From: Bart Van Assche Date: Wed, 17 Jan 2018 00:14:13 +0000 (-0800) Subject: IB/srpt: Fix login-related race conditions X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=db7683d7deb25d6edc9c59ac45c56c6a48a45514;p=openwrt%2Fstaging%2Fblogic.git IB/srpt: Fix login-related race conditions Make sure that sport->mutex is not released between the duplicate channel check, adding a channel to the channel list and performing the sport enabled check. Avoid that srpt_disconnect_ch() can be invoked concurrently with the ib_send_cm_rep() call by srpt_cm_req_recv(). Signed-off-by: Bart Van Assche Signed-off-by: Doug Ledford --- diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 866ff4be553c..6278c4448061 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -2040,7 +2040,7 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, struct srpt_rdma_ch *ch; char i_port_id[36]; u32 it_iu_len; - int i, ret = 0; + int i, ret; WARN_ON_ONCE(irqs_disabled()); @@ -2063,69 +2063,43 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, goto out; } + ret = -ENOMEM; rsp = kzalloc(sizeof(*rsp), GFP_KERNEL); rej = kzalloc(sizeof(*rej), GFP_KERNEL); rep_param = kzalloc(sizeof(*rep_param), GFP_KERNEL); - - if (!rsp || !rej || !rep_param) { - ret = -ENOMEM; + if (!rsp || !rej || !rep_param) goto out; - } + ret = -EINVAL; if (it_iu_len > srp_max_req_size || it_iu_len < 64) { rej->reason = cpu_to_be32( - SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE); - ret = -EINVAL; - pr_err("rejected SRP_LOGIN_REQ because its" - " length (%d bytes) is out of range (%d .. %d)\n", + SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE); + pr_err("rejected SRP_LOGIN_REQ because its length (%d bytes) is out of range (%d .. %d)\n", it_iu_len, 64, srp_max_req_size); goto reject; } if (!sport->enabled) { - rej->reason = cpu_to_be32( - SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); - ret = -EINVAL; - pr_err("rejected SRP_LOGIN_REQ because the target port" - " has not yet been enabled\n"); + rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); + pr_info("rejected SRP_LOGIN_REQ because target port %s_%d has not yet been enabled\n", + sport->sdev->device->name, param->port); goto reject; } - if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) { - struct srpt_rdma_ch *ch2; - - rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN; - - mutex_lock(&sport->mutex); - list_for_each_entry(ch2, &nexus->ch_list, list) { - if (srpt_disconnect_ch(ch2) < 0) - continue; - pr_info("Relogin - closed existing channel %s\n", - ch2->sess_name); - rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_TERMINATED; - } - mutex_unlock(&sport->mutex); - } else { - rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED; - } - if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid) || *(__be64 *)(req->target_port_id + 8) != cpu_to_be64(srpt_service_guid)) { rej->reason = cpu_to_be32( - SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL); - ret = -ENOMEM; - pr_err("rejected SRP_LOGIN_REQ because it" - " has an invalid target port identifier.\n"); + SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL); + pr_err("rejected SRP_LOGIN_REQ because it has an invalid target port identifier.\n"); goto reject; } + ret = -ENOMEM; ch = kzalloc(sizeof(*ch), GFP_KERNEL); if (!ch) { - rej->reason = cpu_to_be32( - SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); - pr_err("rejected SRP_LOGIN_REQ because no memory.\n"); - ret = -ENOMEM; + rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); + pr_err("rejected SRP_LOGIN_REQ because out of memory.\n"); goto reject; } @@ -2153,8 +2127,11 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size, sizeof(*ch->ioctx_ring[0]), ch->max_rsp_size, DMA_TO_DEVICE); - if (!ch->ioctx_ring) + if (!ch->ioctx_ring) { + pr_err("rejected SRP_LOGIN_REQ because creating a new QP SQ ring failed.\n"); + rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); goto free_ch; + } INIT_LIST_HEAD(&ch->free_list); for (i = 0; i < ch->rq_size; i++) { @@ -2176,20 +2153,10 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, } ret = srpt_create_ch_ib(ch); - if (ret) { - rej->reason = cpu_to_be32( - SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); - pr_err("rejected SRP_LOGIN_REQ because creating" - " a new RDMA channel failed.\n"); - goto free_recv_ring; - } - - ret = srpt_ch_qp_rtr(ch, ch->qp); if (ret) { rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); - pr_err("rejected SRP_LOGIN_REQ because enabling" - " RTR failed (error code = %d)\n", ret); - goto destroy_ib; + pr_err("rejected SRP_LOGIN_REQ because creating a new RDMA channel failed.\n"); + goto free_recv_ring; } srpt_format_guid(ch->sess_name, sizeof(ch->sess_name), @@ -2214,11 +2181,51 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, TARGET_PROT_NORMAL, i_port_id + 2, ch, NULL); if (IS_ERR_OR_NULL(ch->sess)) { - pr_info("Rejected login because no ACL has been configured yet for initiator %s.\n", - ch->sess_name); - rej->reason = cpu_to_be32((PTR_ERR(ch->sess) == -ENOMEM) ? + ret = PTR_ERR(ch->sess); + pr_info("Rejected login for initiator %s: ret = %d.\n", + ch->sess_name, ret); + rej->reason = cpu_to_be32(ret == -ENOMEM ? SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES : SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED); + goto reject; + } + + mutex_lock(&sport->mutex); + + if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) { + struct srpt_rdma_ch *ch2; + + rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN; + + list_for_each_entry(ch2, &nexus->ch_list, list) { + if (srpt_disconnect_ch(ch2) < 0) + continue; + pr_info("Relogin - closed existing channel %s\n", + ch2->sess_name); + rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_TERMINATED; + } + } else { + rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED; + } + + list_add_tail_rcu(&ch->list, &nexus->ch_list); + + if (!sport->enabled) { + rej->reason = cpu_to_be32( + SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); + pr_info("rejected SRP_LOGIN_REQ because target %s_%d is not enabled\n", + sdev->device->name, param->port); + mutex_unlock(&sport->mutex); + goto reject; + } + + mutex_unlock(&sport->mutex); + + ret = srpt_ch_qp_rtr(ch, ch->qp); + if (ret) { + rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); + pr_err("rejected SRP_LOGIN_REQ because enabling RTR failed (error code = %d)\n", + ret); goto destroy_ib; } @@ -2231,8 +2238,8 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, rsp->max_it_iu_len = req->req_it_iu_len; rsp->max_ti_iu_len = req->req_it_iu_len; ch->max_ti_iu_len = it_iu_len; - rsp->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT - | SRP_BUF_FORMAT_INDIRECT); + rsp->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT | + SRP_BUF_FORMAT_INDIRECT); rsp->req_lim_delta = cpu_to_be32(ch->rq_size); atomic_set(&ch->req_lim, ch->rq_size); atomic_set(&ch->req_lim_delta, 0); @@ -2248,24 +2255,30 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id, rep_param->responder_resources = 4; rep_param->initiator_depth = 4; - ret = ib_send_cm_rep(cm_id, rep_param); - if (ret) { - pr_err("sending SRP_LOGIN_REQ response failed" - " (error code = %d)\n", ret); - goto release_channel; - } - + /* + * Hold the sport mutex while accepting a connection to avoid that + * srpt_disconnect_ch() is invoked concurrently with this code. + */ mutex_lock(&sport->mutex); - list_add_tail_rcu(&ch->list, &nexus->ch_list); + if (sport->enabled && ch->state == CH_CONNECTING) + ret = ib_send_cm_rep(cm_id, rep_param); + else + ret = -EINVAL; mutex_unlock(&sport->mutex); - goto out; + switch (ret) { + case 0: + break; + case -EINVAL: + goto reject; + default: + rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES); + pr_err("sending SRP_LOGIN_REQ response failed (error code = %d)\n", + ret); + goto reject; + } -release_channel: - srpt_disconnect_ch(ch); - transport_deregister_session_configfs(ch->sess); - transport_deregister_session(ch->sess); - ch->sess = NULL; + goto out; destroy_ib: srpt_destroy_ch_ib(ch); @@ -2280,13 +2293,18 @@ free_ring: ch->sport->sdev, ch->rq_size, ch->max_rsp_size, DMA_TO_DEVICE); free_ch: + cm_id->context = NULL; kfree(ch); + ch = NULL; + + WARN_ON_ONCE(ret == 0); reject: + pr_info("Rejecting login with reason %#x\n", be32_to_cpu(rej->reason)); rej->opcode = SRP_LOGIN_REJ; rej->tag = req->tag; - rej->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT - | SRP_BUF_FORMAT_INDIRECT); + rej->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT | + SRP_BUF_FORMAT_INDIRECT); ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0, (void *)rej, sizeof(*rej)); @@ -2329,17 +2347,26 @@ static void srpt_cm_rtu_recv(struct srpt_rdma_ch *ch) { int ret; - if (srpt_set_ch_state(ch, CH_LIVE)) { - ret = srpt_ch_qp_rts(ch, ch->qp); - - if (ret == 0) { - /* Trigger wait list processing. */ - ret = srpt_zerolength_write(ch); - WARN_ONCE(ret < 0, "%d\n", ret); - } else { - srpt_close_ch(ch); - } + ret = srpt_ch_qp_rts(ch, ch->qp); + if (ret < 0) { + pr_err("%s-%d: QP transition to RTS failed\n", ch->sess_name, + ch->qp->qp_num); + srpt_close_ch(ch); + return; } + + /* Trigger wait list processing. */ + ret = srpt_zerolength_write(ch); + WARN_ONCE(ret < 0, "%d\n", ret); + + /* + * Note: calling srpt_close_ch() if the transition to the LIVE state + * fails is not necessary since that means that that function has + * already been invoked from another thread. + */ + if (!srpt_set_ch_state(ch, CH_LIVE)) + pr_err("%s-%d: channel transition to LIVE state failed\n", + ch->sess_name, ch->qp->qp_num); } /**