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nvme-tcp: fix H2CData PDU send accounting (again)

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We should not access request members after the last send, even to
determine if indeed it was the last data payload send. The reason is
that a completion could have arrived and trigger a new execution of the
request which overridden these members. This was fixed by commit
825619b09a ("nvme-tcp: fix possible use-after-completion").

Commit e371af033c broke that assumption again to address cases where
multiple r2t pdus are sent per request. To fix it, we need to record the
request data_sent and data_len and after the payload network send we
reference these counters to determine weather we should advance the
request iterator.

Fixes: e371af033c ("nvme-tcp: fix incorrect h2cdata pdu offset accounting")
Reported-by: Keith Busch <kbusch@kernel.org>
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Sagi Grimberg 2021-10-24 10:43:31 +03:00 committed by Christoph Hellwig
parent 926245c7d2
commit 25e1f67eda
1 changed files with 3 additions and 1 deletions
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4
drivers/nvme/host/tcp.c
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@ -926,12 +926,14 @@ static void nvme_tcp_fail_request(struct nvme_tcp_request *req)
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;
while (true) {
struct page *page = nvme_tcp_req_cur_page(req);
size_t offset = nvme_tcp_req_cur_offset(req);
size_t len = nvme_tcp_req_cur_length(req);
bool last = nvme_tcp_pdu_last_send(req, len);
int req_data_sent = req->data_sent;
int ret, flags = MSG_DONTWAIT;
if (last && !queue->data_digest && !nvme_tcp_queue_more(queue))
@ -958,7 +960,7 @@ static int nvme_tcp_try_send_data(struct nvme_tcp_request *req)
* in the request where we don't want to modify it as we may
* compete with the RX path completing the request.
*/
if (req->data_sent + ret < req->data_len)
if (req_data_sent + ret < req_data_len)
nvme_tcp_advance_req(req, ret);
/* fully successful last send in current PDU */