block: make queue flags non-atomic

We can save some atomic ops in the IO path, if we clearly define
the rules of how to modify the queue flags.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index b5c5c4a9e3f0..73b23562af20 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -55,7 +55,7 @@ void blk_recalc_rq_segments(struct request *rq)
         if (!rq->bio)
                 return;
 
-        cluster = q->queue_flags & (1 << QUEUE_FLAG_CLUSTER);
+        cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
         hw_seg_size = seg_size = 0;
         phys_size = hw_size = nr_phys_segs = nr_hw_segs = 0;
         rq_for_each_segment(bv, rq, iter) {
@@ -128,7 +128,7 @@ EXPORT_SYMBOL(blk_recount_segments);
 static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
                                    struct bio *nxt)
 {
-        if (!(q->queue_flags & (1 << QUEUE_FLAG_CLUSTER)))
+        if (!test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
                 return 0;
 
         if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
@@ -175,7 +175,7 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
         int nsegs, cluster;
 
         nsegs = 0;
-        cluster = q->queue_flags & (1 << QUEUE_FLAG_CLUSTER);
+        cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
 
         /*
          * for each bio in rq