From da8b066262e12d1d0a3b1e6d3486e500169bf730 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 13 Apr 2012 13:11:29 -0700 Subject: [PATCH] blkcg: make blkg_conf_prep() take @pol and return with queue lock held Add @pol to blkg_conf_prep() and let it return with queue lock held (to be released by blkg_conf_finish()). Note that @pol isn't used yet. This is to prepare for per-queue policy activation and doesn't cause any visible difference. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 17 ++++++++++------- block/blk-cgroup.h | 3 ++- block/blk-throttle.c | 2 +- block/cfq-iosched.c | 2 +- 4 files changed, 14 insertions(+), 10 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 2d4d7d6d9ae9..f6581a090b9d 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -464,17 +464,19 @@ EXPORT_SYMBOL_GPL(blkg_prfill_rwstat); /** * blkg_conf_prep - parse and prepare for per-blkg config update * @blkcg: target block cgroup + * @pol: target policy * @input: input string * @ctx: blkg_conf_ctx to be filled * * Parse per-blkg config update from @input and initialize @ctx with the * result. @ctx->blkg points to the blkg to be updated and @ctx->v the new - * value. This function returns with RCU read locked and must be paired - * with blkg_conf_finish(). + * value. This function returns with RCU read lock and queue lock held and + * must be paired with blkg_conf_finish(). */ -int blkg_conf_prep(struct blkio_cgroup *blkcg, const char *input, +int blkg_conf_prep(struct blkio_cgroup *blkcg, + const struct blkio_policy_type *pol, const char *input, struct blkg_conf_ctx *ctx) - __acquires(rcu) + __acquires(rcu) __acquires(disk->queue->queue_lock) { struct gendisk *disk; struct blkio_group *blkg; @@ -490,14 +492,14 @@ int blkg_conf_prep(struct blkio_cgroup *blkcg, const char *input, return -EINVAL; rcu_read_lock(); - spin_lock_irq(disk->queue->queue_lock); + blkg = blkg_lookup_create(blkcg, disk->queue, false); - spin_unlock_irq(disk->queue->queue_lock); if (IS_ERR(blkg)) { ret = PTR_ERR(blkg); rcu_read_unlock(); + spin_unlock_irq(disk->queue->queue_lock); put_disk(disk); /* * If queue was bypassing, we should retry. Do so after a @@ -527,8 +529,9 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep); * with blkg_conf_prep(). */ void blkg_conf_finish(struct blkg_conf_ctx *ctx) - __releases(rcu) + __releases(ctx->disk->queue->queue_lock) __releases(rcu) { + spin_unlock_irq(ctx->disk->queue->queue_lock); rcu_read_unlock(); put_disk(ctx->disk); } diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index be80d6eb6531..df1c7b290c22 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -128,7 +128,8 @@ struct blkg_conf_ctx { u64 v; }; -int blkg_conf_prep(struct blkio_cgroup *blkcg, const char *input, +int blkg_conf_prep(struct blkio_cgroup *blkcg, + const struct blkio_policy_type *pol, const char *input, struct blkg_conf_ctx *ctx); void blkg_conf_finish(struct blkg_conf_ctx *ctx); diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 0dc4645aa7fe..6f1bfdf9a1b7 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -993,7 +993,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, struct throtl_grp *tg; int ret; - ret = blkg_conf_prep(blkcg, buf, &ctx); + ret = blkg_conf_prep(blkcg, &blkio_policy_throtl, buf, &ctx); if (ret) return ret; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 08db2fc70c29..de95f9a2acf8 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1400,7 +1400,7 @@ static int cfqg_set_weight_device(struct cgroup *cgrp, struct cftype *cft, struct cfq_group *cfqg; int ret; - ret = blkg_conf_prep(blkcg, buf, &ctx); + ret = blkg_conf_prep(blkcg, &blkio_policy_cfq, buf, &ctx); if (ret) return ret; -- 2.30.2