block: pass io_comp_batch to rq_end_io_fn callback

Add a third parameter 'const struct io_comp_batch *' to the rq_end_io_fn
callback signature. This allows end_io handlers to access the completion
batch context when requests are completed via blk_mq_end_request_batch().

The io_comp_batch is passed from blk_mq_end_request_batch(), while NULL
is passed from __blk_mq_end_request() and blk_mq_put_rq_ref() which don't
have batch context.

This infrastructure change enables drivers to detect whether they're
being called from a batched completion path (like iopoll) and access
additional context stored in the io_comp_batch.

Update all rq_end_io_fn implementations:
- block/blk-mq.c: blk_end_sync_rq
- block/blk-flush.c: flush_end_io, mq_flush_data_end_io
- drivers/nvme/host/ioctl.c: nvme_uring_cmd_end_io
- drivers/nvme/host/core.c: nvme_keep_alive_end_io
- drivers/nvme/host/pci.c: abort_endio, nvme_del_queue_end, nvme_del_cq_end
- drivers/nvme/target/passthru.c: nvmet_passthru_req_done
- drivers/scsi/scsi_error.c: eh_lock_door_done
- drivers/scsi/sg.c: sg_rq_end_io
- drivers/scsi/st.c: st_scsi_execute_end
- drivers/target/target_core_pscsi.c: pscsi_req_done
- drivers/md/dm-rq.c: end_clone_request

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

4 files changed, 13 insertions, 7 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 7bf228df6001..19b67cf5d550 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1333,7 +1333,8 @@ static void nvme_queue_keep_alive_work(struct nvme_ctrl *ctrl)
 }
 
 static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
-						 blk_status_t status)
+						 blk_status_t status,
+						 const struct io_comp_batch *iob)
 {
 	struct nvme_ctrl *ctrl = rq->end_io_data;
 	unsigned long rtt = jiffies - (rq->deadline - rq->timeout);
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index a9c097dacad6..e45ac0ca174e 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -410,7 +410,8 @@ static void nvme_uring_task_cb(struct io_tw_req tw_req, io_tw_token_t tw)
 }
 
 static enum rq_end_io_ret nvme_uring_cmd_end_io(struct request *req,
-						blk_status_t err)
+						blk_status_t err,
+						const struct io_comp_batch *iob)
 {
 	struct io_uring_cmd *ioucmd = req->end_io_data;
 	struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 065555576d2f..d87c56c62861 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1615,7 +1615,8 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
 	return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
 }
 
-static enum rq_end_io_ret abort_endio(struct request *req, blk_status_t error)
+static enum rq_end_io_ret abort_endio(struct request *req, blk_status_t error,
+				      const struct io_comp_batch *iob)
 {
 	struct nvme_queue *nvmeq = req->mq_hctx->driver_data;
 
@@ -2858,7 +2859,8 @@ out_unlock:
 }
 
 static enum rq_end_io_ret nvme_del_queue_end(struct request *req,
-					     blk_status_t error)
+					     blk_status_t error,
+					     const struct io_comp_batch *iob)
 {
 	struct nvme_queue *nvmeq = req->end_io_data;
 
@@ -2868,14 +2870,15 @@ static enum rq_end_io_ret nvme_del_queue_end(struct request *req,
 }
 
 static enum rq_end_io_ret nvme_del_cq_end(struct request *req,
-					  blk_status_t error)
+					  blk_status_t error,
+					  const struct io_comp_batch *iob)
 {
 	struct nvme_queue *nvmeq = req->end_io_data;
 
 	if (error)
 		set_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags);
 
-	return nvme_del_queue_end(req, error);
+	return nvme_del_queue_end(req, error, iob);
 }
 
 static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index 96648ec2fadb..0823c87637d3 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -247,7 +247,8 @@ static void nvmet_passthru_execute_cmd_work(struct work_struct *w)
 }
 
 static enum rq_end_io_ret nvmet_passthru_req_done(struct request *rq,
-						  blk_status_t blk_status)
+						  blk_status_t blk_status,
+						  const struct io_comp_batch *iob)
 {
 	struct nvmet_req *req = rq->end_io_data;