diff options
| -rw-r--r-- | Documentation/cgroups/cgroups.txt | 31 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 28 | ||||
| -rw-r--r-- | kernel/cgroup.c | 99 | ||||
| -rw-r--r-- | kernel/cgroup_freezer.c | 2 | ||||
| -rw-r--r-- | kernel/cpuset.c | 18 | ||||
| -rw-r--r-- | mm/memcontrol.c | 16 | ||||
| -rw-r--r-- | security/device_cgroup.c | 7 |
7 files changed, 158 insertions, 43 deletions
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 60d82e1..f915606 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -603,15 +603,25 @@ return 0, the attach will be allowed to proceed, even if the default permission check (root or same user) fails. int can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *task) + struct cgroup_taskset *tset) (cgroup_mutex held by caller) -Called prior to moving a task into a cgroup; if the subsystem -returns an error, this will abort the attach operation. If a NULL -task is passed, then a successful result indicates that *any* -unspecified task can be moved into the cgroup. Note that this isn't -called on a fork. If this method returns 0 (success) then this should -remain valid while the caller holds cgroup_mutex and it is ensured that either +Called prior to moving one or more tasks into a cgroup; if the +subsystem returns an error, this will abort the attach operation. +@tset contains the tasks to be attached and is guaranteed to have at +least one task in it. + +If there are multiple tasks in the taskset, then: + - it's guaranteed that all are from the same thread group + - @tset contains all tasks from the thread group whether or not + they're switching cgroups + - the first task is the leader + +Each @tset entry also contains the task's old cgroup and tasks which +aren't switching cgroup can be skipped easily using the +cgroup_taskset_for_each() iterator. Note that this isn't called on a +fork. If this method returns 0 (success) then this should remain valid +while the caller holds cgroup_mutex and it is ensured that either attach() or cancel_attach() will be called in future. int can_attach_task(struct cgroup *cgrp, struct task_struct *tsk); @@ -622,14 +632,14 @@ attached (possibly many when using cgroup_attach_proc). Called after can_attach. void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *task, bool threadgroup) + struct cgroup_taskset *tset) (cgroup_mutex held by caller) Called when a task attach operation has failed after can_attach() has succeeded. A subsystem whose can_attach() has some side-effects should provide this function, so that the subsystem can implement a rollback. If not, not necessary. This will be called only about subsystems whose can_attach() operation have -succeeded. +succeeded. The parameters are identical to can_attach(). void pre_attach(struct cgroup *cgrp); (cgroup_mutex held by caller) @@ -638,11 +648,12 @@ For any non-per-thread attachment work that needs to happen before attach_task. Needed by cpuset. void attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cgrp, struct task_struct *task) + struct cgroup_taskset *tset) (cgroup_mutex held by caller) Called after the task has been attached to the cgroup, to allow any post-attachment activity that requires memory allocations or blocking. +The parameters are identical to can_attach(). void attach_task(struct cgroup *cgrp, struct task_struct *tsk); (cgroup_mutex held by caller) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 543250e..18dfab8 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -450,6 +450,28 @@ void cgroup_exclude_rmdir(struct cgroup_subsys_state *css); void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css); /* + * Control Group taskset, used to pass around set of tasks to cgroup_subsys + * methods. + */ +struct cgroup_taskset; +struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset); +struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset); +struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset); +int cgroup_taskset_size(struct cgroup_taskset *tset); + +/** + * cgroup_taskset_for_each - iterate cgroup_taskset + * @task: the loop cursor + * @skip_cgrp: skip if task's cgroup matches this, %NULL to iterate through all + * @tset: taskset to iterate + */ +#define cgroup_taskset_for_each(task, skip_cgrp, tset) \ + for ((task) = cgroup_taskset_first((tset)); (task); \ + (task) = cgroup_taskset_next((tset))) \ + if (!(skip_cgrp) || \ + cgroup_taskset_cur_cgroup((tset)) != (skip_cgrp)) + +/* * Control Group subsystem type. * See Documentation/cgroups/cgroups.txt for details */ @@ -461,14 +483,14 @@ struct cgroup_subsys { void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cgrp); int (*allow_attach)(struct cgroup *cgrp, struct task_struct *tsk); int (*can_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *tsk); + struct cgroup_taskset *tset); int (*can_attach_task)(struct cgroup *cgrp, struct task_struct *tsk); void (*cancel_attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *tsk); + struct cgroup_taskset *tset); void (*pre_attach)(struct cgroup *cgrp); void (*attach_task)(struct cgroup *cgrp, struct task_struct *tsk); void (*attach)(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cgrp, struct task_struct *tsk); + struct cgroup_taskset *tset); void (*fork)(struct cgroup_subsys *ss, struct task_struct *task); void (*exit)(struct cgroup_subsys *ss, struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *task); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 34ef57c..ba2226c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1747,11 +1747,85 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) } EXPORT_SYMBOL_GPL(cgroup_path); +/* + * Control Group taskset + */ struct task_and_cgroup { struct task_struct *task; struct cgroup *cgrp; }; +struct cgroup_taskset { + struct task_and_cgroup single; + struct flex_array *tc_array; + int tc_array_len; + int idx; + struct cgroup *cur_cgrp; +}; + +/** + * cgroup_taskset_first - reset taskset and return the first task + * @tset: taskset of interest + * + * @tset iteration is initialized and the first task is returned. + */ +struct task_struct *cgroup_taskset_first(struct cgroup_taskset *tset) +{ + if (tset->tc_array) { + tset->idx = 0; + return cgroup_taskset_next(tset); + } else { + tset->cur_cgrp = tset->single.cgrp; + return tset->single.task; + } +} +EXPORT_SYMBOL_GPL(cgroup_taskset_first); + +/** + * cgroup_taskset_next - iterate to the next task in taskset + * @tset: taskset of interest + * + * Return the next task in @tset. Iteration must have been initialized + * with cgroup_taskset_first(). + */ +struct task_struct *cgroup_taskset_next(struct cgroup_taskset *tset) +{ + struct task_and_cgroup *tc; + + if (!tset->tc_array || tset->idx >= tset->tc_array_len) + return NULL; + + tc = flex_array_get(tset->tc_array, tset->idx++); + tset->cur_cgrp = tc->cgrp; + return tc->task; +} +EXPORT_SYMBOL_GPL(cgroup_taskset_next); + +/** + * cgroup_taskset_cur_cgroup - return the matching cgroup for the current task + * @tset: taskset of interest + * + * Return the cgroup for the current (last returned) task of @tset. This + * function must be preceded by either cgroup_taskset_first() or + * cgroup_taskset_next(). + */ +struct cgroup *cgroup_taskset_cur_cgroup(struct cgroup_taskset *tset) +{ + return tset->cur_cgrp; +} +EXPORT_SYMBOL_GPL(cgroup_taskset_cur_cgroup); + +/** + * cgroup_taskset_size - return the number of tasks in taskset + * @tset: taskset of interest + */ +int cgroup_taskset_size(struct cgroup_taskset *tset) +{ + return tset->tc_array ? tset->tc_array_len : 1; +} +EXPORT_SYMBOL_GPL(cgroup_taskset_size); + + /* * cgroup_task_migrate - move a task from one cgroup to another. * @@ -1832,6 +1906,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) struct cgroup *oldcgrp; struct cgroupfs_root *root = cgrp->root; struct css_set *cg; + struct cgroup_taskset tset = { }; /* @tsk either already exited or can't exit until the end */ if (tsk->flags & PF_EXITING) @@ -1842,9 +1917,12 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) if (cgrp == oldcgrp) return 0; + tset.single.task = tsk; + tset.single.cgrp = oldcgrp; + for_each_subsys(root, ss) { if (ss->can_attach) { - retval = ss->can_attach(ss, cgrp, tsk); + retval = ss->can_attach(ss, cgrp, &tset); if (retval) { /* * Remember on which subsystem the can_attach() @@ -1880,7 +1958,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) if (ss->attach_task) ss->attach_task(cgrp, tsk); if (ss->attach) - ss->attach(ss, cgrp, oldcgrp, tsk); + ss->attach(ss, cgrp, &tset); } set_bit(CGRP_RELEASABLE, &cgrp->flags); /* put_css_set will not destroy cg until after an RCU grace period */ @@ -1903,7 +1981,7 @@ out: */ break; if (ss->cancel_attach) - ss->cancel_attach(ss, cgrp, tsk); + ss->cancel_attach(ss, cgrp, &tset); } } return retval; @@ -2019,6 +2097,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) struct task_struct *tsk; struct task_and_cgroup *tc; struct flex_array *group; + struct cgroup_taskset tset = { }; /* * we need to make sure we have css_sets for all the tasks we're * going to move -before- we actually start moving them, so that in @@ -2085,6 +2164,8 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) } while_each_thread(leader, tsk); /* remember the number of threads in the array for later. */ group_size = i; + tset.tc_array = group; + tset.tc_array_len = group_size; read_unlock(&tasklist_lock); /* methods shouldn't be called if no task is actually migrating */ @@ -2097,7 +2178,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) */ for_each_subsys(root, ss) { if (ss->can_attach) { - retval = ss->can_attach(ss, cgrp, leader); + retval = ss->can_attach(ss, cgrp, &tset); if (retval) { failed_ss = ss; goto out_cancel_attach; @@ -2180,10 +2261,8 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader) * being moved, this call will need to be reworked to communicate that. */ for_each_subsys(root, ss) { - if (ss->attach) { - tc = flex_array_get(group, 0); - ss->attach(ss, cgrp, tc->cgrp, tc->task); - } + if (ss->attach) + ss->attach(ss, cgrp, &tset); } /* @@ -2204,11 +2283,11 @@ out_cancel_attach: for_each_subsys(root, ss) { if (ss == failed_ss) { if (cancel_failed_ss && ss->cancel_attach) - ss->cancel_attach(ss, cgrp, leader); + ss->cancel_attach(ss, cgrp, &tset); break; } if (ss->cancel_attach) - ss->cancel_attach(ss, cgrp, leader); + ss->cancel_attach(ss, cgrp, &tset); } } out_put_tasks: diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index a3f638a..2df17b0 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -167,7 +167,7 @@ static bool is_task_frozen_enough(struct task_struct *task) */ static int freezer_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, - struct task_struct *task) + struct cgroup_taskset *tset) { struct freezer *freezer; diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 112790d..4ec1112 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1363,10 +1363,10 @@ static int fmeter_getrate(struct fmeter *fmp) } /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ -static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, - struct task_struct *tsk) +static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct cgroup_taskset *tset) { - struct cpuset *cs = cgroup_cs(cont); + struct cpuset *cs = cgroup_cs(cgrp); if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) return -ENOSPC; @@ -1379,7 +1379,7 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, * set_cpus_allowed_ptr() on all attached tasks before cpus_allowed may * be changed. */ - if (tsk->flags & PF_THREAD_BOUND) + if (cgroup_taskset_first(tset)->flags & PF_THREAD_BOUND) return -EINVAL; return 0; @@ -1429,12 +1429,14 @@ static void cpuset_attach_task(struct cgroup *cont, struct task_struct *tsk) cpuset_update_task_spread_flag(cs, tsk); } -static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont, - struct cgroup *oldcont, struct task_struct *tsk) +static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct cgroup_taskset *tset) { struct mm_struct *mm; - struct cpuset *cs = cgroup_cs(cont); - struct cpuset *oldcs = cgroup_cs(oldcont); + struct task_struct *tsk = cgroup_taskset_first(tset); + struct cgroup *oldcgrp = cgroup_taskset_cur_cgroup(tset); + struct cpuset *cs = cgroup_cs(cgrp); + struct cpuset *oldcs = cgroup_cs(oldcgrp); /* * Change mm, possibly for multiple threads in a threadgroup. This is diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1043698..013bdbc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5442,8 +5442,9 @@ static void mem_cgroup_clear_mc(void) static int mem_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgroup, - struct task_struct *p) + struct cgroup_taskset *tset) { + struct task_struct *p = cgroup_taskset_first(tset); int ret = 0; struct mem_cgroup *mem = mem_cgroup_from_cont(cgroup); @@ -5481,7 +5482,7 @@ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgroup, - struct task_struct *p) + struct cgroup_taskset *tset) { mem_cgroup_clear_mc(); } @@ -5600,9 +5601,9 @@ retry: static void mem_cgroup_move_task(struct cgroup_subsys *ss, struct cgroup *cont, - struct cgroup *old_cont, - struct task_struct *p) + struct cgroup_taskset *tset) { + struct task_struct *p = cgroup_taskset_first(tset); struct mm_struct *mm = get_task_mm(p); if (mm) { @@ -5617,19 +5618,18 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss, #else /* !CONFIG_MMU */ static int mem_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgroup, - struct task_struct *p) + struct cgroup_taskset *tset) { return 0; } static void mem_cgroup_cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgroup, - struct task_struct *p) + struct cgroup_taskset *tset) { } static void mem_cgroup_move_task(struct cgroup_subsys *ss, struct cgroup *cont, - struct cgroup *old_cont, - struct task_struct *p) + struct cgroup_taskset *tset) { } #endif diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 1be6826..eb5827a 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -62,11 +62,12 @@ static inline struct dev_cgroup *task_devcgroup(struct task_struct *task) struct cgroup_subsys devices_subsys; static int devcgroup_can_attach(struct cgroup_subsys *ss, - struct cgroup *new_cgroup, struct task_struct *task) + struct cgroup *new_cgrp, struct cgroup_taskset *set) { - if (current != task && !capable(CAP_SYS_ADMIN)) - return -EPERM; + struct task_struct *task = cgroup_taskset_first(set); + if (current != task && !capable(CAP_SYS_ADMIN)) + return -EPERM; return 0; } |