[PATCH 4.0 08/22] iser-target: Fix variable-length response error completion

Greg Kroah-Hartman
2015-06-27T01:14:23Z

From: Sagi Grimberg <sagig@mellanox.com>

commit 9253e667ab50fd4611a60e1cdd6a6e05a1d91cf1 upstream.

Since commit "2426bd456a6 target: Report correct response ..."
we might get a command with data_size that does not fit to
the number of allocated data sg elements. Given that we rely on
cmd t_data_nents which might be different than the data_size,
we sometimes receive local length error completion. The correct
approach would be to take the command data_size into account when
constructing the ib sg_list.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jenny Falkovich <jennyf@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/ulp/isert/ib_isert.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -2316,7 +2316,6 @@ isert_build_rdma_wr(struct isert_conn *i
page_off = offset % PAGE_SIZE;

send_wr->sg_list = ib_sge;
- send_wr->num_sge = sg_nents;
send_wr->wr_id = (uintptr_t)&isert_cmd->tx_desc;
/*
* Perform mapping of TCM scatterlist memory ib_sge dma_addr.
@@ -2336,14 +2335,17 @@ isert_build_rdma_wr(struct isert_conn *i
ib_sge->addr, ib_sge->length, ib_sge->lkey);
page_off = 0;
data_left -= ib_sge->length;
+ if (!data_left)
+ break;
ib_sge++;
isert_dbg("Incrementing ib_sge pointer to %p\n", ib_sge);
}

+ send_wr->num_sge = ++i;
isert_dbg("Set outgoing sg_list: %p num_sg: %u from TCM SGLs\n",
send_wr->sg_list, send_wr->num_sge);

- return sg_nents;
+ return send_wr->num_sge;
}

static int