ib_srpt: Convert I/O path to target_submit_cmd + drop legacy ioctx->kref

This patch converts the main srpt_handle_cmd() I/O path to use modern
target_submit_cmd() with TARGET_SCF_ACK_KREF flag usage.  This includes
dropping the original internal ioctx->kref + srpt_put_send_ioctx() usage
in favor of target_put_sess_cmd() w/ se_cmd_t->cmd_kref within ib_srpt
response callbacks.

It also updates srpt_abort_cmd() to call target_put_sess_cmd() for
completion of aborted commands, and adds target_wait_for_sess_cmds() into
srpt_release_channel_work() to allow outstanding I/O to complete during
session shutdown.

Also, go ahead and update srpt_handle_tsk_mgmt() to make the remaining
transport_init_se_cmd() to setup the ioctx->cmd with se_tmr_req.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index e6fafc6..77b6368 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1269,7 +1269,6 @@ static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
                return ioctx;
 
        BUG_ON(ioctx->ch != ch);
-       kref_init(&ioctx->kref);
        spin_lock_init(&ioctx->spinlock);
        ioctx->state = SRPT_STATE_NEW;
        ioctx->n_rbuf = 0;
@@ -1291,39 +1290,6 @@ static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
 }
 
 /**
- * srpt_put_send_ioctx() - Free up resources.
- */
-static void srpt_put_send_ioctx(struct srpt_send_ioctx *ioctx)
-{
-       struct srpt_rdma_ch *ch;
-       unsigned long flags;
-
-       BUG_ON(!ioctx);
-       ch = ioctx->ch;
-       BUG_ON(!ch);
-
-       WARN_ON(srpt_get_cmd_state(ioctx) != SRPT_STATE_DONE);
-
-       srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
-       transport_generic_free_cmd(&ioctx->cmd, 0);
-
-       if (ioctx->n_rbuf > 1) {
-               kfree(ioctx->rbufs);
-               ioctx->rbufs = NULL;
-               ioctx->n_rbuf = 0;
-       }
-
-       spin_lock_irqsave(&ch->spinlock, flags);
-       list_add(&ioctx->free_list, &ch->free_list);
-       spin_unlock_irqrestore(&ch->spinlock, flags);
-}
-
-static void srpt_put_send_ioctx_kref(struct kref *kref)
-{
-       srpt_put_send_ioctx(container_of(kref, struct srpt_send_ioctx, kref));
-}
-
-/**
  * srpt_abort_cmd() - Abort a SCSI command.
  * @ioctx:   I/O context associated with the SCSI command.
  * @context: Preferred execution context.
@@ -1359,8 +1325,14 @@ static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
        }
        spin_unlock_irqrestore(&ioctx->spinlock, flags);
 
-       if (state == SRPT_STATE_DONE)
+       if (state == SRPT_STATE_DONE) {
+               struct srpt_rdma_ch *ch = ioctx->ch;
+
+               BUG_ON(ch->sess == NULL);
+
+               target_put_sess_cmd(ch->sess, &ioctx->cmd);
                goto out;
+       }
 
        pr_debug("Aborting cmd with state %d and tag %lld\n", state,
                 ioctx->tag);
@@ -1395,11 +1367,11 @@ static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
                spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
                ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
                spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
-               kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
+               target_put_sess_cmd(ioctx->ch->sess, &ioctx->cmd);
                break;
        case SRPT_STATE_MGMT_RSP_SENT:
                srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
-               kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
+               target_put_sess_cmd(ioctx->ch->sess, &ioctx->cmd);
                break;
        default:
                WARN_ON("ERROR: unexpected command state");
@@ -1457,11 +1429,13 @@ static void srpt_handle_send_comp(struct srpt_rdma_ch *ch,
                    && state != SRPT_STATE_DONE))
                pr_debug("state = %d\n", state);
 
-       if (state != SRPT_STATE_DONE)
-               kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
-       else
+       if (state != SRPT_STATE_DONE) {
+               srpt_unmap_sg_to_ib_sge(ch, ioctx);
+               transport_generic_free_cmd(&ioctx->cmd, 0);
+       } else {
                printk(KERN_ERR "IB completion has been received too late for"
                       " wr_id = %u.\n", ioctx->ioctx.index);
+       }
 }
 
 /**
@@ -1712,10 +1686,10 @@ out_err:
 
 static int srpt_check_stop_free(struct se_cmd *cmd)
 {
-       struct srpt_send_ioctx *ioctx;
+       struct srpt_send_ioctx *ioctx = container_of(cmd,
+                               struct srpt_send_ioctx, cmd);
 
-       ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
-       return kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
+       return target_put_sess_cmd(ioctx->ch->sess, &ioctx->cmd);
 }
 
 /**
@@ -1731,11 +1705,11 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
        u64 data_len;
        enum dma_data_direction dir;
        sense_reason_t ret;
+       int rc;
 
        BUG_ON(!send_ioctx);
 
        srp_cmd = recv_ioctx->ioctx.buf;
-       kref_get(&send_ioctx->kref);
        cmd = &send_ioctx->cmd;
        send_ioctx->tag = srp_cmd->tag;
 
@@ -1759,30 +1733,18 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
                printk(KERN_ERR "0x%llx: parsing SRP descriptor table failed.\n",
                       srp_cmd->tag);
                ret = TCM_INVALID_CDB_FIELD;
-               kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
                goto send_sense;
        }
 
-       cmd->data_length = data_len;
-       cmd->data_direction = dir;
        unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_cmd->lun,
                                       sizeof(srp_cmd->lun));
-       ret = transport_lookup_cmd_lun(cmd, unpacked_lun);
-       if (ret) {
-               kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
+       rc = target_submit_cmd(cmd, ch->sess, srp_cmd->cdb,
+                       &send_ioctx->sense_data[0], unpacked_lun, data_len,
+                       MSG_SIMPLE_TAG, dir, TARGET_SCF_ACK_KREF);
+       if (rc != 0) {
+               ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
                goto send_sense;
        }
-       ret = target_setup_cmd_from_cdb(cmd, srp_cmd->cdb);
-       if (ret) {
-               kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
-               if (ret == TCM_RESERVATION_CONFLICT) {
-                       srpt_queue_status(cmd);
-                       return 0;
-               }
-               goto send_sense;
-       }
-
-       transport_handle_cdb_direct(cmd);
        return 0;
 
 send_sense:
@@ -1884,6 +1846,9 @@ static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
                        TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
                goto fail;
        }
+       transport_init_se_cmd(&send_ioctx->cmd, &srpt_target->tf_ops, ch->sess,
+                       0, DMA_NONE, MSG_SIMPLE_TAG, send_ioctx->sense_data);
+
        res = core_tmr_alloc_req(cmd, NULL, tcm_tmr, GFP_KERNEL);
        if (res < 0) {
                send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
@@ -1902,11 +1867,9 @@ static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
        if (srp_tsk->tsk_mgmt_func == SRP_TSK_ABORT_TASK)
                srpt_rx_mgmt_fn_tag(send_ioctx, srp_tsk->task_tag);
 
-       kref_get(&send_ioctx->kref);
        transport_generic_handle_tmr(&send_ioctx->cmd);
        return;
 fail:
-       kref_get(&send_ioctx->kref);
        transport_send_check_condition_and_sense(cmd, 0, 0); // XXX:
 }
 
@@ -1949,10 +1912,6 @@ static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
                }
        }
 
-       transport_init_se_cmd(&send_ioctx->cmd, &srpt_target->tf_ops, ch->sess,
-                             0, DMA_NONE, MSG_SIMPLE_TAG,
-                             send_ioctx->sense_data);
-
        switch (srp_cmd->opcode) {
        case SRP_CMD:
                srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
@@ -2358,6 +2317,7 @@ static void srpt_release_channel_work(struct work_struct *w)
 {
        struct srpt_rdma_ch *ch;
        struct srpt_device *sdev;
+       struct se_session *se_sess;
 
        ch = container_of(w, struct srpt_rdma_ch, release_work);
        pr_debug("ch = %p; ch->sess = %p; release_done = %p\n", ch, ch->sess,
@@ -2366,8 +2326,13 @@ static void srpt_release_channel_work(struct work_struct *w)
        sdev = ch->sport->sdev;
        BUG_ON(!sdev);
 
-       transport_deregister_session_configfs(ch->sess);
-       transport_deregister_session(ch->sess);
+       se_sess = ch->sess;
+       BUG_ON(!se_sess);
+
+       target_wait_for_sess_cmds(se_sess, 0);
+
+       transport_deregister_session_configfs(se_sess);
+       transport_deregister_session(se_sess);
        ch->sess = NULL;
 
        srpt_destroy_ch_ib(ch);
@@ -3092,7 +3057,7 @@ static int srpt_queue_response(struct se_cmd *cmd)
                       ioctx->tag);
                srpt_unmap_sg_to_ib_sge(ch, ioctx);
                srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
-               kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
+               target_put_sess_cmd(ioctx->ch->sess, &ioctx->cmd);
        }
 
 out:
@@ -3483,6 +3448,23 @@ static u32 srpt_tpg_get_inst_index(struct se_portal_group *se_tpg)
 
 static void srpt_release_cmd(struct se_cmd *se_cmd)
 {
+       struct srpt_send_ioctx *ioctx = container_of(se_cmd,
+                               struct srpt_send_ioctx, cmd);
+       struct srpt_rdma_ch *ch = ioctx->ch;
+       unsigned long flags;
+
+       WARN_ON(ioctx->state != SRPT_STATE_DONE);
+       WARN_ON(ioctx->mapped_sg_count != 0);
+
+       if (ioctx->n_rbuf > 1) {
+               kfree(ioctx->rbufs);
+               ioctx->rbufs = NULL;
+               ioctx->n_rbuf = 0;
+       }
+
+       spin_lock_irqsave(&ch->spinlock, flags);
+       list_add(&ioctx->free_list, &ch->free_list);
+       spin_unlock_irqrestore(&ch->spinlock, flags);
 }
 
 /**

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h
index 61e52b8..4caf55c 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.h
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.h
@@ -228,7 +228,6 @@ struct srpt_recv_ioctx {
 struct srpt_send_ioctx {
        struct srpt_ioctx       ioctx;
        struct srpt_rdma_ch     *ch;
-       struct kref              kref;
        struct rdma_iu          *rdma_ius;
        struct srp_direct_buf   *rbufs;
        struct srp_direct_buf   single_rbuf;