On Tue, May 29, 2018 at 05:17:14PM -0400, Josef Bacik wrote:
...

+		mutex_lock(&blkcg_pol_mutex);
+		for (i = 0; i < BLKCG_MAX_POLS; i++) {
+			struct blkcg_policy *pol = blkcg_policy[i];
+
+			if (!blkg->pd[i] || !pol->pd_stat_fn)
+				continue;
+
+			count = pol->pd_stat_fn(blkg->pd[i], buf, size);

Wouldn't it be easier to simply pass in the seq_file?

+			if (count >= size)
+				continue;
+			buf += count;
+			total += count;
+			size -= count + 1;
+		}
+		mutex_unlock(&blkcg_pol_mutex);
+		if (total) {
+			count = snprintf(buf, size, "\n");
+			if (count >= size)
+				continue;

scnprintf() might make this less painful.

+			total += count;
+			seq_commit(sf, total);
+		}

Thanks.

-- 
tejun