mm/damon/sysfs: move targets setup code to a separated function

This commit separates DAMON sysfs interface's monitoring context targets
setup code to a new function for better readability.

Link: https://lkml.kernel.org/r/20220429160606.127307-8-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/sysfs.c

@@ -2120,38 +2120,45 @@ static int damon_sysfs_set_regions(struct damon_target *t,
 	return 0;
 }
 
-static int damon_sysfs_set_targets(struct damon_ctx *ctx,
-		struct damon_sysfs_targets *sysfs_targets)
+static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
+		struct damon_ctx *ctx)
 {
-	int i, err;
-
-	/* Multiple physical address space monitoring targets makes no sense */
-	if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
-		return -EINVAL;
-
-	for (i = 0; i < sysfs_targets->nr; i++) {
-		struct damon_sysfs_target *sys_target =
-			sysfs_targets->targets_arr[i];
 	struct damon_target *t = damon_new_target();
+	int err = -EINVAL;
 
-		if (!t) {
-			damon_sysfs_destroy_targets(ctx);
+	if (!t)
 		return -ENOMEM;
-		}
 	if (ctx->ops.id == DAMON_OPS_VADDR ||
 			ctx->ops.id == DAMON_OPS_FVADDR) {
 		t->pid = find_get_pid(sys_target->pid);
-			if (!t->pid) {
-				damon_sysfs_destroy_targets(ctx);
-				return -EINVAL;
-			}
+		if (!t->pid)
+			goto destroy_targets_out;
 	}
 	damon_add_target(ctx, t);
 	err = damon_sysfs_set_regions(t, sys_target->regions);
-		if (err) {
+	if (err)
+		goto destroy_targets_out;
+	return 0;
+
+destroy_targets_out:
 	damon_sysfs_destroy_targets(ctx);
 	return err;
-		}
+}
+
+static int damon_sysfs_set_targets(struct damon_ctx *ctx,
+		struct damon_sysfs_targets *sysfs_targets)
+{
+	int i, err;
+
+	/* Multiple physical address space monitoring targets makes no sense */
+	if (ctx->ops.id == DAMON_OPS_PADDR && sysfs_targets->nr > 1)
+		return -EINVAL;
+
+	for (i = 0; i < sysfs_targets->nr; i++) {
+		err = damon_sysfs_add_target(
+				sysfs_targets->targets_arr[i], ctx);
+		if (err)
+			return err;
 	}
 	return 0;
 }