(root, ss) seq_printf(seq, ",%s", ss->name); + if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) + seq_puts(seq, ",sane_behavior"); if (root->flags & CGRP_ROOT_NOPREFIX) seq_puts(seq, ",noprefix"); if (root->flags & CGRP_ROOT_XATTR) @@ -1144,6 +1146,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) all_ss = true; continue; } + if (!strcmp(token, "__DEVEL__sane_behavior")) { + opts->flags |= CGRP_ROOT_SANE_BEHAVIOR; + continue; + } if (!strcmp(token, "noprefix")) { opts->flags |= CGRP_ROOT_NOPREFIX; continue; @@ -1231,6 +1237,20 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) /* Consistency checks */ + if (opts->flags & CGRP_ROOT_SANE_BEHAVIOR) { + pr_warning("cgroup: sane_behavior: this is still under development and its behaviors will change, proceed at your own risk\n"); + + if (opts->flags & CGRP_ROOT_NOPREFIX) { + pr_err("cgroup: sane_behavior: noprefix is not allowed\n"); + return -EINVAL; + } + + if (opts->cpuset_clone_children) { + pr_err("cgroup: sane_behavior: clone_children is not allowed\n"); + return -EINVAL; + } + } + /* * Option noprefix was introduced just for backward compatibility * with the old cpuset, so we allow noprefix only if mounting just @@ -1307,6 +1327,11 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) struct cgroup_sb_opts opts; unsigned long added_mask, removed_mask; + if (root->flags & CGRP_ROOT_SANE_BEHAVIOR) { + pr_err("cgroup: sane_behavior: remount is not allowed\n"); + return -EINVAL; + } + mutex_lock(&cgrp->dentry->d_inode->i_mutex); mutex_lock(&cgroup_mutex); mutex_lock(&cgroup_root_mutex); @@ -1657,6 +1682,14 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, * any) is not needed */ cgroup_drop_root(opts.new_root); + + if (((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) && + root->flags != opts.flags) { + pr_err("cgroup: sane_behavior: new mount options should match the existing superblock\n"); + ret = -EINVAL; + goto drop_new_super; + } + /* no subsys rebinding, so refcounts don't change */ drop_parsed_module_refcounts(opts.subsys_mask); } @@ -2200,6 +2233,13 @@ static int cgroup_release_agent_show(struct cgroup *cgrp, struct cftype *cft, return 0; } +static int cgroup_sane_behavior_show(struct cgroup *cgrp, struct cftype *cft, + struct seq_file *seq) +{ + seq_printf(seq, "%d\n", cgroup_sane_behavior(cgrp)); + return 0; +} + /* A buffer size big enough for numbers or short strings */ #define CGROUP_LOCAL_BUFFER_SIZE 64 @@ -2681,6 +2721,8 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, for (cft = cfts; cft->name[0] != '\0'; cft++) { /* does cft->flags tell us to skip this file on @cgrp? */ + if ((cft->flags & CFTYPE_INSANE) && cgroup_sane_behavior(cgrp)) + continue; if ((cft->flags & CFTYPE_NOT_ON_ROOT) && !cgrp->parent) continue; if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent) @@ -3918,9 +3960,15 @@ static struct cftype files[] = { }, { .name = "cgroup.clone_children", + .flags = CFTYPE_INSANE, .read_u64 = cgroup_clone_children_read, .write_u64 = cgroup_clone_children_write, }, + { + .name = "cgroup.sane_behavior", + .flags = CFTYPE_ONLY_ON_ROOT, + .read_seq_string = cgroup_sane_behavior_show, + }, { .name = "release_agent", .flags = CFTYPE_ONLY_ON_ROOT, -- cgit v1.2.3 From 05fb22ec5456a472a5eadcaacb3e51eca1f8c79c Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 15 Apr 2013 14:25:05 +0800 Subject: cgroup: remove cgrp->top_cgroup It's not used, and it can be retrieved via cgrp->root->top_cgroup. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 1 - kernel/cgroup.c | 2 -- 2 files changed, 3 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 9c300ad9a911..64047ae7fde1 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -204,7 +204,6 @@ struct cgroup { struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; struct cgroupfs_root *root; - struct cgroup *top_cgroup; /* * List of cg_cgroup_links pointing at css_sets with diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 67804590d4b0..c16719e056ab 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1418,7 +1418,6 @@ static void init_cgroup_root(struct cgroupfs_root *root) root->number_of_cgroups = 1; cgrp->root = root; cgrp->name = &root_cgroup_name; - cgrp->top_cgroup = cgrp; init_cgroup_housekeeping(cgrp); list_add_tail(&cgrp->allcg_node, &root->allcg_list); } @@ -4145,7 +4144,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, cgrp->parent = parent; cgrp->root = parent->root; - cgrp->top_cgroup = parent->top_cgroup; if (notify_on_release(parent)) set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); -- cgit v1.2.3 From f00baae7ad6c5f1503528efa852f0be8e9513f0e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 15 Apr 2013 13:41:15 -0700 Subject: memcg: force use_hierarchy if sane_behavior Turn on use_hierarchy by default if sane_behavior is specified and don't create .use_hierarchy file. It is debatable whether to remove .use_hierarchy file or make it ro as the former could make transition easier in certain cases; however, the behavior changes which will be gated by sane_behavior are intensive including changing basic meaning of certain control knobs in a few controllers and I don't really think keeping this piece would make things easier in any noticeable way, so let's remove it. v2: Explain that mem_cgroup_bind() doesn't have to worry about children as suggested by Michal Hocko. Signed-off-by: Tejun Heo Acked-by: Serge E. Hallyn Acked-by: Li Zefan Acked-by: Michal Hocko Acked-by: KAMEZAWA Hiroyuki --- include/linux/cgroup.h | 3 +++ mm/memcontrol.c | 17 +++++++++++++++++ 2 files changed, 20 insertions(+) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 64047ae7fde1..cda7eb2239e1 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -268,6 +268,9 @@ enum { * * - Remount is disallowed. * + * - memcg: use_hierarchy is on by default and the cgroup file for + * the flag is not created. + * * The followings are planned changes. * * - release_agent will be disallowed once replacement notification diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9715c0c491b0..df87bdd4d692 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5814,6 +5814,7 @@ static struct cftype mem_cgroup_files[] = { }, { .name = "use_hierarchy", + .flags = CFTYPE_INSANE, .write_u64 = mem_cgroup_hierarchy_write, .read_u64 = mem_cgroup_hierarchy_read, }, @@ -6784,6 +6785,21 @@ static void mem_cgroup_move_task(struct cgroup *cont, } #endif +/* + * Cgroup retains root cgroups across [un]mount cycles making it necessary + * to verify sane_behavior flag on each mount attempt. + */ +static void mem_cgroup_bind(struct cgroup *root) +{ + /* + * use_hierarchy is forced with sane_behavior. cgroup core + * guarantees that @root doesn't have any children, so turning it + * on for the root memcg is enough. + */ + if (cgroup_sane_behavior(root)) + mem_cgroup_from_cont(root)->use_hierarchy = true; +} + struct cgroup_subsys mem_cgroup_subsys = { .name = "memory", .subsys_id = mem_cgroup_subsys_id, @@ -6794,6 +6810,7 @@ struct cgroup_subsys mem_cgroup_subsys = { .can_attach = mem_cgroup_can_attach, .cancel_attach = mem_cgroup_cancel_attach, .attach = mem_cgroup_move_task, + .bind = mem_cgroup_bind, .base_cftypes = mem_cgroup_files, .early_init = 0, .use_id = 1, -- cgit v1.2.3 From 712317ad97f41e738e1a19aa0a6392a78a84094e Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 18 Apr 2013 23:09:52 -0700 Subject: cgroup: fix broken file xattrs We should store file xattrs in struct cfent instead of struct cftype, because cftype is a type while cfent is object instance of cftype. For example each cgroup has a tasks file, and each tasks file is associated with a uniq cfent, but all those files share the same struct cftype. Alexey Kodanev reported a crash, which can be reproduced: # mount -t cgroup -o xattr /sys/fs/cgroup # mkdir /sys/fs/cgroup/test # setfattr -n trusted.value -v test_value /sys/fs/cgroup/tasks # rmdir /sys/fs/cgroup/test # umount /sys/fs/cgroup oops! In this case, simple_xattrs_free() will free the same struct simple_xattrs twice. tj: Dropped unused local variable @cft from cgroup_diput(). Cc: # 3.8.x Reported-by: Alexey Kodanev Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 3 --- kernel/cgroup.c | 11 ++++++----- 2 files changed, 6 insertions(+), 8 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index cda7eb2239e1..c371888298d5 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -422,9 +422,6 @@ struct cftype { /* CFTYPE_* flags */ unsigned int flags; - /* file xattrs */ - struct simple_xattrs xattrs; - int (*open)(struct inode *inode, struct file *file); ssize_t (*read)(struct cgroup *cgrp, struct cftype *cft, struct file *file, diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c16719e056ab..192d762ec1f4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -117,6 +117,9 @@ struct cfent { struct list_head node; struct dentry *dentry; struct cftype *type; + + /* file xattrs */ + struct simple_xattrs xattrs; }; /* @@ -882,13 +885,12 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode) } else { struct cfent *cfe = __d_cfe(dentry); struct cgroup *cgrp = dentry->d_parent->d_fsdata; - struct cftype *cft = cfe->type; WARN_ONCE(!list_empty(&cfe->node) && cgrp != &cgrp->root->top_cgroup, "cfe still linked for %s\n", cfe->type->name); + simple_xattrs_free(&cfe->xattrs); kfree(cfe); - simple_xattrs_free(&cft->xattrs); } iput(inode); } @@ -2501,7 +2503,7 @@ static struct simple_xattrs *__d_xattrs(struct dentry *dentry) if (S_ISDIR(dentry->d_inode->i_mode)) return &__d_cgrp(dentry)->xattrs; else - return &__d_cft(dentry)->xattrs; + return &__d_cfe(dentry)->xattrs; } static inline int xattr_enabled(struct dentry *dentry) @@ -2677,8 +2679,6 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, umode_t mode; char name[MAX_CGROUP_TYPE_NAMELEN + MAX_CFTYPE_NAME + 2] = { 0 }; - simple_xattrs_init(&cft->xattrs); - if (subsys && !(cgrp->root->flags & CGRP_ROOT_NOPREFIX)) { strcpy(name, subsys->name); strcat(name, "."); @@ -2703,6 +2703,7 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, cfe->type = (void *)cft; cfe->dentry = dentry; dentry->d_fsdata = cfe; + simple_xattrs_init(&cfe->xattrs); list_add_tail(&cfe->node, &parent->files); cfe = NULL; } -- cgit v1.2.3 From 6d2488f64a240191f0733c1f32d73607916b01b7 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 29 Apr 2013 15:07:21 -0700 Subject: cgroup: remove css_get_next Now that we have generic and well ordered cgroup tree walkers there is no need to keep css_get_next in the place. Signed-off-by: Michal Hocko Acked-by: KAMEZAWA Hiroyuki Acked-by: Li Zefan Cc: Johannes Weiner Cc: Ying Han Cc: Tejun Heo Cc: Glauber Costa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/cgroup.h | 7 ------- kernel/cgroup.c | 49 ------------------------------------------------- 2 files changed, 56 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 900af5964f55..470073bf93d0 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -687,13 +687,6 @@ void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css); struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id); -/* - * Get a cgroup whose id is greater than or equal to id under tree of root. - * Returning a cgroup_subsys_state or NULL. - */ -struct cgroup_subsys_state *css_get_next(struct cgroup_subsys *ss, int id, - struct cgroup_subsys_state *root, int *foundid); - /* Returns true if root is ancestor of cg */ bool css_is_ancestor(struct cgroup_subsys_state *cg, const struct cgroup_subsys_state *root); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a32f9432666c..dfaf50d4705e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -5416,55 +5416,6 @@ struct cgroup_subsys_state *css_lookup(struct cgroup_subsys *ss, int id) } EXPORT_SYMBOL_GPL(css_lookup); -/** - * 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); - WARN_ON_ONCE(!rcu_read_lock_held()); - - /* fill start point for scan */ - tmpid = id; - while (1) { - /* - * scan next entry from bitmap(tree), tmpid is updated after - * idr_get_next(). - */ - tmp = idr_get_next(&ss->idr, &tmpid); - 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; -} - /* * get corresponding css from file open on cgroupfs directory */ -- cgit v1.2.3 From 8d8b97ba499cb69fccb5fd9f2b439e3265fc3f27 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 19 Apr 2013 23:11:24 -0400 Subject: take cgroup_open() and cpuset_open() to fs/proc/base.c Signed-off-by: Al Viro --- fs/proc/base.c | 31 +++++++++++++++++++++++++++++++ include/linux/cgroup.h | 2 +- include/linux/cpuset.h | 3 +-- kernel/cgroup.c | 15 +-------------- kernel/cpuset.c | 15 +-------------- 5 files changed, 35 insertions(+), 31 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/fs/proc/base.c b/fs/proc/base.c index f2637c972160..8281986693be 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -404,6 +404,37 @@ static const struct file_operations proc_lstats_operations = { #endif +#ifdef CONFIG_CGROUPS +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); +} + +static const struct file_operations proc_cgroup_operations = { + .open = cgroup_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + +#ifdef CONFIG_PROC_PID_CPUSET + +static int cpuset_open(struct inode *inode, struct file *file) +{ + struct pid *pid = PROC_I(inode)->pid; + return single_open(file, proc_cpuset_show, pid); +} + +static const struct file_operations proc_cpuset_operations = { + .open = cpuset_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + static int proc_oom_score(struct task_struct *task, char *buffer) { unsigned long totalpages = totalram_pages + total_swap_pages; diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 900af5964f55..68f2157b71d4 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -42,7 +42,7 @@ extern int cgroupstats_build(struct cgroupstats *stats, extern int cgroup_load_subsys(struct cgroup_subsys *ss); extern void cgroup_unload_subsys(struct cgroup_subsys *ss); -extern const struct file_operations proc_cgroup_operations; +extern int proc_cgroup_show(struct seq_file *, void *); /* Define the enumeration of all builtin cgroup subsystems */ #define SUBSYS(_x) _x ## _subsys_id, diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index 8c8a60d29407..22b637c5ecae 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -64,10 +64,9 @@ extern int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, extern int cpuset_memory_pressure_enabled; extern void __cpuset_memory_pressure_bump(void); -extern const struct file_operations proc_cpuset_operations; -struct seq_file; extern void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task); +extern int proc_cpuset_show(struct seq_file *, void *); extern int cpuset_mem_spread_node(void); extern int cpuset_slab_spread_node(void); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a32f9432666c..d5cffe80b469 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4769,7 +4769,7 @@ out: */ /* TODO: Use a proper seq_file iterator */ -static int proc_cgroup_show(struct seq_file *m, void *v) +int proc_cgroup_show(struct seq_file *m, void *v) { struct pid *pid; struct task_struct *tsk; @@ -4821,19 +4821,6 @@ 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); -} - -const struct file_operations proc_cgroup_operations = { - .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) { diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 4f9dfe43ecbd..1b6f615be587 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2666,7 +2666,7 @@ void __cpuset_memory_pressure_bump(void) * and we take cpuset_mutex, keeping cpuset_attach() from changing it * anyway. */ -static int proc_cpuset_show(struct seq_file *m, void *unused_v) +int proc_cpuset_show(struct seq_file *m, void *unused_v) { struct pid *pid; struct task_struct *tsk; @@ -2700,19 +2700,6 @@ out_free: out: return retval; } - -static int cpuset_open(struct inode *inode, struct file *file) -{ - struct pid *pid = PROC_I(inode)->pid; - return single_open(file, proc_cpuset_show, pid); -} - -const struct file_operations proc_cpuset_operations = { - .open = cpuset_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; #endif /* CONFIG_PROC_PID_CPUSET */ /* Display task mems_allowed in /proc//status file. */ -- cgit v1.2.3 From a27bb332c04cec8c4afd7912df0dc7890db27560 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Tue, 7 May 2013 16:19:08 -0700 Subject: aio: don't include aio.h in sched.h Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet Cc: Zach Brown Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: Mark Fasheh Cc: Joel Becker Cc: Rusty Russell Cc: Jens Axboe Cc: Asai Thambi S P Cc: Selvan Mani Cc: Sam Bradshaw Cc: Jeff Moyer Cc: Al Viro Cc: Benjamin LaHaise Reviewed-by: "Theodore Ts'o" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/hypfs/inode.c | 1 + block/scsi_ioctl.c | 1 + drivers/char/mem.c | 1 + drivers/infiniband/hw/ipath/ipath_file_ops.c | 1 + drivers/infiniband/hw/qib/qib_file_ops.c | 2 +- drivers/scsi/sg.c | 1 + drivers/staging/android/logger.c | 1 + fs/9p/vfs_addr.c | 1 + fs/afs/write.c | 1 + fs/bio.c | 1 + fs/block_dev.c | 1 + fs/btrfs/file.c | 1 + fs/btrfs/inode.c | 1 + fs/ceph/file.c | 1 + fs/compat.c | 1 + fs/direct-io.c | 1 + fs/ecryptfs/file.c | 1 + fs/ext2/inode.c | 1 + fs/ext3/inode.c | 1 + fs/ext4/file.c | 1 + fs/ext4/indirect.c | 1 + fs/ext4/inode.c | 1 + fs/ext4/page-io.c | 1 + fs/f2fs/data.c | 1 + fs/fat/inode.c | 1 + fs/fuse/cuse.c | 1 + fs/fuse/dev.c | 1 + fs/fuse/file.c | 1 + fs/gfs2/aops.c | 1 + fs/gfs2/file.c | 1 + fs/hfs/inode.c | 1 + fs/hfsplus/inode.c | 1 + fs/jfs/inode.c | 1 + fs/nilfs2/inode.c | 2 +- fs/ntfs/file.c | 1 + fs/ntfs/inode.c | 1 + fs/ocfs2/aops.h | 2 ++ fs/ocfs2/inode.h | 2 -- fs/pipe.c | 1 + fs/read_write.c | 1 + fs/reiserfs/inode.c | 1 + fs/ubifs/file.c | 1 + fs/udf/inode.c | 1 + fs/xfs/xfs_aops.c | 1 + fs/xfs/xfs_file.c | 1 + include/linux/cgroup.h | 1 + include/linux/pid_namespace.h | 1 + include/linux/sched.h | 2 -- include/linux/writeback.h | 1 + kernel/fork.c | 1 + kernel/printk.c | 1 + kernel/ptrace.c | 1 + mm/page_io.c | 1 + mm/shmem.c | 1 + mm/swap.c | 1 + security/keys/internal.h | 2 ++ security/keys/keyctl.c | 1 + sound/core/pcm_native.c | 2 +- 58 files changed, 58 insertions(+), 7 deletions(-) (limited to 'include/linux/cgroup.h') diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c index 5f7d7ba2874c..7a539f4f5e30 100644 --- a/arch/s390/hypfs/inode.c +++ b/arch/s390/hypfs/inode.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include "hypfs.h" diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 9a87daa6f4fb..a5ffcc988f0b 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include diff --git a/drivers/char/mem.c b/drivers/char/mem.c index e49265f18f86..1ccbe9482faa 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -28,6 +28,7 @@ #include #include #include +#include #include diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c index aed8afee56da..6d7f453b4d05 100644 --- a/drivers/infiniband/hw/ipath/ipath_file_ops.c +++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include diff --git a/drivers/infiniband/hw/qib/qib_file_ops.c b/drivers/infiniband/hw/qib/qib_file_ops.c index 4f7aa301b3b1..b56c9428f3c5 100644 --- a/drivers/infiniband/hw/qib/qib_file_ops.c +++ b/drivers/infiniband/hw/qib/qib_file_ops.c @@ -39,7 +39,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 9f0c46547459..df5e961484e1 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -35,6 +35,7 @@ static int sg_version_num = 30534; /* 2 digits for each component */ #include #include #include +#include #include #include #include diff --git a/drivers/staging/android/logger.c b/drivers/staging/android/logger.c index b14a55742559..b040200a5a55 100644 --- a/drivers/staging/android/logger.c +++ b/drivers/staging/android/logger.c @@ -28,6 +28,7 @@ #include #include #include +#include #include "logger.h" #include diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 0ad61c6a65a5..055562c580b4 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include diff --git a/fs/afs/write.c b/fs/afs/write.c index 7e03eadb40c0..a890db4b9898 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "internal.h" static int afs_write_back_from_locked_page(struct afs_writeback *wb, diff --git a/fs/bio.c b/fs/bio.c index b96fc6ce4855..954d73124b41 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/block_dev.c b/fs/block_dev.c index ce08de7467a3..95ff88b54e98 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include "internal.h" diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index bb8b7a0e28a6..bc4d54c465a0 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 09c58a35b429..898da0a01e04 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/ceph/file.c b/fs/ceph/file.c index d70830c66833..656e16907430 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -7,6 +7,7 @@ #include #include #include +#include #include "super.h" #include "mds_client.h" diff --git a/fs/compat.c b/fs/compat.c index 93f7d021b716..fc3b55dce184 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include diff --git a/fs/direct-io.c b/fs/direct-io.c index cfb816dc6d9f..51d16e067d68 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -37,6 +37,7 @@ #include #include #include +#include /* * How many user pages to map in one call to get_user_pages(). This determines diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 63b1f54b6a1f..201f0a0d6b0a 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -31,6 +31,7 @@ #include #include #include +#include #include "ecryptfs_kernel.h" /** diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index fe60cc1117d8..0a87bb10998d 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -31,6 +31,7 @@ #include #include #include +#include #include "ext2.h" #include "acl.h" #include "xip.h" diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index d706dbfa6220..23c712825640 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "ext3.h" #include "xattr.h" #include "acl.h" diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 64848b595b24..4959e29573b6 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include "ext4.h" diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 98be6f697463..b8d5d351e24f 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -20,6 +20,7 @@ * (sct@redhat.com), 1993, 1998 */ +#include #include "ext4_jbd2.h" #include "truncate.h" #include "ext4_extents.h" /* Needed for EXT_MAX_BLOCKS */ diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 793d44b84d7f..0723774bdfb5 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "ext4_jbd2.h" #include "xattr.h" diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 5929cd0baa20..19599bded62a 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 7bd22a201125..d0ed4ba4b61b 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 4ff901632b26..dfce656ddb33 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c index 6f96a8def147..06b5e086ab3a 100644 --- a/fs/fuse/cuse.c +++ b/fs/fuse/cuse.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 9bfd1a3214e6..a45c19093eb4 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -19,6 +19,7 @@ #include #include #include +#include MODULE_ALIAS_MISCDEV(FUSE_MINOR); MODULE_ALIAS("devname:fuse"); diff --git a/fs/fuse/file.c b/fs/fuse/file.c index d15c6f21c17f..82f7ee581245 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -15,6 +15,7 @@ #include #include #include +#include static const struct file_operations fuse_direct_io_file_operations; diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 9883694f1e7c..0bad69ed6336 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index d79c2dadc536..acd16764b133 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c index 716e1aafb2e2..f9299d8a64e3 100644 --- a/fs/hfs/inode.c +++ b/fs/hfs/inode.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "hfs_fs.h" #include "btree.h" diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c index 7faaa964968e..f833d35630ab 100644 --- a/fs/hfsplus/inode.c +++ b/fs/hfsplus/inode.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "hfsplus_fs.h" #include "hfsplus_raw.h" diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c index 77554b61d124..730f24e282a6 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "jfs_incore.h" #include "jfs_inode.h" #include "jfs_filsys.h" diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index cf02f5530713..689fb608648e 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -25,7 +25,7 @@ #include #include #include -#include +#include #include "nilfs.h" #include "btnode.h" #include "segment.h" diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index 1da4b81e6f76..c5670b8d198c 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c index d3e118cc6ffa..2778b0255dc6 100644 --- a/fs/ntfs/inode.c +++ b/fs/ntfs/inode.c @@ -28,6 +28,7 @@ #include #include #include +#include #include "aops.h" #include "attrib.h" diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h index ffb2da370a99..f671e49beb34 100644 --- a/fs/ocfs2/aops.h +++ b/fs/ocfs2/aops.h @@ -22,6 +22,8 @@ #ifndef OCFS2_AOPS_H #define OCFS2_AOPS_H +#include + handle_t *ocfs2_start_walk_page_trans(struct inode *inode, struct page *page, unsigned from, diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h index 88924a3133fa..621fc73bf23d 100644 --- a/fs/ocfs2/inode.h +++ b/fs/ocfs2/inode.h @@ -147,8 +147,6 @@ void ocfs2_refresh_inode(struct inode *inode, int ocfs2_mark_inode_dirty(handle_t *handle, struct inode *inode, struct buffer_head *bh); -int ocfs2_aio_read(struct file *file, struct kiocb *req, struct iocb *iocb); -int ocfs2_aio_write(struct file *file, struct kiocb *req, struct iocb *iocb); struct buffer_head *ocfs2_bread(struct inode *inode, int block, int *err, int reada); diff --git a/fs/pipe.c b/fs/pipe.c index a029a14bacf1..d2c45e14e6d8 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include diff --git a/fs/read_write.c b/fs/read_write.c index bce289afd21a..03430008704e 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index ea5061fd4f3e..77d6d47abc83 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -18,6 +18,7 @@ #include #include #include +#include int reiserfs_commit_write(struct file *f, struct page *page, unsigned from, unsigned to); diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index f12189d2db1d..14374530784c 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -50,6 +50,7 @@ */ #include "ubifs.h" +#include #include #include #include diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 7a12e48ad819..b6d15d349810 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -38,6 +38,7 @@ #include #include #include +#include #include "udf_i.h" #include "udf_sb.h" diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 3244c988d379..2b2691b73428 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -31,6 +31,7 @@ #include "xfs_vnodeops.h" #include "xfs_trace.h" #include "xfs_bmap.h" +#include #include #include #include diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 054d60c0ac57..a5f2042aec8b 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -36,6 +36,7 @@ #include "xfs_ioctl.h" #include "xfs_trace.h" +#include #include #include #include diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 3bff9ce09cf7..5047355b9a0f 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -28,6 +28,7 @@ struct cgroup_subsys; struct inode; struct cgroup; struct css_id; +struct eventfd_ctx; extern int cgroup_init_early(void); extern int cgroup_init(void); diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 731e4ecee3bd..e2772666f004 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include diff --git a/include/linux/sched.h b/include/linux/sched.h index 4800e9d1864c..022c085ac3c5 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -313,8 +313,6 @@ extern void schedule_preempt_disabled(void); struct nsproxy; struct user_namespace; -#include - #ifdef CONFIG_MMU extern void arch_pick_mmap_layout(struct mm_struct *mm); extern unsigned long diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 9a9367c0c076..579a5007c696 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -5,6 +5,7 @@ #define WRITEBACK_H #include +#include #include DECLARE_PER_CPU(int, dirty_throttle_leaks); diff --git a/kernel/fork.c b/kernel/fork.c index 7d40687b1434..c509cc4a0d53 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -70,6 +70,7 @@ #include #include #include +#include #include #include diff --git a/kernel/printk.c b/kernel/printk.c index 96dcfcd9a2d4..fa36e1494420 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 17ae54da0ec2..aed981a3f69c 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include diff --git a/mm/page_io.c b/mm/page_io.c index bb5d75274686..06a8842a6ec6 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -20,6 +20,7 @@ #include #include #include +#include #include static struct bio *get_swap_bio(gfp_t gfp_flags, diff --git a/mm/shmem.c b/mm/shmem.c index 39b2a0b86fe8..5e6a8422658b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -31,6 +31,7 @@ #include #include #include +#include static struct vfsmount *shm_mnt; diff --git a/mm/swap.c b/mm/swap.c index acd40bfffa82..dfd7d71d6841 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "internal.h" diff --git a/security/keys/internal.h b/security/keys/internal.h index 8bbefc3b55d4..d4f1468b9b50 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -16,6 +16,8 @@ #include #include +struct iovec; + #ifdef __KDEBUG #define kenter(FMT, ...) \ printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 4b5c948eb414..33cfd27b4de2 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include "internal.h" diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 23e3c46cd0a4..ccfa383f1fda 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -25,7 +25,7 @@ #include #include #include -#include +#include #include #include #include -- cgit v1.2.3