blk-mq: remove REQ_END
Pass an explicit parameter for the last request in a batch to ->queue_rq
instead of using a request flag. Besides being a cleaner and non-stateful
interface this is also required for the next patch, which fixes the blk-mq
I/O submission code to not start a time too early.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e743d28..32b4797 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -384,7 +384,7 @@
}
EXPORT_SYMBOL(blk_mq_complete_request);
-static void blk_mq_start_request(struct request *rq, bool last)
+static void blk_mq_start_request(struct request *rq)
{
struct request_queue *q = rq->q;
@@ -421,16 +421,6 @@
*/
rq->nr_phys_segments++;
}
-
- /*
- * Flag the last request in the series so that drivers know when IO
- * should be kicked off, if they don't do it on a per-request basis.
- *
- * Note: the flag isn't the only condition drivers should do kick off.
- * If drive is busy, the last request might not have the bit set.
- */
- if (last)
- rq->cmd_flags |= REQ_END;
}
static void __blk_mq_requeue_request(struct request *rq)
@@ -440,8 +430,6 @@
trace_block_rq_requeue(q, rq);
clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
- rq->cmd_flags &= ~REQ_END;
-
if (q->dma_drain_size && blk_rq_bytes(rq))
rq->nr_phys_segments--;
}
@@ -755,9 +743,9 @@
rq = list_first_entry(&rq_list, struct request, queuelist);
list_del_init(&rq->queuelist);
- blk_mq_start_request(rq, list_empty(&rq_list));
+ blk_mq_start_request(rq);
- ret = q->mq_ops->queue_rq(hctx, rq);
+ ret = q->mq_ops->queue_rq(hctx, rq, list_empty(&rq_list));
switch (ret) {
case BLK_MQ_RQ_QUEUE_OK:
queued++;
@@ -1198,14 +1186,14 @@
int ret;
blk_mq_bio_to_request(rq, bio);
- blk_mq_start_request(rq, true);
+ blk_mq_start_request(rq);
/*
* For OK queue, we are done. For error, kill it. Any other
* error (busy), just add it to our list as we previously
* would have done
*/
- ret = q->mq_ops->queue_rq(data.hctx, rq);
+ ret = q->mq_ops->queue_rq(data.hctx, rq, true);
if (ret == BLK_MQ_RQ_QUEUE_OK)
goto done;
else {
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 5c8e7fe..0e2084f 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -3775,7 +3775,8 @@
return false;
}
-static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool last)
{
int ret;
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 00d469c..c5b7315 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -313,7 +313,8 @@
}
}
-static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool last)
{
struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 0a58140..13756e0 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -164,14 +164,14 @@
spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
}
-static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
+static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
+ bool last)
{
struct virtio_blk *vblk = hctx->queue->queuedata;
struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
unsigned long flags;
unsigned int num;
int qid = hctx->queue_num;
- const bool last = (req->cmd_flags & REQ_END) != 0;
int err;
bool notify = false;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1f2bae4..f1df411 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1855,7 +1855,8 @@
blk_mq_complete_request(cmd->request);
}
-static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
+static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req,
+ bool last)
{
struct request_queue *q = req->q;
struct scsi_device *sdev = q->queuedata;
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a1e31f2..9c4e306 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -77,7 +77,7 @@
struct list_head tag_list;
};
-typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
+typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *, bool);
typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 66c2167..bb7d664 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -188,7 +188,6 @@
__REQ_MIXED_MERGE, /* merge of different types, fail separately */
__REQ_KERNEL, /* direct IO to kernel pages */
__REQ_PM, /* runtime pm request */
- __REQ_END, /* last of chain of requests */
__REQ_HASHED, /* on IO scheduler merge hash */
__REQ_MQ_INFLIGHT, /* track inflight for MQ */
__REQ_NR_BITS, /* stops here */
@@ -242,7 +241,6 @@
#define REQ_SECURE (1ULL << __REQ_SECURE)
#define REQ_KERNEL (1ULL << __REQ_KERNEL)
#define REQ_PM (1ULL << __REQ_PM)
-#define REQ_END (1ULL << __REQ_END)
#define REQ_HASHED (1ULL << __REQ_HASHED)
#define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)