blkcg: separate out tg_conf_updated() from tg_set_conf()

tg_set_conf() is largely consisted of parsing and setting the new
config and the follow-up application and propagation.  This patch
separates out the latter part into tg_conf_updated().  This will be
used to implement interface for the unified hierarchy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 32 insertions, 28 deletions

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 0e17c8f92d25..a8bb2fd8f523 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1144,35 +1144,11 @@ static int tg_print_conf_uint(struct seq_file *sf, void *v)
         return 0;
 }
 
-static ssize_t tg_set_conf(struct kernfs_open_file *of,
-                           char *buf, size_t nbytes, loff_t off, bool is_u64)
+static void tg_conf_updated(struct throtl_grp *tg)
 {
-        struct blkcg *blkcg = css_to_blkcg(of_css(of));
-        struct blkg_conf_ctx ctx;
-        struct throtl_grp *tg;
-        struct throtl_service_queue *sq;
-        struct blkcg_gq *blkg;
+        struct throtl_service_queue *sq = &tg->service_queue;
         struct cgroup_subsys_state *pos_css;
-        int ret;
-        u64 v;
-
-        ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
-        if (ret)
-                return ret;
-
-        ret = -EINVAL;
-        if (sscanf(ctx.body, "%llu", &v) != 1)
-                goto out_finish;
-        if (!v)
-                v = -1;
-
-        tg = blkg_to_tg(ctx.blkg);
-        sq = &tg->service_queue;
-
-        if (is_u64)
-                *(u64 *)((void *)tg + of_cft(of)->private) = v;
-        else
-                *(unsigned int *)((void *)tg + of_cft(of)->private) = v;
+        struct blkcg_gq *blkg;
 
         throtl_log(&tg->service_queue,
                    "limit change rbps=%llu wbps=%llu riops=%u wiops=%u",
@@ -1186,7 +1162,7 @@ static ssize_t tg_set_conf(struct kernfs_open_file *of,
          * restrictions in the whole hierarchy and allows them to bypass
          * blk-throttle.
          */
-        blkg_for_each_descendant_pre(blkg, pos_css, ctx.blkg)
+        blkg_for_each_descendant_pre(blkg, pos_css, tg_to_blkg(tg))
                 tg_update_has_rules(blkg_to_tg(blkg));
 
         /*
@@ -1204,7 +1180,35 @@ static ssize_t tg_set_conf(struct kernfs_open_file *of,
                 tg_update_disptime(tg);
                 throtl_schedule_next_dispatch(sq->parent_sq, true);
         }
+}
+
+static ssize_t tg_set_conf(struct kernfs_open_file *of,
+                           char *buf, size_t nbytes, loff_t off, bool is_u64)
+{
+        struct blkcg *blkcg = css_to_blkcg(of_css(of));
+        struct blkg_conf_ctx ctx;
+        struct throtl_grp *tg;
+        int ret;
+        u64 v;
+
+        ret = blkg_conf_prep(blkcg, &blkcg_policy_throtl, buf, &ctx);
+        if (ret)
+                return ret;
+
+        ret = -EINVAL;
+        if (sscanf(ctx.body, "%llu", &v) != 1)
+                goto out_finish;
+        if (!v)
+                v = -1;
+
+        tg = blkg_to_tg(ctx.blkg);
+
+        if (is_u64)
+                *(u64 *)((void *)tg + of_cft(of)->private) = v;
+        else
+                *(unsigned int *)((void *)tg + of_cft(of)->private) = v;
 
+        tg_conf_updated(tg);
         ret = 0;
 out_finish:
         blkg_conf_finish(&ctx);