nvme-tcp: fix request PDU size when header digest is enabled

Since commit 61b0ed3be81b ("nvme-tcp: parallelize I/O queue allocation
and startup") the I/O tag set is allocated before the I/O queues.
nvme_tcp_init_request() sizes the PDU with nvme_tcp_hdgst_len(queue),
but queue->hdr_digest is only set later by nvme_tcp_alloc_queue(), so
every I/O PDU is allocated without room for the header digest.

With hdr_digest enabled, the digest is then written 4 bytes past the
PDU, over the header of the next PDU in the page_frag cache, and the
target drops the connection on the first I/O:

  nvmet_tcp: unexpected pdu type 159
  nvmet: ctrl 1 fatal error occurred!

Queues that a later reconnect adds for the first time have the same
problem.

Set queue->hdr_digest when allocating the controller, together with
pf_cache_lock, so it is valid before any request is initialized.

Fixes: 61b0ed3be81b ("nvme-tcp: parallelize I/O queue allocation and startup")
Signed-off-by: Christian Aurich Zanettini Martins <christian.aurichzm@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index dbefe36b0575..191e5811d25e 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2079,7 +2079,6 @@ static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl, int qid,
 		}
 	}
 
-	queue->hdr_digest = nctrl->opts->hdr_digest;
 	queue->data_digest = nctrl->opts->data_digest;
 
 	rcv_pdu_size = sizeof(struct nvme_tcp_rsp_pdu) +
@@ -3229,10 +3228,13 @@ static struct nvme_tcp_ctrl *nvme_tcp_alloc_ctrl(struct device *dev,
 	/*
 	 * The I/O tag set is allocated before the I/O queues, and initializing
 	 * its requests already allocates the PDUs from the page frag caches of
-	 * the queues, so initialize their locks here.
+	 * the queues, sized by their header digest setting, so set up the
+	 * locks and hdr_digest here.
 	 */
-	for (i = 0; i < ctrl->ctrl.queue_count; i++)
+	for (i = 0; i < ctrl->ctrl.queue_count; i++) {
 		mutex_init(&ctrl->queues[i].pf_cache_lock);
+		ctrl->queues[i].hdr_digest = opts->hdr_digest;
+	}
 
 	ctrl->net = get_net(current->nsproxy->net_ns);