kernel/git/stable/linux.git/block/blk-cgroup.c, branch linux-3.5.y

blkcg: drop local variable @q from blkg_destroy()

2012-06-06T06:35:31+00:00

blkg_destroy() caches @blkg->q in local variable @q. While there are two places which needs @blkg->q, only lockdep_assert_held() used the local variable leading to unused local variable warning if lockdep is configured out. Drop the local variable and just use @blkg->q directly. Signed-off-by: Tejun Heo Reported-by: Rakesh Iyer Signed-off-by: Jens Axboe

blkcg: fix blkg_alloc() failure path

2012-06-04T08:03:21+00:00

When policy data allocation fails in the middle, blkg_alloc() invokes blkg_free() to destroy the half constructed blkg. This ends up calling pd_exit_fn() on policy datas which didn't go through pd_init_fn(). Fix it by making blkg_alloc() call pd_init_fn() immediately after each policy data allocation. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: use radix tree to index blkgs from blkcg

2012-04-20T08:06:40+00:00

blkg lookup is currently performed by traversing linked list anchored at blkcg->blkg_list. This is very unscalable and with blk-throttle enabled and enough request queues on the system, this can get very ugly quickly (blk-throttle performs look up on every bio submission). This patch makes blkcg use radix tree to index blkgs combined with simple last-looked-up hint. This is mostly identical to how icqs are indexed from ioc. Note that because __blkg_lookup() may be invoked without holding queue lock, hint is only updated from __blkg_lookup_create(). Due to cfq's cfqq caching, this makes hint updates overly lazy. This will be improved with scheduled blkcg aware request allocation. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: fix blkcg->css ref leak in __blkg_lookup_create()

2012-04-20T08:06:40+00:00

__blkg_lookup_create() leaked blkcg->css ref if blkg allocation failed. Fix it. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: collapse blkcg_policy_ops into blkcg_policy

2012-04-20T08:06:17+00:00

There's no reason to keep blkcg_policy_ops separate. Collapse it into blkcg_policy. This patch doesn't introduce any functional change. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: embed struct blkg_policy_data in policy specific data

2012-04-20T08:06:17+00:00

Currently blkg_policy_data carries policy specific data as char flex array instead of being embedded in policy specific data. This was forced by oddities around blkg allocation which are all gone now. This patch makes blkg_policy_data embedded in policy specific data - throtl_grp and cfq_group so that it's more conventional and consistent with how io_cq is handled. * blkcg_policy->pdata_size is renamed to ->pd_size. * Functions which used to take void *pdata now takes struct blkg_policy_data *pd. * blkg_to_pdata/pdata_to_blkg() updated to blkg_to_pd/pd_to_blkg(). * Dummy struct blkg_policy_data definition added. Dummy pdata_to_blkg() definition was unused and inconsistent with the non-dummy version - correct dummy pd_to_blkg() added. * throtl and cfq updated accordingly. * As dummy blkg_to_pd/pd_to_blkg() are provided, blkg_to_cfqg/cfqg_to_blkg() don't need to be ifdef'd. Moved outside ifdef block. This patch doesn't introduce any functional change. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: mass rename of blkcg API

2012-04-20T08:06:17+00:00

During the recent blkcg cleanup, most of blkcg API has changed to such extent that mass renaming wouldn't cause any noticeable pain. Take the chance and cleanup the naming. * Rename blkio_cgroup to blkcg. * Drop blkio / blkiocg prefixes and consistently use blkcg. * Rename blkio_group to blkcg_gq, which is consistent with io_cq but keep the blkg prefix / variable name. * Rename policy method type and field names to signify they're dealing with policy data. * Rename blkio_policy_type to blkcg_policy. This patch doesn't cause any functional change. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: remove blkio_group->path[]

2012-04-20T08:06:16+00:00

blkio_group->path[] stores the path of the associated cgroup and is used only for debug messages. Just format the path from blkg->cgroup when printing debug messages. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: shoot down blkgs if all policies are deactivated

2012-04-20T08:06:06+00:00

There's no reason to keep blkgs around if no policy is activated for the queue. This patch moves queue locking out of blkg_destroy_all() and call it from blkg_deactivate_policy() on deactivation of the last policy on the queue. This change was suggested by Vivek. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe

blkcg: drop stuff unused after per-queue policy activation update

2012-04-20T08:06:06+00:00

* All_q_list is unused. Drop all_q_{mutex|list}. * @for_root of blkg_lookup_create() is always %false when called from outside blk-cgroup.c proper. Factor out __blkg_lookup_create() so that it doesn't check whether @q is bypassing and use the underscored version for the @for_root callsite. * blkg_destroy_all() is used only from blkcg proper and @destroy_root is always %true. Make it static and drop @destroy_root. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe