From a77aea92010acf54ad785047234418d5d68772e2 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Thu, 26 May 2011 16:25:23 -0700 Subject: cgroup: remove the ns_cgroup The ns_cgroup is an annoying cgroup at the namespace / cgroup frontier and leads to some problems: * cgroup creation is out-of-control * cgroup name can conflict when pids are looping * it is not possible to have a single process handling a lot of namespaces without falling in a exponential creation time * we may want to create a namespace without creating a cgroup The ns_cgroup was replaced by a compatibility flag 'clone_children', where a newly created cgroup will copy the parent cgroup values. The userspace has to manually create a cgroup and add a task to the 'tasks' file. This patch removes the ns_cgroup as suggested in the following thread: https://lists.linux-foundation.org/pipermail/containers/2009-June/018616.html The 'cgroup_clone' function is removed because it is no longer used. This is a userspace-visible change. Commit 45531757b45c ("cgroup: notify ns_cgroup deprecated") (merged into 2.6.27) caused the kernel to emit a printk warning users that the feature is planned for removal. Since that time we have heard from XXX users who were affected by this. Signed-off-by: Daniel Lezcano Signed-off-by: Serge E. Hallyn Cc: Eric W. Biederman Cc: Jamal Hadi Salim Reviewed-by: Li Zefan Acked-by: Paul Menage Acked-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/cgroups/cgroups.txt | 2 +- arch/mips/configs/bcm47xx_defconfig | 1 - arch/mn10300/configs/asb2364_defconfig | 1 - arch/powerpc/configs/ppc6xx_defconfig | 1 - arch/powerpc/configs/pseries_defconfig | 1 - arch/sh/configs/apsh4ad0a_defconfig | 1 - arch/sh/configs/sdk7786_defconfig | 1 - arch/sh/configs/se7206_defconfig | 1 - arch/sh/configs/shx3_defconfig | 1 - arch/sh/configs/urquell_defconfig | 1 - arch/x86/configs/i386_defconfig | 1 - arch/x86/configs/x86_64_defconfig | 1 - include/linux/cgroup.h | 3 - include/linux/cgroup_subsys.h | 6 -- include/linux/nsproxy.h | 9 --- init/Kconfig | 8 --- kernel/Makefile | 1 - kernel/cgroup.c | 116 -------------------------------- kernel/cpuset.c | 7 +- kernel/fork.c | 6 -- kernel/ns_cgroup.c | 118 --------------------------------- kernel/nsproxy.c | 4 -- 22 files changed, 4 insertions(+), 287 deletions(-) delete mode 100644 kernel/ns_cgroup.c diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 8c4f346..0ed99f0 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -651,7 +651,7 @@ always handled well. void post_clone(struct cgroup_subsys *ss, struct cgroup *cgrp) (cgroup_mutex held by caller) -Called at the end of cgroup_clone() to do any parameter +Called during cgroup_create() to do any parameter initialization which might be required before a task could attach. For example in cpusets, no task may attach before 'cpus' and 'mems' are set up. diff --git a/arch/mips/configs/bcm47xx_defconfig b/arch/mips/configs/bcm47xx_defconfig index 22fdf2f..ad15fb1 100644 --- a/arch/mips/configs/bcm47xx_defconfig +++ b/arch/mips/configs/bcm47xx_defconfig @@ -16,7 +16,6 @@ CONFIG_TASK_IO_ACCOUNTING=y CONFIG_AUDIT=y CONFIG_TINY_RCU=y CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_CPUACCT=y CONFIG_RELAY=y CONFIG_BLK_DEV_INITRD=y diff --git a/arch/mn10300/configs/asb2364_defconfig b/arch/mn10300/configs/asb2364_defconfig index 31d7626..fbb96ae 100644 --- a/arch/mn10300/configs/asb2364_defconfig +++ b/arch/mn10300/configs/asb2364_defconfig @@ -8,7 +8,6 @@ CONFIG_TASK_XACCT=y CONFIG_TASK_IO_ACCOUNTING=y CONFIG_LOG_BUF_SHIFT=14 CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_DEVICE=y CONFIG_CGROUP_CPUACCT=y diff --git a/arch/powerpc/configs/ppc6xx_defconfig b/arch/powerpc/configs/ppc6xx_defconfig index 2142089..04360f9 100644 --- a/arch/powerpc/configs/ppc6xx_defconfig +++ b/arch/powerpc/configs/ppc6xx_defconfig @@ -10,7 +10,6 @@ CONFIG_TASK_XACCT=y CONFIG_TASK_IO_ACCOUNTING=y CONFIG_AUDIT=y CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_DEVICE=y CONFIG_CGROUP_CPUACCT=y CONFIG_RESOURCE_COUNTERS=y diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig index 7de1386..c9f212b 100644 --- a/arch/powerpc/configs/pseries_defconfig +++ b/arch/powerpc/configs/pseries_defconfig @@ -15,7 +15,6 @@ CONFIG_AUDITSYSCALL=y CONFIG_IKCONFIG=y CONFIG_IKCONFIG_PROC=y CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_DEVICE=y CONFIG_CPUSETS=y diff --git a/arch/sh/configs/apsh4ad0a_defconfig b/arch/sh/configs/apsh4ad0a_defconfig index 77ec0e7..e758348 100644 --- a/arch/sh/configs/apsh4ad0a_defconfig +++ b/arch/sh/configs/apsh4ad0a_defconfig @@ -7,7 +7,6 @@ CONFIG_IKCONFIG=y CONFIG_IKCONFIG_PROC=y CONFIG_LOG_BUF_SHIFT=14 CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_DEVICE=y CONFIG_CGROUP_CPUACCT=y diff --git a/arch/sh/configs/sdk7786_defconfig b/arch/sh/configs/sdk7786_defconfig index c416505..8a7dd7b 100644 --- a/arch/sh/configs/sdk7786_defconfig +++ b/arch/sh/configs/sdk7786_defconfig @@ -12,7 +12,6 @@ CONFIG_IKCONFIG=y CONFIG_IKCONFIG_PROC=y CONFIG_CGROUPS=y CONFIG_CGROUP_DEBUG=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_DEVICE=y CONFIG_CPUSETS=y diff --git a/arch/sh/configs/se7206_defconfig b/arch/sh/configs/se7206_defconfig index a468ff2..72c3fad 100644 --- a/arch/sh/configs/se7206_defconfig +++ b/arch/sh/configs/se7206_defconfig @@ -8,7 +8,6 @@ CONFIG_RCU_TRACE=y CONFIG_LOG_BUF_SHIFT=14 CONFIG_CGROUPS=y CONFIG_CGROUP_DEBUG=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_DEVICE=y CONFIG_CGROUP_CPUACCT=y CONFIG_RESOURCE_COUNTERS=y diff --git a/arch/sh/configs/shx3_defconfig b/arch/sh/configs/shx3_defconfig index 3f92d37..6bb4130 100644 --- a/arch/sh/configs/shx3_defconfig +++ b/arch/sh/configs/shx3_defconfig @@ -9,7 +9,6 @@ CONFIG_IKCONFIG=y CONFIG_IKCONFIG_PROC=y CONFIG_LOG_BUF_SHIFT=14 CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_DEVICE=y CONFIG_CGROUP_CPUACCT=y diff --git a/arch/sh/configs/urquell_defconfig b/arch/sh/configs/urquell_defconfig index 7b3daec..8bfa4d0 100644 --- a/arch/sh/configs/urquell_defconfig +++ b/arch/sh/configs/urquell_defconfig @@ -9,7 +9,6 @@ CONFIG_IKCONFIG_PROC=y CONFIG_LOG_BUF_SHIFT=14 CONFIG_CGROUPS=y CONFIG_CGROUP_DEBUG=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_DEVICE=y CONFIG_CPUSETS=y diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig index 6f98726..2bf18059f 100644 --- a/arch/x86/configs/i386_defconfig +++ b/arch/x86/configs/i386_defconfig @@ -10,7 +10,6 @@ CONFIG_TASK_IO_ACCOUNTING=y CONFIG_AUDIT=y CONFIG_LOG_BUF_SHIFT=18 CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CPUSETS=y CONFIG_CGROUP_CPUACCT=y diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig index ee01a9d..22a0dc8 100644 --- a/arch/x86/configs/x86_64_defconfig +++ b/arch/x86/configs/x86_64_defconfig @@ -11,7 +11,6 @@ CONFIG_TASK_IO_ACCOUNTING=y CONFIG_AUDIT=y CONFIG_LOG_BUF_SHIFT=18 CONFIG_CGROUPS=y -CONFIG_CGROUP_NS=y CONFIG_CGROUP_FREEZER=y CONFIG_CPUSETS=y CONFIG_CGROUP_CPUACCT=y diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 1e6cde2..ab4ac0c 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -555,9 +555,6 @@ static inline struct cgroup* task_cgroup(struct task_struct *task, return task_subsys_state(task, subsys_id)->cgroup; } -int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *ss, - char *nodename); - /* A cgroup_iter should be treated as an opaque object */ struct cgroup_iter { struct list_head *cg_link; diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index cdbfcb8..ac663c1 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -19,12 +19,6 @@ SUBSYS(debug) /* */ -#ifdef CONFIG_CGROUP_NS -SUBSYS(ns) -#endif - -/* */ - #ifdef CONFIG_CGROUP_SCHED SUBSYS(cpu_cgroup) #endif diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index 7b370c7..50d20ab 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -81,13 +81,4 @@ static inline void get_nsproxy(struct nsproxy *ns) atomic_inc(&ns->count); } -#ifdef CONFIG_CGROUP_NS -int ns_cgroup_clone(struct task_struct *tsk, struct pid *pid); -#else -static inline int ns_cgroup_clone(struct task_struct *tsk, struct pid *pid) -{ - return 0; -} -#endif - #endif diff --git a/init/Kconfig b/init/Kconfig index 332aac6..ebafac4 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -589,14 +589,6 @@ config CGROUP_DEBUG Say N if unsure. -config CGROUP_NS - bool "Namespace cgroup subsystem" - help - Provides a simple namespace cgroup subsystem to - provide hierarchical naming of sets of namespaces, - for instance virtual servers and checkpoint/restart - jobs. - config CGROUP_FREEZER bool "Freezer cgroup subsystem" help diff --git a/kernel/Makefile b/kernel/Makefile index e9cf191..2d64cfc 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -61,7 +61,6 @@ obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o obj-$(CONFIG_CPUSETS) += cpuset.o -obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o obj-$(CONFIG_UTS_NS) += utsname.o obj-$(CONFIG_USER_NS) += user_namespace.o obj-$(CONFIG_PID_NS) += pid_namespace.o diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 00a8843..2731d11 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4630,122 +4630,6 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) } /** - * cgroup_clone - clone the cgroup the given subsystem is attached to - * @tsk: the task to be moved - * @subsys: the given subsystem - * @nodename: the name for the new cgroup - * - * Duplicate the current cgroup in the hierarchy that the given - * subsystem is attached to, and move this task into the new - * child. - */ -int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys, - char *nodename) -{ - struct dentry *dentry; - int ret = 0; - struct cgroup *parent, *child; - struct inode *inode; - struct css_set *cg; - struct cgroupfs_root *root; - struct cgroup_subsys *ss; - - /* We shouldn't be called by an unregistered subsystem */ - BUG_ON(!subsys->active); - - /* First figure out what hierarchy and cgroup we're dealing - * with, and pin them so we can drop cgroup_mutex */ - mutex_lock(&cgroup_mutex); - again: - root = subsys->root; - if (root == &rootnode) { - mutex_unlock(&cgroup_mutex); - return 0; - } - - /* Pin the hierarchy */ - if (!atomic_inc_not_zero(&root->sb->s_active)) { - /* We race with the final deactivate_super() */ - mutex_unlock(&cgroup_mutex); - return 0; - } - - /* Keep the cgroup alive */ - task_lock(tsk); - parent = task_cgroup(tsk, subsys->subsys_id); - cg = tsk->cgroups; - get_css_set(cg); - task_unlock(tsk); - - mutex_unlock(&cgroup_mutex); - - /* Now do the VFS work to create a cgroup */ - inode = parent->dentry->d_inode; - - /* Hold the parent directory mutex across this operation to - * stop anyone else deleting the new cgroup */ - mutex_lock(&inode->i_mutex); - dentry = lookup_one_len(nodename, parent->dentry, strlen(nodename)); - if (IS_ERR(dentry)) { - printk(KERN_INFO - "cgroup: Couldn't allocate dentry for %s: %ld\n", nodename, - PTR_ERR(dentry)); - ret = PTR_ERR(dentry); - goto out_release; - } - - /* Create the cgroup directory, which also creates the cgroup */ - ret = vfs_mkdir(inode, dentry, 0755); - child = __d_cgrp(dentry); - dput(dentry); - if (ret) { - printk(KERN_INFO - "Failed to create cgroup %s: %d\n", nodename, - ret); - goto out_release; - } - - /* The cgroup now exists. Retake cgroup_mutex and check - * that we're still in the same state that we thought we - * were. */ - mutex_lock(&cgroup_mutex); - if ((root != subsys->root) || - (parent != task_cgroup(tsk, subsys->subsys_id))) { - /* Aargh, we raced ... */ - mutex_unlock(&inode->i_mutex); - put_css_set(cg); - - deactivate_super(root->sb); - /* The cgroup is still accessible in the VFS, but - * we're not going to try to rmdir() it at this - * point. */ - printk(KERN_INFO - "Race in cgroup_clone() - leaking cgroup %s\n", - nodename); - goto again; - } - - /* do any required auto-setup */ - for_each_subsys(root, ss) { - if (ss->post_clone) - ss->post_clone(ss, child); - } - - /* All seems fine. Finish by moving the task into the new cgroup */ - ret = cgroup_attach_task(child, tsk); - mutex_unlock(&cgroup_mutex); - - out_release: - mutex_unlock(&inode->i_mutex); - - mutex_lock(&cgroup_mutex); - put_css_set(cg); - mutex_unlock(&cgroup_mutex); - deactivate_super(root->sb); - return ret; -} - -/** * cgroup_is_descendant - see if @cgrp is a descendant of @task's cgrp * @cgrp: the cgroup in question * @task: the task in question diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 55b297d..1ceeb04 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1802,10 +1802,9 @@ static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont) } /* - * post_clone() is called at the end of cgroup_clone(). - * 'cgroup' was just created automatically as a result of - * a cgroup_clone(), and the current task is about to - * be moved into 'cgroup'. + * post_clone() is called during cgroup_create() when the + * clone_children mount argument was specified. The cgroup + * can not yet have any tasks. * * Currently we refuse to set up the cgroup - thereby * refusing the task to be entered, and as a result refusing diff --git a/kernel/fork.c b/kernel/fork.c index 1fa9d94..1f84099 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1229,12 +1229,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (clone_flags & CLONE_THREAD) p->tgid = current->tgid; - if (current->nsproxy != p->nsproxy) { - retval = ns_cgroup_clone(p, pid); - if (retval) - goto bad_fork_free_pid; - } - p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL; /* * Clear TID on mm_release()? diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c deleted file mode 100644 index 2c98ad9..0000000 --- a/kernel/ns_cgroup.c +++ /dev/null @@ -1,118 +0,0 @@ -/* - * ns_cgroup.c - namespace cgroup subsystem - * - * Copyright 2006, 2007 IBM Corp - */ - -#include -#include -#include -#include -#include -#include - -struct ns_cgroup { - struct cgroup_subsys_state css; -}; - -struct cgroup_subsys ns_subsys; - -static inline struct ns_cgroup *cgroup_to_ns( - struct cgroup *cgroup) -{ - return container_of(cgroup_subsys_state(cgroup, ns_subsys_id), - struct ns_cgroup, css); -} - -int ns_cgroup_clone(struct task_struct *task, struct pid *pid) -{ - char name[PROC_NUMBUF]; - - snprintf(name, PROC_NUMBUF, "%d", pid_vnr(pid)); - return cgroup_clone(task, &ns_subsys, name); -} - -/* - * Rules: - * 1. you can only enter a cgroup which is a descendant of your current - * cgroup - * 2. you can only place another process into a cgroup if - * a. you have CAP_SYS_ADMIN - * b. your cgroup is an ancestor of task's destination cgroup - * (hence either you are in the same cgroup as task, or in an - * ancestor cgroup thereof) - */ -static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, - struct task_struct *task, bool threadgroup) -{ - if (current != task) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - if (!cgroup_is_descendant(new_cgroup, current)) - return -EPERM; - } - - if (!cgroup_is_descendant(new_cgroup, task)) - return -EPERM; - - if (threadgroup) { - struct task_struct *c; - rcu_read_lock(); - list_for_each_entry_rcu(c, &task->thread_group, thread_group) { - if (!cgroup_is_descendant(new_cgroup, c)) { - rcu_read_unlock(); - return -EPERM; - } - } - rcu_read_unlock(); - } - - return 0; -} - -/* - * Rules: you can only create a cgroup if - * 1. you are capable(CAP_SYS_ADMIN) - * 2. the target cgroup is a descendant of your own cgroup - */ -static struct cgroup_subsys_state *ns_create(struct cgroup_subsys *ss, - struct cgroup *cgroup) -{ - struct ns_cgroup *ns_cgroup; - - if (!capable(CAP_SYS_ADMIN)) - return ERR_PTR(-EPERM); - if (!cgroup_is_descendant(cgroup, current)) - return ERR_PTR(-EPERM); - if (test_bit(CGRP_CLONE_CHILDREN, &cgroup->flags)) { - printk("ns_cgroup can't be created with parent " - "'clone_children' set.\n"); - return ERR_PTR(-EINVAL); - } - - printk_once("ns_cgroup deprecated: consider using the " - "'clone_children' flag without the ns_cgroup.\n"); - - ns_cgroup = kzalloc(sizeof(*ns_cgroup), GFP_KERNEL); - if (!ns_cgroup) - return ERR_PTR(-ENOMEM); - return &ns_cgroup->css; -} - -static void ns_destroy(struct cgroup_subsys *ss, - struct cgroup *cgroup) -{ - struct ns_cgroup *ns_cgroup; - - ns_cgroup = cgroup_to_ns(cgroup); - kfree(ns_cgroup); -} - -struct cgroup_subsys ns_subsys = { - .name = "ns", - .can_attach = ns_can_attach, - .create = ns_create, - .destroy = ns_destroy, - .subsys_id = ns_subsys_id, -}; diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 5424e37..d6a00f3 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -201,10 +201,6 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, goto out; } - err = ns_cgroup_clone(current, task_pid(current)); - if (err) - put_nsproxy(*new_nsp); - out: return err; } -- cgit v1.1