mm/damon/sysfs: deduplicate inputs applying

DAMON sysfs interface's DAMON context building and its online parameter
update have duplicated code.  This commit removes the duplicate.

Link: https://lkml.kernel.org/r/20220606182310.48781-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/sysfs.c

@@ -2357,6 +2357,23 @@ static inline bool damon_sysfs_kdamond_running(
 		damon_sysfs_ctx_running(kdamond->damon_ctx);
 }
 
+static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
+		struct damon_sysfs_context *sys_ctx)
+{
+	int err;
+
+	err = damon_select_ops(ctx, sys_ctx->ops_id);
+	if (err)
+		return err;
+	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
+	if (err)
+		return err;
+	err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
+	if (err)
+		return err;
+	return damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
+}
+
 /*
  * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
  * @kdamond:	The kobject wrapper for the associated kdamond.
@@ -2365,31 +2382,14 @@ static inline bool damon_sysfs_kdamond_running(
  */
 static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)
 {
-	struct damon_ctx *ctx = kdamond->damon_ctx;
-	struct damon_sysfs_context *sys_ctx;
-	int err = 0;
-
 	if (!damon_sysfs_kdamond_running(kdamond))
 		return -EINVAL;
 	/* TODO: Support multiple contexts per kdamond */
 	if (kdamond->contexts->nr != 1)
 		return -EINVAL;
 
-	sys_ctx = kdamond->contexts->contexts_arr[0];
-
-	err = damon_select_ops(ctx, sys_ctx->ops_id);
-	if (err)
-		return err;
-	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
-	if (err)
-		return err;
-	err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
-	if (err)
-		return err;
-	err = damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
-	if (err)
-		return err;
-	return err;
+	return damon_sysfs_apply_inputs(kdamond->damon_ctx,
+			kdamond->contexts->contexts_arr[0]);
 }
 
 /*
@@ -2436,27 +2436,16 @@ static struct damon_ctx *damon_sysfs_build_ctx(
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);
 
-	err = damon_select_ops(ctx, sys_ctx->ops_id);
-	if (err)
-		goto out;
-	err = damon_sysfs_set_attrs(ctx, sys_ctx->attrs);
-	if (err)
-		goto out;
-	err = damon_sysfs_set_targets(ctx, sys_ctx->targets);
-	if (err)
-		goto out;
-	err = damon_sysfs_set_schemes(ctx, sys_ctx->schemes);
-	if (err)
-		goto out;
+	err = damon_sysfs_apply_inputs(ctx, sys_ctx);
+	if (err) {
+		damon_destroy_ctx(ctx);
+		return ERR_PTR(err);
+	}
 
 	ctx->callback.after_wmarks_check = damon_sysfs_cmd_request_callback;
 	ctx->callback.after_aggregation = damon_sysfs_cmd_request_callback;
 	ctx->callback.before_terminate = damon_sysfs_before_terminate;
 	return ctx;
-
-out:
-	damon_destroy_ctx(ctx);
-	return ERR_PTR(err);
 }
 
 static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)