blk-mq: ensure that we set REQ_IO_STAT so diskstats work
If disk stats are enabled on the queue, a request needs to
be marked with REQ_IO_STAT for accounting to be active on
that request. This fixes an issue with virtio-blk not
showing up in /proc/diskstats after the conversion to
blk-mq.
Add QUEUE_FLAG_MQ_DEFAULT, setting stats and same cpu-group
completion on by default.
Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 862f458..32593db 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -171,9 +171,12 @@
}
EXPORT_SYMBOL(blk_mq_can_queue);
-static void blk_mq_rq_ctx_init(struct blk_mq_ctx *ctx, struct request *rq,
- unsigned int rw_flags)
+static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
+ struct request *rq, unsigned int rw_flags)
{
+ if (blk_queue_io_stat(q))
+ rw_flags |= REQ_IO_STAT;
+
rq->mq_ctx = ctx;
rq->cmd_flags = rw_flags;
ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
@@ -197,7 +200,7 @@
rq = __blk_mq_alloc_request(hctx, gfp & ~__GFP_WAIT, reserved);
if (rq) {
- blk_mq_rq_ctx_init(ctx, rq, rw);
+ blk_mq_rq_ctx_init(q, ctx, rq, rw);
break;
} else if (!(gfp & __GFP_WAIT))
break;
@@ -921,7 +924,7 @@
trace_block_getrq(q, bio, rw);
rq = __blk_mq_alloc_request(hctx, GFP_ATOMIC, false);
if (likely(rq))
- blk_mq_rq_ctx_init(ctx, rq, rw);
+ blk_mq_rq_ctx_init(q, ctx, rq, rw);
else {
blk_mq_put_ctx(ctx);
trace_block_sleeprq(q, bio, rw);
@@ -1377,6 +1380,7 @@
q->queue_hw_ctx = hctxs;
q->mq_ops = reg->ops;
+ q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
blk_queue_make_request(q, blk_mq_make_request);
blk_queue_rq_timed_out(q, reg->ops->timeout);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f26ec20f..1b135d4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -505,6 +505,9 @@
(1 << QUEUE_FLAG_SAME_COMP) | \
(1 << QUEUE_FLAG_ADD_RANDOM))
+#define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
+ (1 << QUEUE_FLAG_SAME_COMP))
+
static inline void queue_lockdep_assert_held(struct request_queue *q)
{
if (q->queue_lock)