X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=block%2Fblk-throttle.c;h=16f5766620a41043645756c51d441f4488af9edf;hb=refs%2Fheads%2Fsandbox%2Fklewandowski%2Frpi5;hp=38a881cf97d0b4d4f8cd6b321ead22d055c46aa7;hpb=4f6cee60453dbb06292907943a185247ef17d584;p=platform%2Fkernel%2Flinux-rpi.git

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 38a881c..16f5766 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -723,6 +723,12 @@ static unsigned int calculate_io_allowed(u32 iops_limit,
 
 static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed)
 {
+	/*
+	 * Can result be wider than 64 bits?
+	 * We check against 62, not 64, due to ilog2 truncation.
+	 */
+	if (ilog2(bps_limit) + ilog2(jiffy_elapsed) - ilog2(HZ) > 62)
+		return U64_MAX;
 	return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ);
 }
 
@@ -1314,6 +1320,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 		   tg_bps_limit(tg, READ), tg_bps_limit(tg, WRITE),
 		   tg_iops_limit(tg, READ), tg_iops_limit(tg, WRITE));
 
+	rcu_read_lock();
 	/*
 	 * Update has_rules[] flags for the updated tg's subtree.  A tg is
 	 * considered to have rules if either the tg itself or any of its
@@ -1341,6 +1348,7 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 		this_tg->latency_target = max(this_tg->latency_target,
 				parent_tg->latency_target);
 	}
+	rcu_read_unlock();
 
 	/*
 	 * We're already holding queue_lock and know @tg is valid.  Let's