xavi/android_kernel_m2note/block/blk-cgroup.c, branch ng-7.1.2

blkcg: move bulk of blkcg_gq release operations to the RCU callback

2016-09-18T10:46:42+00:00

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 Acked-by: Vivek Goyal

blkcg: invoke blkcg_policy->pd_init() after parent is linked

2016-09-18T10:46:41+00:00

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 Acked-by: Vivek Goyal

blkcg: move blkg_for_each_descendant_pre() to block/blk-cgroup.h

2016-09-18T10:46:39+00:00

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 Acked-by: Vivek Goyal

blkcg: fix error return path in blkg_create()

2016-09-18T10:46:39+00:00

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 Acked-by: Vivek Goyal

blk-throttle: implement proper hierarchy support

2016-09-18T10:46:28+00:00

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 Acked-by: Vivek Goyal Cc: Li Zefan

blkcg: fix gendisk reference leak in blkg_conf_prep()

2016-08-26T17:58:46+00:00

commit 5f6c2d2b7dbb541c1e922538c49fa04c494ae3d7 upstream. When a blkcg configuration is targeted to a partition rather than a whole device, blkg_conf_prep fails with -EINVAL; unfortunately, it forgets to put the gendisk ref in that case. Fix it. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman Signed-off-by: Stefan Guendhoer

first commit

2016-08-15T02:19:42+00:00