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authorTejun Heo <tj@kernel.org>2015-05-22 23:13:38 +0200
committerJens Axboe <axboe@fb.com>2015-06-02 16:33:35 +0200
commitce7acfeaf0363c8b75810908448f61af04d38f91 (patch)
treed1f45850fc6a225662f1e959d26572f70539a24b /block/blk-cgroup.c
parentwriteback: make backing_dev_info host cgroup-specific bdi_writebacks (diff)
downloadlinux-ce7acfeaf0363c8b75810908448f61af04d38f91.tar.xz
linux-ce7acfeaf0363c8b75810908448f61af04d38f91.zip
writeback, blkcg: associate each blkcg_gq with the corresponding bdi_writeback_congested
A blkg (blkcg_gq) can be congested and decongested independently from other blkgs on the same request_queue. Accordingly, for cgroup writeback support, the congestion status at bdi (backing_dev_info) should be split and updated separately from matching blkg's. This patch prepares by adding blkg->wb_congested and associating a blkg with its matching per-blkcg bdi_writeback_congested on creation. v2: Updated to associate bdi_writeback_congested instead of bdi_writeback. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-cgroup.c')
-rw-r--r--block/blk-cgroup.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 979cfdbb94e0..31610ae0ebff 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -182,6 +182,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
struct blkcg_gq *new_blkg)
{
struct blkcg_gq *blkg;
+ struct bdi_writeback_congested *wb_congested;
int i, ret;
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -193,22 +194,30 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
goto err_free_blkg;
}
+ wb_congested = wb_congested_get_create(&q->backing_dev_info,
+ blkcg->css.id, GFP_ATOMIC);
+ if (!wb_congested) {
+ ret = -ENOMEM;
+ goto err_put_css;
+ }
+
/* allocate */
if (!new_blkg) {
new_blkg = blkg_alloc(blkcg, q, GFP_ATOMIC);
if (unlikely(!new_blkg)) {
ret = -ENOMEM;
- goto err_put_css;
+ goto err_put_congested;
}
}
blkg = new_blkg;
+ blkg->wb_congested = wb_congested;
/* link parent */
if (blkcg_parent(blkcg)) {
blkg->parent = __blkg_lookup(blkcg_parent(blkcg), q, false);
if (WARN_ON_ONCE(!blkg->parent)) {
ret = -EINVAL;
- goto err_put_css;
+ goto err_put_congested;
}
blkg_get(blkg->parent);
}
@@ -245,6 +254,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
blkg_put(blkg);
return ERR_PTR(ret);
+err_put_congested:
+ wb_congested_put(wb_congested);
err_put_css:
css_put(&blkcg->css);
err_free_blkg:
@@ -391,6 +402,8 @@ void __blkg_release_rcu(struct rcu_head *rcu_head)
if (blkg->parent)
blkg_put(blkg->parent);
+ wb_congested_put(blkg->wb_congested);
+
blkg_free(blkg);
}
EXPORT_SYMBOL_GPL(__blkg_release_rcu);