[PATCH RFC 3/5] lightnvm: add sync support for submit_io

["Matias Bjørling" <m@bjorling.me>]

Allow read and write I/Os to be issued synchronous. Users include the
LightNVM core to implement system block support and similar.

Signed-off-by: Matias Bjørling <m@bjorling.me>
---
 drivers/nvme/host/lightnvm.c | 7 +++++++
 include/linux/lightnvm.h     | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 15f2acb..1454e53 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -496,6 +496,13 @@ static int nvme_nvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 	rq->cmd_len = sizeof(struct nvme_nvm_command);
 	rq->special = (void *)0;
 
+	if (rqd->flags & NVM_IO_F_SYNC) {
+		int err = blk_execute_rq(q, NULL, rq, 0);
+		kfree(cmd);
+		blk_mq_free_request(rq);
+		return err;
+	}
+
 	rq->end_io_data = rqd;
 
 	blk_execute_rq_nowait(q, NULL, rq, 0, nvme_nvm_end_io);
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 2fd6871..770278a 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -60,6 +60,9 @@ enum {
 	NVM_BLK_T_BAD		= 0x1,
 	NVM_BLK_T_DEV		= 0x2,
 	NVM_BLK_T_HOST		= 0x4,
+
+	/* NVM Request Flags */
+	NVM_IO_F_SYNC		= 0x1,
 };
 
 struct nvm_id_group {
-- 
2.1.4