From: Long Li Date: Thu, 23 Nov 2017 00:38:44 +0000 (-0700) Subject: CIFS: SMBD: Implement RDMA memory registration X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=c7398583340a6d82b8bb7f7f21edcde27dc6a898;p=openwrt%2Fstaging%2Fblogic.git CIFS: SMBD: Implement RDMA memory registration Memory registration is used for transferring payload via RDMA read or write. After I/O is done, memory registrations are recovered and reused. This process can be time consuming and is done in a work queue. Signed-off-by: Long Li Reviewed-by: Pavel Shilovsky Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French --- diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index 3351873db93f..731577d4317f 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -48,6 +48,9 @@ static int smbd_post_send_page(struct smbd_connection *info, struct page *page, unsigned long offset, size_t size, int remaining_data_length); +static void destroy_mr_list(struct smbd_connection *info); +static int allocate_mr_list(struct smbd_connection *info); + /* SMBD version number */ #define SMBD_V1 0x0100 @@ -198,6 +201,12 @@ static void smbd_destroy_rdma_work(struct work_struct *work) wait_event(info->wait_send_payload_pending, atomic_read(&info->send_payload_pending) == 0); + log_rdma_event(INFO, "freeing mr list\n"); + wake_up_interruptible_all(&info->wait_mr); + wait_event(info->wait_for_mr_cleanup, + atomic_read(&info->mr_used_count) == 0); + destroy_mr_list(info); + /* It's not posssible for upper layer to get to reassembly */ log_rdma_event(INFO, "drain the reassembly queue\n"); do { @@ -453,6 +462,16 @@ static bool process_negotiation_response( } info->max_fragmented_send_size = le32_to_cpu(packet->max_fragmented_size); + info->rdma_readwrite_threshold = + rdma_readwrite_threshold > info->max_fragmented_send_size ? + info->max_fragmented_send_size : + rdma_readwrite_threshold; + + + info->max_readwrite_size = min_t(u32, + le32_to_cpu(packet->max_readwrite_size), + info->max_frmr_depth * PAGE_SIZE); + info->max_frmr_depth = info->max_readwrite_size / PAGE_SIZE; return true; } @@ -748,6 +767,12 @@ static int smbd_ia_open( rc = -EPROTONOSUPPORT; goto out2; } + info->max_frmr_depth = min_t(int, + smbd_max_frmr_depth, + info->id->device->attrs.max_fast_reg_page_list_len); + info->mr_type = IB_MR_TYPE_MEM_REG; + if (info->id->device->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG) + info->mr_type = IB_MR_TYPE_SG_GAPS; info->pd = ib_alloc_pd(info->id->device, 0); if (IS_ERR(info->pd)) { @@ -1582,6 +1607,8 @@ struct smbd_connection *_smbd_get_connection( struct rdma_conn_param conn_param; struct ib_qp_init_attr qp_attr; struct sockaddr_in *addr_in = (struct sockaddr_in *) dstaddr; + struct ib_port_immutable port_immutable; + u32 ird_ord_hdr[2]; info = kzalloc(sizeof(struct smbd_connection), GFP_KERNEL); if (!info) @@ -1670,6 +1697,28 @@ struct smbd_connection *_smbd_get_connection( memset(&conn_param, 0, sizeof(conn_param)); conn_param.initiator_depth = 0; + conn_param.responder_resources = + info->id->device->attrs.max_qp_rd_atom + < SMBD_CM_RESPONDER_RESOURCES ? + info->id->device->attrs.max_qp_rd_atom : + SMBD_CM_RESPONDER_RESOURCES; + info->responder_resources = conn_param.responder_resources; + log_rdma_mr(INFO, "responder_resources=%d\n", + info->responder_resources); + + /* Need to send IRD/ORD in private data for iWARP */ + info->id->device->get_port_immutable( + info->id->device, info->id->port_num, &port_immutable); + if (port_immutable.core_cap_flags & RDMA_CORE_PORT_IWARP) { + ird_ord_hdr[0] = info->responder_resources; + ird_ord_hdr[1] = 1; + conn_param.private_data = ird_ord_hdr; + conn_param.private_data_len = sizeof(ird_ord_hdr); + } else { + conn_param.private_data = NULL; + conn_param.private_data_len = 0; + } + conn_param.retry_count = SMBD_CM_RETRY; conn_param.rnr_retry_count = SMBD_CM_RNR_RETRY; conn_param.flow_control = 0; @@ -1734,8 +1783,19 @@ struct smbd_connection *_smbd_get_connection( goto negotiation_failed; } + rc = allocate_mr_list(info); + if (rc) { + log_rdma_mr(ERR, "memory registration allocation failed\n"); + goto allocate_mr_failed; + } + return info; +allocate_mr_failed: + /* At this point, need to a full transport shutdown */ + smbd_destroy(info); + return NULL; + negotiation_failed: cancel_delayed_work_sync(&info->idle_timer_work); destroy_caches_and_workqueue(info); @@ -2189,3 +2249,364 @@ done: return rc; } + +static void register_mr_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct smbd_mr *mr; + struct ib_cqe *cqe; + + if (wc->status) { + log_rdma_mr(ERR, "status=%d\n", wc->status); + cqe = wc->wr_cqe; + mr = container_of(cqe, struct smbd_mr, cqe); + smbd_disconnect_rdma_connection(mr->conn); + } +} + +/* + * The work queue function that recovers MRs + * We need to call ib_dereg_mr() and ib_alloc_mr() before this MR can be used + * again. Both calls are slow, so finish them in a workqueue. This will not + * block I/O path. + * There is one workqueue that recovers MRs, there is no need to lock as the + * I/O requests calling smbd_register_mr will never update the links in the + * mr_list. + */ +static void smbd_mr_recovery_work(struct work_struct *work) +{ + struct smbd_connection *info = + container_of(work, struct smbd_connection, mr_recovery_work); + struct smbd_mr *smbdirect_mr; + int rc; + + list_for_each_entry(smbdirect_mr, &info->mr_list, list) { + if (smbdirect_mr->state == MR_INVALIDATED || + smbdirect_mr->state == MR_ERROR) { + + if (smbdirect_mr->state == MR_INVALIDATED) { + ib_dma_unmap_sg( + info->id->device, smbdirect_mr->sgl, + smbdirect_mr->sgl_count, + smbdirect_mr->dir); + smbdirect_mr->state = MR_READY; + } else if (smbdirect_mr->state == MR_ERROR) { + + /* recover this MR entry */ + rc = ib_dereg_mr(smbdirect_mr->mr); + if (rc) { + log_rdma_mr(ERR, + "ib_dereg_mr faield rc=%x\n", + rc); + smbd_disconnect_rdma_connection(info); + } + + smbdirect_mr->mr = ib_alloc_mr( + info->pd, info->mr_type, + info->max_frmr_depth); + if (IS_ERR(smbdirect_mr->mr)) { + log_rdma_mr(ERR, + "ib_alloc_mr failed mr_type=%x " + "max_frmr_depth=%x\n", + info->mr_type, + info->max_frmr_depth); + smbd_disconnect_rdma_connection(info); + } + + smbdirect_mr->state = MR_READY; + } + /* smbdirect_mr->state is updated by this function + * and is read and updated by I/O issuing CPUs trying + * to get a MR, the call to atomic_inc_return + * implicates a memory barrier and guarantees this + * value is updated before waking up any calls to + * get_mr() from the I/O issuing CPUs + */ + if (atomic_inc_return(&info->mr_ready_count) == 1) + wake_up_interruptible(&info->wait_mr); + } + } +} + +static void destroy_mr_list(struct smbd_connection *info) +{ + struct smbd_mr *mr, *tmp; + + cancel_work_sync(&info->mr_recovery_work); + list_for_each_entry_safe(mr, tmp, &info->mr_list, list) { + if (mr->state == MR_INVALIDATED) + ib_dma_unmap_sg(info->id->device, mr->sgl, + mr->sgl_count, mr->dir); + ib_dereg_mr(mr->mr); + kfree(mr->sgl); + kfree(mr); + } +} + +/* + * Allocate MRs used for RDMA read/write + * The number of MRs will not exceed hardware capability in responder_resources + * All MRs are kept in mr_list. The MR can be recovered after it's used + * Recovery is done in smbd_mr_recovery_work. The content of list entry changes + * as MRs are used and recovered for I/O, but the list links will not change + */ +static int allocate_mr_list(struct smbd_connection *info) +{ + int i; + struct smbd_mr *smbdirect_mr, *tmp; + + INIT_LIST_HEAD(&info->mr_list); + init_waitqueue_head(&info->wait_mr); + spin_lock_init(&info->mr_list_lock); + atomic_set(&info->mr_ready_count, 0); + atomic_set(&info->mr_used_count, 0); + init_waitqueue_head(&info->wait_for_mr_cleanup); + /* Allocate more MRs (2x) than hardware responder_resources */ + for (i = 0; i < info->responder_resources * 2; i++) { + smbdirect_mr = kzalloc(sizeof(*smbdirect_mr), GFP_KERNEL); + if (!smbdirect_mr) + goto out; + smbdirect_mr->mr = ib_alloc_mr(info->pd, info->mr_type, + info->max_frmr_depth); + if (IS_ERR(smbdirect_mr->mr)) { + log_rdma_mr(ERR, "ib_alloc_mr failed mr_type=%x " + "max_frmr_depth=%x\n", + info->mr_type, info->max_frmr_depth); + goto out; + } + smbdirect_mr->sgl = kcalloc( + info->max_frmr_depth, + sizeof(struct scatterlist), + GFP_KERNEL); + if (!smbdirect_mr->sgl) { + log_rdma_mr(ERR, "failed to allocate sgl\n"); + ib_dereg_mr(smbdirect_mr->mr); + goto out; + } + smbdirect_mr->state = MR_READY; + smbdirect_mr->conn = info; + + list_add_tail(&smbdirect_mr->list, &info->mr_list); + atomic_inc(&info->mr_ready_count); + } + INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work); + return 0; + +out: + kfree(smbdirect_mr); + + list_for_each_entry_safe(smbdirect_mr, tmp, &info->mr_list, list) { + ib_dereg_mr(smbdirect_mr->mr); + kfree(smbdirect_mr->sgl); + kfree(smbdirect_mr); + } + return -ENOMEM; +} + +/* + * Get a MR from mr_list. This function waits until there is at least one + * MR available in the list. It may access the list while the + * smbd_mr_recovery_work is recovering the MR list. This doesn't need a lock + * as they never modify the same places. However, there may be several CPUs + * issueing I/O trying to get MR at the same time, mr_list_lock is used to + * protect this situation. + */ +static struct smbd_mr *get_mr(struct smbd_connection *info) +{ + struct smbd_mr *ret; + int rc; +again: + rc = wait_event_interruptible(info->wait_mr, + atomic_read(&info->mr_ready_count) || + info->transport_status != SMBD_CONNECTED); + if (rc) { + log_rdma_mr(ERR, "wait_event_interruptible rc=%x\n", rc); + return NULL; + } + + if (info->transport_status != SMBD_CONNECTED) { + log_rdma_mr(ERR, "info->transport_status=%x\n", + info->transport_status); + return NULL; + } + + spin_lock(&info->mr_list_lock); + list_for_each_entry(ret, &info->mr_list, list) { + if (ret->state == MR_READY) { + ret->state = MR_REGISTERED; + spin_unlock(&info->mr_list_lock); + atomic_dec(&info->mr_ready_count); + atomic_inc(&info->mr_used_count); + return ret; + } + } + + spin_unlock(&info->mr_list_lock); + /* + * It is possible that we could fail to get MR because other processes may + * try to acquire a MR at the same time. If this is the case, retry it. + */ + goto again; +} + +/* + * Register memory for RDMA read/write + * pages[]: the list of pages to register memory with + * num_pages: the number of pages to register + * tailsz: if non-zero, the bytes to register in the last page + * writing: true if this is a RDMA write (SMB read), false for RDMA read + * need_invalidate: true if this MR needs to be locally invalidated after I/O + * return value: the MR registered, NULL if failed. + */ +struct smbd_mr *smbd_register_mr( + struct smbd_connection *info, struct page *pages[], int num_pages, + int tailsz, bool writing, bool need_invalidate) +{ + struct smbd_mr *smbdirect_mr; + int rc, i; + enum dma_data_direction dir; + struct ib_reg_wr *reg_wr; + struct ib_send_wr *bad_wr; + + if (num_pages > info->max_frmr_depth) { + log_rdma_mr(ERR, "num_pages=%d max_frmr_depth=%d\n", + num_pages, info->max_frmr_depth); + return NULL; + } + + smbdirect_mr = get_mr(info); + if (!smbdirect_mr) { + log_rdma_mr(ERR, "get_mr returning NULL\n"); + return NULL; + } + smbdirect_mr->need_invalidate = need_invalidate; + smbdirect_mr->sgl_count = num_pages; + sg_init_table(smbdirect_mr->sgl, num_pages); + + for (i = 0; i < num_pages - 1; i++) + sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0); + + sg_set_page(&smbdirect_mr->sgl[i], pages[i], + tailsz ? tailsz : PAGE_SIZE, 0); + + dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + smbdirect_mr->dir = dir; + rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgl, num_pages, dir); + if (!rc) { + log_rdma_mr(INFO, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n", + num_pages, dir, rc); + goto dma_map_error; + } + + rc = ib_map_mr_sg(smbdirect_mr->mr, smbdirect_mr->sgl, num_pages, + NULL, PAGE_SIZE); + if (rc != num_pages) { + log_rdma_mr(INFO, + "ib_map_mr_sg failed rc = %x num_pages = %x\n", + rc, num_pages); + goto map_mr_error; + } + + ib_update_fast_reg_key(smbdirect_mr->mr, + ib_inc_rkey(smbdirect_mr->mr->rkey)); + reg_wr = &smbdirect_mr->wr; + reg_wr->wr.opcode = IB_WR_REG_MR; + smbdirect_mr->cqe.done = register_mr_done; + reg_wr->wr.wr_cqe = &smbdirect_mr->cqe; + reg_wr->wr.num_sge = 0; + reg_wr->wr.send_flags = IB_SEND_SIGNALED; + reg_wr->mr = smbdirect_mr->mr; + reg_wr->key = smbdirect_mr->mr->rkey; + reg_wr->access = writing ? + IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE : + IB_ACCESS_REMOTE_READ; + + /* + * There is no need for waiting for complemtion on ib_post_send + * on IB_WR_REG_MR. Hardware enforces a barrier and order of execution + * on the next ib_post_send when we actaully send I/O to remote peer + */ + rc = ib_post_send(info->id->qp, ®_wr->wr, &bad_wr); + if (!rc) + return smbdirect_mr; + + log_rdma_mr(ERR, "ib_post_send failed rc=%x reg_wr->key=%x\n", + rc, reg_wr->key); + + /* If all failed, attempt to recover this MR by setting it MR_ERROR*/ +map_mr_error: + ib_dma_unmap_sg(info->id->device, smbdirect_mr->sgl, + smbdirect_mr->sgl_count, smbdirect_mr->dir); + +dma_map_error: + smbdirect_mr->state = MR_ERROR; + if (atomic_dec_and_test(&info->mr_used_count)) + wake_up(&info->wait_for_mr_cleanup); + + return NULL; +} + +static void local_inv_done(struct ib_cq *cq, struct ib_wc *wc) +{ + struct smbd_mr *smbdirect_mr; + struct ib_cqe *cqe; + + cqe = wc->wr_cqe; + smbdirect_mr = container_of(cqe, struct smbd_mr, cqe); + smbdirect_mr->state = MR_INVALIDATED; + if (wc->status != IB_WC_SUCCESS) { + log_rdma_mr(ERR, "invalidate failed status=%x\n", wc->status); + smbdirect_mr->state = MR_ERROR; + } + complete(&smbdirect_mr->invalidate_done); +} + +/* + * Deregister a MR after I/O is done + * This function may wait if remote invalidation is not used + * and we have to locally invalidate the buffer to prevent data is being + * modified by remote peer after upper layer consumes it + */ +int smbd_deregister_mr(struct smbd_mr *smbdirect_mr) +{ + struct ib_send_wr *wr, *bad_wr; + struct smbd_connection *info = smbdirect_mr->conn; + int rc = 0; + + if (smbdirect_mr->need_invalidate) { + /* Need to finish local invalidation before returning */ + wr = &smbdirect_mr->inv_wr; + wr->opcode = IB_WR_LOCAL_INV; + smbdirect_mr->cqe.done = local_inv_done; + wr->wr_cqe = &smbdirect_mr->cqe; + wr->num_sge = 0; + wr->ex.invalidate_rkey = smbdirect_mr->mr->rkey; + wr->send_flags = IB_SEND_SIGNALED; + + init_completion(&smbdirect_mr->invalidate_done); + rc = ib_post_send(info->id->qp, wr, &bad_wr); + if (rc) { + log_rdma_mr(ERR, "ib_post_send failed rc=%x\n", rc); + smbd_disconnect_rdma_connection(info); + goto done; + } + wait_for_completion(&smbdirect_mr->invalidate_done); + smbdirect_mr->need_invalidate = false; + } else + /* + * For remote invalidation, just set it to MR_INVALIDATED + * and defer to mr_recovery_work to recover the MR for next use + */ + smbdirect_mr->state = MR_INVALIDATED; + + /* + * Schedule the work to do MR recovery for future I/Os + * MR recovery is slow and we don't want it to block the current I/O + */ + queue_work(info->workqueue, &info->mr_recovery_work); + +done: + if (atomic_dec_and_test(&info->mr_used_count)) + wake_up(&info->wait_for_mr_cleanup); + + return rc; +} diff --git a/fs/cifs/smbdirect.h b/fs/cifs/smbdirect.h index 27453ef2181f..fdb8df84fa1f 100644 --- a/fs/cifs/smbdirect.h +++ b/fs/cifs/smbdirect.h @@ -90,6 +90,29 @@ struct smbd_connection { int receive_credit_target; int fragment_reassembly_remaining; + /* Memory registrations */ + /* Maximum number of RDMA read/write outstanding on this connection */ + int responder_resources; + /* Maximum number of SGEs in a RDMA write/read */ + int max_frmr_depth; + /* + * If payload is less than or equal to the threshold, + * use RDMA send/recv to send upper layer I/O. + * If payload is more than the threshold, + * use RDMA read/write through memory registration for I/O. + */ + int rdma_readwrite_threshold; + enum ib_mr_type mr_type; + struct list_head mr_list; + spinlock_t mr_list_lock; + /* The number of available MRs ready for memory registration */ + atomic_t mr_ready_count; + atomic_t mr_used_count; + wait_queue_head_t wait_mr; + struct work_struct mr_recovery_work; + /* Used by transport to wait until all MRs are returned */ + wait_queue_head_t wait_for_mr_cleanup; + /* Activity accoutning */ /* Pending reqeusts issued from upper layer */ int smbd_send_pending; @@ -262,6 +285,36 @@ void smbd_destroy(struct smbd_connection *info); int smbd_recv(struct smbd_connection *info, struct msghdr *msg); int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst); +enum mr_state { + MR_READY, + MR_REGISTERED, + MR_INVALIDATED, + MR_ERROR +}; + +struct smbd_mr { + struct smbd_connection *conn; + struct list_head list; + enum mr_state state; + struct ib_mr *mr; + struct scatterlist *sgl; + int sgl_count; + enum dma_data_direction dir; + union { + struct ib_reg_wr wr; + struct ib_send_wr inv_wr; + }; + struct ib_cqe cqe; + bool need_invalidate; + struct completion invalidate_done; +}; + +/* Interfaces to register and deregister MR for RDMA read/write */ +struct smbd_mr *smbd_register_mr( + struct smbd_connection *info, struct page *pages[], int num_pages, + int tailsz, bool writing, bool need_invalidate); +int smbd_deregister_mr(struct smbd_mr *mr); + #else #define cifs_rdma_enabled(server) 0 struct smbd_connection {};