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1/*2 * iSCSI Initiator over iSER Data-Path3 *4 * Copyright (C) 2004 Dmitry Yusupov5 * Copyright (C) 2004 Alex Aizman6 * Copyright (C) 2005 Mike Christie7 * Copyright (c) 2005, 2006 Voltaire, Inc. All rights reserved.8 * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.9 * maintained by openib-general@openib.org10 *11 * This software is available to you under a choice of one of two12 * licenses.  You may choose to be licensed under the terms of the GNU13 * General Public License (GPL) Version 2, available from the file14 * COPYING in the main directory of this source tree, or the15 * OpenIB.org BSD license below:16 *17 *     Redistribution and use in source and binary forms, with or18 *     without modification, are permitted provided that the following19 *     conditions are met:20 *21 *	- Redistributions of source code must retain the above22 *	  copyright notice, this list of conditions and the following23 *	  disclaimer.24 *25 *	- Redistributions in binary form must reproduce the above26 *	  copyright notice, this list of conditions and the following27 *	  disclaimer in the documentation and/or other materials28 *	  provided with the distribution.29 *30 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,31 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF32 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND33 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS34 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN35 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN36 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE37 * SOFTWARE.38 *39 * Credits:40 *	Christoph Hellwig41 *	FUJITA Tomonori42 *	Arne Redlich43 *	Zhenyu Wang44 * Modified by:45 *      Erez Zilber46 */47 48#include <linux/types.h>49#include <linux/list.h>50#include <linux/hardirq.h>51#include <linux/kfifo.h>52#include <linux/blkdev.h>53#include <linux/init.h>54#include <linux/ioctl.h>55#include <linux/cdev.h>56#include <linux/in.h>57#include <linux/net.h>58#include <linux/scatterlist.h>59#include <linux/delay.h>60#include <linux/slab.h>61#include <linux/module.h>62 63#include <net/sock.h>64 65#include <linux/uaccess.h>66 67#include <scsi/scsi_cmnd.h>68#include <scsi/scsi_device.h>69#include <scsi/scsi_eh.h>70#include <scsi/scsi_tcq.h>71#include <scsi/scsi_host.h>72#include <scsi/scsi.h>73#include <scsi/scsi_transport_iscsi.h>74 75#include "iscsi_iser.h"76 77MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover");78MODULE_LICENSE("Dual BSD/GPL");79MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");80 81static const struct scsi_host_template iscsi_iser_sht;82static struct iscsi_transport iscsi_iser_transport;83static struct scsi_transport_template *iscsi_iser_scsi_transport;84static struct workqueue_struct *release_wq;85static DEFINE_MUTEX(unbind_iser_conn_mutex);86struct iser_global ig;87 88int iser_debug_level = 0;89module_param_named(debug_level, iser_debug_level, int, S_IRUGO | S_IWUSR);90MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");91 92static int iscsi_iser_set(const char *val, const struct kernel_param *kp);93static const struct kernel_param_ops iscsi_iser_size_ops = {94	.set = iscsi_iser_set,95	.get = param_get_uint,96};97 98static unsigned int iscsi_max_lun = 512;99module_param_cb(max_lun, &iscsi_iser_size_ops, &iscsi_max_lun, S_IRUGO);100MODULE_PARM_DESC(max_lun, "Max LUNs to allow per session, should > 0 (default:512)");101 102unsigned int iser_max_sectors = ISER_DEF_MAX_SECTORS;103module_param_cb(max_sectors, &iscsi_iser_size_ops, &iser_max_sectors,104		S_IRUGO | S_IWUSR);105MODULE_PARM_DESC(max_sectors, "Max number of sectors in a single scsi command, should > 0 (default:1024)");106 107bool iser_always_reg = true;108module_param_named(always_register, iser_always_reg, bool, S_IRUGO);109MODULE_PARM_DESC(always_register,110		 "Always register memory, even for continuous memory regions (default:true)");111 112bool iser_pi_enable = false;113module_param_named(pi_enable, iser_pi_enable, bool, S_IRUGO);114MODULE_PARM_DESC(pi_enable, "Enable T10-PI offload support (default:disabled)");115 116static int iscsi_iser_set(const char *val, const struct kernel_param *kp)117{118	int ret;119	unsigned int n = 0;120 121	ret = kstrtouint(val, 10, &n);122	if (ret != 0 || n == 0)123		return -EINVAL;124 125	return param_set_uint(val, kp);126}127 128/*129 * iscsi_iser_recv() - Process a successful recv completion130 * @conn:         iscsi connection131 * @hdr:          iscsi header132 * @rx_data:      buffer containing receive data payload133 * @rx_data_len:  length of rx_data134 *135 * Notes: In case of data length errors or iscsi PDU completion failures136 *        this routine will signal iscsi layer of connection failure.137 */138void iscsi_iser_recv(struct iscsi_conn *conn, struct iscsi_hdr *hdr,139		     char *rx_data, int rx_data_len)140{141	int rc = 0;142	int datalen;143 144	/* verify PDU length */145	datalen = ntoh24(hdr->dlength);146	if (datalen > rx_data_len || (datalen + 4) < rx_data_len) {147		iser_err("wrong datalen %d (hdr), %d (IB)\n",148			datalen, rx_data_len);149		rc = ISCSI_ERR_DATALEN;150		goto error;151	}152 153	if (datalen != rx_data_len)154		iser_dbg("aligned datalen (%d) hdr, %d (IB)\n",155			datalen, rx_data_len);156 157	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);158	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)159		goto error;160 161	return;162error:163	iscsi_conn_failure(conn, rc);164}165 166/**167 * iscsi_iser_pdu_alloc() - allocate an iscsi-iser PDU168 * @task:     iscsi task169 * @opcode:   iscsi command opcode170 *171 * Netes: This routine can't fail, just assign iscsi task172 *        hdr and max hdr size.173 */174static int iscsi_iser_pdu_alloc(struct iscsi_task *task, uint8_t opcode)175{176	struct iscsi_iser_task *iser_task = task->dd_data;177 178	task->hdr = (struct iscsi_hdr *)&iser_task->desc.iscsi_header;179	task->hdr_max = sizeof(iser_task->desc.iscsi_header);180 181	return 0;182}183 184/**185 * iser_initialize_task_headers() - Initialize task headers186 * @task:       iscsi task187 * @tx_desc:    iser tx descriptor188 *189 * Notes:190 * This routine may race with iser teardown flow for scsi191 * error handling TMFs. So for TMF we should acquire the192 * state mutex to avoid dereferencing the IB device which193 * may have already been terminated.194 */195int iser_initialize_task_headers(struct iscsi_task *task,196				 struct iser_tx_desc *tx_desc)197{198	struct iser_conn *iser_conn = task->conn->dd_data;199	struct iser_device *device = iser_conn->ib_conn.device;200	struct iscsi_iser_task *iser_task = task->dd_data;201	u64 dma_addr;202 203	if (unlikely(iser_conn->state != ISER_CONN_UP))204		return -ENODEV;205 206	dma_addr = ib_dma_map_single(device->ib_device, (void *)tx_desc,207				ISER_HEADERS_LEN, DMA_TO_DEVICE);208	if (ib_dma_mapping_error(device->ib_device, dma_addr))209		return -ENOMEM;210 211	tx_desc->inv_wr.next = NULL;212	tx_desc->reg_wr.wr.next = NULL;213	tx_desc->mapped = true;214	tx_desc->dma_addr = dma_addr;215	tx_desc->tx_sg[0].addr   = tx_desc->dma_addr;216	tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;217	tx_desc->tx_sg[0].lkey   = device->pd->local_dma_lkey;218 219	iser_task->iser_conn = iser_conn;220 221	return 0;222}223 224/**225 * iscsi_iser_task_init() - Initialize iscsi-iser task226 * @task: iscsi task227 *228 * Initialize the task for the scsi command or mgmt command.229 *230 * Return: Returns zero on success or -ENOMEM when failing231 *         to init task headers (dma mapping error).232 */233static int iscsi_iser_task_init(struct iscsi_task *task)234{235	struct iscsi_iser_task *iser_task = task->dd_data;236	int ret;237 238	ret = iser_initialize_task_headers(task, &iser_task->desc);239	if (ret) {240		iser_err("Failed to init task %p, err = %d\n",241			 iser_task, ret);242		return ret;243	}244 245	/* mgmt task */246	if (!task->sc)247		return 0;248 249	iser_task->command_sent = 0;250	iser_task_rdma_init(iser_task);251	iser_task->sc = task->sc;252 253	return 0;254}255 256/**257 * iscsi_iser_mtask_xmit() - xmit management (immediate) task258 * @conn: iscsi connection259 * @task: task management task260 *261 * Notes:262 *	The function can return -EAGAIN in which case caller must263 *	call it again later, or recover. '0' return code means successful264 *	xmit.265 *266 **/267static int iscsi_iser_mtask_xmit(struct iscsi_conn *conn,268				 struct iscsi_task *task)269{270	int error = 0;271 272	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);273 274	error = iser_send_control(conn, task);275 276	/* since iser xmits control with zero copy, tasks can not be recycled277	 * right after sending them.278	 * The recycling scheme is based on whether a response is expected279	 * - if yes, the task is recycled at iscsi_complete_pdu280	 * - if no,  the task is recycled at iser_snd_completion281	 */282	return error;283}284 285static int iscsi_iser_task_xmit_unsol_data(struct iscsi_conn *conn,286					   struct iscsi_task *task)287{288	struct iscsi_r2t_info *r2t = &task->unsol_r2t;289	struct iscsi_data hdr;290	int error = 0;291 292	/* Send data-out PDUs while there's still unsolicited data to send */293	while (iscsi_task_has_unsol_data(task)) {294		iscsi_prep_data_out_pdu(task, r2t, &hdr);295		iser_dbg("Sending data-out: itt 0x%x, data count %d\n",296			   hdr.itt, r2t->data_count);297 298		/* the buffer description has been passed with the command */299		/* Send the command */300		error = iser_send_data_out(conn, task, &hdr);301		if (error) {302			r2t->datasn--;303			goto iscsi_iser_task_xmit_unsol_data_exit;304		}305		r2t->sent += r2t->data_count;306		iser_dbg("Need to send %d more as data-out PDUs\n",307			   r2t->data_length - r2t->sent);308	}309 310iscsi_iser_task_xmit_unsol_data_exit:311	return error;312}313 314/**315 * iscsi_iser_task_xmit() - xmit iscsi-iser task316 * @task: iscsi task317 *318 * Return: zero on success or escalates $error on failure.319 */320static int iscsi_iser_task_xmit(struct iscsi_task *task)321{322	struct iscsi_conn *conn = task->conn;323	struct iscsi_iser_task *iser_task = task->dd_data;324	int error = 0;325 326	if (!task->sc)327		return iscsi_iser_mtask_xmit(conn, task);328 329	if (task->sc->sc_data_direction == DMA_TO_DEVICE) {330		BUG_ON(scsi_bufflen(task->sc) == 0);331 332		iser_dbg("cmd [itt %x total %d imm %d unsol_data %d\n",333			   task->itt, scsi_bufflen(task->sc),334			   task->imm_count, task->unsol_r2t.data_length);335	}336 337	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",338		   conn->id, task->itt);339 340	/* Send the cmd PDU */341	if (!iser_task->command_sent) {342		error = iser_send_command(conn, task);343		if (error)344			goto iscsi_iser_task_xmit_exit;345		iser_task->command_sent = 1;346	}347 348	/* Send unsolicited data-out PDU(s) if necessary */349	if (iscsi_task_has_unsol_data(task))350		error = iscsi_iser_task_xmit_unsol_data(conn, task);351 352 iscsi_iser_task_xmit_exit:353	return error;354}355 356/**357 * iscsi_iser_cleanup_task() - cleanup an iscsi-iser task358 * @task: iscsi task359 *360 * Notes: In case the RDMA device is already NULL (might have361 *        been removed in DEVICE_REMOVAL CM event it will bail-out362 *        without doing dma unmapping.363 */364static void iscsi_iser_cleanup_task(struct iscsi_task *task)365{366	struct iscsi_iser_task *iser_task = task->dd_data;367	struct iser_tx_desc *tx_desc = &iser_task->desc;368	struct iser_conn *iser_conn = task->conn->dd_data;369	struct iser_device *device = iser_conn->ib_conn.device;370 371	/* DEVICE_REMOVAL event might have already released the device */372	if (!device)373		return;374 375	if (likely(tx_desc->mapped)) {376		ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,377				    ISER_HEADERS_LEN, DMA_TO_DEVICE);378		tx_desc->mapped = false;379	}380 381	/* mgmt tasks do not need special cleanup */382	if (!task->sc)383		return;384 385	if (iser_task->status == ISER_TASK_STATUS_STARTED) {386		iser_task->status = ISER_TASK_STATUS_COMPLETED;387		iser_task_rdma_finalize(iser_task);388	}389}390 391/**392 * iscsi_iser_check_protection() - check protection information status of task.393 * @task:     iscsi task394 * @sector:   error sector if exsists (output)395 *396 * Return: zero if no data-integrity errors have occured397 *         0x1: data-integrity error occured in the guard-block398 *         0x2: data-integrity error occured in the reference tag399 *         0x3: data-integrity error occured in the application tag400 *401 *         In addition the error sector is marked.402 */403static u8 iscsi_iser_check_protection(struct iscsi_task *task, sector_t *sector)404{405	struct iscsi_iser_task *iser_task = task->dd_data;406	enum iser_data_dir dir = iser_task->dir[ISER_DIR_IN] ?407					ISER_DIR_IN : ISER_DIR_OUT;408 409	return iser_check_task_pi_status(iser_task, dir, sector);410}411 412/**413 * iscsi_iser_conn_create() - create a new iscsi-iser connection414 * @cls_session: iscsi class connection415 * @conn_idx:    connection index within the session (for MCS)416 *417 * Return: iscsi_cls_conn when iscsi_conn_setup succeeds or NULL418 *         otherwise.419 */420static struct iscsi_cls_conn *421iscsi_iser_conn_create(struct iscsi_cls_session *cls_session,422		       uint32_t conn_idx)423{424	struct iscsi_conn *conn;425	struct iscsi_cls_conn *cls_conn;426 427	cls_conn = iscsi_conn_setup(cls_session, 0, conn_idx);428	if (!cls_conn)429		return NULL;430	conn = cls_conn->dd_data;431 432	/*433	 * due to issues with the login code re iser sematics434	 * this not set in iscsi_conn_setup - FIXME435	 */436	conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;437 438	return cls_conn;439}440 441/**442 * iscsi_iser_conn_bind() - bind iscsi and iser connection structures443 * @cls_session:     iscsi class session444 * @cls_conn:        iscsi class connection445 * @transport_eph:   transport end-point handle446 * @is_leading:      indicate if this is the session leading connection (MCS)447 *448 * Return: zero on success, $error if iscsi_conn_bind fails and449 *         -EINVAL in case end-point doesn't exists anymore or iser connection450 *         state is not UP (teardown already started).451 */452static int iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,453				struct iscsi_cls_conn *cls_conn,454				uint64_t transport_eph, int is_leading)455{456	struct iscsi_conn *conn = cls_conn->dd_data;457	struct iser_conn *iser_conn;458	struct iscsi_endpoint *ep;459	int error;460 461	error = iscsi_conn_bind(cls_session, cls_conn, is_leading);462	if (error)463		return error;464 465	/* the transport ep handle comes from user space so it must be466	 * verified against the global ib connections list */467	ep = iscsi_lookup_endpoint(transport_eph);468	if (!ep) {469		iser_err("can't bind eph %llx\n",470			 (unsigned long long)transport_eph);471		return -EINVAL;472	}473	iser_conn = ep->dd_data;474 475	mutex_lock(&iser_conn->state_mutex);476	if (iser_conn->state != ISER_CONN_UP) {477		error = -EINVAL;478		iser_err("iser_conn %p state is %d, teardown started\n",479			 iser_conn, iser_conn->state);480		goto out;481	}482 483	error = iser_alloc_rx_descriptors(iser_conn, conn->session);484	if (error)485		goto out;486 487	/* binds the iSER connection retrieved from the previously488	 * connected ep_handle to the iSCSI layer connection. exchanges489	 * connection pointers */490	iser_info("binding iscsi conn %p to iser_conn %p\n", conn, iser_conn);491 492	conn->dd_data = iser_conn;493	iser_conn->iscsi_conn = conn;494 495out:496	iscsi_put_endpoint(ep);497	mutex_unlock(&iser_conn->state_mutex);498	return error;499}500 501/**502 * iscsi_iser_conn_start() - start iscsi-iser connection503 * @cls_conn: iscsi class connection504 *505 * Notes: Here iser intialize (or re-initialize) stop_completion as506 *        from this point iscsi must call conn_stop in session/connection507 *        teardown so iser transport must wait for it.508 */509static int iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)510{511	struct iscsi_conn *iscsi_conn;512	struct iser_conn *iser_conn;513 514	iscsi_conn = cls_conn->dd_data;515	iser_conn = iscsi_conn->dd_data;516	reinit_completion(&iser_conn->stop_completion);517 518	return iscsi_conn_start(cls_conn);519}520 521/**522 * iscsi_iser_conn_stop() - stop iscsi-iser connection523 * @cls_conn:  iscsi class connection524 * @flag:      indicate if recover or terminate (passed as is)525 *526 * Notes: Calling iscsi_conn_stop might theoretically race with527 *        DEVICE_REMOVAL event and dereference a previously freed RDMA device528 *        handle, so we call it under iser the state lock to protect against529 *        this kind of race.530 */531static void iscsi_iser_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)532{533	struct iscsi_conn *conn = cls_conn->dd_data;534	struct iser_conn *iser_conn = conn->dd_data;535 536	iser_info("stopping iscsi_conn: %p, iser_conn: %p\n", conn, iser_conn);537 538	/*539	 * Userspace may have goofed up and not bound the connection or540	 * might have only partially setup the connection.541	 */542	if (iser_conn) {543		mutex_lock(&iser_conn->state_mutex);544		mutex_lock(&unbind_iser_conn_mutex);545		iser_conn_terminate(iser_conn);546		iscsi_conn_stop(cls_conn, flag);547 548		/* unbind */549		iser_conn->iscsi_conn = NULL;550		conn->dd_data = NULL;551		mutex_unlock(&unbind_iser_conn_mutex);552 553		complete(&iser_conn->stop_completion);554		mutex_unlock(&iser_conn->state_mutex);555	} else {556		iscsi_conn_stop(cls_conn, flag);557	}558}559 560/**561 * iscsi_iser_session_destroy() - destroy iscsi-iser session562 * @cls_session: iscsi class session563 *564 * Removes and free iscsi host.565 */566static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)567{568	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);569 570	iscsi_session_teardown(cls_session);571	iscsi_host_remove(shost, false);572	iscsi_host_free(shost);573}574 575static inline unsigned int iser_dif_prot_caps(int prot_caps)576{577	int ret = 0;578 579	if (prot_caps & IB_PROT_T10DIF_TYPE_1)580		ret |= SHOST_DIF_TYPE1_PROTECTION |581		       SHOST_DIX_TYPE0_PROTECTION |582		       SHOST_DIX_TYPE1_PROTECTION;583	if (prot_caps & IB_PROT_T10DIF_TYPE_2)584		ret |= SHOST_DIF_TYPE2_PROTECTION |585		       SHOST_DIX_TYPE2_PROTECTION;586	if (prot_caps & IB_PROT_T10DIF_TYPE_3)587		ret |= SHOST_DIF_TYPE3_PROTECTION |588		       SHOST_DIX_TYPE3_PROTECTION;589 590	return ret;591}592 593/**594 * iscsi_iser_session_create() - create an iscsi-iser session595 * @ep:             iscsi end-point handle596 * @cmds_max:       maximum commands in this session597 * @qdepth:         session command queue depth598 * @initial_cmdsn:  initiator command sequnce number599 *600 * Allocates and adds a scsi host, expose DIF supprot if601 * exists, and sets up an iscsi session.602 */603static struct iscsi_cls_session *604iscsi_iser_session_create(struct iscsi_endpoint *ep,605			  uint16_t cmds_max, uint16_t qdepth,606			  uint32_t initial_cmdsn)607{608	struct iscsi_cls_session *cls_session;609	struct Scsi_Host *shost;610	struct iser_conn *iser_conn = NULL;611	struct ib_conn *ib_conn;612	struct ib_device *ib_dev;613	u32 max_fr_sectors;614 615	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);616	if (!shost)617		return NULL;618	shost->transportt = iscsi_iser_scsi_transport;619	shost->cmd_per_lun = qdepth;620	shost->max_lun = iscsi_max_lun;621	shost->max_id = 0;622	shost->max_channel = 0;623	shost->max_cmd_len = 16;624 625	/*626	 * older userspace tools (before 2.0-870) did not pass us627	 * the leading conn's ep so this will be NULL;628	 */629	if (ep) {630		iser_conn = ep->dd_data;631		shost->sg_tablesize = iser_conn->scsi_sg_tablesize;632		shost->can_queue = min_t(u16, cmds_max, iser_conn->max_cmds);633 634		mutex_lock(&iser_conn->state_mutex);635		if (iser_conn->state != ISER_CONN_UP) {636			iser_err("iser conn %p already started teardown\n",637				 iser_conn);638			mutex_unlock(&iser_conn->state_mutex);639			goto free_host;640		}641 642		ib_conn = &iser_conn->ib_conn;643		ib_dev = ib_conn->device->ib_device;644		if (ib_conn->pi_support) {645			u32 sig_caps = ib_dev->attrs.sig_prot_cap;646 647			shost->sg_prot_tablesize = shost->sg_tablesize;648			scsi_host_set_prot(shost, iser_dif_prot_caps(sig_caps));649			scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP |650						   SHOST_DIX_GUARD_CRC);651		}652 653		if (!(ib_dev->attrs.kernel_cap_flags & IBK_SG_GAPS_REG))654			shost->virt_boundary_mask = SZ_4K - 1;655 656		if (iscsi_host_add(shost, ib_dev->dev.parent)) {657			mutex_unlock(&iser_conn->state_mutex);658			goto free_host;659		}660		mutex_unlock(&iser_conn->state_mutex);661	} else {662		shost->can_queue = min_t(u16, cmds_max, ISER_DEF_XMIT_CMDS_MAX);663		if (iscsi_host_add(shost, NULL))664			goto free_host;665	}666 667	max_fr_sectors = (shost->sg_tablesize * PAGE_SIZE) >> 9;668	shost->max_sectors = min(iser_max_sectors, max_fr_sectors);669 670	iser_dbg("iser_conn %p, sg_tablesize %u, max_sectors %u\n",671		 iser_conn, shost->sg_tablesize,672		 shost->max_sectors);673 674	if (shost->max_sectors < iser_max_sectors)675		iser_warn("max_sectors was reduced from %u to %u\n",676			  iser_max_sectors, shost->max_sectors);677 678	cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,679					  shost->can_queue, 0,680					  sizeof(struct iscsi_iser_task),681					  initial_cmdsn, 0);682	if (!cls_session)683		goto remove_host;684 685	return cls_session;686 687remove_host:688	iscsi_host_remove(shost, false);689free_host:690	iscsi_host_free(shost);691	return NULL;692}693 694static int iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,695				enum iscsi_param param, char *buf, int buflen)696{697	int value;698 699	switch (param) {700	case ISCSI_PARAM_MAX_RECV_DLENGTH:701		/* TBD */702		break;703	case ISCSI_PARAM_HDRDGST_EN:704		sscanf(buf, "%d", &value);705		if (value) {706			iser_err("DataDigest wasn't negotiated to None\n");707			return -EPROTO;708		}709		break;710	case ISCSI_PARAM_DATADGST_EN:711		sscanf(buf, "%d", &value);712		if (value) {713			iser_err("DataDigest wasn't negotiated to None\n");714			return -EPROTO;715		}716		break;717	case ISCSI_PARAM_IFMARKER_EN:718		sscanf(buf, "%d", &value);719		if (value) {720			iser_err("IFMarker wasn't negotiated to No\n");721			return -EPROTO;722		}723		break;724	case ISCSI_PARAM_OFMARKER_EN:725		sscanf(buf, "%d", &value);726		if (value) {727			iser_err("OFMarker wasn't negotiated to No\n");728			return -EPROTO;729		}730		break;731	default:732		return iscsi_set_param(cls_conn, param, buf, buflen);733	}734 735	return 0;736}737 738/**739 * iscsi_iser_conn_get_stats() - get iscsi connection statistics740 * @cls_conn:    iscsi class connection741 * @stats:       iscsi stats to output742 *743 * Output connection statistics.744 */745static void iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn,746				      struct iscsi_stats *stats)747{748	struct iscsi_conn *conn = cls_conn->dd_data;749 750	stats->txdata_octets = conn->txdata_octets;751	stats->rxdata_octets = conn->rxdata_octets;752	stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;753	stats->dataout_pdus = conn->dataout_pdus_cnt;754	stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;755	stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */756	stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */757	stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;758	stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;759	stats->custom_length = 0;760}761 762static int iscsi_iser_get_ep_param(struct iscsi_endpoint *ep,763				   enum iscsi_param param, char *buf)764{765	struct iser_conn *iser_conn = ep->dd_data;766 767	switch (param) {768	case ISCSI_PARAM_CONN_PORT:769	case ISCSI_PARAM_CONN_ADDRESS:770		if (!iser_conn || !iser_conn->ib_conn.cma_id)771			return -ENOTCONN;772 773		return iscsi_conn_get_addr_param((struct sockaddr_storage *)774				&iser_conn->ib_conn.cma_id->route.addr.dst_addr,775				param, buf);776	default:777		break;778	}779	return -ENOSYS;780}781 782/**783 * iscsi_iser_ep_connect() - Initiate iSER connection establishment784 * @shost:          scsi_host785 * @dst_addr:       destination address786 * @non_blocking:   indicate if routine can block787 *788 * Allocate an iscsi endpoint, an iser_conn structure and bind them.789 * After that start RDMA connection establishment via rdma_cm. We790 * don't allocate iser_conn embedded in iscsi_endpoint since in teardown791 * the endpoint will be destroyed at ep_disconnect while iser_conn will792 * cleanup its resources asynchronuously.793 *794 * Return: iscsi_endpoint created by iscsi layer or ERR_PTR(error)795 *         if fails.796 */797static struct iscsi_endpoint *iscsi_iser_ep_connect(struct Scsi_Host *shost,798						    struct sockaddr *dst_addr,799						    int non_blocking)800{801	int err;802	struct iser_conn *iser_conn;803	struct iscsi_endpoint *ep;804 805	ep = iscsi_create_endpoint(0);806	if (!ep)807		return ERR_PTR(-ENOMEM);808 809	iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);810	if (!iser_conn) {811		err = -ENOMEM;812		goto failure;813	}814 815	ep->dd_data = iser_conn;816	iser_conn->ep = ep;817	iser_conn_init(iser_conn);818 819	err = iser_connect(iser_conn, NULL, dst_addr, non_blocking);820	if (err)821		goto failure;822 823	return ep;824failure:825	iscsi_destroy_endpoint(ep);826	return ERR_PTR(err);827}828 829/**830 * iscsi_iser_ep_poll() - poll for iser connection establishment to complete831 * @ep:            iscsi endpoint (created at ep_connect)832 * @timeout_ms:    polling timeout allowed in ms.833 *834 * This routine boils down to waiting for up_completion signaling835 * that cma_id got CONNECTED event.836 *837 * Return: 1 if succeeded in connection establishment, 0 if timeout expired838 *         (libiscsi will retry will kick in) or -1 if interrupted by signal839 *         or more likely iser connection state transitioned to TEMINATING or840 *         DOWN during the wait period.841 */842static int iscsi_iser_ep_poll(struct iscsi_endpoint *ep, int timeout_ms)843{844	struct iser_conn *iser_conn = ep->dd_data;845	int rc;846 847	rc = wait_for_completion_interruptible_timeout(&iser_conn->up_completion,848						       msecs_to_jiffies(timeout_ms));849	/* if conn establishment failed, return error code to iscsi */850	if (rc == 0) {851		mutex_lock(&iser_conn->state_mutex);852		if (iser_conn->state == ISER_CONN_TERMINATING ||853		    iser_conn->state == ISER_CONN_DOWN)854			rc = -1;855		mutex_unlock(&iser_conn->state_mutex);856	}857 858	iser_info("iser conn %p rc = %d\n", iser_conn, rc);859 860	if (rc > 0)861		return 1; /* success, this is the equivalent of EPOLLOUT */862	else if (!rc)863		return 0; /* timeout */864	else865		return rc; /* signal */866}867 868/**869 * iscsi_iser_ep_disconnect() - Initiate connection teardown process870 * @ep:    iscsi endpoint handle871 *872 * This routine is not blocked by iser and RDMA termination process873 * completion as we queue a deffered work for iser/RDMA destruction874 * and cleanup or actually call it immediately in case we didn't pass875 * iscsi conn bind/start stage, thus it is safe.876 */877static void iscsi_iser_ep_disconnect(struct iscsi_endpoint *ep)878{879	struct iser_conn *iser_conn = ep->dd_data;880 881	iser_info("ep %p iser conn %p\n", ep, iser_conn);882 883	mutex_lock(&iser_conn->state_mutex);884	iser_conn_terminate(iser_conn);885 886	/*887	 * if iser_conn and iscsi_conn are bound, we must wait for888	 * iscsi_conn_stop and flush errors completion before freeing889	 * the iser resources. Otherwise we are safe to free resources890	 * immediately.891	 */892	if (iser_conn->iscsi_conn) {893		INIT_WORK(&iser_conn->release_work, iser_release_work);894		queue_work(release_wq, &iser_conn->release_work);895		mutex_unlock(&iser_conn->state_mutex);896	} else {897		iser_conn->state = ISER_CONN_DOWN;898		mutex_unlock(&iser_conn->state_mutex);899		iser_conn_release(iser_conn);900	}901 902	iscsi_destroy_endpoint(ep);903}904 905static umode_t iser_attr_is_visible(int param_type, int param)906{907	switch (param_type) {908	case ISCSI_HOST_PARAM:909		switch (param) {910		case ISCSI_HOST_PARAM_NETDEV_NAME:911		case ISCSI_HOST_PARAM_HWADDRESS:912		case ISCSI_HOST_PARAM_INITIATOR_NAME:913			return S_IRUGO;914		default:915			return 0;916		}917	case ISCSI_PARAM:918		switch (param) {919		case ISCSI_PARAM_MAX_RECV_DLENGTH:920		case ISCSI_PARAM_MAX_XMIT_DLENGTH:921		case ISCSI_PARAM_HDRDGST_EN:922		case ISCSI_PARAM_DATADGST_EN:923		case ISCSI_PARAM_CONN_ADDRESS:924		case ISCSI_PARAM_CONN_PORT:925		case ISCSI_PARAM_EXP_STATSN:926		case ISCSI_PARAM_PERSISTENT_ADDRESS:927		case ISCSI_PARAM_PERSISTENT_PORT:928		case ISCSI_PARAM_PING_TMO:929		case ISCSI_PARAM_RECV_TMO:930		case ISCSI_PARAM_INITIAL_R2T_EN:931		case ISCSI_PARAM_MAX_R2T:932		case ISCSI_PARAM_IMM_DATA_EN:933		case ISCSI_PARAM_FIRST_BURST:934		case ISCSI_PARAM_MAX_BURST:935		case ISCSI_PARAM_PDU_INORDER_EN:936		case ISCSI_PARAM_DATASEQ_INORDER_EN:937		case ISCSI_PARAM_TARGET_NAME:938		case ISCSI_PARAM_TPGT:939		case ISCSI_PARAM_USERNAME:940		case ISCSI_PARAM_PASSWORD:941		case ISCSI_PARAM_USERNAME_IN:942		case ISCSI_PARAM_PASSWORD_IN:943		case ISCSI_PARAM_FAST_ABORT:944		case ISCSI_PARAM_ABORT_TMO:945		case ISCSI_PARAM_LU_RESET_TMO:946		case ISCSI_PARAM_TGT_RESET_TMO:947		case ISCSI_PARAM_IFACE_NAME:948		case ISCSI_PARAM_INITIATOR_NAME:949		case ISCSI_PARAM_DISCOVERY_SESS:950			return S_IRUGO;951		default:952			return 0;953		}954	}955 956	return 0;957}958 959static const struct scsi_host_template iscsi_iser_sht = {960	.module                 = THIS_MODULE,961	.name                   = "iSCSI Initiator over iSER",962	.queuecommand           = iscsi_queuecommand,963	.change_queue_depth	= scsi_change_queue_depth,964	.sg_tablesize           = ISCSI_ISER_DEF_SG_TABLESIZE,965	.cmd_per_lun            = ISER_DEF_CMD_PER_LUN,966	.eh_timed_out		= iscsi_eh_cmd_timed_out,967	.eh_abort_handler       = iscsi_eh_abort,968	.eh_device_reset_handler= iscsi_eh_device_reset,969	.eh_target_reset_handler = iscsi_eh_recover_target,970	.target_alloc		= iscsi_target_alloc,971	.proc_name              = "iscsi_iser",972	.this_id                = -1,973	.track_queue_depth	= 1,974	.cmd_size		= sizeof(struct iscsi_cmd),975};976 977static struct iscsi_transport iscsi_iser_transport = {978	.owner                  = THIS_MODULE,979	.name                   = "iser",980	.caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_TEXT_NEGO,981	/* session management */982	.create_session         = iscsi_iser_session_create,983	.destroy_session        = iscsi_iser_session_destroy,984	/* connection management */985	.create_conn            = iscsi_iser_conn_create,986	.bind_conn              = iscsi_iser_conn_bind,987	.unbind_conn		= iscsi_conn_unbind,988	.destroy_conn           = iscsi_conn_teardown,989	.attr_is_visible	= iser_attr_is_visible,990	.set_param              = iscsi_iser_set_param,991	.get_conn_param		= iscsi_conn_get_param,992	.get_ep_param		= iscsi_iser_get_ep_param,993	.get_session_param	= iscsi_session_get_param,994	.start_conn             = iscsi_iser_conn_start,995	.stop_conn              = iscsi_iser_conn_stop,996	/* iscsi host params */997	.get_host_param		= iscsi_host_get_param,998	.set_host_param		= iscsi_host_set_param,999	/* IO */1000	.send_pdu		= iscsi_conn_send_pdu,1001	.get_stats		= iscsi_iser_conn_get_stats,1002	.init_task		= iscsi_iser_task_init,1003	.xmit_task		= iscsi_iser_task_xmit,1004	.cleanup_task		= iscsi_iser_cleanup_task,1005	.alloc_pdu		= iscsi_iser_pdu_alloc,1006	.check_protection	= iscsi_iser_check_protection,1007	/* recovery */1008	.session_recovery_timedout = iscsi_session_recovery_timedout,1009 1010	.ep_connect             = iscsi_iser_ep_connect,1011	.ep_poll                = iscsi_iser_ep_poll,1012	.ep_disconnect          = iscsi_iser_ep_disconnect1013};1014 1015static int __init iser_init(void)1016{1017	int err;1018 1019	iser_dbg("Starting iSER datamover...\n");1020 1021	memset(&ig, 0, sizeof(struct iser_global));1022 1023	ig.desc_cache = kmem_cache_create("iser_descriptors",1024					  sizeof(struct iser_tx_desc),1025					  0, SLAB_HWCACHE_ALIGN,1026					  NULL);1027	if (ig.desc_cache == NULL)1028		return -ENOMEM;1029 1030	/* device init is called only after the first addr resolution */1031	mutex_init(&ig.device_list_mutex);1032	INIT_LIST_HEAD(&ig.device_list);1033	mutex_init(&ig.connlist_mutex);1034	INIT_LIST_HEAD(&ig.connlist);1035 1036	release_wq = alloc_workqueue("release workqueue", 0, 0);1037	if (!release_wq) {1038		iser_err("failed to allocate release workqueue\n");1039		err = -ENOMEM;1040		goto err_alloc_wq;1041	}1042 1043	iscsi_iser_scsi_transport = iscsi_register_transport(1044							&iscsi_iser_transport);1045	if (!iscsi_iser_scsi_transport) {1046		iser_err("iscsi_register_transport failed\n");1047		err = -EINVAL;1048		goto err_reg;1049	}1050 1051	return 0;1052 1053err_reg:1054	destroy_workqueue(release_wq);1055err_alloc_wq:1056	kmem_cache_destroy(ig.desc_cache);1057 1058	return err;1059}1060 1061static void __exit iser_exit(void)1062{1063	struct iser_conn *iser_conn, *n;1064	int connlist_empty;1065 1066	iser_dbg("Removing iSER datamover...\n");1067	destroy_workqueue(release_wq);1068 1069	mutex_lock(&ig.connlist_mutex);1070	connlist_empty = list_empty(&ig.connlist);1071	mutex_unlock(&ig.connlist_mutex);1072 1073	if (!connlist_empty) {1074		iser_err("Error cleanup stage completed but we still have iser "1075			 "connections, destroying them anyway\n");1076		list_for_each_entry_safe(iser_conn, n, &ig.connlist,1077					 conn_list) {1078			iser_conn_release(iser_conn);1079		}1080	}1081 1082	iscsi_unregister_transport(&iscsi_iser_transport);1083	kmem_cache_destroy(ig.desc_cache);1084}1085 1086module_init(iser_init);1087module_exit(iser_exit);1088