[PATCH for-next v6 5/5] nvme: wire up fixed buffer support for nvme passthrough

Kanchan Joshi
2022-09-08T18:46:05Z

if io_uring sends passthrough command with IORING_URING_CMD_FIXED flag,
use the pre-registered buffer to form the bio.
While at it, modify nvme_submit_user_cmd to take ubuffer as plain integer
argument, and do away with nvme_to_user_ptr conversion in callers.

Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
---
drivers/nvme/host/ioctl.c | 40 ++++++++++++++++++++++++++-------------
1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index cb2fa4db50dd..e47ef12ce047 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -81,9 +81,10 @@ static struct request *nvme_alloc_user_request(struct request_queue *q,
return req;
}

-static int nvme_map_user_request(struct request *req, void __user *ubuffer,
+static int nvme_map_user_request(struct request *req, u64 ubuffer,
unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
- u32 meta_seed, void **metap, bool vec)
+ u32 meta_seed, void **metap, struct io_uring_cmd *ioucmd,
+ bool vec)
{
struct request_queue *q = req->q;
struct nvme_ns *ns = q->queuedata;
@@ -91,20 +92,33 @@ static int nvme_map_user_request(struct request *req, void __user *ubuffer,
struct bio *bio = NULL;
void *meta = NULL;
int ret;
+ bool fixedbufs = ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED);

if (!ubuffer || !bufflen)
return 0;

if (!vec)
- ret = blk_rq_map_user(q, req, NULL, ubuffer, bufflen,
- GFP_KERNEL);
+ if (fixedbufs) {
+ struct iov_iter iter;
+
+ ret = io_uring_cmd_import_fixed(ubuffer, bufflen,
+ rq_data_dir(req), &iter, ioucmd);
+ if (ret < 0)
+ goto out;
+ ret = blk_rq_map_user_bvec(req, &iter);
+
+ } else {
+ ret = blk_rq_map_user(q, req, NULL,
+ nvme_to_user_ptr(ubuffer), bufflen,
+ GFP_KERNEL);
+ }
else {
struct iovec fast_iov[UIO_FASTIOV];
struct iovec *iov = fast_iov;
struct iov_iter iter;

- ret = import_iovec(rq_data_dir(req), ubuffer, bufflen,
- UIO_FASTIOV, &iov, &iter);
+ ret = import_iovec(rq_data_dir(req), nvme_to_user_ptr(ubuffer),
+ bufflen, UIO_FASTIOV, &iov, &iter);
if (ret < 0)
goto out;
ret = blk_rq_map_user_iov(q, req, NULL, &iter, GFP_KERNEL);
@@ -136,7 +150,7 @@ static int nvme_map_user_request(struct request *req, void __user *ubuffer,
}

static int nvme_submit_user_cmd(struct request_queue *q,
- struct nvme_command *cmd, void __user *ubuffer,
+ struct nvme_command *cmd, u64 ubuffer,
unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
u32 meta_seed, u64 *result, unsigned timeout, bool vec)
{
@@ -150,7 +164,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
return PTR_ERR(req);

ret = nvme_map_user_request(req, ubuffer, bufflen, meta_buffer,
- meta_len, meta_seed, &meta, vec);
+ meta_len, meta_seed, &meta, NULL, vec);
if (ret)
goto out;

@@ -228,7 +242,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
c.rw.appmask = cpu_to_le16(io.appmask);

return nvme_submit_user_cmd(ns->queue, &c,
- nvme_to_user_ptr(io.addr), length,
+ io.addr, length,
metadata, meta_len, lower_32_bits(io.slba), NULL, 0,
false);
}
@@ -282,7 +296,7 @@ static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
timeout = msecs_to_jiffies(cmd.timeout_ms);

status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
- nvme_to_user_ptr(cmd.addr), cmd.data_len,
+ cmd.addr, cmd.data_len,
nvme_to_user_ptr(cmd.metadata), cmd.metadata_len,
0, &result, timeout, false);

@@ -328,7 +342,7 @@ static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
timeout = msecs_to_jiffies(cmd.timeout_ms);

status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
- nvme_to_user_ptr(cmd.addr), cmd.data_len,
+ cmd.addr, cmd.data_len,
nvme_to_user_ptr(cmd.metadata), cmd.metadata_len,
0, &cmd.result, timeout, vec);

@@ -472,9 +486,9 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
if (IS_ERR(req))
return PTR_ERR(req);

- ret = nvme_map_user_request(req, nvme_to_user_ptr(d.addr),
+ ret = nvme_map_user_request(req, d.addr,
d.data_len, nvme_to_user_ptr(d.metadata),
- d.metadata_len, 0, &meta, vec);
+ d.metadata_len, 0, &meta, ioucmd, vec);
if (ret)
goto out_err;
req->end_io = nvme_uring_cmd_end_io;
--
2.25.1