[RFC 11/13] nvme: enable bio-cache for fixed-buffer passthru

[Kanchan Joshi]

Since we do submission/completion in task, we can have this up.
Add a bio-set for nvme as we need that for bio-cache.

Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
Signed-off-by: Anuj Gupta <anuj20.g at samsung.com>
---
 block/blk-map.c           | 4 ++--
 drivers/nvme/host/core.c  | 9 +++++++++
 drivers/nvme/host/ioctl.c | 6 ++++--
 drivers/nvme/host/nvme.h  | 1 +
 include/linux/blk-mq.h    | 2 +-
 5 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/block/blk-map.c b/block/blk-map.c
index 9aa9864eab55..e3e28b628fba 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -580,7 +580,7 @@ EXPORT_SYMBOL(blk_rq_map_user);
 
 /* Unlike blk_rq_map_user () this is only for fixed-buffer async passthrough. */
 int blk_rq_map_user_fixedb(struct request_queue *q, struct request *rq,
-		     u64 ubuf, unsigned long len, gfp_t gfp_mask,
+		     u64 ubuf, unsigned long len, struct bio_set *bs,
 		     struct io_uring_cmd *ioucmd)
 {
 	struct iov_iter iter;
@@ -604,7 +604,7 @@ int blk_rq_map_user_fixedb(struct request_queue *q, struct request *rq,
 	if (nr_segs > queue_max_segments(q))
 		return -EINVAL;
 	/* no iovecs to alloc, as we already have a BVEC iterator */
-	bio = bio_alloc(gfp_mask, 0);
+	bio = bio_from_cache(0, bs);
 	if (!bio)
 		return -ENOMEM;
 
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index bce2e93d14a3..0c231946a310 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -30,6 +30,9 @@
 
 #define NVME_MINORS		(1U << MINORBITS)
 
+#define NVME_BIO_POOL_SZ	(4)
+struct bio_set nvme_bio_pool;
+
 unsigned int admin_timeout = 60;
 module_param(admin_timeout, uint, 0644);
 MODULE_PARM_DESC(admin_timeout, "timeout in seconds for admin commands");
@@ -4793,6 +4796,11 @@ static int __init nvme_core_init(void)
 		goto unregister_generic_ns;
 	}
 
+	result = bioset_init(&nvme_bio_pool, NVME_BIO_POOL_SZ, 0,
+			BIOSET_NEED_BVECS | BIOSET_PERCPU_CACHE);
+	if (result < 0)
+		goto unregister_generic_ns;
+
 	return 0;
 
 unregister_generic_ns:
@@ -4815,6 +4823,7 @@ static int __init nvme_core_init(void)
 
 static void __exit nvme_core_exit(void)
 {
+	bioset_exit(&nvme_bio_pool);
 	class_destroy(nvme_ns_chr_class);
 	class_destroy(nvme_subsys_class);
 	class_destroy(nvme_class);
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index dc6a5f1b81ca..013ff9baa78e 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -43,6 +43,7 @@ static void nvme_pt_task_cb(struct io_uring_cmd *ioucmd)
 	struct request *req = cmd->req;
 	int status;
 	u64 result;
+	struct bio *bio = req->bio;
 
 	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
 		status = -EINTR;
@@ -52,6 +53,7 @@ static void nvme_pt_task_cb(struct io_uring_cmd *ioucmd)
 
 	/* we can free request */
 	blk_mq_free_request(req);
+	blk_rq_unmap_user(bio);
 
 	if (cmd->meta) {
 		if (status)
@@ -73,9 +75,9 @@ static void nvme_end_async_pt(struct request *req, blk_status_t err)
 	struct bio *bio = cmd->bio;
 
 	cmd->req = req;
+	req->bio = bio;
 	/* this takes care of setting up task-work */
 	io_uring_cmd_complete_in_task(ioucmd, nvme_pt_task_cb);
-	blk_rq_unmap_user(bio);
 }
 
 static void nvme_setup_uring_cmd_data(struct request *rq,
@@ -164,7 +166,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
 					bufflen, GFP_KERNEL);
 		else
 			ret = blk_rq_map_user_fixedb(q, req, ubuffer, bufflen,
-					GFP_KERNEL, ioucmd);
+					&nvme_bio_pool, ioucmd);
 		if (ret)
 			goto out;
 		bio = req->bio;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 9a901b954a87..6bbb8ed868eb 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -47,6 +47,7 @@ extern unsigned int admin_timeout;
 extern struct workqueue_struct *nvme_wq;
 extern struct workqueue_struct *nvme_reset_wq;
 extern struct workqueue_struct *nvme_delete_wq;
+extern struct bio_set nvme_bio_pool;
 
 /*
  * List of workarounds for devices that required behavior not specified in
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index a82b054eebde..e35a5d835b1f 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -923,7 +923,7 @@ struct rq_map_data {
 int blk_rq_map_user(struct request_queue *, struct request *,
 		struct rq_map_data *, void __user *, unsigned long, gfp_t);
 int blk_rq_map_user_fixedb(struct request_queue *, struct request *,
-		     u64 ubuf, unsigned long, gfp_t,
+		     u64 ubuf, unsigned long, struct bio_set *,
 		     struct io_uring_cmd *);
 int blk_rq_map_user_iov(struct request_queue *, struct request *,
 		struct rq_map_data *, const struct iov_iter *, gfp_t);
-- 
2.25.1