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>

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 0e17c8f92d254053e3ac5790498dfb9eeeb89b8a..a8bb2fd8f5230a512665cf0d7d220f807e2d2e7d 100644 (file)
--- 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);