[PATCH 3.12 003/182] iser-target: Match FRMR descriptors to available session tags

Jiri Slaby
2014-05-13T10:02:52Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit f46d6a8a01d6bbd83a97140f30a72a89b038807b upstream.

This patch changes isert_conn_create_fastreg_pool() to follow
logic in iscsi_target_locate_portal() for determining how many
FRMR descriptors to allocate based upon the number of possible
per-session command slots that are available.

This addresses an OOPs in isert_reg_rdma() where due to the
use of ISCSI_DEF_XMIT_CMDS_MAX could end up returning a bogus
fast_reg_descriptor when the number of active tags exceeded
the original hardcoded max.

Note this also includes moving isert_conn_create_fastreg_pool()
from isert_connect_request() to isert_put_login_tx() before
posting the final Login Response PDU in order to determine the
se_nacl->queue_depth (eg: number of tags) per session the target
will be enforcing.

v2 changes:
- Move isert_conn->conn_fr_pool list_head init into
isert_conn_request()
v3 changes:
- Drop unnecessary list_empty() check in isert_reg_rdma()
(Sagi)

(Fix up v3.12.y context changes - nab)

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/infiniband/ulp/isert/ib_isert.c | 34 +++++++++++++++++++--------------
1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 09c71293ab4b..65f979979005 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -426,11 +426,18 @@ isert_conn_create_frwr_pool(struct isert_conn *isert_conn)
{
struct fast_reg_descriptor *fr_desc;
struct isert_device *device = isert_conn->conn_device;
- int i, ret;
+ struct se_session *se_sess = isert_conn->conn->sess->se_sess;
+ struct se_node_acl *se_nacl = se_sess->se_node_acl;
+ int i, ret, tag_num;
+ /*
+ * Setup the number of FRMRs based upon the number of tags
+ * available to session in iscsi_target_locate_portal().
+ */
+ tag_num = max_t(u32, ISCSIT_MIN_TAGS, se_nacl->queue_depth);
+ tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;

- INIT_LIST_HEAD(&isert_conn->conn_frwr_pool);
isert_conn->conn_frwr_pool_size = 0;
- for (i = 0; i < ISCSI_DEF_XMIT_CMDS_MAX; i++) {
+ for (i = 0; i < tag_num; i++) {
fr_desc = kzalloc(sizeof(*fr_desc), GFP_KERNEL);
if (!fr_desc) {
pr_err("Failed to allocate fast_reg descriptor\n");
@@ -502,6 +509,7 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
kref_get(&isert_conn->conn_kref);
mutex_init(&isert_conn->conn_mutex);
spin_lock_init(&isert_conn->conn_lock);
+ INIT_LIST_HEAD(&isert_conn->conn_frwr_pool);

cma_id->context = isert_conn;
isert_conn->conn_cm_id = cma_id;
@@ -559,14 +567,6 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
isert_conn->conn_pd = device->dev_pd;
isert_conn->conn_mr = device->dev_mr;

- if (device->use_frwr) {
- ret = isert_conn_create_frwr_pool(isert_conn);
- if (ret) {
- pr_err("Conn: %p failed to create frwr_pool\n", isert_conn);
- goto out_frwr;
- }
- }
-
ret = isert_conn_setup_qp(isert_conn, cma_id);
if (ret)
goto out_conn_dev;
@@ -580,9 +580,6 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
return 0;

out_conn_dev:
- if (device->use_frwr)
- isert_conn_free_frwr_pool(isert_conn);
-out_frwr:
isert_device_try_release(device);
out_rsp_dma_map:
ib_dma_unmap_single(ib_dev, isert_conn->login_rsp_dma,
@@ -930,6 +927,15 @@ isert_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
}
if (!login->login_failed) {
if (login->login_complete) {
+ if (isert_conn->conn_device->use_frwr) {
+ ret = isert_conn_create_frwr_pool(isert_conn);
+ if (ret) {
+ pr_err("Conn: %p failed to create"
+ " frwr_pool\n", isert_conn);
+ return ret;
+ }
+ }
+
ret = isert_alloc_rx_descriptors(isert_conn);
if (ret)
return ret;
--
1.9.3