On Mon, Jan 03, 2022 at 05:23:08PM +0200, Max Gurtovoy wrote:
On 12/30/2021 5:30 PM, Keith Busch wrote:
I think it just may work if we export blk_mq_get_driver_tag().
do you have a suggestion for the NVMe/PCI driver ?
The following tests fine with my multi-namespace setups. I have real
hardware with namespace management capabilities, but qemu can also
easily emulate it too for anyone who doesn't have one.
---
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 5668e28be0b7..84f2e73d0c7c 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -41,12 +41,6 @@ static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
return sbq_wait_ptr(bt, &hctx->wait_index);
}
-enum {
- BLK_MQ_NO_TAG = -1U,
- BLK_MQ_TAG_MIN = 1,
- BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
-};
-
extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0d7c9d3e0329..b4540723077a 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1589,6 +1589,7 @@ bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq)
hctx->tags->rqs[rq->tag] = rq;
return true;
}
+EXPORT_SYMBOL_GPL(__blk_mq_get_driver_tag);
static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
int flags, void *key)
@@ -2582,11 +2583,10 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
* same queue, caller must ensure that's the case.
*
* Since we pass off the full list to the driver at this point,
- * we do not increment the active request count for the queue.
- * Bypass shared tags for now because of that.
+ * we are counting on the driver to increment the active
+ * request count for the queue.
*/
- if (q->mq_ops->queue_rqs &&
- !(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
+ if (q->mq_ops->queue_rqs) {
blk_mq_run_dispatch_ops(q,
__blk_mq_flush_plug_list(q, plug));
if (rq_list_empty(plug->mq_list))
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 948791ea2a3e..0f37ae906901 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -268,21 +268,6 @@ static inline void blk_mq_put_driver_tag(struct request *rq)
__blk_mq_put_driver_tag(rq->mq_hctx, rq);
}
-bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
-
-static inline bool blk_mq_get_driver_tag(struct request *rq)
-{
- struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
-
- if (rq->tag != BLK_MQ_NO_TAG &&
- !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
- hctx->tags->rqs[rq->tag] = rq;
- return true;
- }
-
- return __blk_mq_get_driver_tag(hctx, rq);
-}
-
static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
{
int cpu;
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 50deb8b69c40..f50483475c12 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -992,8 +992,9 @@ static bool nvme_prep_rq_batch(struct nvme_queue *nvmeq, struct request *req)
return false;
if (unlikely(!nvme_check_ready(&nvmeq->dev->ctrl, req, true)))
return false;
+ if (!blk_mq_get_driver_tag(req))
+ return false;
- req->mq_hctx->tags->rqs[req->tag] = req;
return nvme_prep_rq(nvmeq->dev, req) == BLK_STS_OK;
}
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 550996cf419c..8fb544a35330 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -1072,6 +1072,27 @@ static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
}
void blk_dump_rq_flags(struct request *, char *);
+enum {
+ BLK_MQ_NO_TAG = -1U,
+ BLK_MQ_TAG_MIN = 1,
+ BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
+};
+
+bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
+
+static inline bool blk_mq_get_driver_tag(struct request *rq)
+{
+ struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
+
+ if (rq->tag != BLK_MQ_NO_TAG &&
+ !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
+ hctx->tags->rqs[rq->tag] = rq;
+ return true;
+ }
+
+ return __blk_mq_get_driver_tag(hctx, rq);
+}
+
#ifdef CONFIG_BLK_DEV_ZONED
static inline unsigned int blk_rq_zone_no(struct request *rq)
{
--
