[PATCH v3 2/2] nvme-tcp: send H2CData PDUs based on MAXH2CDATA
Varun Prakash
varun at chelsio.com
Tue Nov 23 02:59:22 PST 2021
As per NVMe/TCP specification (revision 1.0a, section 3.6.2.3)
Maximum Host to Controller Data length (MAXH2CDATA): Specifies the
maximum number of PDU-Data bytes per H2CData PDU in bytes. This value
is a multiple of dwords and should be no less than 4,096.
Current code sets H2CData PDU data_length to r2t_length,
it does not check MAXH2CDATA value. Fix this by setting H2CData PDU
data_length to min(req->h2cdata_left, queue->maxh2cdata).
Also validate MAXH2CDATA value returned by target in ICResp PDU,
if it is not a multiple of dword or if it is less than 4096 return
-EINVAL from nvme_tcp_init_connection().
Signed-off-by: Varun Prakash <varun at chelsio.com>
---
v3:
- added h2cdata_left, h2cdata_offset
- removed unnecessary local variables from nvme_tcp_try_send_data_pdu()
v2:
- removed nvme_tcp_update_h2c_data_pdu()
- used sock_no_sendpage() instead of kernel_sendmsg()
drivers/nvme/host/tcp.c | 63 +++++++++++++++++++++++++++++++++++++-----------
include/linux/nvme-tcp.h | 1 +
2 files changed, 50 insertions(+), 14 deletions(-)
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 5f8ad4d..0065892 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -44,6 +44,8 @@ struct nvme_tcp_request {
u32 data_len;
u32 pdu_len;
u32 pdu_sent;
+ u32 h2cdata_left;
+ u32 h2cdata_offset;
u16 ttag;
__le16 status;
struct list_head entry;
@@ -95,6 +97,7 @@ struct nvme_tcp_queue {
struct nvme_tcp_request *request;
int queue_size;
+ u32 maxh2cdata;
size_t cmnd_capsule_len;
struct nvme_tcp_ctrl *ctrl;
unsigned long flags;
@@ -572,23 +575,26 @@ static int nvme_tcp_handle_comp(struct nvme_tcp_queue *queue,
return ret;
}
-static void nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
- struct nvme_tcp_r2t_pdu *pdu)
+static void nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req)
{
struct nvme_tcp_data_pdu *data = req->pdu;
struct nvme_tcp_queue *queue = req->queue;
struct request *rq = blk_mq_rq_from_pdu(req);
+ u32 h2cdata_sent = req->pdu_len;
u8 hdgst = nvme_tcp_hdgst_len(queue);
u8 ddgst = nvme_tcp_ddgst_len(queue);
req->state = NVME_TCP_SEND_H2C_PDU;
req->offset = 0;
- req->pdu_len = le32_to_cpu(pdu->r2t_length);
+ req->pdu_len = min(req->h2cdata_left, queue->maxh2cdata);
req->pdu_sent = 0;
+ req->h2cdata_left -= req->pdu_len;
+ req->h2cdata_offset += h2cdata_sent;
memset(data, 0, sizeof(*data));
data->hdr.type = nvme_tcp_h2c_data;
- data->hdr.flags = NVME_TCP_F_DATA_LAST;
+ if (!req->h2cdata_left)
+ data->hdr.flags = NVME_TCP_F_DATA_LAST;
if (queue->hdr_digest)
data->hdr.flags |= NVME_TCP_F_HDGST;
if (queue->data_digest)
@@ -597,9 +603,9 @@ static void nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
data->hdr.pdo = data->hdr.hlen + hdgst;
data->hdr.plen =
cpu_to_le32(data->hdr.hlen + hdgst + req->pdu_len + ddgst);
- data->ttag = pdu->ttag;
+ data->ttag = req->ttag;
data->command_id = nvme_cid(rq);
- data->data_offset = pdu->r2t_offset;
+ data->data_offset = cpu_to_le32(req->h2cdata_offset);
data->data_length = cpu_to_le32(req->pdu_len);
}
@@ -609,6 +615,7 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
struct nvme_tcp_request *req;
struct request *rq;
u32 r2t_length = le32_to_cpu(pdu->r2t_length);
+ u32 r2t_offset = le32_to_cpu(pdu->r2t_offset);
rq = nvme_find_rq(nvme_tcp_tagset(queue), pdu->command_id);
if (!rq) {
@@ -633,14 +640,19 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
return -EPROTO;
}
- if (unlikely(le32_to_cpu(pdu->r2t_offset) < req->data_sent)) {
+ if (unlikely(r2t_offset < req->data_sent)) {
dev_err(queue->ctrl->ctrl.device,
"req %d unexpected r2t offset %u (expected %zu)\n",
- rq->tag, le32_to_cpu(pdu->r2t_offset), req->data_sent);
+ rq->tag, r2t_offset, req->data_sent);
return -EPROTO;
}
- nvme_tcp_setup_h2c_data_pdu(req, pdu);
+ req->pdu_len = 0;
+ req->h2cdata_left = r2t_length;
+ req->h2cdata_offset = r2t_offset;
+ req->ttag = pdu->ttag;
+
+ nvme_tcp_setup_h2c_data_pdu(req);
nvme_tcp_queue_request(req, false, true);
return 0;
@@ -920,6 +932,7 @@ static int nvme_tcp_try_send_data(struct nvme_tcp_request *req)
{
struct nvme_tcp_queue *queue = req->queue;
int req_data_len = req->data_len;
+ u32 h2cdata_left = req->h2cdata_left;
while (true) {
struct page *page = nvme_tcp_req_cur_page(req);
@@ -964,7 +977,10 @@ static int nvme_tcp_try_send_data(struct nvme_tcp_request *req)
req->state = NVME_TCP_SEND_DDGST;
req->offset = 0;
} else {
- nvme_tcp_done_send_req(queue);
+ if (h2cdata_left)
+ nvme_tcp_setup_h2c_data_pdu(req);
+ else
+ nvme_tcp_done_send_req(queue);
}
return 1;
}
@@ -1022,9 +1038,14 @@ static int nvme_tcp_try_send_data_pdu(struct nvme_tcp_request *req)
if (queue->hdr_digest && !req->offset)
nvme_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
- ret = kernel_sendpage(queue->sock, virt_to_page(pdu),
- offset_in_page(pdu) + req->offset, len,
- MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
+ if (!req->h2cdata_left)
+ ret = kernel_sendpage(queue->sock, virt_to_page(pdu),
+ offset_in_page(pdu) + req->offset, len,
+ MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
+ else
+ ret = sock_no_sendpage(queue->sock, virt_to_page(pdu),
+ offset_in_page(pdu) + req->offset, len,
+ MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
if (unlikely(ret <= 0))
return ret;
@@ -1044,6 +1065,7 @@ static int nvme_tcp_try_send_ddgst(struct nvme_tcp_request *req)
{
struct nvme_tcp_queue *queue = req->queue;
size_t offset = req->offset;
+ u32 h2cdata_left = req->h2cdata_left;
int ret;
struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
struct kvec iov = {
@@ -1061,7 +1083,10 @@ static int nvme_tcp_try_send_ddgst(struct nvme_tcp_request *req)
return ret;
if (offset + ret == NVME_TCP_DIGEST_LENGTH) {
- nvme_tcp_done_send_req(queue);
+ if (h2cdata_left)
+ nvme_tcp_setup_h2c_data_pdu(req);
+ else
+ nvme_tcp_done_send_req(queue);
return 1;
}
@@ -1247,6 +1272,7 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
struct msghdr msg = {};
struct kvec iov;
bool ctrl_hdgst, ctrl_ddgst;
+ u32 maxh2cdata;
int ret;
icreq = kzalloc(sizeof(*icreq), GFP_KERNEL);
@@ -1330,6 +1356,14 @@ static int nvme_tcp_init_connection(struct nvme_tcp_queue *queue)
goto free_icresp;
}
+ maxh2cdata = le32_to_cpu(icresp->maxdata);
+ if ((maxh2cdata % 4) || (maxh2cdata < NVME_TCP_MIN_MAXH2CDATA)) {
+ pr_err("queue %d: invalid maxh2cdata returned %u\n",
+ nvme_tcp_queue_id(queue), maxh2cdata);
+ goto free_icresp;
+ }
+ queue->maxh2cdata = maxh2cdata;
+
ret = 0;
free_icresp:
kfree(icresp);
@@ -2314,6 +2348,7 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns,
req->data_sent = 0;
req->pdu_len = 0;
req->pdu_sent = 0;
+ req->h2cdata_left = 0;
req->data_len = blk_rq_nr_phys_segments(rq) ?
blk_rq_payload_bytes(rq) : 0;
req->curr_bio = rq->bio;
diff --git a/include/linux/nvme-tcp.h b/include/linux/nvme-tcp.h
index 959e0bd..7547015 100644
--- a/include/linux/nvme-tcp.h
+++ b/include/linux/nvme-tcp.h
@@ -12,6 +12,7 @@
#define NVME_TCP_DISC_PORT 8009
#define NVME_TCP_ADMIN_CCSZ SZ_8K
#define NVME_TCP_DIGEST_LENGTH 4
+#define NVME_TCP_MIN_MAXH2CDATA 4096
enum nvme_tcp_pfv {
NVME_TCP_PFV_1_0 = 0x0,
--
2.0.2
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