X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=block%2Fblk-merge.c;h=89b97b5e0881853054c0807c5607c20d91d90762;hb=b6444bd0a18eb47343e16749ce80a6ebd521f124;hp=b3ac40aef46b317c5a432a92ba9b40c8e1942504;hpb=136a713d80476fe993284bdf8b21709c179c9965;p=firefly-linux-kernel-4.4.55.git

diff --git a/block/blk-merge.c b/block/blk-merge.c
index b3ac40aef46b..89b97b5e0881 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -97,19 +97,22 @@ void blk_recalc_rq_segments(struct request *rq)
 
 void blk_recount_segments(struct request_queue *q, struct bio *bio)
 {
-	bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE,
-			&q->queue_flags);
-	bool merge_not_need = bio->bi_vcnt < queue_max_segments(q);
+	unsigned short seg_cnt;
+
+	/* estimate segment number by bi_vcnt for non-cloned bio */
+	if (bio_flagged(bio, BIO_CLONED))
+		seg_cnt = bio_segments(bio);
+	else
+		seg_cnt = bio->bi_vcnt;
 
-	if (no_sg_merge && !bio_flagged(bio, BIO_CLONED) &&
-			merge_not_need)
-		bio->bi_phys_segments = bio->bi_vcnt;
+	if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) &&
+			(seg_cnt < queue_max_segments(q)))
+		bio->bi_phys_segments = seg_cnt;
 	else {
 		struct bio *nxt = bio->bi_next;
 
 		bio->bi_next = NULL;
-		bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio,
-				no_sg_merge && merge_not_need);
+		bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false);
 		bio->bi_next = nxt;
 	}