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| author | Tejun Heo <tj@kernel.org> | 2019-07-24 10:37:22 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-04-01 14:56:42 -0600 |
| commit | d866dbf6178713e37d2fec2870af00b345684e1a (patch) | |
| tree | f87bdafbbe76c032b7d56a4612d63d3c89167e1a /mm/backing-dev.c | |
| parent | 1a323ea5356edbb3073dc59d51b9e6b86908857d (diff) | |
| download | linux-d866dbf6178713e37d2fec2870af00b345684e1a.tar.gz linux-d866dbf6178713e37d2fec2870af00b345684e1a.tar.bz2 linux-d866dbf6178713e37d2fec2870af00b345684e1a.zip | |
blkcg: rename blkcg->cgwb_refcnt to ->online_pin and always use it
blkcg->cgwb_refcnt is used to delay blkcg offlining so that blkgs
don't get offlined while there are active cgwbs on them. However, it
ends up making offlining unordered sometimes causing parents to be
offlined before children.
To fix it, we want child blkcgs to pin the parents' online states
turning the refcnt into a more generic online pinning mechanism.
In prepartion,
* blkcg->cgwb_refcnt -> blkcg->online_pin
* blkcg_cgwb_get/put() -> blkcg_pin/unpin_online()
* Take them out of CONFIG_CGROUP_WRITEBACK
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'mm/backing-dev.c')
| -rw-r--r-- | mm/backing-dev.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 62f05f605fb5..c81b4f3a7268 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -491,8 +491,8 @@ static void cgwb_release_workfn(struct work_struct *work) css_put(wb->blkcg_css); mutex_unlock(&wb->bdi->cgwb_release_mutex); - /* triggers blkg destruction if cgwb_refcnt becomes zero */ - blkcg_cgwb_put(blkcg); + /* triggers blkg destruction if no online users left */ + blkcg_unpin_online(blkcg); fprop_local_destroy_percpu(&wb->memcg_completions); percpu_ref_exit(&wb->refcnt); @@ -592,7 +592,7 @@ static int cgwb_create(struct backing_dev_info *bdi, list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list); list_add(&wb->memcg_node, memcg_cgwb_list); list_add(&wb->blkcg_node, blkcg_cgwb_list); - blkcg_cgwb_get(blkcg); + blkcg_pin_online(blkcg); css_get(memcg_css); css_get(blkcg_css); } |