diff options
Diffstat (limited to 'fs/smb/client/smbdirect.c')
| -rw-r--r-- | fs/smb/client/smbdirect.c | 2611 | 
1 files changed, 2611 insertions, 0 deletions
diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c new file mode 100644 index 000000000000..0362ebd4fa0f --- /dev/null +++ b/fs/smb/client/smbdirect.c @@ -0,0 +1,2611 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + *   Copyright (C) 2017, Microsoft Corporation. + * + *   Author(s): Long Li <longli@microsoft.com> + */ +#include <linux/module.h> +#include <linux/highmem.h> +#include "smbdirect.h" +#include "cifs_debug.h" +#include "cifsproto.h" +#include "smb2proto.h" + +static struct smbd_response *get_empty_queue_buffer( +		struct smbd_connection *info); +static struct smbd_response *get_receive_buffer( +		struct smbd_connection *info); +static void put_receive_buffer( +		struct smbd_connection *info, +		struct smbd_response *response); +static int allocate_receive_buffers(struct smbd_connection *info, int num_buf); +static void destroy_receive_buffers(struct smbd_connection *info); + +static void put_empty_packet( +		struct smbd_connection *info, struct smbd_response *response); +static void enqueue_reassembly( +		struct smbd_connection *info, +		struct smbd_response *response, int data_length); +static struct smbd_response *_get_first_reassembly( +		struct smbd_connection *info); + +static int smbd_post_recv( +		struct smbd_connection *info, +		struct smbd_response *response); + +static int smbd_post_send_empty(struct smbd_connection *info); + +static void destroy_mr_list(struct smbd_connection *info); +static int allocate_mr_list(struct smbd_connection *info); + +struct smb_extract_to_rdma { +	struct ib_sge		*sge; +	unsigned int		nr_sge; +	unsigned int		max_sge; +	struct ib_device	*device; +	u32			local_dma_lkey; +	enum dma_data_direction	direction; +}; +static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len, +					struct smb_extract_to_rdma *rdma); + +/* SMBD version number */ +#define SMBD_V1	0x0100 + +/* Port numbers for SMBD transport */ +#define SMB_PORT	445 +#define SMBD_PORT	5445 + +/* Address lookup and resolve timeout in ms */ +#define RDMA_RESOLVE_TIMEOUT	5000 + +/* SMBD negotiation timeout in seconds */ +#define SMBD_NEGOTIATE_TIMEOUT	120 + +/* SMBD minimum receive size and fragmented sized defined in [MS-SMBD] */ +#define SMBD_MIN_RECEIVE_SIZE		128 +#define SMBD_MIN_FRAGMENTED_SIZE	131072 + +/* + * Default maximum number of RDMA read/write outstanding on this connection + * This value is possibly decreased during QP creation on hardware limit + */ +#define SMBD_CM_RESPONDER_RESOURCES	32 + +/* Maximum number of retries on data transfer operations */ +#define SMBD_CM_RETRY			6 +/* No need to retry on Receiver Not Ready since SMBD manages credits */ +#define SMBD_CM_RNR_RETRY		0 + +/* + * User configurable initial values per SMBD transport connection + * as defined in [MS-SMBD] 3.1.1.1 + * Those may change after a SMBD negotiation + */ +/* The local peer's maximum number of credits to grant to the peer */ +int smbd_receive_credit_max = 255; + +/* The remote peer's credit request of local peer */ +int smbd_send_credit_target = 255; + +/* The maximum single message size can be sent to remote peer */ +int smbd_max_send_size = 1364; + +/*  The maximum fragmented upper-layer payload receive size supported */ +int smbd_max_fragmented_recv_size = 1024 * 1024; + +/*  The maximum single-message size which can be received */ +int smbd_max_receive_size = 1364; + +/* The timeout to initiate send of a keepalive message on idle */ +int smbd_keep_alive_interval = 120; + +/* + * User configurable initial values for RDMA transport + * The actual values used may be lower and are limited to hardware capabilities + */ +/* Default maximum number of pages in a single RDMA write/read */ +int smbd_max_frmr_depth = 2048; + +/* If payload is less than this byte, use RDMA send/recv not read/write */ +int rdma_readwrite_threshold = 4096; + +/* Transport logging functions + * Logging are defined as classes. They can be OR'ed to define the actual + * logging level via module parameter smbd_logging_class + * e.g. cifs.smbd_logging_class=0xa0 will log all log_rdma_recv() and + * log_rdma_event() + */ +#define LOG_OUTGOING			0x1 +#define LOG_INCOMING			0x2 +#define LOG_READ			0x4 +#define LOG_WRITE			0x8 +#define LOG_RDMA_SEND			0x10 +#define LOG_RDMA_RECV			0x20 +#define LOG_KEEP_ALIVE			0x40 +#define LOG_RDMA_EVENT			0x80 +#define LOG_RDMA_MR			0x100 +static unsigned int smbd_logging_class; +module_param(smbd_logging_class, uint, 0644); +MODULE_PARM_DESC(smbd_logging_class, +	"Logging class for SMBD transport 0x0 to 0x100"); + +#define ERR		0x0 +#define INFO		0x1 +static unsigned int smbd_logging_level = ERR; +module_param(smbd_logging_level, uint, 0644); +MODULE_PARM_DESC(smbd_logging_level, +	"Logging level for SMBD transport, 0 (default): error, 1: info"); + +#define log_rdma(level, class, fmt, args...)				\ +do {									\ +	if (level <= smbd_logging_level || class & smbd_logging_class)	\ +		cifs_dbg(VFS, "%s:%d " fmt, __func__, __LINE__, ##args);\ +} while (0) + +#define log_outgoing(level, fmt, args...) \ +		log_rdma(level, LOG_OUTGOING, fmt, ##args) +#define log_incoming(level, fmt, args...) \ +		log_rdma(level, LOG_INCOMING, fmt, ##args) +#define log_read(level, fmt, args...)	log_rdma(level, LOG_READ, fmt, ##args) +#define log_write(level, fmt, args...)	log_rdma(level, LOG_WRITE, fmt, ##args) +#define log_rdma_send(level, fmt, args...) \ +		log_rdma(level, LOG_RDMA_SEND, fmt, ##args) +#define log_rdma_recv(level, fmt, args...) \ +		log_rdma(level, LOG_RDMA_RECV, fmt, ##args) +#define log_keep_alive(level, fmt, args...) \ +		log_rdma(level, LOG_KEEP_ALIVE, fmt, ##args) +#define log_rdma_event(level, fmt, args...) \ +		log_rdma(level, LOG_RDMA_EVENT, fmt, ##args) +#define log_rdma_mr(level, fmt, args...) \ +		log_rdma(level, LOG_RDMA_MR, fmt, ##args) + +static void smbd_disconnect_rdma_work(struct work_struct *work) +{ +	struct smbd_connection *info = +		container_of(work, struct smbd_connection, disconnect_work); + +	if (info->transport_status == SMBD_CONNECTED) { +		info->transport_status = SMBD_DISCONNECTING; +		rdma_disconnect(info->id); +	} +} + +static void smbd_disconnect_rdma_connection(struct smbd_connection *info) +{ +	queue_work(info->workqueue, &info->disconnect_work); +} + +/* Upcall from RDMA CM */ +static int smbd_conn_upcall( +		struct rdma_cm_id *id, struct rdma_cm_event *event) +{ +	struct smbd_connection *info = id->context; + +	log_rdma_event(INFO, "event=%d status=%d\n", +		event->event, event->status); + +	switch (event->event) { +	case RDMA_CM_EVENT_ADDR_RESOLVED: +	case RDMA_CM_EVENT_ROUTE_RESOLVED: +		info->ri_rc = 0; +		complete(&info->ri_done); +		break; + +	case RDMA_CM_EVENT_ADDR_ERROR: +		info->ri_rc = -EHOSTUNREACH; +		complete(&info->ri_done); +		break; + +	case RDMA_CM_EVENT_ROUTE_ERROR: +		info->ri_rc = -ENETUNREACH; +		complete(&info->ri_done); +		break; + +	case RDMA_CM_EVENT_ESTABLISHED: +		log_rdma_event(INFO, "connected event=%d\n", event->event); +		info->transport_status = SMBD_CONNECTED; +		wake_up_interruptible(&info->conn_wait); +		break; + +	case RDMA_CM_EVENT_CONNECT_ERROR: +	case RDMA_CM_EVENT_UNREACHABLE: +	case RDMA_CM_EVENT_REJECTED: +		log_rdma_event(INFO, "connecting failed event=%d\n", event->event); +		info->transport_status = SMBD_DISCONNECTED; +		wake_up_interruptible(&info->conn_wait); +		break; + +	case RDMA_CM_EVENT_DEVICE_REMOVAL: +	case RDMA_CM_EVENT_DISCONNECTED: +		/* This happenes when we fail the negotiation */ +		if (info->transport_status == SMBD_NEGOTIATE_FAILED) { +			info->transport_status = SMBD_DISCONNECTED; +			wake_up(&info->conn_wait); +			break; +		} + +		info->transport_status = SMBD_DISCONNECTED; +		wake_up_interruptible(&info->disconn_wait); +		wake_up_interruptible(&info->wait_reassembly_queue); +		wake_up_interruptible_all(&info->wait_send_queue); +		break; + +	default: +		break; +	} + +	return 0; +} + +/* Upcall from RDMA QP */ +static void +smbd_qp_async_error_upcall(struct ib_event *event, void *context) +{ +	struct smbd_connection *info = context; + +	log_rdma_event(ERR, "%s on device %s info %p\n", +		ib_event_msg(event->event), event->device->name, info); + +	switch (event->event) { +	case IB_EVENT_CQ_ERR: +	case IB_EVENT_QP_FATAL: +		smbd_disconnect_rdma_connection(info); +		break; + +	default: +		break; +	} +} + +static inline void *smbd_request_payload(struct smbd_request *request) +{ +	return (void *)request->packet; +} + +static inline void *smbd_response_payload(struct smbd_response *response) +{ +	return (void *)response->packet; +} + +/* Called when a RDMA send is done */ +static void send_done(struct ib_cq *cq, struct ib_wc *wc) +{ +	int i; +	struct smbd_request *request = +		container_of(wc->wr_cqe, struct smbd_request, cqe); + +	log_rdma_send(INFO, "smbd_request 0x%p completed wc->status=%d\n", +		request, wc->status); + +	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) { +		log_rdma_send(ERR, "wc->status=%d wc->opcode=%d\n", +			wc->status, wc->opcode); +		smbd_disconnect_rdma_connection(request->info); +	} + +	for (i = 0; i < request->num_sge; i++) +		ib_dma_unmap_single(request->info->id->device, +			request->sge[i].addr, +			request->sge[i].length, +			DMA_TO_DEVICE); + +	if (atomic_dec_and_test(&request->info->send_pending)) +		wake_up(&request->info->wait_send_pending); + +	wake_up(&request->info->wait_post_send); + +	mempool_free(request, request->info->request_mempool); +} + +static void dump_smbd_negotiate_resp(struct smbd_negotiate_resp *resp) +{ +	log_rdma_event(INFO, "resp message min_version %u max_version %u negotiated_version %u credits_requested %u credits_granted %u status %u max_readwrite_size %u preferred_send_size %u max_receive_size %u max_fragmented_size %u\n", +		       resp->min_version, resp->max_version, +		       resp->negotiated_version, resp->credits_requested, +		       resp->credits_granted, resp->status, +		       resp->max_readwrite_size, resp->preferred_send_size, +		       resp->max_receive_size, resp->max_fragmented_size); +} + +/* + * Process a negotiation response message, according to [MS-SMBD]3.1.5.7 + * response, packet_length: the negotiation response message + * return value: true if negotiation is a success, false if failed + */ +static bool process_negotiation_response( +		struct smbd_response *response, int packet_length) +{ +	struct smbd_connection *info = response->info; +	struct smbd_negotiate_resp *packet = smbd_response_payload(response); + +	if (packet_length < sizeof(struct smbd_negotiate_resp)) { +		log_rdma_event(ERR, +			"error: packet_length=%d\n", packet_length); +		return false; +	} + +	if (le16_to_cpu(packet->negotiated_version) != SMBD_V1) { +		log_rdma_event(ERR, "error: negotiated_version=%x\n", +			le16_to_cpu(packet->negotiated_version)); +		return false; +	} +	info->protocol = le16_to_cpu(packet->negotiated_version); + +	if (packet->credits_requested == 0) { +		log_rdma_event(ERR, "error: credits_requested==0\n"); +		return false; +	} +	info->receive_credit_target = le16_to_cpu(packet->credits_requested); + +	if (packet->credits_granted == 0) { +		log_rdma_event(ERR, "error: credits_granted==0\n"); +		return false; +	} +	atomic_set(&info->send_credits, le16_to_cpu(packet->credits_granted)); + +	atomic_set(&info->receive_credits, 0); + +	if (le32_to_cpu(packet->preferred_send_size) > info->max_receive_size) { +		log_rdma_event(ERR, "error: preferred_send_size=%d\n", +			le32_to_cpu(packet->preferred_send_size)); +		return false; +	} +	info->max_receive_size = le32_to_cpu(packet->preferred_send_size); + +	if (le32_to_cpu(packet->max_receive_size) < SMBD_MIN_RECEIVE_SIZE) { +		log_rdma_event(ERR, "error: max_receive_size=%d\n", +			le32_to_cpu(packet->max_receive_size)); +		return false; +	} +	info->max_send_size = min_t(int, info->max_send_size, +					le32_to_cpu(packet->max_receive_size)); + +	if (le32_to_cpu(packet->max_fragmented_size) < +			SMBD_MIN_FRAGMENTED_SIZE) { +		log_rdma_event(ERR, "error: max_fragmented_size=%d\n", +			le32_to_cpu(packet->max_fragmented_size)); +		return false; +	} +	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; +} + +static void smbd_post_send_credits(struct work_struct *work) +{ +	int ret = 0; +	int use_receive_queue = 1; +	int rc; +	struct smbd_response *response; +	struct smbd_connection *info = +		container_of(work, struct smbd_connection, +			post_send_credits_work); + +	if (info->transport_status != SMBD_CONNECTED) { +		wake_up(&info->wait_receive_queues); +		return; +	} + +	if (info->receive_credit_target > +		atomic_read(&info->receive_credits)) { +		while (true) { +			if (use_receive_queue) +				response = get_receive_buffer(info); +			else +				response = get_empty_queue_buffer(info); +			if (!response) { +				/* now switch to emtpy packet queue */ +				if (use_receive_queue) { +					use_receive_queue = 0; +					continue; +				} else +					break; +			} + +			response->type = SMBD_TRANSFER_DATA; +			response->first_segment = false; +			rc = smbd_post_recv(info, response); +			if (rc) { +				log_rdma_recv(ERR, +					"post_recv failed rc=%d\n", rc); +				put_receive_buffer(info, response); +				break; +			} + +			ret++; +		} +	} + +	spin_lock(&info->lock_new_credits_offered); +	info->new_credits_offered += ret; +	spin_unlock(&info->lock_new_credits_offered); + +	/* Promptly send an immediate packet as defined in [MS-SMBD] 3.1.1.1 */ +	info->send_immediate = true; +	if (atomic_read(&info->receive_credits) < +		info->receive_credit_target - 1) { +		if (info->keep_alive_requested == KEEP_ALIVE_PENDING || +		    info->send_immediate) { +			log_keep_alive(INFO, "send an empty message\n"); +			smbd_post_send_empty(info); +		} +	} +} + +/* Called from softirq, when recv is done */ +static void recv_done(struct ib_cq *cq, struct ib_wc *wc) +{ +	struct smbd_data_transfer *data_transfer; +	struct smbd_response *response = +		container_of(wc->wr_cqe, struct smbd_response, cqe); +	struct smbd_connection *info = response->info; +	int data_length = 0; + +	log_rdma_recv(INFO, "response=0x%p type=%d wc status=%d wc opcode %d byte_len=%d pkey_index=%u\n", +		      response, response->type, wc->status, wc->opcode, +		      wc->byte_len, wc->pkey_index); + +	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_RECV) { +		log_rdma_recv(INFO, "wc->status=%d opcode=%d\n", +			wc->status, wc->opcode); +		smbd_disconnect_rdma_connection(info); +		goto error; +	} + +	ib_dma_sync_single_for_cpu( +		wc->qp->device, +		response->sge.addr, +		response->sge.length, +		DMA_FROM_DEVICE); + +	switch (response->type) { +	/* SMBD negotiation response */ +	case SMBD_NEGOTIATE_RESP: +		dump_smbd_negotiate_resp(smbd_response_payload(response)); +		info->full_packet_received = true; +		info->negotiate_done = +			process_negotiation_response(response, wc->byte_len); +		complete(&info->negotiate_completion); +		break; + +	/* SMBD data transfer packet */ +	case SMBD_TRANSFER_DATA: +		data_transfer = smbd_response_payload(response); +		data_length = le32_to_cpu(data_transfer->data_length); + +		/* +		 * If this is a packet with data playload place the data in +		 * reassembly queue and wake up the reading thread +		 */ +		if (data_length) { +			if (info->full_packet_received) +				response->first_segment = true; + +			if (le32_to_cpu(data_transfer->remaining_data_length)) +				info->full_packet_received = false; +			else +				info->full_packet_received = true; + +			enqueue_reassembly( +				info, +				response, +				data_length); +		} else +			put_empty_packet(info, response); + +		if (data_length) +			wake_up_interruptible(&info->wait_reassembly_queue); + +		atomic_dec(&info->receive_credits); +		info->receive_credit_target = +			le16_to_cpu(data_transfer->credits_requested); +		if (le16_to_cpu(data_transfer->credits_granted)) { +			atomic_add(le16_to_cpu(data_transfer->credits_granted), +				&info->send_credits); +			/* +			 * We have new send credits granted from remote peer +			 * If any sender is waiting for credits, unblock it +			 */ +			wake_up_interruptible(&info->wait_send_queue); +		} + +		log_incoming(INFO, "data flags %d data_offset %d data_length %d remaining_data_length %d\n", +			     le16_to_cpu(data_transfer->flags), +			     le32_to_cpu(data_transfer->data_offset), +			     le32_to_cpu(data_transfer->data_length), +			     le32_to_cpu(data_transfer->remaining_data_length)); + +		/* Send a KEEP_ALIVE response right away if requested */ +		info->keep_alive_requested = KEEP_ALIVE_NONE; +		if (le16_to_cpu(data_transfer->flags) & +				SMB_DIRECT_RESPONSE_REQUESTED) { +			info->keep_alive_requested = KEEP_ALIVE_PENDING; +		} + +		return; + +	default: +		log_rdma_recv(ERR, +			"unexpected response type=%d\n", response->type); +	} + +error: +	put_receive_buffer(info, response); +} + +static struct rdma_cm_id *smbd_create_id( +		struct smbd_connection *info, +		struct sockaddr *dstaddr, int port) +{ +	struct rdma_cm_id *id; +	int rc; +	__be16 *sport; + +	id = rdma_create_id(&init_net, smbd_conn_upcall, info, +		RDMA_PS_TCP, IB_QPT_RC); +	if (IS_ERR(id)) { +		rc = PTR_ERR(id); +		log_rdma_event(ERR, "rdma_create_id() failed %i\n", rc); +		return id; +	} + +	if (dstaddr->sa_family == AF_INET6) +		sport = &((struct sockaddr_in6 *)dstaddr)->sin6_port; +	else +		sport = &((struct sockaddr_in *)dstaddr)->sin_port; + +	*sport = htons(port); + +	init_completion(&info->ri_done); +	info->ri_rc = -ETIMEDOUT; + +	rc = rdma_resolve_addr(id, NULL, (struct sockaddr *)dstaddr, +		RDMA_RESOLVE_TIMEOUT); +	if (rc) { +		log_rdma_event(ERR, "rdma_resolve_addr() failed %i\n", rc); +		goto out; +	} +	rc = wait_for_completion_interruptible_timeout( +		&info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT)); +	/* e.g. if interrupted returns -ERESTARTSYS */ +	if (rc < 0) { +		log_rdma_event(ERR, "rdma_resolve_addr timeout rc: %i\n", rc); +		goto out; +	} +	rc = info->ri_rc; +	if (rc) { +		log_rdma_event(ERR, "rdma_resolve_addr() completed %i\n", rc); +		goto out; +	} + +	info->ri_rc = -ETIMEDOUT; +	rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT); +	if (rc) { +		log_rdma_event(ERR, "rdma_resolve_route() failed %i\n", rc); +		goto out; +	} +	rc = wait_for_completion_interruptible_timeout( +		&info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT)); +	/* e.g. if interrupted returns -ERESTARTSYS */ +	if (rc < 0)  { +		log_rdma_event(ERR, "rdma_resolve_addr timeout rc: %i\n", rc); +		goto out; +	} +	rc = info->ri_rc; +	if (rc) { +		log_rdma_event(ERR, "rdma_resolve_route() completed %i\n", rc); +		goto out; +	} + +	return id; + +out: +	rdma_destroy_id(id); +	return ERR_PTR(rc); +} + +/* + * Test if FRWR (Fast Registration Work Requests) is supported on the device + * This implementation requries FRWR on RDMA read/write + * return value: true if it is supported + */ +static bool frwr_is_supported(struct ib_device_attr *attrs) +{ +	if (!(attrs->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS)) +		return false; +	if (attrs->max_fast_reg_page_list_len == 0) +		return false; +	return true; +} + +static int smbd_ia_open( +		struct smbd_connection *info, +		struct sockaddr *dstaddr, int port) +{ +	int rc; + +	info->id = smbd_create_id(info, dstaddr, port); +	if (IS_ERR(info->id)) { +		rc = PTR_ERR(info->id); +		goto out1; +	} + +	if (!frwr_is_supported(&info->id->device->attrs)) { +		log_rdma_event(ERR, "Fast Registration Work Requests (FRWR) is not supported\n"); +		log_rdma_event(ERR, "Device capability flags = %llx max_fast_reg_page_list_len = %u\n", +			       info->id->device->attrs.device_cap_flags, +			       info->id->device->attrs.max_fast_reg_page_list_len); +		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.kernel_cap_flags & IBK_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)) { +		rc = PTR_ERR(info->pd); +		log_rdma_event(ERR, "ib_alloc_pd() returned %d\n", rc); +		goto out2; +	} + +	return 0; + +out2: +	rdma_destroy_id(info->id); +	info->id = NULL; + +out1: +	return rc; +} + +/* + * Send a negotiation request message to the peer + * The negotiation procedure is in [MS-SMBD] 3.1.5.2 and 3.1.5.3 + * After negotiation, the transport is connected and ready for + * carrying upper layer SMB payload + */ +static int smbd_post_send_negotiate_req(struct smbd_connection *info) +{ +	struct ib_send_wr send_wr; +	int rc = -ENOMEM; +	struct smbd_request *request; +	struct smbd_negotiate_req *packet; + +	request = mempool_alloc(info->request_mempool, GFP_KERNEL); +	if (!request) +		return rc; + +	request->info = info; + +	packet = smbd_request_payload(request); +	packet->min_version = cpu_to_le16(SMBD_V1); +	packet->max_version = cpu_to_le16(SMBD_V1); +	packet->reserved = 0; +	packet->credits_requested = cpu_to_le16(info->send_credit_target); +	packet->preferred_send_size = cpu_to_le32(info->max_send_size); +	packet->max_receive_size = cpu_to_le32(info->max_receive_size); +	packet->max_fragmented_size = +		cpu_to_le32(info->max_fragmented_recv_size); + +	request->num_sge = 1; +	request->sge[0].addr = ib_dma_map_single( +				info->id->device, (void *)packet, +				sizeof(*packet), DMA_TO_DEVICE); +	if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) { +		rc = -EIO; +		goto dma_mapping_failed; +	} + +	request->sge[0].length = sizeof(*packet); +	request->sge[0].lkey = info->pd->local_dma_lkey; + +	ib_dma_sync_single_for_device( +		info->id->device, request->sge[0].addr, +		request->sge[0].length, DMA_TO_DEVICE); + +	request->cqe.done = send_done; + +	send_wr.next = NULL; +	send_wr.wr_cqe = &request->cqe; +	send_wr.sg_list = request->sge; +	send_wr.num_sge = request->num_sge; +	send_wr.opcode = IB_WR_SEND; +	send_wr.send_flags = IB_SEND_SIGNALED; + +	log_rdma_send(INFO, "sge addr=0x%llx length=%u lkey=0x%x\n", +		request->sge[0].addr, +		request->sge[0].length, request->sge[0].lkey); + +	atomic_inc(&info->send_pending); +	rc = ib_post_send(info->id->qp, &send_wr, NULL); +	if (!rc) +		return 0; + +	/* if we reach here, post send failed */ +	log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc); +	atomic_dec(&info->send_pending); +	ib_dma_unmap_single(info->id->device, request->sge[0].addr, +		request->sge[0].length, DMA_TO_DEVICE); + +	smbd_disconnect_rdma_connection(info); + +dma_mapping_failed: +	mempool_free(request, info->request_mempool); +	return rc; +} + +/* + * Extend the credits to remote peer + * This implements [MS-SMBD] 3.1.5.9 + * The idea is that we should extend credits to remote peer as quickly as + * it's allowed, to maintain data flow. We allocate as much receive + * buffer as possible, and extend the receive credits to remote peer + * return value: the new credtis being granted. + */ +static int manage_credits_prior_sending(struct smbd_connection *info) +{ +	int new_credits; + +	spin_lock(&info->lock_new_credits_offered); +	new_credits = info->new_credits_offered; +	info->new_credits_offered = 0; +	spin_unlock(&info->lock_new_credits_offered); + +	return new_credits; +} + +/* + * Check if we need to send a KEEP_ALIVE message + * The idle connection timer triggers a KEEP_ALIVE message when expires + * SMB_DIRECT_RESPONSE_REQUESTED is set in the message flag to have peer send + * back a response. + * return value: + * 1 if SMB_DIRECT_RESPONSE_REQUESTED needs to be set + * 0: otherwise + */ +static int manage_keep_alive_before_sending(struct smbd_connection *info) +{ +	if (info->keep_alive_requested == KEEP_ALIVE_PENDING) { +		info->keep_alive_requested = KEEP_ALIVE_SENT; +		return 1; +	} +	return 0; +} + +/* Post the send request */ +static int smbd_post_send(struct smbd_connection *info, +		struct smbd_request *request) +{ +	struct ib_send_wr send_wr; +	int rc, i; + +	for (i = 0; i < request->num_sge; i++) { +		log_rdma_send(INFO, +			"rdma_request sge[%d] addr=0x%llx length=%u\n", +			i, request->sge[i].addr, request->sge[i].length); +		ib_dma_sync_single_for_device( +			info->id->device, +			request->sge[i].addr, +			request->sge[i].length, +			DMA_TO_DEVICE); +	} + +	request->cqe.done = send_done; + +	send_wr.next = NULL; +	send_wr.wr_cqe = &request->cqe; +	send_wr.sg_list = request->sge; +	send_wr.num_sge = request->num_sge; +	send_wr.opcode = IB_WR_SEND; +	send_wr.send_flags = IB_SEND_SIGNALED; + +	rc = ib_post_send(info->id->qp, &send_wr, NULL); +	if (rc) { +		log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc); +		smbd_disconnect_rdma_connection(info); +		rc = -EAGAIN; +	} else +		/* Reset timer for idle connection after packet is sent */ +		mod_delayed_work(info->workqueue, &info->idle_timer_work, +			info->keep_alive_interval*HZ); + +	return rc; +} + +static int smbd_post_send_iter(struct smbd_connection *info, +			       struct iov_iter *iter, +			       int *_remaining_data_length) +{ +	int i, rc; +	int header_length; +	int data_length; +	struct smbd_request *request; +	struct smbd_data_transfer *packet; +	int new_credits = 0; + +wait_credit: +	/* Wait for send credits. A SMBD packet needs one credit */ +	rc = wait_event_interruptible(info->wait_send_queue, +		atomic_read(&info->send_credits) > 0 || +		info->transport_status != SMBD_CONNECTED); +	if (rc) +		goto err_wait_credit; + +	if (info->transport_status != SMBD_CONNECTED) { +		log_outgoing(ERR, "disconnected not sending on wait_credit\n"); +		rc = -EAGAIN; +		goto err_wait_credit; +	} +	if (unlikely(atomic_dec_return(&info->send_credits) < 0)) { +		atomic_inc(&info->send_credits); +		goto wait_credit; +	} + +wait_send_queue: +	wait_event(info->wait_post_send, +		atomic_read(&info->send_pending) < info->send_credit_target || +		info->transport_status != SMBD_CONNECTED); + +	if (info->transport_status != SMBD_CONNECTED) { +		log_outgoing(ERR, "disconnected not sending on wait_send_queue\n"); +		rc = -EAGAIN; +		goto err_wait_send_queue; +	} + +	if (unlikely(atomic_inc_return(&info->send_pending) > +				info->send_credit_target)) { +		atomic_dec(&info->send_pending); +		goto wait_send_queue; +	} + +	request = mempool_alloc(info->request_mempool, GFP_KERNEL); +	if (!request) { +		rc = -ENOMEM; +		goto err_alloc; +	} + +	request->info = info; +	memset(request->sge, 0, sizeof(request->sge)); + +	/* Fill in the data payload to find out how much data we can add */ +	if (iter) { +		struct smb_extract_to_rdma extract = { +			.nr_sge		= 1, +			.max_sge	= SMBDIRECT_MAX_SEND_SGE, +			.sge		= request->sge, +			.device		= info->id->device, +			.local_dma_lkey	= info->pd->local_dma_lkey, +			.direction	= DMA_TO_DEVICE, +		}; + +		rc = smb_extract_iter_to_rdma(iter, *_remaining_data_length, +					      &extract); +		if (rc < 0) +			goto err_dma; +		data_length = rc; +		request->num_sge = extract.nr_sge; +		*_remaining_data_length -= data_length; +	} else { +		data_length = 0; +		request->num_sge = 1; +	} + +	/* Fill in the packet header */ +	packet = smbd_request_payload(request); +	packet->credits_requested = cpu_to_le16(info->send_credit_target); + +	new_credits = manage_credits_prior_sending(info); +	atomic_add(new_credits, &info->receive_credits); +	packet->credits_granted = cpu_to_le16(new_credits); + +	info->send_immediate = false; + +	packet->flags = 0; +	if (manage_keep_alive_before_sending(info)) +		packet->flags |= cpu_to_le16(SMB_DIRECT_RESPONSE_REQUESTED); + +	packet->reserved = 0; +	if (!data_length) +		packet->data_offset = 0; +	else +		packet->data_offset = cpu_to_le32(24); +	packet->data_length = cpu_to_le32(data_length); +	packet->remaining_data_length = cpu_to_le32(*_remaining_data_length); +	packet->padding = 0; + +	log_outgoing(INFO, "credits_requested=%d credits_granted=%d data_offset=%d data_length=%d remaining_data_length=%d\n", +		     le16_to_cpu(packet->credits_requested), +		     le16_to_cpu(packet->credits_granted), +		     le32_to_cpu(packet->data_offset), +		     le32_to_cpu(packet->data_length), +		     le32_to_cpu(packet->remaining_data_length)); + +	/* Map the packet to DMA */ +	header_length = sizeof(struct smbd_data_transfer); +	/* If this is a packet without payload, don't send padding */ +	if (!data_length) +		header_length = offsetof(struct smbd_data_transfer, padding); + +	request->sge[0].addr = ib_dma_map_single(info->id->device, +						 (void *)packet, +						 header_length, +						 DMA_TO_DEVICE); +	if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) { +		rc = -EIO; +		request->sge[0].addr = 0; +		goto err_dma; +	} + +	request->sge[0].length = header_length; +	request->sge[0].lkey = info->pd->local_dma_lkey; + +	rc = smbd_post_send(info, request); +	if (!rc) +		return 0; + +err_dma: +	for (i = 0; i < request->num_sge; i++) +		if (request->sge[i].addr) +			ib_dma_unmap_single(info->id->device, +					    request->sge[i].addr, +					    request->sge[i].length, +					    DMA_TO_DEVICE); +	mempool_free(request, info->request_mempool); + +	/* roll back receive credits and credits to be offered */ +	spin_lock(&info->lock_new_credits_offered); +	info->new_credits_offered += new_credits; +	spin_unlock(&info->lock_new_credits_offered); +	atomic_sub(new_credits, &info->receive_credits); + +err_alloc: +	if (atomic_dec_and_test(&info->send_pending)) +		wake_up(&info->wait_send_pending); + +err_wait_send_queue: +	/* roll back send credits and pending */ +	atomic_inc(&info->send_credits); + +err_wait_credit: +	return rc; +} + +/* + * Send an empty message + * Empty message is used to extend credits to peer to for keep live + * while there is no upper layer payload to send at the time + */ +static int smbd_post_send_empty(struct smbd_connection *info) +{ +	int remaining_data_length = 0; + +	info->count_send_empty++; +	return smbd_post_send_iter(info, NULL, &remaining_data_length); +} + +/* + * Post a receive request to the transport + * The remote peer can only send data when a receive request is posted + * The interaction is controlled by send/receive credit system + */ +static int smbd_post_recv( +		struct smbd_connection *info, struct smbd_response *response) +{ +	struct ib_recv_wr recv_wr; +	int rc = -EIO; + +	response->sge.addr = ib_dma_map_single( +				info->id->device, response->packet, +				info->max_receive_size, DMA_FROM_DEVICE); +	if (ib_dma_mapping_error(info->id->device, response->sge.addr)) +		return rc; + +	response->sge.length = info->max_receive_size; +	response->sge.lkey = info->pd->local_dma_lkey; + +	response->cqe.done = recv_done; + +	recv_wr.wr_cqe = &response->cqe; +	recv_wr.next = NULL; +	recv_wr.sg_list = &response->sge; +	recv_wr.num_sge = 1; + +	rc = ib_post_recv(info->id->qp, &recv_wr, NULL); +	if (rc) { +		ib_dma_unmap_single(info->id->device, response->sge.addr, +				    response->sge.length, DMA_FROM_DEVICE); +		smbd_disconnect_rdma_connection(info); +		log_rdma_recv(ERR, "ib_post_recv failed rc=%d\n", rc); +	} + +	return rc; +} + +/* Perform SMBD negotiate according to [MS-SMBD] 3.1.5.2 */ +static int smbd_negotiate(struct smbd_connection *info) +{ +	int rc; +	struct smbd_response *response = get_receive_buffer(info); + +	response->type = SMBD_NEGOTIATE_RESP; +	rc = smbd_post_recv(info, response); +	log_rdma_event(INFO, "smbd_post_recv rc=%d iov.addr=0x%llx iov.length=%u iov.lkey=0x%x\n", +		       rc, response->sge.addr, +		       response->sge.length, response->sge.lkey); +	if (rc) +		return rc; + +	init_completion(&info->negotiate_completion); +	info->negotiate_done = false; +	rc = smbd_post_send_negotiate_req(info); +	if (rc) +		return rc; + +	rc = wait_for_completion_interruptible_timeout( +		&info->negotiate_completion, SMBD_NEGOTIATE_TIMEOUT * HZ); +	log_rdma_event(INFO, "wait_for_completion_timeout rc=%d\n", rc); + +	if (info->negotiate_done) +		return 0; + +	if (rc == 0) +		rc = -ETIMEDOUT; +	else if (rc == -ERESTARTSYS) +		rc = -EINTR; +	else +		rc = -ENOTCONN; + +	return rc; +} + +static void put_empty_packet( +		struct smbd_connection *info, struct smbd_response *response) +{ +	spin_lock(&info->empty_packet_queue_lock); +	list_add_tail(&response->list, &info->empty_packet_queue); +	info->count_empty_packet_queue++; +	spin_unlock(&info->empty_packet_queue_lock); + +	queue_work(info->workqueue, &info->post_send_credits_work); +} + +/* + * Implement Connection.FragmentReassemblyBuffer defined in [MS-SMBD] 3.1.1.1 + * This is a queue for reassembling upper layer payload and present to upper + * layer. All the inncoming payload go to the reassembly queue, regardless of + * if reassembly is required. The uuper layer code reads from the queue for all + * incoming payloads. + * Put a received packet to the reassembly queue + * response: the packet received + * data_length: the size of payload in this packet + */ +static void enqueue_reassembly( +	struct smbd_connection *info, +	struct smbd_response *response, +	int data_length) +{ +	spin_lock(&info->reassembly_queue_lock); +	list_add_tail(&response->list, &info->reassembly_queue); +	info->reassembly_queue_length++; +	/* +	 * Make sure reassembly_data_length is updated after list and +	 * reassembly_queue_length are updated. On the dequeue side +	 * reassembly_data_length is checked without a lock to determine +	 * if reassembly_queue_length and list is up to date +	 */ +	virt_wmb(); +	info->reassembly_data_length += data_length; +	spin_unlock(&info->reassembly_queue_lock); +	info->count_reassembly_queue++; +	info->count_enqueue_reassembly_queue++; +} + +/* + * Get the first entry at the front of reassembly queue + * Caller is responsible for locking + * return value: the first entry if any, NULL if queue is empty + */ +static struct smbd_response *_get_first_reassembly(struct smbd_connection *info) +{ +	struct smbd_response *ret = NULL; + +	if (!list_empty(&info->reassembly_queue)) { +		ret = list_first_entry( +			&info->reassembly_queue, +			struct smbd_response, list); +	} +	return ret; +} + +static struct smbd_response *get_empty_queue_buffer( +		struct smbd_connection *info) +{ +	struct smbd_response *ret = NULL; +	unsigned long flags; + +	spin_lock_irqsave(&info->empty_packet_queue_lock, flags); +	if (!list_empty(&info->empty_packet_queue)) { +		ret = list_first_entry( +			&info->empty_packet_queue, +			struct smbd_response, list); +		list_del(&ret->list); +		info->count_empty_packet_queue--; +	} +	spin_unlock_irqrestore(&info->empty_packet_queue_lock, flags); + +	return ret; +} + +/* + * Get a receive buffer + * For each remote send, we need to post a receive. The receive buffers are + * pre-allocated in advance. + * return value: the receive buffer, NULL if none is available + */ +static struct smbd_response *get_receive_buffer(struct smbd_connection *info) +{ +	struct smbd_response *ret = NULL; +	unsigned long flags; + +	spin_lock_irqsave(&info->receive_queue_lock, flags); +	if (!list_empty(&info->receive_queue)) { +		ret = list_first_entry( +			&info->receive_queue, +			struct smbd_response, list); +		list_del(&ret->list); +		info->count_receive_queue--; +		info->count_get_receive_buffer++; +	} +	spin_unlock_irqrestore(&info->receive_queue_lock, flags); + +	return ret; +} + +/* + * Return a receive buffer + * Upon returning of a receive buffer, we can post new receive and extend + * more receive credits to remote peer. This is done immediately after a + * receive buffer is returned. + */ +static void put_receive_buffer( +	struct smbd_connection *info, struct smbd_response *response) +{ +	unsigned long flags; + +	ib_dma_unmap_single(info->id->device, response->sge.addr, +		response->sge.length, DMA_FROM_DEVICE); + +	spin_lock_irqsave(&info->receive_queue_lock, flags); +	list_add_tail(&response->list, &info->receive_queue); +	info->count_receive_queue++; +	info->count_put_receive_buffer++; +	spin_unlock_irqrestore(&info->receive_queue_lock, flags); + +	queue_work(info->workqueue, &info->post_send_credits_work); +} + +/* Preallocate all receive buffer on transport establishment */ +static int allocate_receive_buffers(struct smbd_connection *info, int num_buf) +{ +	int i; +	struct smbd_response *response; + +	INIT_LIST_HEAD(&info->reassembly_queue); +	spin_lock_init(&info->reassembly_queue_lock); +	info->reassembly_data_length = 0; +	info->reassembly_queue_length = 0; + +	INIT_LIST_HEAD(&info->receive_queue); +	spin_lock_init(&info->receive_queue_lock); +	info->count_receive_queue = 0; + +	INIT_LIST_HEAD(&info->empty_packet_queue); +	spin_lock_init(&info->empty_packet_queue_lock); +	info->count_empty_packet_queue = 0; + +	init_waitqueue_head(&info->wait_receive_queues); + +	for (i = 0; i < num_buf; i++) { +		response = mempool_alloc(info->response_mempool, GFP_KERNEL); +		if (!response) +			goto allocate_failed; + +		response->info = info; +		list_add_tail(&response->list, &info->receive_queue); +		info->count_receive_queue++; +	} + +	return 0; + +allocate_failed: +	while (!list_empty(&info->receive_queue)) { +		response = list_first_entry( +				&info->receive_queue, +				struct smbd_response, list); +		list_del(&response->list); +		info->count_receive_queue--; + +		mempool_free(response, info->response_mempool); +	} +	return -ENOMEM; +} + +static void destroy_receive_buffers(struct smbd_connection *info) +{ +	struct smbd_response *response; + +	while ((response = get_receive_buffer(info))) +		mempool_free(response, info->response_mempool); + +	while ((response = get_empty_queue_buffer(info))) +		mempool_free(response, info->response_mempool); +} + +/* Implement idle connection timer [MS-SMBD] 3.1.6.2 */ +static void idle_connection_timer(struct work_struct *work) +{ +	struct smbd_connection *info = container_of( +					work, struct smbd_connection, +					idle_timer_work.work); + +	if (info->keep_alive_requested != KEEP_ALIVE_NONE) { +		log_keep_alive(ERR, +			"error status info->keep_alive_requested=%d\n", +			info->keep_alive_requested); +		smbd_disconnect_rdma_connection(info); +		return; +	} + +	log_keep_alive(INFO, "about to send an empty idle message\n"); +	smbd_post_send_empty(info); + +	/* Setup the next idle timeout work */ +	queue_delayed_work(info->workqueue, &info->idle_timer_work, +			info->keep_alive_interval*HZ); +} + +/* + * Destroy the transport and related RDMA and memory resources + * Need to go through all the pending counters and make sure on one is using + * the transport while it is destroyed + */ +void smbd_destroy(struct TCP_Server_Info *server) +{ +	struct smbd_connection *info = server->smbd_conn; +	struct smbd_response *response; +	unsigned long flags; + +	if (!info) { +		log_rdma_event(INFO, "rdma session already destroyed\n"); +		return; +	} + +	log_rdma_event(INFO, "destroying rdma session\n"); +	if (info->transport_status != SMBD_DISCONNECTED) { +		rdma_disconnect(server->smbd_conn->id); +		log_rdma_event(INFO, "wait for transport being disconnected\n"); +		wait_event_interruptible( +			info->disconn_wait, +			info->transport_status == SMBD_DISCONNECTED); +	} + +	log_rdma_event(INFO, "destroying qp\n"); +	ib_drain_qp(info->id->qp); +	rdma_destroy_qp(info->id); + +	log_rdma_event(INFO, "cancelling idle timer\n"); +	cancel_delayed_work_sync(&info->idle_timer_work); + +	log_rdma_event(INFO, "wait for all send posted to IB to finish\n"); +	wait_event(info->wait_send_pending, +		atomic_read(&info->send_pending) == 0); + +	/* It's not possible for upper layer to get to reassembly */ +	log_rdma_event(INFO, "drain the reassembly queue\n"); +	do { +		spin_lock_irqsave(&info->reassembly_queue_lock, flags); +		response = _get_first_reassembly(info); +		if (response) { +			list_del(&response->list); +			spin_unlock_irqrestore( +				&info->reassembly_queue_lock, flags); +			put_receive_buffer(info, response); +		} else +			spin_unlock_irqrestore( +				&info->reassembly_queue_lock, flags); +	} while (response); +	info->reassembly_data_length = 0; + +	log_rdma_event(INFO, "free receive buffers\n"); +	wait_event(info->wait_receive_queues, +		info->count_receive_queue + info->count_empty_packet_queue +			== info->receive_credit_max); +	destroy_receive_buffers(info); + +	/* +	 * For performance reasons, memory registration and deregistration +	 * are not locked by srv_mutex. It is possible some processes are +	 * blocked on transport srv_mutex while holding memory registration. +	 * Release the transport srv_mutex to allow them to hit the failure +	 * path when sending data, and then release memory registartions. +	 */ +	log_rdma_event(INFO, "freeing mr list\n"); +	wake_up_interruptible_all(&info->wait_mr); +	while (atomic_read(&info->mr_used_count)) { +		cifs_server_unlock(server); +		msleep(1000); +		cifs_server_lock(server); +	} +	destroy_mr_list(info); + +	ib_free_cq(info->send_cq); +	ib_free_cq(info->recv_cq); +	ib_dealloc_pd(info->pd); +	rdma_destroy_id(info->id); + +	/* free mempools */ +	mempool_destroy(info->request_mempool); +	kmem_cache_destroy(info->request_cache); + +	mempool_destroy(info->response_mempool); +	kmem_cache_destroy(info->response_cache); + +	info->transport_status = SMBD_DESTROYED; + +	destroy_workqueue(info->workqueue); +	log_rdma_event(INFO,  "rdma session destroyed\n"); +	kfree(info); +	server->smbd_conn = NULL; +} + +/* + * Reconnect this SMBD connection, called from upper layer + * return value: 0 on success, or actual error code + */ +int smbd_reconnect(struct TCP_Server_Info *server) +{ +	log_rdma_event(INFO, "reconnecting rdma session\n"); + +	if (!server->smbd_conn) { +		log_rdma_event(INFO, "rdma session already destroyed\n"); +		goto create_conn; +	} + +	/* +	 * This is possible if transport is disconnected and we haven't received +	 * notification from RDMA, but upper layer has detected timeout +	 */ +	if (server->smbd_conn->transport_status == SMBD_CONNECTED) { +		log_rdma_event(INFO, "disconnecting transport\n"); +		smbd_destroy(server); +	} + +create_conn: +	log_rdma_event(INFO, "creating rdma session\n"); +	server->smbd_conn = smbd_get_connection( +		server, (struct sockaddr *) &server->dstaddr); + +	if (server->smbd_conn) +		cifs_dbg(VFS, "RDMA transport re-established\n"); + +	return server->smbd_conn ? 0 : -ENOENT; +} + +static void destroy_caches_and_workqueue(struct smbd_connection *info) +{ +	destroy_receive_buffers(info); +	destroy_workqueue(info->workqueue); +	mempool_destroy(info->response_mempool); +	kmem_cache_destroy(info->response_cache); +	mempool_destroy(info->request_mempool); +	kmem_cache_destroy(info->request_cache); +} + +#define MAX_NAME_LEN	80 +static int allocate_caches_and_workqueue(struct smbd_connection *info) +{ +	char name[MAX_NAME_LEN]; +	int rc; + +	scnprintf(name, MAX_NAME_LEN, "smbd_request_%p", info); +	info->request_cache = +		kmem_cache_create( +			name, +			sizeof(struct smbd_request) + +				sizeof(struct smbd_data_transfer), +			0, SLAB_HWCACHE_ALIGN, NULL); +	if (!info->request_cache) +		return -ENOMEM; + +	info->request_mempool = +		mempool_create(info->send_credit_target, mempool_alloc_slab, +			mempool_free_slab, info->request_cache); +	if (!info->request_mempool) +		goto out1; + +	scnprintf(name, MAX_NAME_LEN, "smbd_response_%p", info); +	info->response_cache = +		kmem_cache_create( +			name, +			sizeof(struct smbd_response) + +				info->max_receive_size, +			0, SLAB_HWCACHE_ALIGN, NULL); +	if (!info->response_cache) +		goto out2; + +	info->response_mempool = +		mempool_create(info->receive_credit_max, mempool_alloc_slab, +		       mempool_free_slab, info->response_cache); +	if (!info->response_mempool) +		goto out3; + +	scnprintf(name, MAX_NAME_LEN, "smbd_%p", info); +	info->workqueue = create_workqueue(name); +	if (!info->workqueue) +		goto out4; + +	rc = allocate_receive_buffers(info, info->receive_credit_max); +	if (rc) { +		log_rdma_event(ERR, "failed to allocate receive buffers\n"); +		goto out5; +	} + +	return 0; + +out5: +	destroy_workqueue(info->workqueue); +out4: +	mempool_destroy(info->response_mempool); +out3: +	kmem_cache_destroy(info->response_cache); +out2: +	mempool_destroy(info->request_mempool); +out1: +	kmem_cache_destroy(info->request_cache); +	return -ENOMEM; +} + +/* Create a SMBD connection, called by upper layer */ +static struct smbd_connection *_smbd_get_connection( +	struct TCP_Server_Info *server, struct sockaddr *dstaddr, int port) +{ +	int rc; +	struct smbd_connection *info; +	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) +		return NULL; + +	info->transport_status = SMBD_CONNECTING; +	rc = smbd_ia_open(info, dstaddr, port); +	if (rc) { +		log_rdma_event(INFO, "smbd_ia_open rc=%d\n", rc); +		goto create_id_failed; +	} + +	if (smbd_send_credit_target > info->id->device->attrs.max_cqe || +	    smbd_send_credit_target > info->id->device->attrs.max_qp_wr) { +		log_rdma_event(ERR, "consider lowering send_credit_target = %d. Possible CQE overrun, device reporting max_cqe %d max_qp_wr %d\n", +			       smbd_send_credit_target, +			       info->id->device->attrs.max_cqe, +			       info->id->device->attrs.max_qp_wr); +		goto config_failed; +	} + +	if (smbd_receive_credit_max > info->id->device->attrs.max_cqe || +	    smbd_receive_credit_max > info->id->device->attrs.max_qp_wr) { +		log_rdma_event(ERR, "consider lowering receive_credit_max = %d. Possible CQE overrun, device reporting max_cqe %d max_qp_wr %d\n", +			       smbd_receive_credit_max, +			       info->id->device->attrs.max_cqe, +			       info->id->device->attrs.max_qp_wr); +		goto config_failed; +	} + +	info->receive_credit_max = smbd_receive_credit_max; +	info->send_credit_target = smbd_send_credit_target; +	info->max_send_size = smbd_max_send_size; +	info->max_fragmented_recv_size = smbd_max_fragmented_recv_size; +	info->max_receive_size = smbd_max_receive_size; +	info->keep_alive_interval = smbd_keep_alive_interval; + +	if (info->id->device->attrs.max_send_sge < SMBDIRECT_MAX_SEND_SGE || +	    info->id->device->attrs.max_recv_sge < SMBDIRECT_MAX_RECV_SGE) { +		log_rdma_event(ERR, +			"device %.*s max_send_sge/max_recv_sge = %d/%d too small\n", +			IB_DEVICE_NAME_MAX, +			info->id->device->name, +			info->id->device->attrs.max_send_sge, +			info->id->device->attrs.max_recv_sge); +		goto config_failed; +	} + +	info->send_cq = NULL; +	info->recv_cq = NULL; +	info->send_cq = +		ib_alloc_cq_any(info->id->device, info, +				info->send_credit_target, IB_POLL_SOFTIRQ); +	if (IS_ERR(info->send_cq)) { +		info->send_cq = NULL; +		goto alloc_cq_failed; +	} + +	info->recv_cq = +		ib_alloc_cq_any(info->id->device, info, +				info->receive_credit_max, IB_POLL_SOFTIRQ); +	if (IS_ERR(info->recv_cq)) { +		info->recv_cq = NULL; +		goto alloc_cq_failed; +	} + +	memset(&qp_attr, 0, sizeof(qp_attr)); +	qp_attr.event_handler = smbd_qp_async_error_upcall; +	qp_attr.qp_context = info; +	qp_attr.cap.max_send_wr = info->send_credit_target; +	qp_attr.cap.max_recv_wr = info->receive_credit_max; +	qp_attr.cap.max_send_sge = SMBDIRECT_MAX_SEND_SGE; +	qp_attr.cap.max_recv_sge = SMBDIRECT_MAX_RECV_SGE; +	qp_attr.cap.max_inline_data = 0; +	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR; +	qp_attr.qp_type = IB_QPT_RC; +	qp_attr.send_cq = info->send_cq; +	qp_attr.recv_cq = info->recv_cq; +	qp_attr.port_num = ~0; + +	rc = rdma_create_qp(info->id, info->pd, &qp_attr); +	if (rc) { +		log_rdma_event(ERR, "rdma_create_qp failed %i\n", rc); +		goto create_qp_failed; +	} + +	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->ops.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; + +	log_rdma_event(INFO, "connecting to IP %pI4 port %d\n", +		&addr_in->sin_addr, port); + +	init_waitqueue_head(&info->conn_wait); +	init_waitqueue_head(&info->disconn_wait); +	init_waitqueue_head(&info->wait_reassembly_queue); +	rc = rdma_connect(info->id, &conn_param); +	if (rc) { +		log_rdma_event(ERR, "rdma_connect() failed with %i\n", rc); +		goto rdma_connect_failed; +	} + +	wait_event_interruptible( +		info->conn_wait, info->transport_status != SMBD_CONNECTING); + +	if (info->transport_status != SMBD_CONNECTED) { +		log_rdma_event(ERR, "rdma_connect failed port=%d\n", port); +		goto rdma_connect_failed; +	} + +	log_rdma_event(INFO, "rdma_connect connected\n"); + +	rc = allocate_caches_and_workqueue(info); +	if (rc) { +		log_rdma_event(ERR, "cache allocation failed\n"); +		goto allocate_cache_failed; +	} + +	init_waitqueue_head(&info->wait_send_queue); +	INIT_DELAYED_WORK(&info->idle_timer_work, idle_connection_timer); +	queue_delayed_work(info->workqueue, &info->idle_timer_work, +		info->keep_alive_interval*HZ); + +	init_waitqueue_head(&info->wait_send_pending); +	atomic_set(&info->send_pending, 0); + +	init_waitqueue_head(&info->wait_post_send); + +	INIT_WORK(&info->disconnect_work, smbd_disconnect_rdma_work); +	INIT_WORK(&info->post_send_credits_work, smbd_post_send_credits); +	info->new_credits_offered = 0; +	spin_lock_init(&info->lock_new_credits_offered); + +	rc = smbd_negotiate(info); +	if (rc) { +		log_rdma_event(ERR, "smbd_negotiate rc=%d\n", rc); +		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 */ +	server->smbd_conn = info; +	smbd_destroy(server); +	return NULL; + +negotiation_failed: +	cancel_delayed_work_sync(&info->idle_timer_work); +	destroy_caches_and_workqueue(info); +	info->transport_status = SMBD_NEGOTIATE_FAILED; +	init_waitqueue_head(&info->conn_wait); +	rdma_disconnect(info->id); +	wait_event(info->conn_wait, +		info->transport_status == SMBD_DISCONNECTED); + +allocate_cache_failed: +rdma_connect_failed: +	rdma_destroy_qp(info->id); + +create_qp_failed: +alloc_cq_failed: +	if (info->send_cq) +		ib_free_cq(info->send_cq); +	if (info->recv_cq) +		ib_free_cq(info->recv_cq); + +config_failed: +	ib_dealloc_pd(info->pd); +	rdma_destroy_id(info->id); + +create_id_failed: +	kfree(info); +	return NULL; +} + +struct smbd_connection *smbd_get_connection( +	struct TCP_Server_Info *server, struct sockaddr *dstaddr) +{ +	struct smbd_connection *ret; +	int port = SMBD_PORT; + +try_again: +	ret = _smbd_get_connection(server, dstaddr, port); + +	/* Try SMB_PORT if SMBD_PORT doesn't work */ +	if (!ret && port == SMBD_PORT) { +		port = SMB_PORT; +		goto try_again; +	} +	return ret; +} + +/* + * Receive data from receive reassembly queue + * All the incoming data packets are placed in reassembly queue + * buf: the buffer to read data into + * size: the length of data to read + * return value: actual data read + * Note: this implementation copies the data from reassebmly queue to receive + * buffers used by upper layer. This is not the optimal code path. A better way + * to do it is to not have upper layer allocate its receive buffers but rather + * borrow the buffer from reassembly queue, and return it after data is + * consumed. But this will require more changes to upper layer code, and also + * need to consider packet boundaries while they still being reassembled. + */ +static int smbd_recv_buf(struct smbd_connection *info, char *buf, +		unsigned int size) +{ +	struct smbd_response *response; +	struct smbd_data_transfer *data_transfer; +	int to_copy, to_read, data_read, offset; +	u32 data_length, remaining_data_length, data_offset; +	int rc; + +again: +	/* +	 * No need to hold the reassembly queue lock all the time as we are +	 * the only one reading from the front of the queue. The transport +	 * may add more entries to the back of the queue at the same time +	 */ +	log_read(INFO, "size=%d info->reassembly_data_length=%d\n", size, +		info->reassembly_data_length); +	if (info->reassembly_data_length >= size) { +		int queue_length; +		int queue_removed = 0; + +		/* +		 * Need to make sure reassembly_data_length is read before +		 * reading reassembly_queue_length and calling +		 * _get_first_reassembly. This call is lock free +		 * as we never read at the end of the queue which are being +		 * updated in SOFTIRQ as more data is received +		 */ +		virt_rmb(); +		queue_length = info->reassembly_queue_length; +		data_read = 0; +		to_read = size; +		offset = info->first_entry_offset; +		while (data_read < size) { +			response = _get_first_reassembly(info); +			data_transfer = smbd_response_payload(response); +			data_length = le32_to_cpu(data_transfer->data_length); +			remaining_data_length = +				le32_to_cpu( +					data_transfer->remaining_data_length); +			data_offset = le32_to_cpu(data_transfer->data_offset); + +			/* +			 * The upper layer expects RFC1002 length at the +			 * beginning of the payload. Return it to indicate +			 * the total length of the packet. This minimize the +			 * change to upper layer packet processing logic. This +			 * will be eventually remove when an intermediate +			 * transport layer is added +			 */ +			if (response->first_segment && size == 4) { +				unsigned int rfc1002_len = +					data_length + remaining_data_length; +				*((__be32 *)buf) = cpu_to_be32(rfc1002_len); +				data_read = 4; +				response->first_segment = false; +				log_read(INFO, "returning rfc1002 length %d\n", +					rfc1002_len); +				goto read_rfc1002_done; +			} + +			to_copy = min_t(int, data_length - offset, to_read); +			memcpy( +				buf + data_read, +				(char *)data_transfer + data_offset + offset, +				to_copy); + +			/* move on to the next buffer? */ +			if (to_copy == data_length - offset) { +				queue_length--; +				/* +				 * No need to lock if we are not at the +				 * end of the queue +				 */ +				if (queue_length) +					list_del(&response->list); +				else { +					spin_lock_irq( +						&info->reassembly_queue_lock); +					list_del(&response->list); +					spin_unlock_irq( +						&info->reassembly_queue_lock); +				} +				queue_removed++; +				info->count_reassembly_queue--; +				info->count_dequeue_reassembly_queue++; +				put_receive_buffer(info, response); +				offset = 0; +				log_read(INFO, "put_receive_buffer offset=0\n"); +			} else +				offset += to_copy; + +			to_read -= to_copy; +			data_read += to_copy; + +			log_read(INFO, "_get_first_reassembly memcpy %d bytes data_transfer_length-offset=%d after that to_read=%d data_read=%d offset=%d\n", +				 to_copy, data_length - offset, +				 to_read, data_read, offset); +		} + +		spin_lock_irq(&info->reassembly_queue_lock); +		info->reassembly_data_length -= data_read; +		info->reassembly_queue_length -= queue_removed; +		spin_unlock_irq(&info->reassembly_queue_lock); + +		info->first_entry_offset = offset; +		log_read(INFO, "returning to thread data_read=%d reassembly_data_length=%d first_entry_offset=%d\n", +			 data_read, info->reassembly_data_length, +			 info->first_entry_offset); +read_rfc1002_done: +		return data_read; +	} + +	log_read(INFO, "wait_event on more data\n"); +	rc = wait_event_interruptible( +		info->wait_reassembly_queue, +		info->reassembly_data_length >= size || +			info->transport_status != SMBD_CONNECTED); +	/* Don't return any data if interrupted */ +	if (rc) +		return rc; + +	if (info->transport_status != SMBD_CONNECTED) { +		log_read(ERR, "disconnected\n"); +		return -ECONNABORTED; +	} + +	goto again; +} + +/* + * Receive a page from receive reassembly queue + * page: the page to read data into + * to_read: the length of data to read + * return value: actual data read + */ +static int smbd_recv_page(struct smbd_connection *info, +		struct page *page, unsigned int page_offset, +		unsigned int to_read) +{ +	int ret; +	char *to_address; +	void *page_address; + +	/* make sure we have the page ready for read */ +	ret = wait_event_interruptible( +		info->wait_reassembly_queue, +		info->reassembly_data_length >= to_read || +			info->transport_status != SMBD_CONNECTED); +	if (ret) +		return ret; + +	/* now we can read from reassembly queue and not sleep */ +	page_address = kmap_atomic(page); +	to_address = (char *) page_address + page_offset; + +	log_read(INFO, "reading from page=%p address=%p to_read=%d\n", +		page, to_address, to_read); + +	ret = smbd_recv_buf(info, to_address, to_read); +	kunmap_atomic(page_address); + +	return ret; +} + +/* + * Receive data from transport + * msg: a msghdr point to the buffer, can be ITER_KVEC or ITER_BVEC + * return: total bytes read, or 0. SMB Direct will not do partial read. + */ +int smbd_recv(struct smbd_connection *info, struct msghdr *msg) +{ +	char *buf; +	struct page *page; +	unsigned int to_read, page_offset; +	int rc; + +	if (iov_iter_rw(&msg->msg_iter) == WRITE) { +		/* It's a bug in upper layer to get there */ +		cifs_dbg(VFS, "Invalid msg iter dir %u\n", +			 iov_iter_rw(&msg->msg_iter)); +		rc = -EINVAL; +		goto out; +	} + +	switch (iov_iter_type(&msg->msg_iter)) { +	case ITER_KVEC: +		buf = msg->msg_iter.kvec->iov_base; +		to_read = msg->msg_iter.kvec->iov_len; +		rc = smbd_recv_buf(info, buf, to_read); +		break; + +	case ITER_BVEC: +		page = msg->msg_iter.bvec->bv_page; +		page_offset = msg->msg_iter.bvec->bv_offset; +		to_read = msg->msg_iter.bvec->bv_len; +		rc = smbd_recv_page(info, page, page_offset, to_read); +		break; + +	default: +		/* It's a bug in upper layer to get there */ +		cifs_dbg(VFS, "Invalid msg type %d\n", +			 iov_iter_type(&msg->msg_iter)); +		rc = -EINVAL; +	} + +out: +	/* SMBDirect will read it all or nothing */ +	if (rc > 0) +		msg->msg_iter.count = 0; +	return rc; +} + +/* + * Send data to transport + * Each rqst is transported as a SMBDirect payload + * rqst: the data to write + * return value: 0 if successfully write, otherwise error code + */ +int smbd_send(struct TCP_Server_Info *server, +	int num_rqst, struct smb_rqst *rqst_array) +{ +	struct smbd_connection *info = server->smbd_conn; +	struct smb_rqst *rqst; +	struct iov_iter iter; +	unsigned int remaining_data_length, klen; +	int rc, i, rqst_idx; + +	if (info->transport_status != SMBD_CONNECTED) +		return -EAGAIN; + +	/* +	 * Add in the page array if there is one. The caller needs to set +	 * rq_tailsz to PAGE_SIZE when the buffer has multiple pages and +	 * ends at page boundary +	 */ +	remaining_data_length = 0; +	for (i = 0; i < num_rqst; i++) +		remaining_data_length += smb_rqst_len(server, &rqst_array[i]); + +	if (unlikely(remaining_data_length > info->max_fragmented_send_size)) { +		/* assertion: payload never exceeds negotiated maximum */ +		log_write(ERR, "payload size %d > max size %d\n", +			remaining_data_length, info->max_fragmented_send_size); +		return -EINVAL; +	} + +	log_write(INFO, "num_rqst=%d total length=%u\n", +			num_rqst, remaining_data_length); + +	rqst_idx = 0; +	do { +		rqst = &rqst_array[rqst_idx]; + +		cifs_dbg(FYI, "Sending smb (RDMA): idx=%d smb_len=%lu\n", +			 rqst_idx, smb_rqst_len(server, rqst)); +		for (i = 0; i < rqst->rq_nvec; i++) +			dump_smb(rqst->rq_iov[i].iov_base, rqst->rq_iov[i].iov_len); + +		log_write(INFO, "RDMA-WR[%u] nvec=%d len=%u iter=%zu rqlen=%lu\n", +			  rqst_idx, rqst->rq_nvec, remaining_data_length, +			  iov_iter_count(&rqst->rq_iter), smb_rqst_len(server, rqst)); + +		/* Send the metadata pages. */ +		klen = 0; +		for (i = 0; i < rqst->rq_nvec; i++) +			klen += rqst->rq_iov[i].iov_len; +		iov_iter_kvec(&iter, ITER_SOURCE, rqst->rq_iov, rqst->rq_nvec, klen); + +		rc = smbd_post_send_iter(info, &iter, &remaining_data_length); +		if (rc < 0) +			break; + +		if (iov_iter_count(&rqst->rq_iter) > 0) { +			/* And then the data pages if there are any */ +			rc = smbd_post_send_iter(info, &rqst->rq_iter, +						 &remaining_data_length); +			if (rc < 0) +				break; +		} + +	} while (++rqst_idx < num_rqst); + +	/* +	 * As an optimization, we don't wait for individual I/O to finish +	 * before sending the next one. +	 * Send them all and wait for pending send count to get to 0 +	 * that means all the I/Os have been out and we are good to return +	 */ + +	wait_event(info->wait_send_pending, +		atomic_read(&info->send_pending) == 0); + +	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_ERROR) { + +			/* recover this MR entry */ +			rc = ib_dereg_mr(smbdirect_mr->mr); +			if (rc) { +				log_rdma_mr(ERR, +					"ib_dereg_mr failed rc=%x\n", +					rc); +				smbd_disconnect_rdma_connection(info); +				continue; +			} + +			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); +				continue; +			} +		} else +			/* This MR is being used, don't recover it */ +			continue; + +		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->sgt.sgl, +				mr->sgt.nents, mr->dir); +		ib_dereg_mr(mr->mr); +		kfree(mr->sgt.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); +	INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work); +	/* 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->sgt.sgl = kcalloc(info->max_frmr_depth, +						sizeof(struct scatterlist), +						GFP_KERNEL); +		if (!smbdirect_mr->sgt.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); +	} +	return 0; + +out: +	kfree(smbdirect_mr); + +	list_for_each_entry_safe(smbdirect_mr, tmp, &info->mr_list, list) { +		list_del(&smbdirect_mr->list); +		ib_dereg_mr(smbdirect_mr->mr); +		kfree(smbdirect_mr->sgt.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; +} + +/* + * Transcribe the pages from an iterator into an MR scatterlist. + */ +static int smbd_iter_to_mr(struct smbd_connection *info, +			   struct iov_iter *iter, +			   struct sg_table *sgt, +			   unsigned int max_sg) +{ +	int ret; + +	memset(sgt->sgl, 0, max_sg * sizeof(struct scatterlist)); + +	ret = netfs_extract_iter_to_sg(iter, iov_iter_count(iter), sgt, max_sg, 0); +	WARN_ON(ret < 0); +	if (sgt->nents > 0) +		sg_mark_end(&sgt->sgl[sgt->nents - 1]); +	return ret; +} + +/* + * Register memory for RDMA read/write + * iter: the buffer to register memory with + * 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 iov_iter *iter, +				 bool writing, bool need_invalidate) +{ +	struct smbd_mr *smbdirect_mr; +	int rc, num_pages; +	enum dma_data_direction dir; +	struct ib_reg_wr *reg_wr; + +	num_pages = iov_iter_npages(iter, info->max_frmr_depth + 1); +	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); +		WARN_ON_ONCE(1); +		return NULL; +	} + +	smbdirect_mr = get_mr(info); +	if (!smbdirect_mr) { +		log_rdma_mr(ERR, "get_mr returning NULL\n"); +		return NULL; +	} + +	dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; +	smbdirect_mr->dir = dir; +	smbdirect_mr->need_invalidate = need_invalidate; +	smbdirect_mr->sgt.nents = 0; +	smbdirect_mr->sgt.orig_nents = 0; + +	log_rdma_mr(INFO, "num_pages=0x%x count=0x%zx depth=%u\n", +		    num_pages, iov_iter_count(iter), info->max_frmr_depth); +	smbd_iter_to_mr(info, iter, &smbdirect_mr->sgt, info->max_frmr_depth); + +	rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgt.sgl, +			   smbdirect_mr->sgt.nents, dir); +	if (!rc) { +		log_rdma_mr(ERR, "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->sgt.sgl, +			  smbdirect_mr->sgt.nents, NULL, PAGE_SIZE); +	if (rc != smbdirect_mr->sgt.nents) { +		log_rdma_mr(ERR, +			"ib_map_mr_sg failed rc = %d nents = %x\n", +			rc, smbdirect_mr->sgt.nents); +		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, NULL); +	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->sgt.sgl, +			smbdirect_mr->sgt.nents, 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); + +	smbd_disconnect_rdma_connection(info); + +	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; +	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, NULL); +		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; + +	if (smbdirect_mr->state == MR_INVALIDATED) { +		ib_dma_unmap_sg( +			info->id->device, smbdirect_mr->sgt.sgl, +			smbdirect_mr->sgt.nents, +			smbdirect_mr->dir); +		smbdirect_mr->state = MR_READY; +		if (atomic_inc_return(&info->mr_ready_count) == 1) +			wake_up_interruptible(&info->wait_mr); +	} else +		/* +		 * Schedule the work to do MR recovery for future I/Os MR +		 * recovery is slow and don't want it to block 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; +} + +static bool smb_set_sge(struct smb_extract_to_rdma *rdma, +			struct page *lowest_page, size_t off, size_t len) +{ +	struct ib_sge *sge = &rdma->sge[rdma->nr_sge]; +	u64 addr; + +	addr = ib_dma_map_page(rdma->device, lowest_page, +			       off, len, rdma->direction); +	if (ib_dma_mapping_error(rdma->device, addr)) +		return false; + +	sge->addr   = addr; +	sge->length = len; +	sge->lkey   = rdma->local_dma_lkey; +	rdma->nr_sge++; +	return true; +} + +/* + * Extract page fragments from a BVEC-class iterator and add them to an RDMA + * element list.  The pages are not pinned. + */ +static ssize_t smb_extract_bvec_to_rdma(struct iov_iter *iter, +					struct smb_extract_to_rdma *rdma, +					ssize_t maxsize) +{ +	const struct bio_vec *bv = iter->bvec; +	unsigned long start = iter->iov_offset; +	unsigned int i; +	ssize_t ret = 0; + +	for (i = 0; i < iter->nr_segs; i++) { +		size_t off, len; + +		len = bv[i].bv_len; +		if (start >= len) { +			start -= len; +			continue; +		} + +		len = min_t(size_t, maxsize, len - start); +		off = bv[i].bv_offset + start; + +		if (!smb_set_sge(rdma, bv[i].bv_page, off, len)) +			return -EIO; + +		ret += len; +		maxsize -= len; +		if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0) +			break; +		start = 0; +	} + +	return ret; +} + +/* + * Extract fragments from a KVEC-class iterator and add them to an RDMA list. + * This can deal with vmalloc'd buffers as well as kmalloc'd or static buffers. + * The pages are not pinned. + */ +static ssize_t smb_extract_kvec_to_rdma(struct iov_iter *iter, +					struct smb_extract_to_rdma *rdma, +					ssize_t maxsize) +{ +	const struct kvec *kv = iter->kvec; +	unsigned long start = iter->iov_offset; +	unsigned int i; +	ssize_t ret = 0; + +	for (i = 0; i < iter->nr_segs; i++) { +		struct page *page; +		unsigned long kaddr; +		size_t off, len, seg; + +		len = kv[i].iov_len; +		if (start >= len) { +			start -= len; +			continue; +		} + +		kaddr = (unsigned long)kv[i].iov_base + start; +		off = kaddr & ~PAGE_MASK; +		len = min_t(size_t, maxsize, len - start); +		kaddr &= PAGE_MASK; + +		maxsize -= len; +		do { +			seg = min_t(size_t, len, PAGE_SIZE - off); + +			if (is_vmalloc_or_module_addr((void *)kaddr)) +				page = vmalloc_to_page((void *)kaddr); +			else +				page = virt_to_page(kaddr); + +			if (!smb_set_sge(rdma, page, off, seg)) +				return -EIO; + +			ret += seg; +			len -= seg; +			kaddr += PAGE_SIZE; +			off = 0; +		} while (len > 0 && rdma->nr_sge < rdma->max_sge); + +		if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0) +			break; +		start = 0; +	} + +	return ret; +} + +/* + * Extract folio fragments from an XARRAY-class iterator and add them to an + * RDMA list.  The folios are not pinned. + */ +static ssize_t smb_extract_xarray_to_rdma(struct iov_iter *iter, +					  struct smb_extract_to_rdma *rdma, +					  ssize_t maxsize) +{ +	struct xarray *xa = iter->xarray; +	struct folio *folio; +	loff_t start = iter->xarray_start + iter->iov_offset; +	pgoff_t index = start / PAGE_SIZE; +	ssize_t ret = 0; +	size_t off, len; +	XA_STATE(xas, xa, index); + +	rcu_read_lock(); + +	xas_for_each(&xas, folio, ULONG_MAX) { +		if (xas_retry(&xas, folio)) +			continue; +		if (WARN_ON(xa_is_value(folio))) +			break; +		if (WARN_ON(folio_test_hugetlb(folio))) +			break; + +		off = offset_in_folio(folio, start); +		len = min_t(size_t, maxsize, folio_size(folio) - off); + +		if (!smb_set_sge(rdma, folio_page(folio, 0), off, len)) { +			rcu_read_unlock(); +			return -EIO; +		} + +		maxsize -= len; +		ret += len; +		if (rdma->nr_sge >= rdma->max_sge || maxsize <= 0) +			break; +	} + +	rcu_read_unlock(); +	return ret; +} + +/* + * Extract page fragments from up to the given amount of the source iterator + * and build up an RDMA list that refers to all of those bits.  The RDMA list + * is appended to, up to the maximum number of elements set in the parameter + * block. + * + * The extracted page fragments are not pinned or ref'd in any way; if an + * IOVEC/UBUF-type iterator is to be used, it should be converted to a + * BVEC-type iterator and the pages pinned, ref'd or otherwise held in some + * way. + */ +static ssize_t smb_extract_iter_to_rdma(struct iov_iter *iter, size_t len, +					struct smb_extract_to_rdma *rdma) +{ +	ssize_t ret; +	int before = rdma->nr_sge; + +	switch (iov_iter_type(iter)) { +	case ITER_BVEC: +		ret = smb_extract_bvec_to_rdma(iter, rdma, len); +		break; +	case ITER_KVEC: +		ret = smb_extract_kvec_to_rdma(iter, rdma, len); +		break; +	case ITER_XARRAY: +		ret = smb_extract_xarray_to_rdma(iter, rdma, len); +		break; +	default: +		WARN_ON_ONCE(1); +		return -EIO; +	} + +	if (ret > 0) { +		iov_iter_advance(iter, ret); +	} else if (ret < 0) { +		while (rdma->nr_sge > before) { +			struct ib_sge *sge = &rdma->sge[rdma->nr_sge--]; + +			ib_dma_unmap_single(rdma->device, sge->addr, sge->length, +					    rdma->direction); +			sge->addr = 0; +		} +	} + +	return ret; +}  | 
