* [PATCH 1/2] iscsi-target: Fix mutex_trylock usage in iscsit_increment_maxcmdsn
2013-11-13 2:11 [PATCH 0/2] iscsi/iser-target: Fix Nicholas A. Bellinger
@ 2013-11-13 2:11 ` Nicholas A. Bellinger
2013-11-13 2:11 ` [PATCH 2/2] ib_isert: Avoid duplicate iscsit_increment_maxcmdsn call Nicholas A. Bellinger
1 sibling, 0 replies; 3+ messages in thread
From: Nicholas A. Bellinger @ 2013-11-13 2:11 UTC (permalink / raw)
To: target-devel
Cc: linux-scsi, linux-kernel, Moussa Ba, Or Gerlitz, Mike Christie,
Nicholas Bellinger
From: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a >= v3.10 regression bug with mutex_trylock() usage
within iscsit_increment_maxcmdsn(), that was originally added to allow
for a special case where ->cmdsn_mutex was already held from the
iscsit_execute_cmd() exception path for ib_isert.
When !mutex_trylock() was occuring under contention during normal RX/TX
process context codepaths, the bug was manifesting itself as the following
protocol error:
Received CmdSN: 0x000fcbb7 is greater than MaxCmdSN: 0x000fcbb6, protocol error.
Received CmdSN: 0x000fcbb8 is greater than MaxCmdSN: 0x000fcbb6, protocol error.
This patch simply avoids the direct ib_isert callback in lio_queue_status()
for the special iscsi_execute_cmd() exception cases, that allows the problematic
mutex_trylock() usage in iscsit_increment_maxcmdsn() to go away.
Reported-by: Moussa Ba <moussaba@micron.com>
Tested-by: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
drivers/target/iscsi/iscsi_target_configfs.c | 5 +++++
drivers/target/iscsi/iscsi_target_device.c | 6 +-----
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 1eec37c..fde3624 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1790,6 +1790,11 @@ static int lio_queue_status(struct se_cmd *se_cmd)
struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
cmd->i_state = ISTATE_SEND_STATUS;
+
+ if (cmd->se_cmd.scsi_status || cmd->sense_reason) {
+ iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
+ return 0;
+ }
cmd->conn->conn_transport->iscsit_queue_status(cmd->conn, cmd);
return 0;
diff --git a/drivers/target/iscsi/iscsi_target_device.c b/drivers/target/iscsi/iscsi_target_device.c
index 6c7a510..7087c73 100644
--- a/drivers/target/iscsi/iscsi_target_device.c
+++ b/drivers/target/iscsi/iscsi_target_device.c
@@ -58,11 +58,7 @@ void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess
cmd->maxcmdsn_inc = 1;
- if (!mutex_trylock(&sess->cmdsn_mutex)) {
- sess->max_cmd_sn += 1;
- pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
- return;
- }
+ mutex_lock(&sess->cmdsn_mutex);
sess->max_cmd_sn += 1;
pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
mutex_unlock(&sess->cmdsn_mutex);
--
1.7.10.4
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH 2/2] ib_isert: Avoid duplicate iscsit_increment_maxcmdsn call
2013-11-13 2:11 [PATCH 0/2] iscsi/iser-target: Fix Nicholas A. Bellinger
2013-11-13 2:11 ` [PATCH 1/2] iscsi-target: Fix mutex_trylock usage in iscsit_increment_maxcmdsn Nicholas A. Bellinger
@ 2013-11-13 2:11 ` Nicholas A. Bellinger
1 sibling, 0 replies; 3+ messages in thread
From: Nicholas A. Bellinger @ 2013-11-13 2:11 UTC (permalink / raw)
To: target-devel
Cc: linux-scsi, linux-kernel, Moussa Ba, Or Gerlitz, Mike Christie,
Nicholas Bellinger
From: Nicholas Bellinger <nab@linux-iscsi.org>
This patch avoids a duplicate iscsit_increment_maxcmdsn() call for
ISER_IB_RDMA_WRITE within isert_map_rdma() + isert_reg_rdma_frwr(),
which will already be occuring once during isert_put_datain() ->
iscsit_build_rsp_pdu() operation.
It also removes the local conn->stat_sn assignment + increment,
and changes the third parameter to iscsit_build_rsp_pdu() to
signal this should be done by iscsi_target_mode code.
Tested-by: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
drivers/infiniband/ulp/isert/ib_isert.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index bbd86e8..5661075 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -2029,8 +2029,6 @@ isert_map_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
if (wr->iser_ib_op == ISER_IB_RDMA_WRITE) {
data_left = se_cmd->data_length;
- iscsit_increment_maxcmdsn(cmd, conn->sess);
- cmd->stat_sn = conn->stat_sn++;
} else {
sg_off = cmd->write_data_done / PAGE_SIZE;
data_left = se_cmd->data_length - cmd->write_data_done;
@@ -2242,8 +2240,6 @@ isert_reg_rdma_frwr(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
if (wr->iser_ib_op == ISER_IB_RDMA_WRITE) {
data_left = se_cmd->data_length;
- iscsit_increment_maxcmdsn(cmd, conn->sess);
- cmd->stat_sn = conn->stat_sn++;
} else {
sg_off = cmd->write_data_done / PAGE_SIZE;
data_left = se_cmd->data_length - cmd->write_data_done;
@@ -2352,7 +2348,7 @@ isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
* Build isert_conn->tx_desc for iSCSI response PDU and attach
*/
isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
- iscsit_build_rsp_pdu(cmd, conn, false, (struct iscsi_scsi_rsp *)
+ iscsit_build_rsp_pdu(cmd, conn, true, (struct iscsi_scsi_rsp *)
&isert_cmd->tx_desc.iscsi_header);
isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
isert_init_send_wr(isert_conn, isert_cmd,
--
1.7.10.4
^ permalink raw reply [flat|nested] 3+ messages in thread