From fcf589364f2a106544d79594dcf722d97528031b Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 16 Jan 2018 16:14:15 -0800 Subject: IB/srpt: Don't allow reordering of commands on wait list If a receive I/O context is removed from the wait list and srpt_handle_new_iu() fails to allocate a send I/O context then re-adding the receive I/O context to the wait list can cause reordering. Avoid this by only removing a receive I/O context from the wait list after allocating a send I/O context succeeded. Signed-off-by: Bart Van Assche Signed-off-by: Doug Ledford --- drivers/infiniband/ulp/srpt/ib_srpt.c | 82 ++++++++++++++++++++--------------- drivers/infiniband/ulp/srpt/ib_srpt.h | 2 + 2 files changed, 49 insertions(+), 35 deletions(-) (limited to 'drivers/infiniband/ulp') diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 372f1eb2fa49..5b2e74b1d808 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -1533,39 +1533,39 @@ fail: * srpt_handle_new_iu - process a newly received information unit * @ch: RDMA channel through which the information unit has been received. * @recv_ioctx: Receive I/O context associated with the information unit. - * @send_ioctx: Send I/O context. */ -static void srpt_handle_new_iu(struct srpt_rdma_ch *ch, - struct srpt_recv_ioctx *recv_ioctx, - struct srpt_send_ioctx *send_ioctx) +static bool +srpt_handle_new_iu(struct srpt_rdma_ch *ch, struct srpt_recv_ioctx *recv_ioctx) { + struct srpt_send_ioctx *send_ioctx = NULL; struct srp_cmd *srp_cmd; + bool res = false; + u8 opcode; BUG_ON(!ch); BUG_ON(!recv_ioctx); + if (unlikely(ch->state == CH_CONNECTING)) + goto push; + ib_dma_sync_single_for_cpu(ch->sport->sdev->device, recv_ioctx->ioctx.dma, srp_max_req_size, DMA_FROM_DEVICE); - if (unlikely(ch->state == CH_CONNECTING)) - goto out_wait; - - if (unlikely(ch->state != CH_LIVE)) - return; - srp_cmd = recv_ioctx->ioctx.buf; - if (srp_cmd->opcode == SRP_CMD || srp_cmd->opcode == SRP_TSK_MGMT) { - if (!send_ioctx) { - if (!list_empty(&ch->cmd_wait_list)) - goto out_wait; - send_ioctx = srpt_get_send_ioctx(ch); - } + opcode = srp_cmd->opcode; + if (opcode == SRP_CMD || opcode == SRP_TSK_MGMT) { + send_ioctx = srpt_get_send_ioctx(ch); if (unlikely(!send_ioctx)) - goto out_wait; + goto push; } - switch (srp_cmd->opcode) { + if (!list_empty(&recv_ioctx->wait_list)) { + WARN_ON_ONCE(!ch->processing_wait_list); + list_del_init(&recv_ioctx->wait_list); + } + + switch (opcode) { case SRP_CMD: srpt_handle_cmd(ch, recv_ioctx, send_ioctx); break; @@ -1585,16 +1585,22 @@ static void srpt_handle_new_iu(struct srpt_rdma_ch *ch, pr_err("Received SRP_RSP\n"); break; default: - pr_err("received IU with unknown opcode 0x%x\n", - srp_cmd->opcode); + pr_err("received IU with unknown opcode 0x%x\n", opcode); break; } srpt_post_recv(ch->sport->sdev, ch, recv_ioctx); - return; + res = true; -out_wait: - list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list); +out: + return res; + +push: + if (list_empty(&recv_ioctx->wait_list)) { + WARN_ON_ONCE(ch->processing_wait_list); + list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list); + } + goto out; } static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc) @@ -1609,7 +1615,7 @@ static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc) req_lim = atomic_dec_return(&ch->req_lim); if (unlikely(req_lim < 0)) pr_err("req_lim = %d < 0\n", req_lim); - srpt_handle_new_iu(ch, ioctx, NULL); + srpt_handle_new_iu(ch, ioctx); } else { pr_info_ratelimited("receiving failed for ioctx %p with status %d\n", ioctx, wc->status); @@ -1623,19 +1629,21 @@ static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc) */ static void srpt_process_wait_list(struct srpt_rdma_ch *ch) { - struct srpt_send_ioctx *ioctx; + struct srpt_recv_ioctx *recv_ioctx, *tmp; - while (!list_empty(&ch->cmd_wait_list) && - ch->state >= CH_LIVE && - (ioctx = srpt_get_send_ioctx(ch)) != NULL) { - struct srpt_recv_ioctx *recv_ioctx; + WARN_ON_ONCE(ch->state == CH_CONNECTING); - recv_ioctx = list_first_entry(&ch->cmd_wait_list, - struct srpt_recv_ioctx, - wait_list); - list_del(&recv_ioctx->wait_list); - srpt_handle_new_iu(ch, recv_ioctx, ioctx); + if (list_empty(&ch->cmd_wait_list)) + return; + + WARN_ON_ONCE(ch->processing_wait_list); + ch->processing_wait_list = true; + list_for_each_entry_safe(recv_ioctx, tmp, &ch->cmd_wait_list, + wait_list) { + if (!srpt_handle_new_iu(ch, recv_ioctx)) + break; } + ch->processing_wait_list = false; } /** @@ -2150,6 +2158,8 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); goto free_ring; } + for (i = 0; i < ch->rq_size; i++) + INIT_LIST_HEAD(&ch->ioctx_recv_ring[i]->wait_list); } ret = srpt_create_ch_ib(ch); @@ -2773,8 +2783,10 @@ static int srpt_alloc_srq(struct srpt_device *sdev) sdev->use_srq = true; sdev->srq = srq; - for (i = 0; i < sdev->srq_size; ++i) + for (i = 0; i < sdev->srq_size; ++i) { + INIT_LIST_HEAD(&sdev->ioctx_ring[i]->wait_list); srpt_post_recv(sdev, NULL, sdev->ioctx_ring[i]); + } return 0; } diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h index 59261d5de292..10f9b2667ef2 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.h +++ b/drivers/infiniband/ulp/srpt/ib_srpt.h @@ -261,6 +261,7 @@ enum rdma_ch_state { * @spinlock: Protects free_list and state. * @free_list: Head of list with free send I/O contexts. * @state: channel state. See also enum rdma_ch_state. + * @processing_wait_list: Whether or not cmd_wait_list is being processed. * @ioctx_ring: Send ring. * @ioctx_recv_ring: Receive I/O context ring. * @list: Node in srpt_nexus.ch_list. @@ -295,6 +296,7 @@ struct srpt_rdma_ch { struct list_head list; struct list_head cmd_wait_list; uint16_t pkey; + bool processing_wait_list; struct se_session *sess; u8 sess_name[24]; struct work_struct release_work; -- cgit v1.2.3-59-g8ed1b