target/iscsi: Remove unneeded locking from iscsi_target_tx_thread

When processing immediate queue, we're switching on a local variable
so it's not necessary to lock around it. However, we are modifying
cmd->i_state in two spots, so lock around those parts only.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index e77b045..8428fa5 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3516,15 +3516,11 @@ restart:
                        state = qr->state;
                        kmem_cache_free(lio_qr_cache, qr);
 
-                       spin_lock_bh(&cmd->istate_lock);
                        switch (state) {
                        case ISTATE_SEND_R2T:
-                               spin_unlock_bh(&cmd->istate_lock);
                                ret = iscsit_send_r2t(cmd, conn);
                                break;
                        case ISTATE_REMOVE:
-                               spin_unlock_bh(&cmd->istate_lock);
-
                                if (cmd->data_direction == DMA_TO_DEVICE)
                                        iscsit_stop_dataout_timer(cmd);
 
@@ -3535,13 +3531,11 @@ restart:
                                iscsit_free_cmd(cmd);
                                continue;
                        case ISTATE_SEND_NOPIN_WANT_RESPONSE:
-                               spin_unlock_bh(&cmd->istate_lock);
                                iscsit_mod_nopin_response_timer(conn);
                                ret = iscsit_send_unsolicited_nopin(cmd,
                                                conn, 1);
                                break;
                        case ISTATE_SEND_NOPIN_NO_RESPONSE:
-                               spin_unlock_bh(&cmd->istate_lock);
                                ret = iscsit_send_unsolicited_nopin(cmd,
                                                conn, 0);
                                break;
@@ -3550,7 +3544,6 @@ restart:
                                " 0x%08x, i_state: %d on CID: %hu\n",
                                cmd->iscsi_opcode, cmd->init_task_tag, state,
                                conn->cid);
-                               spin_unlock_bh(&cmd->istate_lock);
                                goto transport_err;
                        }
                        if (ret < 0)
@@ -3561,19 +3554,19 @@ restart:
                                goto transport_err;
                        }
 
-                       spin_lock_bh(&cmd->istate_lock);
                        switch (state) {
                        case ISTATE_SEND_R2T:
-                               spin_unlock_bh(&cmd->istate_lock);
                                spin_lock_bh(&cmd->dataout_timeout_lock);
                                iscsit_start_dataout_timer(cmd, conn);
                                spin_unlock_bh(&cmd->dataout_timeout_lock);
                                break;
                        case ISTATE_SEND_NOPIN_WANT_RESPONSE:
+                               spin_lock_bh(&cmd->istate_lock);
                                cmd->i_state = ISTATE_SENT_NOPIN_WANT_RESPONSE;
                                spin_unlock_bh(&cmd->istate_lock);
                                break;
                        case ISTATE_SEND_NOPIN_NO_RESPONSE:
+                               spin_lock_bh(&cmd->istate_lock);
                                cmd->i_state = ISTATE_SENT_STATUS;
                                spin_unlock_bh(&cmd->istate_lock);
                                break;
@@ -3582,7 +3575,6 @@ restart:
                                        " 0x%08x, i_state: %d on CID: %hu\n",
                                        cmd->iscsi_opcode, cmd->init_task_tag,
                                        state, conn->cid);
-                               spin_unlock_bh(&cmd->istate_lock);
                                goto transport_err;
                        }
                }