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* Merge branch 'for-4.11-fixes' of ↵Linus Torvalds2017-04-161-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "Unfortunately, the commit to fix the cgroup mount race in the previous pull request can lead to hangs. The original bug has been around for a while and isn't too likely to be triggered in usual use cases. Revert the commit for now" * 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Revert "cgroup: avoid attaching a cgroup root to two different superblocks"
| * Revert "cgroup: avoid attaching a cgroup root to two different superblocks"Tejun Heo2017-04-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | This reverts commit bfb0b80db5f9dca5ac0a5fd0edb765ee555e5a8e. Andrei reports CRIU test hangs with the patch applied. The bug fixed by the patch isn't too likely to trigger in actual uses. Revert the patch for now. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andrei Vagin <avagin@virtuozzo.com> Link: http://lkml.kernel.org/r/20170414232737.GC20350@outlook.office365.com
* | Merge branch 'for-4.11-fixes' of ↵Linus Torvalds2017-04-112-5/+6
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "This contains fixes for two long standing subtle bugs: - kthread_bind() on a new kthread binds it to specific CPUs and prevents userland from messing with the affinity or cgroup membership. Unfortunately, for cgroup membership, there's a window between kthread creation and kthread_bind*() invocation where the kthread can be moved into a non-root cgroup by userland. Depending on what controllers are in effect, this can assign the kthread unexpected attributes. For example, in the reported case, workqueue workers ended up in a non-root cpuset cgroups and had their CPU affinities overridden. This broke workqueue invariants and led to workqueue stalls. Fixed by closing the window between kthread creation and kthread_bind() as suggested by Oleg. - There was a bug in cgroup mount path which could allow two competing mount attempts to attach the same cgroup_root to two different superblocks. This was caused by mishandling return value from kernfs_pin_sb(). Fixed" * 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: avoid attaching a cgroup root to two different superblocks cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups
| * cgroup: avoid attaching a cgroup root to two different superblocksZefan Li2017-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Run this: touch file0 for ((; ;)) { mount -t cpuset xxx file0 } And this concurrently: touch file1 for ((; ;)) { mount -t cpuset xxx file1 } We'll trigger a warning like this: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 4675 at lib/percpu-refcount.c:317 percpu_ref_kill_and_confirm+0x92/0xb0 percpu_ref_kill_and_confirm called more than once on css_release! CPU: 1 PID: 4675 Comm: mount Not tainted 4.11.0-rc5+ #5 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 Call Trace: dump_stack+0x63/0x84 __warn+0xd1/0xf0 warn_slowpath_fmt+0x5f/0x80 percpu_ref_kill_and_confirm+0x92/0xb0 cgroup_kill_sb+0x95/0xb0 deactivate_locked_super+0x43/0x70 deactivate_super+0x46/0x60 ... ---[ end trace a79f61c2a2633700 ]--- Here's a race: Thread A Thread B cgroup1_mount() # alloc a new cgroup root cgroup_setup_root() cgroup1_mount() # no sb yet, returns NULL kernfs_pin_sb() # but succeeds in getting the refcnt, # so re-use cgroup root percpu_ref_tryget_live() # alloc sb with cgroup root cgroup_do_mount() cgroup_kill_sb() # alloc another sb with same root cgroup_do_mount() cgroup_kill_sb() We end up using the same cgroup root for two different superblocks, so percpu_ref_kill() will be called twice on the same root when the two superblocks are destroyed. We should fix to make sure the superblock pinning is really successful. Cc: stable@vger.kernel.org # 3.16+ Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup, kthread: close race window where new kthreads can be migrated to ↵Tejun Heo2017-03-171-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | non-root cgroups Creation of a kthread goes through a couple interlocked stages between the kthread itself and its creator. Once the new kthread starts running, it initializes itself and wakes up the creator. The creator then can further configure the kthread and then let it start doing its job by waking it up. In this configuration-by-creator stage, the creator is the only one that can wake it up but the kthread is visible to userland. When altering the kthread's attributes from userland is allowed, this is fine; however, for cases where CPU affinity is critical, kthread_bind() is used to first disable affinity changes from userland and then set the affinity. This also prevents the kthread from being migrated into non-root cgroups as that can affect the CPU affinity and many other things. Unfortunately, the cgroup side of protection is racy. While the PF_NO_SETAFFINITY flag prevents further migrations, userland can win the race before the creator sets the flag with kthread_bind() and put the kthread in a non-root cgroup, which can lead to all sorts of problems including incorrect CPU affinity and starvation. This bug got triggered by userland which periodically tries to migrate all processes in the root cpuset cgroup to a non-root one. Per-cpu workqueue workers got caught while being created and ended up with incorrected CPU affinity breaking concurrency management and sometimes stalling workqueue execution. This patch adds task->no_cgroup_migration which disallows the task to be migrated by userland. kthreadd starts with the flag set making every child kthread start in the root cgroup with migration disallowed. The flag is cleared after the kthread finishes initialization by which time PF_NO_SETAFFINITY is set if the kthread should stay in the root cgroup. It'd be better to wait for the initialization instead of failing but I couldn't think of a way of implementing that without adding either a new PF flag, or sleeping and retrying from waiting side. Even if userland depends on changing cgroup membership of a kthread, it either has to be synchronized with kthread_create() or periodically repeat, so it's unlikely that this would break anything. v2: Switch to a simpler implementation using a new task_struct bit field suggested by Oleg. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Reported-and-debugged-by: Chris Mason <clm@fb.com> Cc: stable@vger.kernel.org # v4.3+ (we can't close the race on < v4.3) Signed-off-by: Tejun Heo <tj@kernel.org>
* | Merge branch 'for-4.11-fixes' of ↵Linus Torvalds2017-03-142-2/+2
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "Three cgroup fixes. Nothing critical: - the pids controller could trigger suspicious RCU warning spuriously. Fixed. - in the debug controller, %p -> %pK to protect kernel pointer from getting exposed. - documentation formatting fix" * 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroups: censor kernel pointer in debug files cgroup/pids: remove spurious suspicious RCU usage warning cgroup: Fix indenting in PID controller documentation
| * cgroups: censor kernel pointer in debug filesKees Cook2017-03-061-1/+1
| | | | | | | | | | | | | | | | As found in grsecurity, this avoids exposing a kernel pointer through the cgroup debug entries. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup/pids: remove spurious suspicious RCU usage warningTejun Heo2017-03-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pids_can_fork() is special in that the css association is guaranteed to be stable throughout the function and thus doesn't need RCU protection around task_css access. When determining the css to charge the pid, task_css_check() is used to override the RCU sanity check. While adding a warning message on fork rejection from pids limit, 135b8b37bd91 ("cgroup: Add pids controller event when fork fails because of pid limit") incorrectly added a task_css access which is neither RCU protected or explicitly annotated. This triggers the following suspicious RCU usage warning when RCU debugging is enabled. cgroup: fork rejected by pids controller in =============================== [ ERR: suspicious RCU usage. ] 4.10.0-work+ #1 Not tainted ------------------------------- ./include/linux/cgroup.h:435 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 1 lock held by bash/1748: #0: (&cgroup_threadgroup_rwsem){+++++.}, at: [<ffffffff81052c96>] _do_fork+0xe6/0x6e0 stack backtrace: CPU: 3 PID: 1748 Comm: bash Not tainted 4.10.0-work+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014 Call Trace: dump_stack+0x68/0x93 lockdep_rcu_suspicious+0xd7/0x110 pids_can_fork+0x1c7/0x1d0 cgroup_can_fork+0x67/0xc0 copy_process.part.58+0x1709/0x1e90 _do_fork+0xe6/0x6e0 SyS_clone+0x19/0x20 do_syscall_64+0x5c/0x140 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f7853fab93a RSP: 002b:00007ffc12d05c90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7853fab93a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc12d05cc0 R08: 0000000000000000 R09: 00007f78548db700 R10: 00007f78548db9d0 R11: 0000000000000246 R12: 00000000000006d4 R13: 0000000000000001 R14: 0000000000000000 R15: 000055e3ebe2c04d /asdf There's no reason to dereference task_css again here when the associated css is already available. Fix it by replacing the task_cgroup() call with css->cgroup. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Galbraith <efault@gmx.de> Fixes: 135b8b37bd91 ("cgroup: Add pids controller event when fork fails because of pid limit") Cc: Kenny Yu <kennyyu@fb.com> Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Tejun Heo <tj@kernel.org>
* | scripts/spelling.txt: add "disble(d)" pattern and fix typo instancesMasahiro Yamada2017-03-091-1/+1
|/ | | | | | | | | | | | | | | | Fix typos and add the following to the scripts/spelling.txt: disble||disable disbled||disabled I kept the TSL2563_INT_DISBLED in /drivers/iio/light/tsl2563.c untouched. The macro is not referenced at all, but this commit is touching only comment blocks just in case. Link: http://lkml.kernel.org/r/1481573103-11329-20-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h>Ingo Molnar2017-03-031-0/+1
| | | | | | | | | | | It's not used by any of the scheduler methods, but <linux/sched/task_stack.h> needs it to pick up STACK_END_MAGIC. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Move the task_lock()/unlock() APIs to <linux/sched/task.h>Ingo Molnar2017-03-032-1/+2
| | | | | | | | | | | | | | The task_lock()/task_unlock() APIs are not realated to core scheduling, they are task lifetime APIs, i.e. they belong into <linux/sched/task.h>. Move them. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Move task_struct::signal and task_struct::sighand types and ↵Ingo Molnar2017-03-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | accessors into <linux/sched/signal.h> task_struct::signal and task_struct::sighand are pointers, which would normally make it straightforward to not define those types in sched.h. That is not so, because the types are accompanied by a myriad of APIs (macros and inline functions) that dereference them. Split the types and the APIs out of sched.h and move them into a new header, <linux/sched/signal.h>. With this change sched.h does not know about 'struct signal' and 'struct sighand' anymore, trying to put accessors into sched.h as a test fails the following way: ./include/linux/sched.h: In function ‘test_signal_types’: ./include/linux/sched.h:2461:18: error: dereferencing pointer to incomplete type ‘struct signal_struct’ ^ This reduces the size and complexity of sched.h significantly. Update all headers and .c code that relied on getting the signal handling functionality from <linux/sched.h> to include <linux/sched/signal.h>. The list of affected files in the preparatory patch was partly generated by grepping for the APIs, and partly by doing coverage build testing, both all[yes|mod|def|no]config builds on 64-bit and 32-bit x86, and an array of cross-architecture builds. Nevertheless some (trivial) build breakage is still expected related to rare Kconfig combinations and in-flight patches to various kernel code, but most of it should be handled by this patch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare to move the task_lock()/unlock() APIs to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | <linux/sched/task.h> But first update the code that uses these facilities with the new header. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers, cgroups: Remove the threadgroup_change_*() wrapperyIngo Molnar2017-03-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | threadgroup_change_begin()/end() is a pointless wrapper around cgroup_threadgroup_change_begin()/end(), minus a might_sleep() in the !CONFIG_CGROUPS=y case. Remove the wrappery, move the might_sleep() (the down_read() already has a might_sleep() check). This debloats <linux/sched.h> a bit and simplifies this API. Update all call sites. No change in functionality. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'for-4.11' of ↵Linus Torvalds2017-02-271-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Several noteworthy changes. - Parav's rdma controller is finally merged. It is very straight forward and can limit the abosolute numbers of common rdma constructs used by different cgroups. - kernel/cgroup.c got too chubby and disorganized. Created kernel/cgroup/ subdirectory and moved all cgroup related files under kernel/ there and reorganized the core code. This hurts for backporting patches but was long overdue. - cgroup v2 process listing reimplemented so that it no longer depends on allocating a buffer large enough to cache the entire result to sort and uniq the output. v2 has always mangled the sort order to ensure that users don't depend on the sorted output, so this shouldn't surprise anybody. This makes the pid listing functions use the same iterators that are used internally, which have to have the same iterating capabilities anyway. - perf cgroup filtering now works automatically on cgroup v2. This patch was posted a long time ago but somehow fell through the cracks. - misc fixes asnd documentation updates" * 'for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (27 commits) kernfs: fix locking around kernfs_ops->release() callback cgroup: drop the matching uid requirement on migration for cgroup v2 cgroup, perf_event: make perf_event controller work on cgroup2 hierarchy cgroup: misc cleanups cgroup: call subsys->*attach() only for subsystems which are actually affected by migration cgroup: track migration context in cgroup_mgctx cgroup: cosmetic update to cgroup_taskset_add() rdmacg: Fixed uninitialized current resource usage cgroup: Add missing cgroup-v2 PID controller documentation. rdmacg: Added documentation for rdmacg IB/core: added support to use rdma cgroup controller rdmacg: Added rdma cgroup controller cgroup: fix a comment typo cgroup: fix RCU related sparse warnings cgroup: move namespace code to kernel/cgroup/namespace.c cgroup: rename functions for consistency cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.c cgroup: separate out cgroup1_kf_syscall_ops cgroup: refactor mount path and clearly distinguish v1 and v2 paths cgroup: move cgroup v1 specific code to kernel/cgroup/cgroup-v1.c ...
* Merge branch 'cgroup/for-4.11-rdmacg' into cgroup/for-4.11Tejun Heo2017-02-022-0/+620
|\ | | | | | | | | | | | | Merge in to resolve conflicts in Documentation/cgroup-v2.txt. The conflicts are from multiple section additions and trivial to resolve. Signed-off-by: Tejun Heo <tj@kernel.org>
| * rdmacg: Fixed uninitialized current resource usageParav Pandit2017-01-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Fixed warning reported by kbuild test robot. When reading current resource usage value, when no resources are allocated, its possible that it can report a uninitialized value for current resource usage. This fix avoids it by initializing it to zero as no resource is allocated. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * rdmacg: Added rdma cgroup controllerParav Pandit2017-01-102-0/+618
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Added rdma cgroup controller that does accounting, limit enforcement on rdma/IB resources. Added rdma cgroup header file which defines its APIs to perform charging/uncharging functionality. It also defined APIs for RDMA/IB stack for device registration. Devices which are registered will participate in controller functions of accounting and limit enforcements. It define rdmacg_device structure to bind IB stack and RDMA cgroup controller. RDMA resources are tracked using resource pool. Resource pool is per device, per cgroup entity which allows setting up accounting limits on per device basis. Currently resources are defined by the RDMA cgroup. Resource pool is created/destroyed dynamically whenever charging/uncharging occurs respectively and whenever user configuration is done. Its a tradeoff of memory vs little more code space that creates resource pool object whenever necessary, instead of creating them during cgroup creation and device registration time. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: drop the matching uid requirement on migration for cgroup v2Tejun Heo2017-02-021-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Along with the write access to the cgroup.procs or tasks file, cgroup has required the writer's euid, unless root, to match [s]uid of the target process or task. On cgroup v1, this is necessary because there's nothing preventing a delegatee from pulling in tasks or processes from all over the system. If a user has a cgroup subdirectory delegated to it, the user would have write access to the cgroup.procs or tasks file. If there are no further checks than file write access check, the user would be able to pull processes from all over the system into its subhierarchy which is clearly not the intended behavior. The matching [s]uid requirement partially prevents this problem by allowing a delegatee to pull in the processes that belongs to it. This isn't a sufficient protection however, because a user would still be able to jump processes across two disjoint sub-hierarchies that has been delegated to them. cgroup v2 resolves the issue by requiring the writer to have access to the common ancestor of the cgroup.procs file of the source and target cgroups. This confines each delegatee to their own sub-hierarchy proper and bases all permission decisions on the cgroup filesystem rather than having to pull in explicit uid matching. cgroup v2 has still been applying the matching [s]uid requirement just for historical reasons. On cgroup2, the requirement doesn't serve any purpose while unnecessarily complicating the permission model. Let's drop it. Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: misc cleanupsTejun Heo2017-01-301-7/+4
| | | | | | | | | | | | | | | | | | * cgrp_dfl_implicit_ss_mask is ulong instead of u16 unlike other ss_masks. Make it a u16. * Move have_canfork_callback together with other callback ss_masks. Signed-off-by: Tejun Heo <tj@kernel.org>
* | Merge branch 'for-4.10-fixes' into for-4.11Tejun Heo2017-01-261-8/+5
| |
* | cgroup: call subsys->*attach() only for subsystems which are actually ↵Tejun Heo2017-01-153-13/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | affected by migration Currently, subsys->*attach() callbacks are called for all subsystems which are attached to the hierarchy on which the migration is taking place. With cgroup_migrate_prepare_dst() filtering out identity migrations, v1 hierarchies can avoid spurious ->*attach() callback invocations where the source and destination csses are identical; however, this isn't enough on v2 as only a subset of the attached controllers can be affected on controller enable/disable. While spurious ->*attach() invocations aren't critically broken, they're unnecessary overhead and can lead to temporary overcharges on certain controllers. Fix it by tracking which subsystems are affected by a migration and invoking ->*attach() callbacks only on those subsystems. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com>
* | cgroup: track migration context in cgroup_mgctxTejun Heo2017-01-153-98/+122
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup migration is performed in four steps - css_set preloading, addition of target tasks, actual migration, and clean up. A list named preloaded_csets is used to track the preloading. This is a bit too restricted and the code is already depending on the subtlety that all source css_sets appear before destination ones. Let's create struct cgroup_mgctx which keeps track of everything during migration. Currently, it has separate preload lists for source and destination csets and also embeds cgroup_taskset which is used during the actual migration. This moves struct cgroup_taskset definition to cgroup-internal.h. This patch doesn't cause any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com>
* | cgroup: cosmetic update to cgroup_taskset_add()Tejun Heo2017-01-151-2/+2
|/ | | | | | | | | | | | cgroup_taskset_add() was using list_add_tail() when for source csets but list_move_tail() for destination. As the operations are gated by list_empty() test, list_move_tail() is equivalent to list_add_tail() here. Use list_add_tail() too for destination csets too. This doesn't cause any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: fix RCU related sparse warningsTejun Heo2016-12-272-2/+2
| | | | | | | | | | | kn->priv which is a void * is used as a RCU pointer by cgroup. When dereferencing it, it was passing kn->priv to rcu_derefreence() without casting it into a RCU pointer triggering address space mismatch warning from sparse. Fix them. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: move namespace code to kernel/cgroup/namespace.cTejun Heo2016-12-274-175/+189
| | | | | | | get/put_css_set() get exposed in cgroup-internal.h in the process. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: rename functions for consistencyTejun Heo2016-12-273-23/+23
| | | | | | | | | | | | | | | Now that v1 functions are separated out, rename some functions for consistency. cgroup_dfl_base_files -> cgroup_base_files cgroup_legacy_base_files -> cgroup1_base_files cgroup_ssid_no_v1() -> cgroup1_ssid_disabled() cgroup_pidlist_destroy_all -> cgroup1_pidlist_destroy_all() cgroup_release_agent() -> cgroup1_release_agent() check_for_release() -> cgroup1_check_for_release() Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.cTejun Heo2016-12-273-406/+413
| | | | | | | | | | Now that the v1 mount code is split into separate functions, move them to kernel/cgroup/cgroup-v1.c along with the mount option handling code. As this puts all v1-only kernfs_syscall_ops in cgroup-v1.c, move cgroup1_kf_syscall_ops to cgroup-v1.c too. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: separate out cgroup1_kf_syscall_opsTejun Heo2016-12-273-25/+30
| | | | | | | | | | Currently, cgroup_kf_syscall_ops is shared by v1 and v2 and the specific methods test the version and take different actions. Split out v1 functions and put them in cgroup1_kf_syscall_ops and remove the now unnecessary explicit branches in specific methods. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: refactor mount path and clearly distinguish v1 and v2 pathsTejun Heo2016-12-271-61/+79
| | | | | | | | | | | | | | | | | While sharing some mechanisms, the mount paths of v1 and v2 are substantially different. Their implementations were mixed in cgroup_mount(). This patch splits them out so that they're easier to follow and organize. This patch causes one functional change - the WARN_ON(new_sb) gets lost. This is because the actual mounting gets moved to cgroup_do_mount() and thus @new_sb is no longer accessible by default to cgroup1_mount(). While we can add it as an explicit out parameter to cgroup_do_mount(), this part of code hasn't changed and the warning hasn't triggered for quite a while. Dropping it should be fine. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: move cgroup v1 specific code to kernel/cgroup/cgroup-v1.cTejun Heo2016-12-274-1108/+1164
| | | | | | | | | | | cgroup.c is getting too unwieldy. Let's move out cgroup v1 specific code along with the debug controller into kernel/cgroup/cgroup-v1.c. v2: cgroup_mutex and css_set_lock made available in cgroup-internal.h regardless of CONFIG_PROVE_RCU. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
* cgroup: move cgroup files under kernel/cgroup/Tejun Heo2016-12-275-0/+10291
They're growing to be too many and planned to get split further. Move them under their own directory. kernel/cgroup.c -> kernel/cgroup/cgroup.c kernel/cgroup_freezer.c -> kernel/cgroup/freezer.c kernel/cgroup_pids.c -> kernel/cgroup/pids.c kernel/cpuset.c -> kernel/cgroup/cpuset.c Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>