* [PATCH v2] nvme: add vectored-io support for user-passthru
[not found] <CGME20220131142354epcas5p3ff940846a88ae6fcfd8f9b3acb421913@epcas5p3.samsung.com>
@ 2022-01-31 14:18 ` Kanchan Joshi
2022-02-01 8:02 ` Christoph Hellwig
0 siblings, 1 reply; 4+ messages in thread
From: Kanchan Joshi @ 2022-01-31 14:18 UTC (permalink / raw)
To: hch, kbusch, axboe, kch; +Cc: linux-nvme, joshiiitr
wire up support for passthru that takes an array of buffers (using
iovec).
Exposed via a new ioctl NVME_IOCTL_IO64_CMD_VEC for which -
1. cmd.addr is base address of user iovec array
2. cmd.vec_cnt is count of iovec array elements
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
---
Changes since v1:
- added new ioctl rather than reusing NVME_IOCTL_IO64_CMD (hch)
- dropped block-layer helper and open-coded in nvme instead (hch)
https://lore.kernel.org/linux-nvme/20220127082536.7243-1-joshi.k@samsung.com/
drivers/nvme/host/ioctl.c | 44 +++++++++++++++++++++++++++------
include/uapi/linux/nvme_ioctl.h | 6 ++++-
2 files changed, 42 insertions(+), 8 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 22314962842d..54788b1b098e 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -56,7 +56,7 @@ static void *nvme_add_user_metadata(struct bio *bio, void __user *ubuf,
static int nvme_submit_user_cmd(struct request_queue *q,
struct nvme_command *cmd, void __user *ubuffer,
unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
- u32 meta_seed, u64 *result, unsigned timeout)
+ u32 meta_seed, u64 *result, unsigned timeout, bool vec)
{
bool write = nvme_is_write(cmd);
struct nvme_ns *ns = q->queuedata;
@@ -75,8 +75,22 @@ static int nvme_submit_user_cmd(struct request_queue *q,
nvme_req(req)->flags |= NVME_REQ_USERCMD;
if (ubuffer && bufflen) {
- ret = blk_rq_map_user(q, req, NULL, ubuffer, bufflen,
+ if (!vec)
+ ret = blk_rq_map_user(q, req, NULL, 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);
+ if (ret < 0)
+ goto out;
+ ret = blk_rq_map_user_iov(q, req, NULL, &iter,
+ GFP_KERNEL);
+ kfree(iov);
+ }
if (ret)
goto out;
bio = req->bio;
@@ -170,7 +184,8 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
return nvme_submit_user_cmd(ns->queue, &c,
nvme_to_user_ptr(io.addr), length,
- metadata, meta_len, lower_32_bits(io.slba), NULL, 0);
+ metadata, meta_len, lower_32_bits(io.slba), NULL, 0,
+ false);
}
static bool nvme_validate_passthru_nsid(struct nvme_ctrl *ctrl,
@@ -224,7 +239,7 @@ static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
nvme_to_user_ptr(cmd.addr), cmd.data_len,
nvme_to_user_ptr(cmd.metadata), cmd.metadata_len,
- 0, &result, timeout);
+ 0, &result, timeout, false);
if (status >= 0) {
if (put_user(result, &ucmd->result))
@@ -234,8 +249,8 @@ static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
return status;
}
-static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
- struct nvme_passthru_cmd64 __user *ucmd)
+static int nvme_user_cmd64_common(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+ struct nvme_passthru_cmd64 __user *ucmd, bool vec)
{
struct nvme_passthru_cmd64 cmd;
struct nvme_command c;
@@ -270,7 +285,7 @@ static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
status = nvme_submit_user_cmd(ns ? ns->queue : ctrl->admin_q, &c,
nvme_to_user_ptr(cmd.addr), cmd.data_len,
nvme_to_user_ptr(cmd.metadata), cmd.metadata_len,
- 0, &cmd.result, timeout);
+ 0, &cmd.result, timeout, vec);
if (status >= 0) {
if (put_user(cmd.result, &ucmd->result))
@@ -278,6 +293,19 @@ static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
}
return status;
+
+}
+
+static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+ struct nvme_passthru_cmd64 __user *ucmd)
+{
+ return nvme_user_cmd64_common(ctrl, ns, ucmd, false);
+}
+
+static int nvme_user_cmd64_vec(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
+ struct nvme_passthru_cmd64 __user *ucmd)
+{
+ return nvme_user_cmd64_common(ctrl, ns, ucmd, true);
}
static bool is_ctrl_ioctl(unsigned int cmd)
@@ -341,6 +369,8 @@ static int nvme_ns_ioctl(struct nvme_ns *ns, unsigned int cmd,
return nvme_submit_io(ns, argp);
case NVME_IOCTL_IO64_CMD:
return nvme_user_cmd64(ns->ctrl, ns, argp);
+ case NVME_IOCTL_IO64_CMD_VEC:
+ return nvme_user_cmd64_vec(ns->ctrl, ns, argp);
default:
return -ENOTTY;
}
diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h
index d99b5a772698..b2e43185e3b5 100644
--- a/include/uapi/linux/nvme_ioctl.h
+++ b/include/uapi/linux/nvme_ioctl.h
@@ -55,7 +55,10 @@ struct nvme_passthru_cmd64 {
__u64 metadata;
__u64 addr;
__u32 metadata_len;
- __u32 data_len;
+ union {
+ __u32 data_len; /* for non-vectored io */
+ __u32 vec_cnt; /* for vectored io */
+ };
__u32 cdw10;
__u32 cdw11;
__u32 cdw12;
@@ -78,5 +81,6 @@ struct nvme_passthru_cmd64 {
#define NVME_IOCTL_RESCAN _IO('N', 0x46)
#define NVME_IOCTL_ADMIN64_CMD _IOWR('N', 0x47, struct nvme_passthru_cmd64)
#define NVME_IOCTL_IO64_CMD _IOWR('N', 0x48, struct nvme_passthru_cmd64)
+#define NVME_IOCTL_IO64_CMD_VEC _IOWR('N', 0x49, struct nvme_passthru_cmd64)
#endif /* _UAPI_LINUX_NVME_IOCTL_H */
--
2.25.1
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