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* blkcg: remove blkcg->idTejun Heo2014-09-081-2/+0
| | | | | | | | | | | | | blkcg->id is a unique id given to each blkcg; however, the cgroup_subsys_state which each blkcg embeds already has ->serial_nr which can be used for the same purpose. Drop blkcg->id and replace its uses with blkcg->css.serial_nr. Rename cfq_cgroup->blkcg_id to ->blkcg_serial_nr and @id in check_blkcg_changed() to @serial_nr for consistency. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-3.17' of ↵Linus Torvalds2014-08-041-2/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup changes from Tejun Heo: "Mostly changes to get the v2 interface ready. The core features are mostly ready now and I think it's reasonable to expect to drop the devel mask in one or two devel cycles at least for a subset of controllers. - cgroup added a controller dependency mechanism so that block cgroup can depend on memory cgroup. This will be used to finally support IO provisioning on the writeback traffic, which is currently being implemented. - The v2 interface now uses a separate table so that the interface files for the new interface are explicitly declared in one place. Each controller will explicitly review and add the files for the new interface. - cpuset is getting ready for the hierarchical behavior which is in the similar style with other controllers so that an ancestor's configuration change doesn't change the descendants' configurations irreversibly and processes aren't silently migrated when a CPU or node goes down. All the changes are to the new interface and no behavior changed for the multiple hierarchies" * 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (29 commits) cpuset: fix the WARN_ON() in update_nodemasks_hier() cgroup: initialize cgrp_dfl_root_inhibit_ss_mask from !->dfl_files test cgroup: make CFTYPE_ONLY_ON_DFL and CFTYPE_NO_ internal to cgroup core cgroup: distinguish the default and legacy hierarchies when handling cftypes cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes() cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] cpuset: export effective masks to userspace cpuset: allow writing offlined masks to cpuset.cpus/mems cpuset: enable onlined cpu/node in effective masks cpuset: refactor cpuset_hotplug_update_tasks() cpuset: make cs->{cpus, mems}_allowed as user-configured masks cpuset: apply cs->effective_{cpus,mems} cpuset: initialize top_cpuset's configured masks at mount cpuset: use effective cpumask to build sched domains cpuset: inherit ancestor's masks if effective_{cpus, mems} becomes empty cpuset: update cs->effective_{cpus, mems} when config changes cpuset: update cpuset->effective_{cpus,mems} at hotplug cpuset: add cs->effective_cpus and cs->effective_mems cgroup: clean up sane_behavior handling ...
| * cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes()Tejun Heo2014-07-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, cftypes added by cgroup_add_cftypes() are used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through. cgroup_subsys will grow two separate cftype addition functions and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch adds cgroup_add_legacy_cftypes() which currently is a simple wrapper around cgroup_add_cftypes() and replaces all cgroup_add_cftypes() usages with it. While at it, this patch drops a completely spurious return from __hugetlb_cgroup_file_init(). This patch doesn't introduce any functional differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
| * cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypesTejun Heo2014-07-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, cgroup_subsys->base_cftypes is used for both the unified default hierarchy and legacy ones and subsystems can mark each file with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE if it has to appear only on one of them. This is quite hairy and error-prone. Also, we may end up exposing interface files to the default hierarchy without thinking it through. cgroup_subsys will grow two separate cftype arrays and apply each only on the hierarchies of the matching type. This will allow organizing cftypes in a lot clearer way and encourage subsystems to scrutinize the interface which is being exposed in the new default hierarchy. In preparation, this patch renames cgroup_subsys->base_cftypes to cgroup_subsys->legacy_cftypes. This patch is pure rename. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Aristeu Rozanski <aris@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
| * blkcg, memcg: make blkcg depend on memcg on the default hierarchyTejun Heo2014-07-081-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the blkio subsystem attributes all of writeback IOs to the root. One of the issues is that there's no way to tell who originated a writeback IO from block layer. Those IOs are usually issued asynchronously from a task which didn't have anything to do with actually generating the dirty pages. The memory subsystem, when enabled, already keeps track of the ownership of each dirty page and it's desirable for blkio to piggyback instead of adding its own per-page tag. cgroup now has a mechanism to express such dependency - cgroup_subsys->depends_on. This patch declares that blkcg depends on memcg so that memcg is enabled automatically on the default hierarchy when available. Future changes will make blkcg map the memcg tag to find out the cgroup to blame for writeback IOs. As this means that a memcg may be made invisible, this patch also implements css_reset() for memcg which resets its basic configurations. This implementation will probably need to be expanded to cover other states which are used in the default hierarchy. v2: blkcg's dependency on memcg is wrapped with CONFIG_MEMCG to avoid build failure. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk>
* | blkcg: don't call into policy draining if root_blkg is already goneTejun Heo2014-07-121-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While a queue is being destroyed, all the blkgs are destroyed and its ->root_blkg pointer is set to NULL. If someone else starts to drain while the queue is in this state, the following oops happens. NULL pointer dereference at 0000000000000028 IP: [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230 PGD e4a1067 PUD b773067 PMD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched] CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ #2 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000 RIP: 0010:[<ffffffff8144e944>] [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230 RSP: 0018:ffff88000efd7bf0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001 R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450 R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28 FS: 00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0 Stack: ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80 ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58 ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450 Call Trace: [<ffffffff8144ae2f>] blkcg_drain_queue+0x1f/0x60 [<ffffffff81427641>] __blk_drain_queue+0x71/0x180 [<ffffffff81429b3e>] blk_queue_bypass_start+0x6e/0xb0 [<ffffffff814498b8>] blkcg_deactivate_policy+0x38/0x120 [<ffffffff8144ec44>] blk_throtl_exit+0x34/0x50 [<ffffffff8144aea5>] blkcg_exit_queue+0x35/0x40 [<ffffffff8142d476>] blk_release_queue+0x26/0xd0 [<ffffffff81454968>] kobject_cleanup+0x38/0x70 [<ffffffff81454848>] kobject_put+0x28/0x60 [<ffffffff81427505>] blk_put_queue+0x15/0x20 [<ffffffff817d07bb>] scsi_device_dev_release_usercontext+0x16b/0x1c0 [<ffffffff810bc339>] execute_in_process_context+0x89/0xa0 [<ffffffff817d064c>] scsi_device_dev_release+0x1c/0x20 [<ffffffff817930e2>] device_release+0x32/0xa0 [<ffffffff81454968>] kobject_cleanup+0x38/0x70 [<ffffffff81454848>] kobject_put+0x28/0x60 [<ffffffff817934d7>] put_device+0x17/0x20 [<ffffffff817d11b9>] __scsi_remove_device+0xa9/0xe0 [<ffffffff817d121b>] scsi_remove_device+0x2b/0x40 [<ffffffff817d1257>] sdev_store_delete+0x27/0x30 [<ffffffff81792ca8>] dev_attr_store+0x18/0x30 [<ffffffff8126f75e>] sysfs_kf_write+0x3e/0x50 [<ffffffff8126ea87>] kernfs_fop_write+0xe7/0x170 [<ffffffff811f5e9f>] vfs_write+0xaf/0x1d0 [<ffffffff811f69bd>] SyS_write+0x4d/0xc0 [<ffffffff81d24692>] system_call_fastpath+0x16/0x1b 776687bce42b ("block, blk-mq: draining can't be skipped even if bypass_depth was non-zero") made it easier to trigger this bug by making blk_queue_bypass_start() drain even when it loses the first bypass test to blk_cleanup_queue(); however, the bug has always been there even before the commit as blk_queue_bypass_start() could race against queue destruction, win the initial bypass test but perform the actual draining after blk_cleanup_queue() already destroyed all blkgs. Fix it by skippping calling into policy draining if all the blkgs are already gone. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Shirish Pargaonkar <spargaonkar@suse.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Reported-by: Jet Chen <jet.chen@intel.com> Cc: stable@vger.kernel.org Tested-by: Shirish Pargaonkar <spargaonkar@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | Revert "block: add __init to blkcg_policy_register"Jens Axboe2014-06-221-1/+1
| | | | | | | | | | | | | | This reverts commit a2d445d440003f2d70ee4cd4970ea82ace616fee. The original commit is buggy, we do use the registration functions at runtime for modular builds.
* | blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt ↵Tejun Heo2014-06-221-5/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | an atomic_t Hello, So, this patch should do. Joe, Vivek, can one of you guys please verify that the oops goes away with this patch? Jens, the original thread can be read at http://thread.gmane.org/gmane.linux.kernel/1720729 The fix converts blkg->refcnt from int to atomic_t. It does some overhead but it should be minute compared to everything else which is going on and the involved cacheline bouncing, so I think it's highly unlikely to cause any noticeable difference. Also, the refcnt in question should be converted to a perpcu_ref for blk-mq anyway, so the atomic_t is likely to go away pretty soon anyway. Thanks. ------- 8< ------- __blkg_release_rcu() may be invoked after the associated request_queue is released with a RCU grace period inbetween. As such, the function and callbacks invoked from it must not dereference the associated request_queue. This is clearly indicated in the comment above the function. Unfortunately, while trying to fix a different issue, 2a4fd070ee85 ("blkcg: move bulk of blkcg_gq release operations to the RCU callback") ignored this and added [un]locking of @blkg->q->queue_lock to __blkg_release_rcu(). This of course can cause oops as the request_queue may be long gone by the time this code gets executed. general protection fault: 0000 [#1] SMP CPU: 21 PID: 30 Comm: rcuos/21 Not tainted 3.15.0 #1 Hardware name: Stratus ftServer 6400/G7LAZ, BIOS BIOS Version 6.3:57 12/25/2013 task: ffff880854021de0 ti: ffff88085403c000 task.ti: ffff88085403c000 RIP: 0010:[<ffffffff8162e9e5>] [<ffffffff8162e9e5>] _raw_spin_lock_irq+0x15/0x60 RSP: 0018:ffff88085403fdf0 EFLAGS: 00010086 RAX: 0000000000020000 RBX: 0000000000000010 RCX: 0000000000000000 RDX: 000060ef80008248 RSI: 0000000000000286 RDI: 6b6b6b6b6b6b6b6b RBP: ffff88085403fdf0 R08: 0000000000000286 R09: 0000000000009f39 R10: 0000000000020001 R11: 0000000000020001 R12: ffff88103c17a130 R13: ffff88103c17a080 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88107fca0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006e5ab8 CR3: 000000000193d000 CR4: 00000000000407e0 Stack: ffff88085403fe18 ffffffff812cbfc2 ffff88103c17a130 0000000000000000 ffff88103c17a130 ffff88085403fec0 ffffffff810d1d28 ffff880854021de0 ffff880854021de0 ffff88107fcaec58 ffff88085403fe80 ffff88107fcaec30 Call Trace: [<ffffffff812cbfc2>] __blkg_release_rcu+0x72/0x150 [<ffffffff810d1d28>] rcu_nocb_kthread+0x1e8/0x300 [<ffffffff81091d81>] kthread+0xe1/0x100 [<ffffffff8163813c>] ret_from_fork+0x7c/0xb0 Code: ff 47 04 48 8b 7d 08 be 00 02 00 00 e8 55 48 a4 ff 5d c3 0f 1f 00 66 66 66 66 90 55 48 89 e5 +fa 66 66 90 66 66 90 b8 00 00 02 00 <f0> 0f c1 07 89 c2 c1 ea 10 66 39 c2 75 02 5d c3 83 e2 fe 0f +b7 RIP [<ffffffff8162e9e5>] _raw_spin_lock_irq+0x15/0x60 RSP <ffff88085403fdf0> The request_queue locking was added because blkcg_gq->refcnt is an int protected with the queue lock and __blkg_release_rcu() needs to put the parent. Let's fix it by making blkcg_gq->refcnt an atomic_t and dropping queue locking in the function. Given the general heavy weight of the current request_queue and blkcg operations, this is unlikely to cause any noticeable overhead. Moreover, blkcg_gq->refcnt is likely to be converted to percpu_ref in the near future, so whatever (most likely negligible) overhead it may add is temporary. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Joe Lawrence <joe.lawrence@stratus.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Link: http://lkml.kernel.org/g/alpine.DEB.2.02.1406081816540.17948@jlaw-desktop.mno.stratus.com Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2014-06-111-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block layer fixes from Jens Axboe: "Final small batch of fixes to be included before -rc1. Some general cleanups in here as well, but some of the blk-mq fixes we need for the NVMe conversion and/or scsi-mq. The pull request contains: - Support for not merging across a specified "chunk size", if set by the driver. Some NVMe devices perform poorly for IO that crosses such a chunk, so we need to support it generically as part of request merging avoid having to do complicated split logic. From me. - Bump max tag depth to 10Ki tags. Some scsi devices have a huge shared tag space. Before we failed with EINVAL if a too large tag depth was specified, now we truncate it and pass back the actual value. From me. - Various blk-mq rq init fixes from me and others. - A fix for enter on a dying queue for blk-mq from Keith. This is needed to prevent oopsing on hot device removal. - Fixup for blk-mq timer addition from Ming Lei. - Small round of performance fixes for mtip32xx from Sam Bradshaw. - Minor stack leak fix from Rickard Strandqvist. - Two __init annotations from Fabian Frederick" * 'for-linus' of git://git.kernel.dk/linux-block: block: add __init to blkcg_policy_register block: add __init to elv_register block: ensure that bio_add_page() always accepts a page for an empty bio blk-mq: add timer in blk_mq_start_request blk-mq: always initialize request->start_time block: blk-exec.c: Cleaning up local variable address returnd mtip32xx: minor performance enhancements blk-mq: ->timeout should be cleared in blk_mq_rq_ctx_init() blk-mq: don't allow queue entering for a dying queue blk-mq: bump max tag depth to 10K tags block: add blk_rq_set_block_pc() block: add notion of a chunk size for request merging
| * block: add __init to blkcg_policy_registerFabian Frederick2014-06-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | blkcg_policy_register is only called by __init functions: __init cfq_init __init throtl_init Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
* | cgroup: rename css_tryget*() to css_tryget_online*()Tejun Heo2014-05-131-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike the more usual refcnting, what css_tryget() provides is the distinction between online and offline csses instead of protection against upping a refcnt which already reached zero. cgroup is planning to provide actual tryget which fails if the refcnt already reached zero. Let's rename the existing trygets so that they clearly indicate that they're onliness. I thought about keeping the existing names as-are and introducing new names for the planned actual tryget; however, given that each controller participates in the synchronization of the online state, it seems worthwhile to make it explicit that these functions are about on/offline state. Rename css_tryget() to css_tryget_online() and css_tryget_from_dir() to css_tryget_online_from_dir(). This is pure rename. v2: cgroup_freezer grew new usages of css_tryget(). Update accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
* blkcg: use trylock on blkcg_pol_mutex in blkcg_reset_stats()Tejun Heo2014-05-051-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During the recent conversion of cgroup to kernfs, cgroup_tree_mutex which nests above both the kernfs s_active protection and cgroup_mutex is added to synchronize cgroup file type operations as cgroup_mutex needed to be grabbed from some file operations and thus can't be put above s_active protection. While this arrangement mostly worked for cgroup, this triggered the following lockdep warning. ====================================================== [ INFO: possible circular locking dependency detected ] 3.15.0-rc3-next-20140430-sasha-00016-g4e281fa-dirty #429 Tainted: G W ------------------------------------------------------- trinity-c173/9024 is trying to acquire lock: (blkcg_pol_mutex){+.+.+.}, at: blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455) but task is already holding lock: (s_active#89){++++.+}, at: kernfs_fop_write (fs/kernfs/file.c:283) which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (s_active#89){++++.+}: lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) __kernfs_remove (arch/x86/include/asm/atomic.h:27 fs/kernfs/dir.c:352 fs/kernfs/dir.c:1024) kernfs_remove_by_name_ns (fs/kernfs/dir.c:1219) cgroup_addrm_files (include/linux/kernfs.h:427 kernel/cgroup.c:1074 kernel/cgroup.c:2899) cgroup_clear_dir (kernel/cgroup.c:1092 (discriminator 2)) rebind_subsystems (kernel/cgroup.c:1144) cgroup_setup_root (kernel/cgroup.c:1568) cgroup_mount (kernel/cgroup.c:1716) mount_fs (fs/super.c:1094) vfs_kern_mount (fs/namespace.c:899) do_mount (fs/namespace.c:2238 fs/namespace.c:2561) SyS_mount (fs/namespace.c:2758 fs/namespace.c:2729) tracesys (arch/x86/kernel/entry_64.S:746) -> #1 (cgroup_tree_mutex){+.+.+.}: lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587) cgroup_add_cftypes (include/linux/list.h:76 kernel/cgroup.c:3040) blkcg_policy_register (block/blk-cgroup.c:1106) throtl_init (block/blk-throttle.c:1694) do_one_initcall (init/main.c:789) kernel_init_freeable (init/main.c:854 init/main.c:863 init/main.c:882 init/main.c:1003) kernel_init (init/main.c:935) ret_from_fork (arch/x86/kernel/entry_64.S:552) -> #0 (blkcg_pol_mutex){+.+.+.}: __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182) lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587) blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455) cgroup_file_write (kernel/cgroup.c:2714) kernfs_fop_write (fs/kernfs/file.c:295) vfs_write (fs/read_write.c:532) SyS_write (fs/read_write.c:584 fs/read_write.c:576) tracesys (arch/x86/kernel/entry_64.S:746) other info that might help us debug this: Chain exists of: blkcg_pol_mutex --> cgroup_tree_mutex --> s_active#89 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(s_active#89); lock(cgroup_tree_mutex); lock(s_active#89); lock(blkcg_pol_mutex); *** DEADLOCK *** 4 locks held by trinity-c173/9024: #0: (&f->f_pos_lock){+.+.+.}, at: __fdget_pos (fs/file.c:714) #1: (sb_writers#18){.+.+.+}, at: vfs_write (include/linux/fs.h:2255 fs/read_write.c:530) #2: (&of->mutex){+.+.+.}, at: kernfs_fop_write (fs/kernfs/file.c:283) #3: (s_active#89){++++.+}, at: kernfs_fop_write (fs/kernfs/file.c:283) stack backtrace: CPU: 3 PID: 9024 Comm: trinity-c173 Tainted: G W 3.15.0-rc3-next-20140430-sasha-00016-g4e281fa-dirty #429 ffffffff919687b0 ffff8805f6373bb8 ffffffff8e52cdbb 0000000000000002 ffffffff919d8400 ffff8805f6373c08 ffffffff8e51fb88 0000000000000004 ffff8805f6373c98 ffff8805f6373c08 ffff88061be70d98 ffff88061be70dd0 Call Trace: dump_stack (lib/dump_stack.c:52) print_circular_bug (kernel/locking/lockdep.c:1216) __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182) lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587) blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455) cgroup_file_write (kernel/cgroup.c:2714) kernfs_fop_write (fs/kernfs/file.c:295) vfs_write (fs/read_write.c:532) SyS_write (fs/read_write.c:584 fs/read_write.c:576) This is a highly unlikely but valid circular dependency between "echo 1 > blkcg.reset_stats" and cfq module [un]loading. cgroup is going through further locking update which will remove this complication but for now let's use trylock on blkcg_pol_mutex and retry the file operation if the trylock fails. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sasha Levin <sasha.levin@oracle.com> References: http://lkml.kernel.org/g/5363C04B.4010400@oracle.com
* Merge branch 'for-3.15' of ↵Linus Torvalds2014-04-031-7/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "A lot updates for cgroup: - The biggest one is cgroup's conversion to kernfs. cgroup took after the long abandoned vfs-entangled sysfs implementation and made it even more convoluted over time. cgroup's internal objects were fused with vfs objects which also brought in vfs locking and object lifetime rules. Naturally, there are places where vfs rules don't fit and nasty hacks, such as credential switching or lock dance interleaving inode mutex and cgroup_mutex with object serial number comparison thrown in to decide whether the operation is actually necessary, needed to be employed. After conversion to kernfs, internal object lifetime and locking rules are mostly isolated from vfs interactions allowing shedding of several nasty hacks and overall simplification. This will also allow implmentation of operations which may affect multiple cgroups which weren't possible before as it would have required nesting i_mutexes. - Various simplifications including dropping of module support, easier cgroup name/path handling, simplified cgroup file type handling and task_cg_lists optimization. - Prepatory changes for the planned unified hierarchy, which is still a patchset away from being actually operational. The dummy hierarchy is updated to serve as the default unified hierarchy. Controllers which aren't claimed by other hierarchies are associated with it, which BTW was what the dummy hierarchy was for anyway. - Various fixes from Li and others. This pull request includes some patches to add missing slab.h to various subsystems. This was triggered xattr.h include removal from cgroup.h. cgroup.h indirectly got included a lot of files which brought in xattr.h which brought in slab.h. There are several merge commits - one to pull in kernfs updates necessary for converting cgroup (already in upstream through driver-core), others for interfering changes in the fixes branch" * 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (74 commits) cgroup: remove useless argument from cgroup_exit() cgroup: fix spurious lockdep warning in cgroup_exit() cgroup: Use RCU_INIT_POINTER(x, NULL) in cgroup.c cgroup: break kernfs active_ref protection in cgroup directory operations cgroup: fix cgroup_taskset walking order cgroup: implement CFTYPE_ONLY_ON_DFL cgroup: make cgrp_dfl_root mountable cgroup: drop const from @buffer of cftype->write_string() cgroup: rename cgroup_dummy_root and related names cgroup: move ->subsys_mask from cgroupfs_root to cgroup cgroup: treat cgroup_dummy_root as an equivalent hierarchy during rebinding cgroup: remove NULL checks from [pr_cont_]cgroup_{name|path}() cgroup: use cgroup_setup_root() to initialize cgroup_dummy_root cgroup: reorganize cgroup bootstrapping cgroup: relocate setting of CGRP_DEAD cpuset: use rcu_read_lock() to protect task_cs() cgroup_freezer: document freezer_fork() subtleties cgroup: update cgroup_transfer_tasks() to either succeed or fail cgroup: drop task_lock() protection around task->cgroups cgroup: update how a newly forked task gets associated with css_set ...
| * cgroup: drop @skip_css from cgroup_taskset_for_each()Tejun Heo2014-02-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If !NULL, @skip_css makes cgroup_taskset_for_each() skip the matching css. The intention of the interface is to make it easy to skip css's (cgroup_subsys_states) which already match the migration target; however, this is entirely unnecessary as migration taskset doesn't include tasks which are already in the target cgroup. Drop @skip_css from cgroup_taskset_for_each(). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Daniel Borkmann <dborkman@redhat.com>
| * cgroup: clean up cgroup_subsys names and initializationTejun Heo2014-02-081-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_subsys is a bit messier than it needs to be. * The name of a subsys can be different from its internal identifier defined in cgroup_subsys.h. Most subsystems use the matching name but three - cpu, memory and perf_event - use different ones. * cgroup_subsys_id enums are postfixed with _subsys_id and each cgroup_subsys is postfixed with _subsys. cgroup.h is widely included throughout various subsystems, it doesn't and shouldn't have claim on such generic names which don't have any qualifier indicating that they belong to cgroup. * cgroup_subsys->subsys_id should always equal the matching cgroup_subsys_id enum; however, we require each controller to initialize it and then BUG if they don't match, which is a bit silly. This patch cleans up cgroup_subsys names and initialization by doing the followings. * cgroup_subsys_id enums are now postfixed with _cgrp_id, and each cgroup_subsys with _cgrp_subsys. * With the above, renaming subsys identifiers to match the userland visible names doesn't cause any naming conflicts. All non-matching identifiers are renamed to match the official names. cpu_cgroup -> cpu mem_cgroup -> memory perf -> perf_event * controllers no longer need to initialize ->subsys_id and ->name. They're generated in cgroup core and set automatically during boot. * Redundant cgroup_subsys declarations removed. * While updating BUG_ON()s in cgroup_init_early(), convert them to WARN()s. BUGging that early during boot is stupid - the kernel can't print anything, even through serial console and the trap handler doesn't even link stack frame properly for back-tracing. This patch doesn't introduce any behavior changes. v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs classid handling into core"). Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Ingo Molnar <mingo@redhat.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Thomas Graf <tgraf@suug.ch>
| * cgroup: drop module supportTejun Heo2014-02-081-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With module supported dropped from net_prio, no controller is using cgroup module support. None of actual resource controllers can be built as a module and we aren't gonna add new controllers which don't control resources. This patch drops module support from cgroup. * cgroup_[un]load_subsys() and cgroup_subsys->module removed. * As there's no point in distinguishing IS_BUILTIN() and IS_MODULE(), cgroup_subsys.h now uses IS_ENABLED() directly. * enum cgroup_subsys_id now exactly matches the list of enabled controllers as ordered in cgroup_subsys.h. * cgroup_subsys[] is now a contiguously occupied array. Size specification is no longer necessary and dropped. * for_each_builtin_subsys() is removed and for_each_subsys() is updated to not require any locking. * module ref handling is removed from rebind_subsystems(). * Module related comments dropped. v2: Rebased on top of fe1217c4f3f7 ("net: net_cls: move cgroupfs classid handling into core"). v3: Added {} around the if (need_forkexit_callback) block in cgroup_post_fork() for readability as suggested by Li. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
* | block: Substitute rcu_access_pointer() for rcu_dereference_raw()Paul E. McKenney2014-02-181-1/+1
|/ | | | | | | | | | | | | | (Trivial patch.) If the code is looking at the RCU-protected pointer itself, but not dereferencing it, the rcu_dereference() functions can be downgraded to rcu_access_pointer(). This commit makes this downgrade in blkg_destroy() and ioc_destroy_icq(), both of which simply compare the RCU-protected pointer against another pointer with no dereferencing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-3.12/core' of git://git.kernel.dk/linux-blockLinus Torvalds2013-09-221-10/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO fixes from Jens Axboe: "After merge window, no new stuff this time only a collection of neatly confined and simple fixes" * 'for-3.12/core' of git://git.kernel.dk/linux-block: cfq: explicitly use 64bit divide operation for 64bit arguments block: Add nr_bios to block_rq_remap tracepoint If the queue is dying then we only call the rq->end_io callout. This leaves bios setup on the request, because the caller assumes when the blk_execute_rq_nowait/blk_execute_rq call has completed that the rq->bios have been cleaned up. bio-integrity: Fix use of bs->bio_integrity_pool after free blkcg: relocate root_blkg setting and clearing block: Convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...) block: trace all devices plug operation
| * blkcg: relocate root_blkg setting and clearingTejun Heo2013-09-111-10/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hello, Jens. The original thread can be read from http://thread.gmane.org/gmane.linux.kernel.cgroups/8937 While it leads to oops, given that it only triggers under specific configurations which aren't common. I don't think it's necessary to backport it through -stable and merging it during the coming merge window should be enough. Thanks! ----- 8< ----- Currently, q->root_blkg and q->root_rl.blkg are set from blkcg_activate_policy() and cleared from blkg_destroy_all(). This doesn't necessarily coincide with the lifetime of the root blkcg_gq leading to the following oops when blkcg is enabled but no policy is activated because __blk_queue_next_rl() malfunctions expecting the root_blkg pointers to be set. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff810c58cb>] __wake_up_common+0x2b/0x90 PGD 60f7a9067 PUD 60f4c9067 PMD 0 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC gsmi: Log Shutdown Reason 0x03 Modules linked in: act_mirred cls_tcindex cls_prioshift sch_dsmark xt_multiport iptable_mangle sata_mv elephant elephant_dev_num cdc_acm uhci_hcd ehci_hcd i2c_d CPU: 9 PID: 41382 Comm: iSCSI-write- Not tainted 3.11.0-dbg-DEV #19 Hardware name: Intel XXX task: ffff88060d16eec0 ti: ffff88060d170000 task.ti: ffff88060d170000 RIP: 0010:[<ffffffff810c58cb>] [<ffffffff810c58cb>] __wake_up_common+0x2b/0x90 RSP: 0000:ffff88060d171818 EFLAGS: 00010096 RAX: 0000000000000082 RBX: ffff880baa3dee60 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff880baa3dee60 RBP: ffff88060d171858 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000002 R12: ffff880baa3dee98 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000003 FS: 00007f977cba6700(0000) GS:ffff880c79c60000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 000000060f7a5000 CR4: 00000000000007e0 Stack: 0000000000000082 0000000000000000 ffff88060d171858 ffff880baa3dee60 0000000000000082 0000000000000003 0000000000000000 0000000000000000 ffff88060d171898 ffffffff810c7848 ffff88060d171888 ffff880bde4bc4b8 Call Trace: [<ffffffff810c7848>] __wake_up+0x48/0x70 [<ffffffff8131da53>] __blk_drain_queue+0x123/0x190 [<ffffffff8131dbb5>] blk_cleanup_queue+0xf5/0x210 [<ffffffff8141877a>] __scsi_remove_device+0x5a/0xd0 [<ffffffff81418824>] scsi_remove_device+0x34/0x50 [<ffffffff814189cb>] scsi_remove_target+0x16b/0x220 [<ffffffff814210f1>] __iscsi_unbind_session+0xd1/0x1b0 [<ffffffff814212b2>] iscsi_remove_session+0xe2/0x1c0 [<ffffffff814213a6>] iscsi_destroy_session+0x16/0x60 [<ffffffff81423a59>] iscsi_session_teardown+0xd9/0x100 [<ffffffff8142b75a>] iscsi_sw_tcp_session_destroy+0x5a/0xb0 [<ffffffff81420948>] iscsi_if_rx+0x10e8/0x1560 [<ffffffff81573335>] netlink_unicast+0x145/0x200 [<ffffffff815736f3>] netlink_sendmsg+0x303/0x410 [<ffffffff81528196>] sock_sendmsg+0xa6/0xd0 [<ffffffff815294bc>] ___sys_sendmsg+0x38c/0x3a0 [<ffffffff811ea840>] ? fget_light+0x40/0x160 [<ffffffff811ea899>] ? fget_light+0x99/0x160 [<ffffffff811ea840>] ? fget_light+0x40/0x160 [<ffffffff8152bc79>] __sys_sendmsg+0x49/0x90 [<ffffffff8152bcd2>] SyS_sendmsg+0x12/0x20 [<ffffffff815fb642>] system_call_fastpath+0x16/0x1b Code: 66 66 66 66 90 55 48 89 e5 41 57 41 89 f7 41 56 41 89 ce 41 55 41 54 4c 8d 67 38 53 48 83 ec 18 89 55 c4 48 8b 57 38 4c 89 45 c8 <4c> 8b 2a 48 8d 42 e8 49 Fix it by moving r->root_blkg and q->root_rl.blkg setting to blkg_create() and clearing to blkg_destroy() so that they area initialized when a root blkg is created and cleared when destroyed. Reported-and-tested-by: Anatol Pomozov <anatol.pomozov@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | cgroup: make css_for_each_descendant() and friends include the origin css in ↵Tejun Heo2013-08-081-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the iteration Previously, all css descendant iterators didn't include the origin (root of subtree) css in the iteration. The reasons were maintaining consistency with css_for_each_child() and that at the time of introduction more use cases needed skipping the origin anyway; however, given that css_is_descendant() considers self to be a descendant, omitting the origin css has become more confusing and looking at the accumulated use cases rather clearly indicates that including origin would result in simpler code overall. While this is a change which can easily lead to subtle bugs, cgroup API including the iterators has recently gone through major restructuring and no out-of-tree changes will be applicable without adjustments making this a relatively acceptable opportunity for this type of change. The conversions are mostly straight-forward. If the iteration block had explicit origin handling before or after, it's moved inside the iteration. If not, if (pos == origin) continue; is added. Some conversions add extra reference get/put around origin handling by consolidating origin handling and the rest. While the extra ref operations aren't strictly necessary, this shouldn't cause any noticeable difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com>
* | cgroup: make cgroup_taskset deal with cgroup_subsys_state instead of cgroupTejun Heo2013-08-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup is in the process of converting to css (cgroup_subsys_state) from cgroup as the principal subsystem interface handle. This is mostly to prepare for the unified hierarchy support where css's will be created and destroyed dynamically but also helps cleaning up subsystem implementations as css is usually what they are interested in anyway. cgroup_taskset which is used by the subsystem attach methods is the last cgroup subsystem API which isn't using css as the handle. Update cgroup_taskset_cur_cgroup() to cgroup_taskset_cur_css() and cgroup_taskset_for_each() to take @skip_css instead of @skip_cgrp. The conversions are pretty mechanical. One exception is cpuset::cgroup_cs(), which lost its last user and got removed. This patch shouldn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org>
* | cgroup: make hierarchy iterators deal with cgroup_subsys_state instead of cgroupTejun Heo2013-08-081-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup is currently in the process of transitioning to using css (cgroup_subsys_state) as the primary handle instead of cgroup in subsystem API. For hierarchy iterators, this is beneficial because * In most cases, css is the only thing subsystems care about anyway. * On the planned unified hierarchy, iterations for different subsystems will need to skip over different subtrees of the hierarchy depending on which subsystems are enabled on each cgroup. Passing around css makes it unnecessary to explicitly specify the subsystem in question as css is intersection between cgroup and subsystem * For the planned unified hierarchy, css's would need to be created and destroyed dynamically independent from cgroup hierarchy. Having cgroup core manage css iteration makes enforcing deref rules a lot easier. Most subsystem conversions are straight-forward. Noteworthy changes are * blkio: cgroup_to_blkcg() is no longer used. Removed. * freezer: cgroup_freezer() is no longer used. Removed. * devices: cgroup_to_devcgroup() is no longer used. Removed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk>
* | cgroup: pass around cgroup_subsys_state instead of cgroup in file methodsTejun Heo2013-08-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup is currently in the process of transitioning to using struct cgroup_subsys_state * as the primary handle instead of struct cgroup. Please see the previous commit which converts the subsystem methods for rationale. This patch converts all cftype file operations to take @css instead of @cgroup. cftypes for the cgroup core files don't have their subsytem pointer set. These will automatically use the dummy_css added by the previous patch and can be converted the same way. Most subsystem conversions are straight forwards but there are some interesting ones. * freezer: update_if_frozen() is also converted to take @css instead of @cgroup for consistency. This will make the code look simpler too once iterators are converted to use css. * memory/vmpressure: mem_cgroup_from_css() needs to be exported to vmpressure while mem_cgroup_from_cont() can be made static. Updated accordingly. * cpu: cgroup_tg() doesn't have any user left. Removed. * cpuacct: cgroup_ca() doesn't have any user left. Removed. * hugetlb: hugetlb_cgroup_form_cgroup() doesn't have any user left. Removed. * net_cls: cgrp_cls_state() doesn't have any user left. Removed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Steven Rostedt <rostedt@goodmis.org>
* | cgroup: add subsys backlink pointer to cftypeTejun Heo2013-08-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup is transitioning to using css (cgroup_subsys_state) instead of cgroup as the primary subsystem handle. The cgroupfs file interface will be converted to use css's which requires finding out the subsystem from cftype so that the matching css can be determined from the cgroup. This patch adds cftype->ss which points to the subsystem the file belongs to. The field is initialized while a cftype is being registered. This makes it unnecessary to explicitly specify the subsystem for other cftype handling functions. @ss argument dropped from various cftype handling functions. This patch shouldn't introduce any behavior differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk>
* | cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methodsTejun Heo2013-08-081-12/+13
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup is currently in the process of transitioning to using struct cgroup_subsys_state * as the primary handle instead of struct cgroup * in subsystem implementations for the following reasons. * With unified hierarchy, subsystems will be dynamically bound and unbound from cgroups and thus css's (cgroup_subsys_state) may be created and destroyed dynamically over the lifetime of a cgroup, which is different from the current state where all css's are allocated and destroyed together with the associated cgroup. This in turn means that cgroup_css() should be synchronized and may return NULL, making it more cumbersome to use. * Differing levels of per-subsystem granularity in the unified hierarchy means that the task and descendant iterators should behave differently depending on the specific subsystem the iteration is being performed for. * In majority of the cases, subsystems only care about its part in the cgroup hierarchy - ie. the hierarchy of css's. Subsystem methods often obtain the matching css pointer from the cgroup and don't bother with the cgroup pointer itself. Passing around css fits much better. This patch converts all cgroup_subsys methods to take @css instead of @cgroup. The conversions are mostly straight-forward. A few noteworthy changes are * ->css_alloc() now takes css of the parent cgroup rather than the pointer to the new cgroup as the css for the new cgroup doesn't exist yet. Knowing the parent css is enough for all the existing subsystems. * In kernel/cgroup.c::offline_css(), unnecessary open coded css dereference is replaced with local variable access. This patch shouldn't cause any behavior differences. v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced with local variable @css as suggested by Li Zefan. Rebased on top of new for-3.12 which includes for-3.11-fixes so that ->css_free() invocation added by da0a12caff ("cgroup: fix a leak when percpu_ref_init() fails") is converted too. Suggested by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Aristeu Rozanski <aris@redhat.com> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Steven Rostedt <rostedt@goodmis.org>
* blk-throttle: implement proper hierarchy supportTejun Heo2013-05-141-8/+0
| | | | | | | | | | | | | | | | | | | With the recent updates, blk-throttle is finally ready for proper hierarchy support. Dispatching now honors service_queue->parent_sq and propagates correctly. The only thing missing is setting ->parent_sq correctly so that throtl_grp hierarchy matches the cgroup hierarchy. This patch updates throtl_pd_init() such that service_queues form the same hierarchy as the cgroup hierarchy if sane_behavior is enabled. As this concludes proper hierarchy support for blkcg, the shameful .broken_hierarchy tag is removed from blkio_subsys. v2: Updated blkio-controller.txt as suggested by Vivek. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Li Zefan <lizefan@huawei.com>
* blkcg: move bulk of blkcg_gq release operations to the RCU callbackTejun Heo2013-05-141-18/+16
| | | | | | | | | | | | | | | | | | | | | | Currently, when the last reference of a blkcg_gq is put, all then release operations sans the actual freeing happen directly in blkg_put(). As blkg_put() may be called under queue_lock, all pd_exit_fn()s may be too. This makes it impossible for pd_exit_fn()s to use del_timer_sync() on timers which grab the queue_lock which is an irq-safe lock due to the deadlock possibility described in the comment on top of del_timer_sync(). This can be easily avoided by perfoming the release operations in the RCU callback instead of directly from blkg_put(). This patch moves the blkcg_gq release operations to the RCU callback. As this leaves __blkg_release() with only call_rcu() invocation, blkg_rcu_free() is renamed to __blkg_release_rcu(), exported and call_rcu() invocation is now done directly from blkg_put() instead of going through __blkg_release() which is removed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* blkcg: invoke blkcg_policy->pd_init() after parent is linkedTejun Heo2013-05-141-17/+22
| | | | | | | | | | | | | | | | | | | Currently, when creating a new blkcg_gq, each policy's pd_init_fn() is invoked in blkg_alloc() before the parent is linked. This makes it difficult for policies to perform initializations which are dependent on the parent. This patch moves pd_init_fn() invocations to blkg_create() after the parent blkg is linked where the new blkg is fully initialized. As this means that blkg_free() can't assume that pd's are initialized, pd_exit_fn() invocations are moved to __blkg_release(). This guarantees that pd_exit_fn() is also invoked with fully initialized blkgs with valid parent pointers. This will help implementing hierarchy support in blk-throttle. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* blkcg: move blkg_for_each_descendant_pre() to block/blk-cgroup.hTejun Heo2013-05-141-22/+2
| | | | | | | | | blk-throttle hierarchy support will make use of it. Move blkg_for_each_descendant_pre() from block/blk-cgroup.c to block/blk-cgroup.h. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* blkcg: fix error return path in blkg_create()Tejun Heo2013-05-141-1/+1
| | | | | | | | | | | | | | In blkg_create(), after lookup of parent fails, the control jumps to error path with the error code encoded into @blkg. The error path doesn't use @blkg for the return value. It returns ERR_PTR(ret). Make lookup fail path set @ret instead of @blkg. Note that the parent lookup is guaranteed to succeed at that point and the condition check is purely for sanity and triggers WARN when fails. As such, I don't think it's necessary to mark it for -stable. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* blkcg: fix "scheduling while atomic" in blk_queue_bypass_startJun'ichi Nomura2013-04-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 749fefe677 in v3.7 ("block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue()"), the following warning appears when multipath is used with CONFIG_PREEMPT=y. This patch moves blk_queue_bypass_start() before radix_tree_preload() to avoid the sleeping call while preemption is disabled. BUG: scheduling while atomic: multipath/2460/0x00000002 1 lock held by multipath/2460: #0: (&md->type_lock){......}, at: [<ffffffffa019fb05>] dm_lock_md_type+0x17/0x19 [dm_mod] Modules linked in: ... Pid: 2460, comm: multipath Tainted: G W 3.7.0-rc2 #1 Call Trace: [<ffffffff810723ae>] __schedule_bug+0x6a/0x78 [<ffffffff81428ba2>] __schedule+0xb4/0x5e0 [<ffffffff814291e6>] schedule+0x64/0x66 [<ffffffff8142773a>] schedule_timeout+0x39/0xf8 [<ffffffff8108ad5f>] ? put_lock_stats+0xe/0x29 [<ffffffff8108ae30>] ? lock_release_holdtime+0xb6/0xbb [<ffffffff814289e3>] wait_for_common+0x9d/0xee [<ffffffff8107526c>] ? try_to_wake_up+0x206/0x206 [<ffffffff810c0eb8>] ? kfree_call_rcu+0x1c/0x1c [<ffffffff81428aec>] wait_for_completion+0x1d/0x1f [<ffffffff810611f9>] wait_rcu_gp+0x5d/0x7a [<ffffffff81061216>] ? wait_rcu_gp+0x7a/0x7a [<ffffffff8106fb18>] ? complete+0x21/0x53 [<ffffffff810c0556>] synchronize_rcu+0x1e/0x20 [<ffffffff811dd903>] blk_queue_bypass_start+0x5d/0x62 [<ffffffff811ee109>] blkcg_activate_policy+0x73/0x270 [<ffffffff81130521>] ? kmem_cache_alloc_node_trace+0xc7/0x108 [<ffffffff811f04b3>] cfq_init_queue+0x80/0x28e [<ffffffffa01a1600>] ? dm_blk_ioctl+0xa7/0xa7 [dm_mod] [<ffffffff811d8c41>] elevator_init+0xe1/0x115 [<ffffffff811e229f>] ? blk_queue_make_request+0x54/0x59 [<ffffffff811dd743>] blk_init_allocated_queue+0x8c/0x9e [<ffffffffa019ffcd>] dm_setup_md_queue+0x36/0xaa [dm_mod] [<ffffffffa01a60e6>] table_load+0x1bd/0x2c8 [dm_mod] [<ffffffffa01a7026>] ctl_ioctl+0x1d6/0x236 [dm_mod] [<ffffffffa01a5f29>] ? table_clear+0xaa/0xaa [dm_mod] [<ffffffffa01a7099>] dm_ctl_ioctl+0x13/0x17 [dm_mod] [<ffffffff811479fc>] do_vfs_ioctl+0x3fb/0x441 [<ffffffff811b643c>] ? file_has_perm+0x8a/0x99 [<ffffffff81147aa0>] sys_ioctl+0x5e/0x82 [<ffffffff812010be>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff814310d9>] system_call_fastpath+0x16/0x1b Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-blockLinus Torvalds2013-02-281-41/+236
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block IO core bits from Jens Axboe: "Below are the core block IO bits for 3.9. It was delayed a few days since my workstation kept crashing every 2-8h after pulling it into current -git, but turns out it is a bug in the new pstate code (divide by zero, will report separately). In any case, it contains: - The big cfq/blkcg update from Tejun and and Vivek. - Additional block and writeback tracepoints from Tejun. - Improvement of the should sort (based on queues) logic in the plug flushing. - _io() variants of the wait_for_completion() interface, using io_schedule() instead of schedule() to contribute to io wait properly. - Various little fixes. You'll get two trivial merge conflicts, which should be easy enough to fix up" Fix up the trivial conflicts due to hlist traversal cleanups (commit b67bfe0d42ca: "hlist: drop the node parameter from iterators"). * 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits) block: remove redundant check to bd_openers() block: use i_size_write() in bd_set_size() cfq: fix lock imbalance with failed allocations drivers/block/swim3.c: fix null pointer dereference block: don't select PERCPU_RWSEM block: account iowait time when waiting for completion of IO request sched: add wait_for_completion_io[_timeout] writeback: add more tracepoints block: add block_{touch|dirty}_buffer tracepoint buffer: make touch_buffer() an exported function block: add @req to bio_{front|back}_merge tracepoints block: add missing block_bio_complete() tracepoint block: Remove should_sort judgement when flush blk_plug block,elevator: use new hashtable implementation cfq-iosched: add hierarchical cfq_group statistics cfq-iosched: collect stats from dead cfqgs cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats() blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock block: RCU free request_queue blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge() ...
| * blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lockTejun Heo2013-01-091-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | Instead of holding blkcg->lock while walking ->blkg_list and executing prfill(), RCU walk ->blkg_list and hold the blkg's queue lock while executing prfill(). This makes prfill() implementations easier as stats are mostly protected by queue lock. This will be used to implement hierarchical stats. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge()Tejun Heo2013-01-091-0/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge(). The former two collect the [rw]stats designated by the target policy data and offset from the pd's subtree. The latter two add one [rw]stat to another. Note that the recursive sum functions require the queue lock to be held on entry to make blkg online test reliable. This is necessary to properly handle stats of a dying blkg. These will be used to implement hierarchical stats. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * blkcg: export __blkg_prfill_rwstat()Tejun Heo2013-01-091-0/+1
| | | | | | | | | | | | | | | | Hierarchical stats for cfq-iosched will need __blkg_prfill_rwstat(). Export it. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com>
| * blkcg: implement blkcg_policy->on/offline_pd_fn() and blkcg_gq->onlineTejun Heo2013-01-091-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two blkcg_policy methods, ->online_pd_fn() and ->offline_pd_fn(), which are invoked as the policy_data gets activated and deactivated while holding both blkcg and q locks. Also, add blkcg_gq->online bool, which is set and cleared as the blkcg_gq gets activated and deactivated. This flag also is toggled while holding both blkcg and q locks. These will be used to implement hierarchical stats. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * blkcg: add blkg_policy_data->plidTejun Heo2013-01-091-0/+2
| | | | | | | | | | | | | | | | Add pd->plid so that the policy a pd belongs to can be identified easily. This will be used to implement hierarchical blkg_[rw]stats. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * cfq-iosched: add leaf_weightTejun Heo2013-01-091-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cfq blkcg is about to grow proper hierarchy handling, where a child blkg's weight would nest inside the parent's. This makes tasks in a blkg to compete against both tasks in the sibling blkgs and the tasks of child blkgs. We're gonna use the existing weight as the group weight which decides the blkg's weight against its siblings. This patch introduces a new weight - leaf_weight - which decides the weight of a blkg against the child blkgs. It's named leaf_weight because another way to look at it is that each internal blkg nodes have a hidden child leaf node which contains all its tasks and leaf_weight is the weight of the leaf node and handled the same as the weight of the child blkgs. This patch only adds leaf_weight fields and exposes it to userland. The new weight isn't actually used anywhere yet. Note that cfq-iosched currently offcially supports only single level hierarchy and root blkgs compete with the first level blkgs - ie. root weight is basically being used as leaf_weight. For root blkgs, the two weights are kept in sync for backward compatibility. v2: cfqd->root_group->leaf_weight initialization was missing from cfq_init_queue() causing divide by zero when !CONFIG_CFQ_GROUP_SCHED. Fix it. Reported by Fengguang. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Fengguang Wu <fengguang.wu@intel.com>
| * blkcg: make blkcg_gq's hierarchicalTejun Heo2013-01-091-5/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently a child blkg (blkcg_gq) can be created even if its parent doesn't exist. ie. Given a blkg, it's not guaranteed that its ancestors will exist. This makes it difficult to implement proper hierarchy support for blkcg policies. Always create blkgs recursively and make a child blkg hold a reference to its parent. blkg->parent is added so that finding the parent is easy. blkcg_parent() is also added in the process. This change can be visible to userland. e.g. while issuing IO in a nested cgroup didn't affect the ancestors at all, now it will initialize all ancestor blkgs and zero stats for the request_queue will always appear on them. While this is userland visible, this shouldn't cause any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * blkcg: cosmetic updates to blkg_create()Tejun Heo2013-01-091-8/+7
| | | | | | | | | | | | | | | | | | | | | | * Rename out_* labels to err_*. * Do ERR_PTR() conversion once in the error return path. This patch is cosmetic and to prepare for the hierarchy support. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * blkcg: reorganize blkg_lookup_create() and friendsTejun Heo2013-01-091-23/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reorganize such that * __blkg_lookup() takes bool param @update_hint to determine whether to update hint. * __blkg_lookup_create() no longer performs lookup before trying to create. Renamed to blkg_create(). * blkg_lookup_create() now performs lookup and then invokes blkg_create() if lookup fails. * root_blkg creation in blkcg_activate_policy() updated accordingly. Note that blkcg_activate_policy() no longer updates lookup hint if root_blkg already exists. Except for the last lookup hint bit which is immaterial, this is pure reorganization and doesn't introduce any visible behavior change. This is to prepare for proper hierarchy support. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
| * blkcg: fix minor bug in blkg_alloc()Tejun Heo2013-01-091-1/+1
| | | | | | | | | | | | | | | | | | | | blkg_alloc() was mistakenly checking blkcg_policy_enabled() twice. The latter test should have been on whether pol->pd_init_fn() exists. This doesn't cause actual problems because both blkcg policies implement pol->pd_init_fn(). Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
* | hlist: drop the node parameter from iteratorsSasha Levin2013-02-271-4/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-3.8/core' of git://git.kernel.dk/linux-blockLinus Torvalds2012-12-171-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block layer core updates from Jens Axboe: "Here are the core block IO bits for 3.8. The branch contains: - The final version of the surprise device removal fixups from Bart. - Don't hide EFI partitions under advanced partition types. It's fairly wide spread these days. This is especially dangerous for systems that have both msdos and efi partition tables, where you want to keep them in sync. - Cleanup of using -1 instead of the proper NUMA_NO_NODE - Export control of bdi flusher thread CPU mask and default to using the home node (if known) from Jeff. - Export unplug tracepoint for MD. - Core improvements from Shaohua. Reinstate the recursive merge, as the original bug has been fixed. Add plugging for discard and also fix a problem handling non pow-of-2 discard limits. There's a trivial merge in block/blk-exec.c due to a fix that went into 3.7-rc at a later point than -rc4 where this is based." * 'for-3.8/core' of git://git.kernel.dk/linux-block: block: export block_unplug tracepoint block: add plug for blkdev_issue_discard block: discard granularity might not be power of 2 deadline: Allow 0ms deadline latency, increase the read speed partitions: enable EFI/GPT support by default bsg: Remove unused function bsg_goose_queue() block: Make blk_cleanup_queue() wait until request_fn finished block: Avoid scheduling delayed work on a dead queue block: Avoid that request_fn is invoked on a dead queue block: Let blk_drain_queue() caller obtain the queue lock block: Rename queue dead flag bdi: add a user-tunable cpu_list for the bdi flusher threads block: use NUMA_NO_NODE instead of -1 block: recursive merge requests block CFQ: avoid moving request to different queue
| * block: Rename queue dead flagBart Van Assche2012-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | QUEUE_FLAG_DEAD is used to indicate that queuing new requests must stop. After this flag has been set queue draining starts. However, during the queue draining phase it is still safe to invoke the queue's request_fn, so QUEUE_FLAG_DYING is a better name for this flag. This patch has been generated by running the following command over the kernel source tree: git grep -lEw 'blk_queue_dead|QUEUE_FLAG_DEAD' | xargs sed -i.tmp -e 's/blk_queue_dead/blk_queue_dying/g' \ -e 's/QUEUE_FLAG_DEAD/QUEUE_FLAG_DYING/g'; \ sed -i.tmp -e "s/QUEUE_FLAG_DYING$(printf \\t)*5/QUEUE_FLAG_DYING$(printf \\t)5/g" \ include/linux/blkdev.h; \ sed -i.tmp -e 's/ DEAD/ DYING/g' -e 's/dead queue/a dying queue/' \ -e 's/Dead queue/A dying queue/' block/blk-core.c Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: James Bottomley <JBottomley@Parallels.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Jens Axboe <axboe@kernel.dk> Cc: Chanho Min <chanho.min@lge.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | cgroup: rename ->create/post_create/pre_destroy/destroy() to ↵Tejun Heo2012-11-191-7/+7
| | | | | | | | | | | | | | | | | | | | ->css_alloc/online/offline/free() Rename cgroup_subsys css lifetime related callbacks to better describe what their roles are. Also, update documentation. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
* | Merge branch 'cgroup/for-3.7-fixes' into cgroup/for-3.8Tejun Heo2012-11-061-0/+10
|\ \ | |/ | | | | | | | | | | This is to receive device_cgroup fixes so that further device_cgroup changes can be made in cgroup/for-3.8. Signed-off-by: Tejun Heo <tj@kernel.org>
| * blkcg: stop iteration early if root_rl is the only request listJun'ichi Nomura2012-10-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | __blk_queue_next_rl() finds next request list based on blkg_list while skipping root_blkg in the list. OTOH, root_rl is special as it may exist even without root_blkg. Though the later part of the function handles such a case correctly, exiting early is good for readability of the code. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
| * blkcg: Fix use-after-free of q->root_blkg and q->root_rl.blkgJun'ichi Nomura2012-10-221-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_put_rl() does not call blkg_put() for q->root_rl because we don't take request list reference on q->root_blkg. However, if root_blkg is once attached then detached (freed), blk_put_rl() is confused by the bogus pointer in q->root_blkg. For example, with !CONFIG_BLK_DEV_THROTTLING && CONFIG_CFQ_GROUP_IOSCHED, switching IO scheduler from cfq to deadline will cause system stall after the following warning with 3.6: > WARNING: at /work/build/linux/block/blk-cgroup.h:250 > blk_put_rl+0x4d/0x95() > Modules linked in: bridge stp llc sunrpc acpi_cpufreq freq_table mperf > ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 > Pid: 0, comm: swapper/0 Not tainted 3.6.0 #1 > Call Trace: > <IRQ> [<ffffffff810453bd>] warn_slowpath_common+0x85/0x9d > [<ffffffff810453ef>] warn_slowpath_null+0x1a/0x1c > [<ffffffff811d5f8d>] blk_put_rl+0x4d/0x95 > [<ffffffff811d614a>] __blk_put_request+0xc3/0xcb > [<ffffffff811d71a3>] blk_finish_request+0x232/0x23f > [<ffffffff811d76c3>] ? blk_end_bidi_request+0x34/0x5d > [<ffffffff811d76d1>] blk_end_bidi_request+0x42/0x5d > [<ffffffff811d7728>] blk_end_request+0x10/0x12 > [<ffffffff812cdf16>] scsi_io_completion+0x207/0x4d5 > [<ffffffff812c6fcf>] scsi_finish_command+0xfa/0x103 > [<ffffffff812ce2f8>] scsi_softirq_done+0xff/0x108 > [<ffffffff811dcea5>] blk_done_softirq+0x8d/0xa1 > [<ffffffff810915d5>] ? > generic_smp_call_function_single_interrupt+0x9f/0xd7 > [<ffffffff8104cf5b>] __do_softirq+0x102/0x213 > [<ffffffff8108a5ec>] ? lock_release_holdtime+0xb6/0xbb > [<ffffffff8104d2b4>] ? raise_softirq_irqoff+0x9/0x3d > [<ffffffff81424dfc>] call_softirq+0x1c/0x30 > [<ffffffff81011beb>] do_softirq+0x4b/0xa3 > [<ffffffff8104cdb0>] irq_exit+0x53/0xd5 > [<ffffffff8102d865>] smp_call_function_single_interrupt+0x34/0x36 > [<ffffffff8142486f>] call_function_single_interrupt+0x6f/0x80 > <EOI> [<ffffffff8101800b>] ? mwait_idle+0x94/0xcd > [<ffffffff81018002>] ? mwait_idle+0x8b/0xcd > [<ffffffff81017811>] cpu_idle+0xbb/0x114 > [<ffffffff81401fbd>] rest_init+0xc1/0xc8 > [<ffffffff81401efc>] ? csum_partial_copy_generic+0x16c/0x16c > [<ffffffff81cdbd3d>] start_kernel+0x3d4/0x3e1 > [<ffffffff81cdb79e>] ? kernel_init+0x1f7/0x1f7 > [<ffffffff81cdb2dd>] x86_64_start_reservations+0xb8/0xbd > [<ffffffff81cdb3e3>] x86_64_start_kernel+0x101/0x110 This patch clears q->root_blkg and q->root_rl.blkg when root blkg is destroyed. Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | Merge branch 'cgroup-rmdir-updates' into cgroup/for-3.8Tejun Heo2012-11-051-2/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | Pull rmdir updates into for-3.8 so that further callback updates can be put on top. This pull created a trivial conflict between the following two commits. 8c7f6edbda ("cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them") ed95779340 ("cgroup: kill cgroup_subsys->__DEPRECATED_clear_css_refs") The former added a field to cgroup_subsys and the latter removed one from it. They happen to be colocated causing the conflict. Keeping what's added and removing what's removed resolves the conflict. Signed-off-by: Tejun Heo <tj@kernel.org>
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