cgroup: pass around cgroup_subsys_state instead of cgroup in file methods

cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup.
Please see the previous commit which converts the subsystem methods
for rationale.

This patch converts all cftype file operations to take @css instead of
@cgroup.  cftypes for the cgroup core files don't have their subsytem
pointer set.  These will automatically use the dummy_css added by the
previous patch and can be converted the same way.

Most subsystem conversions are straight forwards but there are some
interesting ones.

* freezer: update_if_frozen() is also converted to take @css instead
  of @cgroup for consistency.  This will make the code look simpler
  too once iterators are converted to use css.

* memory/vmpressure: mem_cgroup_from_css() needs to be exported to
  vmpressure while mem_cgroup_from_cont() can be made static.
  Updated accordingly.

* cpu: cgroup_tg() doesn't have any user left.  Removed.

* cpuacct: cgroup_ca() doesn't have any user left.  Removed.

* hugetlb: hugetlb_cgroup_form_cgroup() doesn't have any user left.
  Removed.

* net_cls: cgrp_cls_state() doesn't have any user left.  Removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 16 insertions, 16 deletions

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 08a32dfd384..88bcfb651b0 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1293,10 +1293,10 @@ static u64 tg_prfill_cpu_rwstat(struct seq_file *sf,
 	return __blkg_prfill_rwstat(sf, pd, &rwstat);
 }
 
-static int tg_print_cpu_rwstat(struct cgroup *cgrp, struct cftype *cft,
-			       struct seq_file *sf)
+static int tg_print_cpu_rwstat(struct cgroup_subsys_state *css,
+			       struct cftype *cft, struct seq_file *sf)
 {
-	struct blkcg *blkcg = cgroup_to_blkcg(cgrp);
+	struct blkcg *blkcg = css_to_blkcg(css);
 
 	blkcg_print_blkgs(sf, blkcg, tg_prfill_cpu_rwstat, &blkcg_policy_throtl,
 			  cft->private, true);
@@ -1325,26 +1325,26 @@ static u64 tg_prfill_conf_uint(struct seq_file *sf, struct blkg_policy_data *pd,
 	return __blkg_prfill_u64(sf, pd, v);
 }
 
-static int tg_print_conf_u64(struct cgroup *cgrp, struct cftype *cft,
-			     struct seq_file *sf)
+static int tg_print_conf_u64(struct cgroup_subsys_state *css,
+			     struct cftype *cft, struct seq_file *sf)
 {
-	blkcg_print_blkgs(sf, cgroup_to_blkcg(cgrp), tg_prfill_conf_u64,
+	blkcg_print_blkgs(sf, css_to_blkcg(css), tg_prfill_conf_u64,
 			  &blkcg_policy_throtl, cft->private, false);
 	return 0;
 }
 
-static int tg_print_conf_uint(struct cgroup *cgrp, struct cftype *cft,
-			      struct seq_file *sf)
+static int tg_print_conf_uint(struct cgroup_subsys_state *css,
+			      struct cftype *cft, struct seq_file *sf)
 {
-	blkcg_print_blkgs(sf, cgroup_to_blkcg(cgrp), tg_prfill_conf_uint,
+	blkcg_print_blkgs(sf, css_to_blkcg(css), tg_prfill_conf_uint,
 			  &blkcg_policy_throtl, cft->private, false);
 	return 0;
 }
 
-static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf,
-		       bool is_u64)
+static int tg_set_conf(struct cgroup_subsys_state *css, struct cftype *cft,
+		       const char *buf, bool is_u64)
 {
-	struct blkcg *blkcg = cgroup_to_blkcg(cgrp);
+	struct blkcg *blkcg = css_to_blkcg(css);
 	struct blkg_conf_ctx ctx;
 	struct throtl_grp *tg;
 	struct throtl_service_queue *sq;
@@ -1403,16 +1403,16 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf,
 	return 0;
 }
 
-static int tg_set_conf_u64(struct cgroup *cgrp, struct cftype *cft,
+static int tg_set_conf_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 			   const char *buf)
 {
-	return tg_set_conf(cgrp, cft, buf, true);
+	return tg_set_conf(css, cft, buf, true);
 }
 
-static int tg_set_conf_uint(struct cgroup *cgrp, struct cftype *cft,
+static int tg_set_conf_uint(struct cgroup_subsys_state *css, struct cftype *cft,
 			    const char *buf)
 {
-	return tg_set_conf(cgrp, cft, buf, false);
+	return tg_set_conf(css, cft, buf, false);
 }
 
 static struct cftype throtl_files[] = {