diff options
Diffstat (limited to 'drivers/scsi/libiscsi.c')
| -rw-r--r-- | drivers/scsi/libiscsi.c | 1702 |
1 files changed, 1702 insertions, 0 deletions
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c new file mode 100644 index 0000000..2673a11 --- /dev/null +++ b/drivers/scsi/libiscsi.c @@ -0,0 +1,1702 @@ +/* + * iSCSI lib functions + * + * Copyright (C) 2006 Red Hat, Inc. All rights reserved. + * Copyright (C) 2004 - 2006 Mike Christie + * Copyright (C) 2004 - 2005 Dmitry Yusupov + * Copyright (C) 2004 - 2005 Alex Aizman + * maintained by open-iscsi@googlegroups.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/kfifo.h> +#include <linux/delay.h> +#include <net/tcp.h> +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_device.h> +#include <scsi/scsi_eh.h> +#include <scsi/scsi_tcq.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi.h> +#include <scsi/iscsi_proto.h> +#include <scsi/scsi_transport.h> +#include <scsi/scsi_transport_iscsi.h> +#include <scsi/libiscsi.h> + +struct iscsi_session * +class_to_transport_session(struct iscsi_cls_session *cls_session) +{ + struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); + return iscsi_hostdata(shost->hostdata); +} +EXPORT_SYMBOL_GPL(class_to_transport_session); + +#define INVALID_SN_DELTA 0xffff + +int +iscsi_check_assign_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr) +{ + uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn); + uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn); + + if (max_cmdsn < exp_cmdsn -1 && + max_cmdsn > exp_cmdsn - INVALID_SN_DELTA) + return ISCSI_ERR_MAX_CMDSN; + if (max_cmdsn > session->max_cmdsn || + max_cmdsn < session->max_cmdsn - INVALID_SN_DELTA) + session->max_cmdsn = max_cmdsn; + if (exp_cmdsn > session->exp_cmdsn || + exp_cmdsn < session->exp_cmdsn - INVALID_SN_DELTA) + session->exp_cmdsn = exp_cmdsn; + + return 0; +} +EXPORT_SYMBOL_GPL(iscsi_check_assign_cmdsn); + +void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *ctask, + struct iscsi_data *hdr, + int transport_data_cnt) +{ + struct iscsi_conn *conn = ctask->conn; + + memset(hdr, 0, sizeof(struct iscsi_data)); + hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG); + hdr->datasn = cpu_to_be32(ctask->unsol_datasn); + ctask->unsol_datasn++; + hdr->opcode = ISCSI_OP_SCSI_DATA_OUT; + memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun)); + + hdr->itt = ctask->hdr->itt; + hdr->exp_statsn = cpu_to_be32(conn->exp_statsn); + + hdr->offset = cpu_to_be32(ctask->total_length - + transport_data_cnt - + ctask->unsol_count); + + if (ctask->unsol_count > conn->max_xmit_dlength) { + hton24(hdr->dlength, conn->max_xmit_dlength); + ctask->data_count = conn->max_xmit_dlength; + hdr->flags = 0; + } else { + hton24(hdr->dlength, ctask->unsol_count); + ctask->data_count = ctask->unsol_count; + hdr->flags = ISCSI_FLAG_CMD_FINAL; + } +} +EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu); + +/** + * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu + * @ctask: iscsi cmd task + * + * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set + * fields like dlength or final based on how much data it sends + */ +static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask) +{ + struct iscsi_conn *conn = ctask->conn; + struct iscsi_session *session = conn->session; + struct iscsi_cmd *hdr = ctask->hdr; + struct scsi_cmnd *sc = ctask->sc; + + hdr->opcode = ISCSI_OP_SCSI_CMD; + hdr->flags = ISCSI_ATTR_SIMPLE; + int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun); + hdr->itt = ctask->itt | (conn->id << ISCSI_CID_SHIFT) | + (session->age << ISCSI_AGE_SHIFT); + hdr->data_length = cpu_to_be32(sc->request_bufflen); + hdr->cmdsn = cpu_to_be32(session->cmdsn); + session->cmdsn++; + hdr->exp_statsn = cpu_to_be32(conn->exp_statsn); + memcpy(hdr->cdb, sc->cmnd, sc->cmd_len); + memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len); + + if (sc->sc_data_direction == DMA_TO_DEVICE) { + hdr->flags |= ISCSI_FLAG_CMD_WRITE; + /* + * Write counters: + * + * imm_count bytes to be sent right after + * SCSI PDU Header + * + * unsol_count bytes(as Data-Out) to be sent + * without R2T ack right after + * immediate data + * + * r2t_data_count bytes to be sent via R2T ack's + * + * pad_count bytes to be sent as zero-padding + */ + ctask->imm_count = 0; + ctask->unsol_count = 0; + ctask->unsol_datasn = 0; + + if (session->imm_data_en) { + if (ctask->total_length >= session->first_burst) + ctask->imm_count = min(session->first_burst, + conn->max_xmit_dlength); + else + ctask->imm_count = min(ctask->total_length, + conn->max_xmit_dlength); + hton24(ctask->hdr->dlength, ctask->imm_count); + } else + zero_data(ctask->hdr->dlength); + + if (!session->initial_r2t_en) + ctask->unsol_count = min(session->first_burst, + ctask->total_length) - ctask->imm_count; + if (!ctask->unsol_count) + /* No unsolicit Data-Out's */ + ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL; + } else { + ctask->datasn = 0; + hdr->flags |= ISCSI_FLAG_CMD_FINAL; + zero_data(hdr->dlength); + + if (sc->sc_data_direction == DMA_FROM_DEVICE) + hdr->flags |= ISCSI_FLAG_CMD_READ; + } + + conn->scsicmd_pdus_cnt++; +} +EXPORT_SYMBOL_GPL(iscsi_prep_scsi_cmd_pdu); + +/** + * iscsi_complete_command - return command back to scsi-ml + * @session: iscsi session + * @ctask: iscsi cmd task + * + * Must be called with session lock. + * This function returns the scsi command to scsi-ml and returns + * the cmd task to the pool of available cmd tasks. + */ +static void iscsi_complete_command(struct iscsi_session *session, + struct iscsi_cmd_task *ctask) +{ + struct scsi_cmnd *sc = ctask->sc; + + ctask->sc = NULL; + list_del_init(&ctask->running); + __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*)); + sc->scsi_done(sc); +} + +/** + * iscsi_cmd_rsp - SCSI Command Response processing + * @conn: iscsi connection + * @hdr: iscsi header + * @ctask: scsi command task + * @data: cmd data buffer + * @datalen: len of buffer + * + * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and + * then completes the command and task. + **/ +static int iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr, + struct iscsi_cmd_task *ctask, char *data, + int datalen) +{ + int rc; + struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr; + struct iscsi_session *session = conn->session; + struct scsi_cmnd *sc = ctask->sc; + + rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr); + if (rc) { + sc->result = DID_ERROR << 16; + goto out; + } + + conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1; + + sc->result = (DID_OK << 16) | rhdr->cmd_status; + + if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) { + sc->result = DID_ERROR << 16; + goto out; + } + + if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) { + int senselen; + + if (datalen < 2) { +invalid_datalen: + printk(KERN_ERR "iscsi: Got CHECK_CONDITION but " + "invalid data buffer size of %d\n", datalen); + sc->result = DID_BAD_TARGET << 16; + goto out; + } + + senselen = (data[0] << 8) | data[1]; + if (datalen < senselen) + goto invalid_datalen; + + memcpy(sc->sense_buffer, data + 2, + min(senselen, SCSI_SENSE_BUFFERSIZE)); + debug_scsi("copied %d bytes of sense\n", + min(senselen, SCSI_SENSE_BUFFERSIZE)); + } + + if (sc->sc_data_direction == DMA_TO_DEVICE) + goto out; + + if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) { + int res_count = be32_to_cpu(rhdr->residual_count); + + if (res_count > 0 && res_count <= sc->request_bufflen) + sc->resid = res_count; + else + sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status; + } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW) + sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status; + else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW) + sc->resid = be32_to_cpu(rhdr->residual_count); + +out: + debug_scsi("done [sc %lx res %d itt 0x%x]\n", + (long)sc, sc->result, ctask->itt); + conn->scsirsp_pdus_cnt++; + + iscsi_complete_command(conn->session, ctask); + return rc; +} + +/** + * __iscsi_complete_pdu - complete pdu + * @conn: iscsi conn + * @hdr: iscsi header + * @data: data buffer + * @datalen: len of data buffer + * + * Completes pdu processing by freeing any resources allocated at + * queuecommand or send generic. session lock must be held and verify + * itt must have been called. + */ +int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, + char *data, int datalen) +{ + struct iscsi_session *session = conn->session; + int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0; + struct iscsi_cmd_task *ctask; + struct iscsi_mgmt_task *mtask; + uint32_t itt; + + if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) + itt = hdr->itt & ISCSI_ITT_MASK; + else + itt = hdr->itt; + + if (itt < session->cmds_max) { + ctask = session->cmds[itt]; + + debug_scsi("cmdrsp [op 0x%x cid %d itt 0x%x len %d]\n", + opcode, conn->id, ctask->itt, datalen); + + switch(opcode) { + case ISCSI_OP_SCSI_CMD_RSP: + BUG_ON((void*)ctask != ctask->sc->SCp.ptr); + rc = iscsi_scsi_cmd_rsp(conn, hdr, ctask, data, + datalen); + break; + case ISCSI_OP_SCSI_DATA_IN: + BUG_ON((void*)ctask != ctask->sc->SCp.ptr); + if (hdr->flags & ISCSI_FLAG_DATA_STATUS) { + conn->scsirsp_pdus_cnt++; + iscsi_complete_command(session, ctask); + } + break; + case ISCSI_OP_R2T: + /* LLD handles this for now */ + break; + default: + rc = ISCSI_ERR_BAD_OPCODE; + break; + } + } else if (itt >= ISCSI_MGMT_ITT_OFFSET && + itt < ISCSI_MGMT_ITT_OFFSET + session->mgmtpool_max) { + mtask = session->mgmt_cmds[itt - ISCSI_MGMT_ITT_OFFSET]; + + debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n", + opcode, conn->id, mtask->itt, datalen); + + rc = iscsi_check_assign_cmdsn(session, + (struct iscsi_nopin*)hdr); + if (rc) + goto done; + + switch(opcode) { + case ISCSI_OP_LOGOUT_RSP: + conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1; + /* fall through */ + case ISCSI_OP_LOGIN_RSP: + case ISCSI_OP_TEXT_RSP: + /* + * login related PDU's exp_statsn is handled in + * userspace + */ + rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen); + list_del(&mtask->running); + if (conn->login_mtask != mtask) + __kfifo_put(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*)); + break; + case ISCSI_OP_SCSI_TMFUNC_RSP: + if (datalen) { + rc = ISCSI_ERR_PROTO; + break; + } + + conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1; + conn->tmfrsp_pdus_cnt++; + if (conn->tmabort_state == TMABORT_INITIAL) { + conn->tmabort_state = + ((struct iscsi_tm_rsp *)hdr)-> + response == ISCSI_TMF_RSP_COMPLETE ? + TMABORT_SUCCESS:TMABORT_FAILED; + /* unblock eh_abort() */ + wake_up(&conn->ehwait); + } + break; + case ISCSI_OP_NOOP_IN: + if (hdr->ttt != ISCSI_RESERVED_TAG) { + rc = ISCSI_ERR_PROTO; + break; + } + conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1; + + rc = iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen); + list_del(&mtask->running); + if (conn->login_mtask != mtask) + __kfifo_put(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*)); + break; + default: + rc = ISCSI_ERR_BAD_OPCODE; + break; + } + } else if (itt == ISCSI_RESERVED_TAG) { + switch(opcode) { + case ISCSI_OP_NOOP_IN: + if (!datalen) { + rc = iscsi_check_assign_cmdsn(session, + (struct iscsi_nopin*)hdr); + if (!rc && hdr->ttt != ISCSI_RESERVED_TAG) + rc = iscsi_recv_pdu(conn->cls_conn, + hdr, NULL, 0); + } else + rc = ISCSI_ERR_PROTO; + break; + case ISCSI_OP_REJECT: + /* we need sth like iscsi_reject_rsp()*/ + case ISCSI_OP_ASYNC_EVENT: + conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1; + /* we need sth like iscsi_async_event_rsp() */ + rc = ISCSI_ERR_BAD_OPCODE; + break; + default: + rc = ISCSI_ERR_BAD_OPCODE; + break; + } + } else + rc = ISCSI_ERR_BAD_ITT; + +done: + return rc; +} +EXPORT_SYMBOL_GPL(__iscsi_complete_pdu); + +int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, + char *data, int datalen) +{ + int rc; + + spin_lock(&conn->session->lock); + rc = __iscsi_complete_pdu(conn, hdr, data, datalen); + spin_unlock(&conn->session->lock); + return rc; +} +EXPORT_SYMBOL_GPL(iscsi_complete_pdu); + +/* verify itt (itt encoding: age+cid+itt) */ +int iscsi_verify_itt(struct iscsi_conn *conn, struct iscsi_hdr *hdr, + uint32_t *ret_itt) +{ + struct iscsi_session *session = conn->session; + struct iscsi_cmd_task *ctask; + uint32_t itt; + + if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) { + if ((hdr->itt & ISCSI_AGE_MASK) != + (session->age << ISCSI_AGE_SHIFT)) { + printk(KERN_ERR "iscsi: received itt %x expected " + "session age (%x)\n", hdr->itt, + session->age & ISCSI_AGE_MASK); + return ISCSI_ERR_BAD_ITT; + } + + if ((hdr->itt & ISCSI_CID_MASK) != + (conn->id << ISCSI_CID_SHIFT)) { + printk(KERN_ERR "iscsi: received itt %x, expected " + "CID (%x)\n", hdr->itt, conn->id); + return ISCSI_ERR_BAD_ITT; + } + itt = hdr->itt & ISCSI_ITT_MASK; + } else + itt = hdr->itt; + + if (itt < session->cmds_max) { + ctask = session->cmds[itt]; + + if (!ctask->sc) { + printk(KERN_INFO "iscsi: dropping ctask with " + "itt 0x%x\n", ctask->itt); + /* force drop */ + return ISCSI_ERR_NO_SCSI_CMD; + } + + if (ctask->sc->SCp.phase != session->age) { + printk(KERN_ERR "iscsi: ctask's session age %d, " + "expected %d\n", ctask->sc->SCp.phase, + session->age); + return ISCSI_ERR_SESSION_FAILED; + } + } + + *ret_itt = itt; + return 0; +} +EXPORT_SYMBOL_GPL(iscsi_verify_itt); + +void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err) +{ + struct iscsi_session *session = conn->session; + unsigned long flags; + + spin_lock_irqsave(&session->lock, flags); + if (session->state == ISCSI_STATE_FAILED) { + spin_unlock_irqrestore(&session->lock, flags); + return; + } + + if (conn->stop_stage == 0) + session->state = ISCSI_STATE_FAILED; + spin_unlock_irqrestore(&session->lock, flags); + set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx); + set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx); + iscsi_conn_error(conn->cls_conn, err); +} +EXPORT_SYMBOL_GPL(iscsi_conn_failure); + +/** + * iscsi_data_xmit - xmit any command into the scheduled connection + * @conn: iscsi connection + * + * Notes: + * The function can return -EAGAIN in which case the caller must + * re-schedule it again later or recover. '0' return code means + * successful xmit. + **/ +static int iscsi_data_xmit(struct iscsi_conn *conn) +{ + struct iscsi_transport *tt; + int rc = 0; + + if (unlikely(conn->suspend_tx)) { + debug_scsi("conn %d Tx suspended!\n", conn->id); + return -ENODATA; + } + tt = conn->session->tt; + + /* + * Transmit in the following order: + * + * 1) un-finished xmit (ctask or mtask) + * 2) immediate control PDUs + * 3) write data + * 4) SCSI commands + * 5) non-immediate control PDUs + * + * No need to lock around __kfifo_get as long as + * there's one producer and one consumer. + */ + + BUG_ON(conn->ctask && conn->mtask); + + if (conn->ctask) { + rc = tt->xmit_cmd_task(conn, conn->ctask); + if (rc) + goto again; + /* done with this in-progress ctask */ + conn->ctask = NULL; + } + if (conn->mtask) { + rc = tt->xmit_mgmt_task(conn, conn->mtask); + if (rc) + goto again; + /* done with this in-progress mtask */ + conn->mtask = NULL; + } + + /* process immediate first */ + if (unlikely(__kfifo_len(conn->immqueue))) { + while (__kfifo_get(conn->immqueue, (void*)&conn->mtask, + sizeof(void*))) { + spin_lock_bh(&conn->session->lock); + list_add_tail(&conn->mtask->running, + &conn->mgmt_run_list); + spin_unlock_bh(&conn->session->lock); + rc = tt->xmit_mgmt_task(conn, conn->mtask); + if (rc) + goto again; + } + /* done with this mtask */ + conn->mtask = NULL; + } + + /* process command queue */ + while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask, + sizeof(void*))) { + /* + * iscsi tcp may readd the task to the xmitqueue to send + * write data + */ + spin_lock_bh(&conn->session->lock); + if (list_empty(&conn->ctask->running)) + list_add_tail(&conn->ctask->running, &conn->run_list); + spin_unlock_bh(&conn->session->lock); + rc = tt->xmit_cmd_task(conn, conn->ctask); + if (rc) + goto again; + } + /* done with this ctask */ + conn->ctask = NULL; + + /* process the rest control plane PDUs, if any */ + if (unlikely(__kfifo_len(conn->mgmtqueue))) { + while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask, + sizeof(void*))) { + spin_lock_bh(&conn->session->lock); + list_add_tail(&conn->mtask->running, + &conn->mgmt_run_list); + spin_unlock_bh(&conn->session->lock); + rc = tt->xmit_mgmt_task(conn, conn->mtask); + if (rc) + goto again; + } + /* done with this mtask */ + conn->mtask = NULL; + } + + return -ENODATA; + +again: + if (unlikely(conn->suspend_tx)) + return -ENODATA; + + return rc; +} + +static void iscsi_xmitworker(void *data) +{ + struct iscsi_conn *conn = data; + int rc; + /* + * serialize Xmit worker on a per-connection basis. + */ + mutex_lock(&conn->xmitmutex); + do { + rc = iscsi_data_xmit(conn); + } while (rc >= 0 || rc == -EAGAIN); + mutex_unlock(&conn->xmitmutex); +} + +enum { + FAILURE_BAD_HOST = 1, + FAILURE_SESSION_FAILED, + FAILURE_SESSION_FREED, + FAILURE_WINDOW_CLOSED, + FAILURE_SESSION_TERMINATE, + FAILURE_SESSION_IN_RECOVERY, + FAILURE_SESSION_RECOVERY_TIMEOUT, +}; + +int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *)) +{ + struct Scsi_Host *host; + int reason = 0; + struct iscsi_session *session; + struct iscsi_conn *conn; + struct iscsi_cmd_task *ctask = NULL; + + sc->scsi_done = done; + sc->result = 0; + + host = sc->device->host; + session = iscsi_hostdata(host->hostdata); + + spin_lock(&session->lock); + + /* + * ISCSI_STATE_FAILED is a temp. state. The recovery + * code will decide what is best to do with command queued + * during this time + */ + if (session->state != ISCSI_STATE_LOGGED_IN && + session->state != ISCSI_STATE_FAILED) { + /* + * to handle the race between when we set the recovery state + * and block the session we requeue here (commands could + * be entering our queuecommand while a block is starting + * up because the block code is not locked) + */ + if (session->state == ISCSI_STATE_IN_RECOVERY) { + reason = FAILURE_SESSION_IN_RECOVERY; + goto reject; + } + + if (session->state == ISCSI_STATE_RECOVERY_FAILED) + reason = FAILURE_SESSION_RECOVERY_TIMEOUT; + else if (session->state == ISCSI_STATE_TERMINATE) + reason = FAILURE_SESSION_TERMINATE; + else + reason = FAILURE_SESSION_FREED; + goto fault; + } + + /* + * Check for iSCSI window and take care of CmdSN wrap-around + */ + if ((int)(session->max_cmdsn - session->cmdsn) < 0) { + reason = FAILURE_WINDOW_CLOSED; + goto reject; + } + + conn = session->leadconn; + + __kfifo_get(session->cmdpool.queue, (void*)&ctask, sizeof(void*)); + sc->SCp.phase = session->age; + sc->SCp.ptr = (char *)ctask; + + ctask->mtask = NULL; + ctask->conn = conn; + ctask->sc = sc; + INIT_LIST_HEAD(&ctask->running); + ctask->total_length = sc->request_bufflen; + iscsi_prep_scsi_cmd_pdu(ctask); + + session->tt->init_cmd_task(ctask); + + __kfifo_put(conn->xmitqueue, (void*)&ctask, sizeof(void*)); + debug_scsi( + "ctask enq [%s cid %d sc %lx itt 0x%x len %d cmdsn %d win %d]\n", + sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read", + conn->id, (long)sc, ctask->itt, sc->request_bufflen, + session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1); + spin_unlock(&session->lock); + + scsi_queue_work(host, &conn->xmitwork); + return 0; + +reject: + spin_unlock(&session->lock); + debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason); + return SCSI_MLQUEUE_HOST_BUSY; + +fault: + spin_unlock(&session->lock); + printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n", + sc->cmnd[0], reason); + sc->result = (DID_NO_CONNECT << 16); + sc->resid = sc->request_bufflen; + sc->scsi_done(sc); + return 0; +} +EXPORT_SYMBOL_GPL(iscsi_queuecommand); + +int iscsi_change_queue_depth(struct scsi_device *sdev, int depth) +{ + if (depth > ISCSI_MAX_CMD_PER_LUN) + depth = ISCSI_MAX_CMD_PER_LUN; + scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth); + return sdev->queue_depth; +} +EXPORT_SYMBOL_GPL(iscsi_change_queue_depth); + +static int +iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr, + char *data, uint32_t data_size) +{ + struct iscsi_session *session = conn->session; + struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr; + struct iscsi_mgmt_task *mtask; + + spin_lock_bh(&session->lock); + if (session->state == ISCSI_STATE_TERMINATE) { + spin_unlock_bh(&session->lock); + return -EPERM; + } + if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) || + hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE)) + /* + * Login and Text are sent serially, in + * request-followed-by-response sequence. + * Same mtask can be used. Same ITT must be used. + * Note that login_mtask is preallocated at conn_create(). + */ + mtask = conn->login_mtask; + else { + BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE); + BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED); + + nop->exp_statsn = cpu_to_be32(conn->exp_statsn); + if (!__kfifo_get(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*))) { + spin_unlock_bh(&session->lock); + return -ENOSPC; + } + } + + /* + * pre-format CmdSN for outgoing PDU. + */ + if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) { + hdr->itt = mtask->itt | (conn->id << ISCSI_CID_SHIFT) | + (session->age << ISCSI_AGE_SHIFT); + nop->cmdsn = cpu_to_be32(session->cmdsn); + if (conn->c_stage == ISCSI_CONN_STARTED && + !(hdr->opcode & ISCSI_OP_IMMEDIATE)) + session->cmdsn++; + } else + /* do not advance CmdSN */ + nop->cmdsn = cpu_to_be32(session->cmdsn); + + if (data_size) { + memcpy(mtask->data, data, data_size); + mtask->data_count = data_size; + } else + mtask->data_count = 0; + + INIT_LIST_HEAD(&mtask->running); + memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr)); + if (session->tt->init_mgmt_task) + session->tt->init_mgmt_task(conn, mtask, data, data_size); + spin_unlock_bh(&session->lock); + + debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n", + hdr->opcode, hdr->itt, data_size); + + /* + * since send_pdu() could be called at least from two contexts, + * we need to serialize __kfifo_put, so we don't have to take + * additional lock on fast data-path + */ + if (hdr->opcode & ISCSI_OP_IMMEDIATE) + __kfifo_put(conn->immqueue, (void*)&mtask, sizeof(void*)); + else + __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*)); + + scsi_queue_work(session->host, &conn->xmitwork); + return 0; +} + +int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr, + char *data, uint32_t data_size) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + int rc; + + mutex_lock(&conn->xmitmutex); + rc = iscsi_conn_send_generic(conn, hdr, data, data_size); + mutex_unlock(&conn->xmitmutex); + + return rc; +} +EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu); + +void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session) +{ + struct iscsi_session *session = class_to_transport_session(cls_session); + struct iscsi_conn *conn = session->leadconn; + + spin_lock_bh(&session->lock); + if (session->state != ISCSI_STATE_LOGGED_IN) { + session->state = ISCSI_STATE_RECOVERY_FAILED; + if (conn) + wake_up(&conn->ehwait); + } + spin_unlock_bh(&session->lock); +} +EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout); + +int iscsi_eh_host_reset(struct scsi_cmnd *sc) +{ + struct Scsi_Host *host = sc->device->host; + struct iscsi_session *session = iscsi_hostdata(host->hostdata); + struct iscsi_conn *conn = session->leadconn; + int fail_session = 0; + + spin_lock_bh(&session->lock); + if (session->state == ISCSI_STATE_TERMINATE) { +failed: + debug_scsi("failing host reset: session terminated " + "[CID %d age %d]", conn->id, session->age); + spin_unlock_bh(&session->lock); + return FAILED; + } + + if (sc->SCp.phase == session->age) { + debug_scsi("failing connection CID %d due to SCSI host reset", + conn->id); + fail_session = 1; + } + spin_unlock_bh(&session->lock); + + /* + * we drop the lock here but the leadconn cannot be destoyed while + * we are in the scsi eh + */ + if (fail_session) + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + + debug_scsi("iscsi_eh_host_reset wait for relogin\n"); + wait_event_interruptible(conn->ehwait, + session->state == ISCSI_STATE_TERMINATE || + session->state == ISCSI_STATE_LOGGED_IN || + session->state == ISCSI_STATE_RECOVERY_FAILED); + if (signal_pending(current)) + flush_signals(current); + + spin_lock_bh(&session->lock); + if (session->state == ISCSI_STATE_LOGGED_IN) + printk(KERN_INFO "iscsi: host reset succeeded\n"); + else + goto failed; + spin_unlock_bh(&session->lock); + + return SUCCESS; +} +EXPORT_SYMBOL_GPL(iscsi_eh_host_reset); + +static void iscsi_tmabort_timedout(unsigned long data) +{ + struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data; + struct iscsi_conn *conn = ctask->conn; + struct iscsi_session *session = conn->session; + + spin_lock(&session->lock); + if (conn->tmabort_state == TMABORT_INITIAL) { + conn->tmabort_state = TMABORT_TIMEDOUT; + debug_scsi("tmabort timedout [sc %p itt 0x%x]\n", + ctask->sc, ctask->itt); + /* unblock eh_abort() */ + wake_up(&conn->ehwait); + } + spin_unlock(&session->lock); +} + +/* must be called with the mutex lock */ +static int iscsi_exec_abort_task(struct scsi_cmnd *sc, + struct iscsi_cmd_task *ctask) +{ + struct iscsi_conn *conn = ctask->conn; + struct iscsi_session *session = conn->session; + struct iscsi_tm *hdr = &conn->tmhdr; + int rc; + + /* + * ctask timed out but session is OK requests must be serialized. + */ + memset(hdr, 0, sizeof(struct iscsi_tm)); + hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE; + hdr->flags = ISCSI_TM_FUNC_ABORT_TASK; + hdr->flags |= ISCSI_FLAG_CMD_FINAL; + memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun)); + hdr->rtt = ctask->hdr->itt; + hdr->refcmdsn = ctask->hdr->cmdsn; + + rc = iscsi_conn_send_generic(conn, (struct iscsi_hdr *)hdr, + NULL, 0); + if (rc) { + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + debug_scsi("abort sent failure [itt 0x%x] %d", ctask->itt, rc); + return rc; + } + + debug_scsi("abort sent [itt 0x%x]\n", ctask->itt); + + spin_lock_bh(&session->lock); + ctask->mtask = (struct iscsi_mgmt_task *) + session->mgmt_cmds[(hdr->itt & ISCSI_ITT_MASK) - + ISCSI_MGMT_ITT_OFFSET]; + + if (conn->tmabort_state == TMABORT_INITIAL) { + conn->tmfcmd_pdus_cnt++; + conn->tmabort_timer.expires = 10*HZ + jiffies; + conn->tmabort_timer.function = iscsi_tmabort_timedout; + conn->tmabort_timer.data = (unsigned long)ctask; + add_timer(&conn->tmabort_timer); + debug_scsi("abort set timeout [itt 0x%x]", ctask->itt); + } + spin_unlock_bh(&session->lock); + mutex_unlock(&conn->xmitmutex); + + /* + * block eh thread until: + * + * 1) abort response + * 2) abort timeout + * 3) session is terminated or restarted or userspace has + * given up on recovery + */ + wait_event_interruptible(conn->ehwait, + sc->SCp.phase != session->age || + session->state != ISCSI_STATE_LOGGED_IN || + conn->tmabort_state != TMABORT_INITIAL); + if (signal_pending(current)) + flush_signals(current); + del_timer_sync(&conn->tmabort_timer); + + mutex_lock(&conn->xmitmutex); + return 0; +} + +/* + * xmit mutex and session lock must be held + */ +#define iscsi_remove_task(tasktype) \ +static struct iscsi_##tasktype * \ +iscsi_remove_##tasktype(struct kfifo *fifo, uint32_t itt) \ +{ \ + int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*); \ + struct iscsi_##tasktype *task; \ + \ + debug_scsi("searching %d tasks\n", nr_tasks); \ + \ + for (i = 0; i < nr_tasks; i++) { \ + __kfifo_get(fifo, (void*)&task, sizeof(void*)); \ + debug_scsi("check task %u\n", task->itt); \ + \ + if (task->itt == itt) { \ + debug_scsi("matched task\n"); \ + return task; \ + } \ + \ + __kfifo_put(fifo, (void*)&task, sizeof(void*)); \ + } \ + return NULL; \ +} + +iscsi_remove_task(mgmt_task); +iscsi_remove_task(cmd_task); + +static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask) +{ + struct iscsi_conn *conn = ctask->conn; + struct iscsi_session *session = conn->session; + + if (!ctask->mtask) + return -EINVAL; + + if (!iscsi_remove_mgmt_task(conn->immqueue, ctask->mtask->itt)) + list_del(&ctask->mtask->running); + __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask, + sizeof(void*)); + ctask->mtask = NULL; + return 0; +} + +/* + * session lock and xmitmutex must be held + */ +static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, + int err) +{ + struct scsi_cmnd *sc; + + conn->session->tt->cleanup_cmd_task(conn, ctask); + iscsi_ctask_mtask_cleanup(ctask); + + sc = ctask->sc; + if (!sc) + return; + sc->result = err; + sc->resid = sc->request_bufflen; + iscsi_complete_command(conn->session, ctask); +} + +int iscsi_eh_abort(struct scsi_cmnd *sc) +{ + struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr; + struct iscsi_conn *conn = ctask->conn; + struct iscsi_session *session = conn->session; + struct iscsi_cmd_task *pending_ctask; + int rc; + + conn->eh_abort_cnt++; + debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt); + + mutex_lock(&conn->xmitmutex); + spin_lock_bh(&session->lock); + + /* + * If we are not logged in or we have started a new session + * then let the host reset code handle this + */ + if (session->state != ISCSI_STATE_LOGGED_IN || + sc->SCp.phase != session->age) + goto failed; + + /* ctask completed before time out */ + if (!ctask->sc) + goto success; + + /* what should we do here ? */ + if (conn->ctask == ctask) { + printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. " + "Failing abort\n", sc, ctask->itt); + goto failed; + } + + /* check for the easy pending cmd abort */ + pending_ctask = iscsi_remove_cmd_task(conn->xmitqueue, ctask->itt); + if (pending_ctask) { + /* iscsi_tcp queues write transfers on the xmitqueue */ + if (list_empty(&pending_ctask->running)) { + debug_scsi("found pending task\n"); + goto success; + } else + __kfifo_put(conn->xmitqueue, (void*)&pending_ctask, + sizeof(void*)); + } + + conn->tmabort_state = TMABORT_INITIAL; + + spin_unlock_bh(&session->lock); + rc = iscsi_exec_abort_task(sc, ctask); + spin_lock_bh(&session->lock); + + iscsi_ctask_mtask_cleanup(ctask); + if (rc || sc->SCp.phase != session->age || + session->state != ISCSI_STATE_LOGGED_IN) + goto failed; + + /* ctask completed before tmf abort response */ + if (!ctask->sc) { + debug_scsi("sc completed while abort in progress\n"); + goto success; + } + + if (conn->tmabort_state != TMABORT_SUCCESS) { + spin_unlock_bh(&session->lock); + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + spin_lock_bh(&session->lock); + goto failed; + } + +success: + debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt); + spin_unlock_bh(&session->lock); + + /* + * clean up task if aborted. we have the xmitmutex so grab + * the recv lock as a writer + */ + write_lock_bh(conn->recv_lock); + spin_lock(&session->lock); + fail_command(conn, ctask, DID_ABORT << 16); + spin_unlock(&session->lock); + write_unlock_bh(conn->recv_lock); + + mutex_unlock(&conn->xmitmutex); + return SUCCESS; + +failed: + spin_unlock_bh(&session->lock); + mutex_unlock(&conn->xmitmutex); + + debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt); + return FAILED; +} +EXPORT_SYMBOL_GPL(iscsi_eh_abort); + +int +iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size) +{ + int i; + + *items = kmalloc(max * sizeof(void*), GFP_KERNEL); + if (*items == NULL) + return -ENOMEM; + + q->max = max; + q->pool = kmalloc(max * sizeof(void*), GFP_KERNEL); + if (q->pool == NULL) { + kfree(*items); + return -ENOMEM; + } + + q->queue = kfifo_init((void*)q->pool, max * sizeof(void*), + GFP_KERNEL, NULL); + if (q->queue == ERR_PTR(-ENOMEM)) { + kfree(q->pool); + kfree(*items); + return -ENOMEM; + } + + for (i = 0; i < max; i++) { + q->pool[i] = kmalloc(item_size, GFP_KERNEL); + if (q->pool[i] == NULL) { + int j; + + for (j = 0; j < i; j++) + kfree(q->pool[j]); + + kfifo_free(q->queue); + kfree(q->pool); + kfree(*items); + return -ENOMEM; + } + memset(q->pool[i], 0, item_size); + (*items)[i] = q->pool[i]; + __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*)); + } + return 0; +} +EXPORT_SYMBOL_GPL(iscsi_pool_init); + +void iscsi_pool_free(struct iscsi_queue *q, void **items) +{ + int i; + + for (i = 0; i < q->max; i++) + kfree(items[i]); + kfree(q->pool); + kfree(items); +} +EXPORT_SYMBOL_GPL(iscsi_pool_free); + +/* + * iSCSI Session's hostdata organization: + * + * *------------------* <== hostdata_session(host->hostdata) + * | ptr to class sess| + * |------------------| <== iscsi_hostdata(host->hostdata) + * | iscsi_session | + * *------------------* + */ + +#define hostdata_privsize(_sz) (sizeof(unsigned long) + _sz + \ + _sz % sizeof(unsigned long)) + +#define hostdata_session(_hostdata) (iscsi_ptr(*(unsigned long *)_hostdata)) + +/** + * iscsi_session_setup - create iscsi cls session and host and session + * @scsit: scsi transport template + * @iscsit: iscsi transport template + * @initial_cmdsn: initial CmdSN + * @hostno: host no allocated + * + * This can be used by software iscsi_transports that allocate + * a session per scsi host. + **/ +struct iscsi_cls_session * +iscsi_session_setup(struct iscsi_transport *iscsit, + struct scsi_transport_template *scsit, + int cmd_task_size, int mgmt_task_size, + uint32_t initial_cmdsn, uint32_t *hostno) +{ + struct Scsi_Host *shost; + struct iscsi_session *session; + struct iscsi_cls_session *cls_session; + int cmd_i; + + shost = scsi_host_alloc(iscsit->host_template, + hostdata_privsize(sizeof(*session))); + if (!shost) + return NULL; + + shost->max_id = 1; + shost->max_channel = 0; + shost->max_lun = iscsit->max_lun; + shost->max_cmd_len = iscsit->max_cmd_len; + shost->transportt = scsit; + shost->transportt->create_work_queue = 1; + *hostno = shost->host_no; + + session = iscsi_hostdata(shost->hostdata); + memset(session, 0, sizeof(struct iscsi_session)); + session->host = shost; + session->state = ISCSI_STATE_FREE; + session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX; + session->cmds_max = ISCSI_XMIT_CMDS_MAX; + session->cmdsn = initial_cmdsn; + session->exp_cmdsn = initial_cmdsn + 1; + session->max_cmdsn = initial_cmdsn + 1; + session->max_r2t = 1; + session->tt = iscsit; + + /* initialize SCSI PDU commands pool */ + if (iscsi_pool_init(&session->cmdpool, session->cmds_max, + (void***)&session->cmds, + cmd_task_size + sizeof(struct iscsi_cmd_task))) + goto cmdpool_alloc_fail; + + /* pre-format cmds pool with ITT */ + for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) { + struct iscsi_cmd_task *ctask = session->cmds[cmd_i]; + + if (cmd_task_size) + ctask->dd_data = &ctask[1]; + ctask->itt = cmd_i; + } + + spin_lock_init(&session->lock); + INIT_LIST_HEAD(&session->connections); + + /* initialize immediate command pool */ + if (iscsi_pool_init(&session->mgmtpool, session->mgmtpool_max, + (void***)&session->mgmt_cmds, + mgmt_task_size + sizeof(struct iscsi_mgmt_task))) + goto mgmtpool_alloc_fail; + + + /* pre-format immediate cmds pool with ITT */ + for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) { + struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i]; + + if (mgmt_task_size) + mtask->dd_data = &mtask[1]; + mtask->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i; + } + + if (scsi_add_host(shost, NULL)) + goto add_host_fail; + + cls_session = iscsi_create_session(shost, iscsit, 0); + if (!cls_session) + goto cls_session_fail; + *(unsigned long*)shost->hostdata = (unsigned long)cls_session; + + return cls_session; + +cls_session_fail: + scsi_remove_host(shost); +add_host_fail: + iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds); +mgmtpool_alloc_fail: + iscsi_pool_free(&session->cmdpool, (void**)session->cmds); +cmdpool_alloc_fail: + scsi_host_put(shost); + return NULL; +} +EXPORT_SYMBOL_GPL(iscsi_session_setup); + +/** + * iscsi_session_teardown - destroy session, host, and cls_session + * shost: scsi host + * + * This can be used by software iscsi_transports that allocate + * a session per scsi host. + **/ +void iscsi_session_teardown(struct iscsi_cls_session *cls_session) +{ + struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); + struct iscsi_session *session = iscsi_hostdata(shost->hostdata); + + scsi_remove_host(shost); + + iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds); + iscsi_pool_free(&session->cmdpool, (void**)session->cmds); + + iscsi_destroy_session(cls_session); + scsi_host_put(shost); +} +EXPORT_SYMBOL_GPL(iscsi_session_teardown); + +/** + * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn + * @cls_session: iscsi_cls_session + * @conn_idx: cid + **/ +struct iscsi_cls_conn * +iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx) +{ + struct iscsi_session *session = class_to_transport_session(cls_session); + struct iscsi_conn *conn; + struct iscsi_cls_conn *cls_conn; + char *data; + + cls_conn = iscsi_create_conn(cls_session, conn_idx); + if (!cls_conn) + return NULL; + conn = cls_conn->dd_data; + memset(conn, 0, sizeof(*conn)); + + conn->session = session; + conn->cls_conn = cls_conn; + conn->c_stage = ISCSI_CONN_INITIAL_STAGE; + conn->id = conn_idx; + conn->exp_statsn = 0; + conn->tmabort_state = TMABORT_INITIAL; + INIT_LIST_HEAD(&conn->run_list); + INIT_LIST_HEAD(&conn->mgmt_run_list); + + /* initialize general xmit PDU commands queue */ + conn->xmitqueue = kfifo_alloc(session->cmds_max * sizeof(void*), + GFP_KERNEL, NULL); + if (conn->xmitqueue == ERR_PTR(-ENOMEM)) + goto xmitqueue_alloc_fail; + + /* initialize general immediate & non-immediate PDU commands queue */ + conn->immqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*), + GFP_KERNEL, NULL); + if (conn->immqueue == ERR_PTR(-ENOMEM)) + goto immqueue_alloc_fail; + + conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*), + GFP_KERNEL, NULL); + if (conn->mgmtqueue == ERR_PTR(-ENOMEM)) + goto mgmtqueue_alloc_fail; + + INIT_WORK(&conn->xmitwork, iscsi_xmitworker, conn); + + /* allocate login_mtask used for the login/text sequences */ + spin_lock_bh(&session->lock); + if (!__kfifo_get(session->mgmtpool.queue, + (void*)&conn->login_mtask, + sizeof(void*))) { + spin_unlock_bh(&session->lock); + goto login_mtask_alloc_fail; + } + spin_unlock_bh(&session->lock); + + data = kmalloc(DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL); + if (!data) + goto login_mtask_data_alloc_fail; + conn->login_mtask->data = data; + + init_timer(&conn->tmabort_timer); + mutex_init(&conn->xmitmutex); + init_waitqueue_head(&conn->ehwait); + + return cls_conn; + +login_mtask_data_alloc_fail: + __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask, + sizeof(void*)); +login_mtask_alloc_fail: + kfifo_free(conn->mgmtqueue); +mgmtqueue_alloc_fail: + kfifo_free(conn->immqueue); +immqueue_alloc_fail: + kfifo_free(conn->xmitqueue); +xmitqueue_alloc_fail: + iscsi_destroy_conn(cls_conn); + return NULL; +} +EXPORT_SYMBOL_GPL(iscsi_conn_setup); + +/** + * iscsi_conn_teardown - teardown iscsi connection + * cls_conn: iscsi class connection + * + * TODO: we may need to make this into a two step process + * like scsi-mls remove + put host + */ +void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_session *session = conn->session; + unsigned long flags; + + set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx); + mutex_lock(&conn->xmitmutex); + if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE) { + if (session->tt->suspend_conn_recv) + session->tt->suspend_conn_recv(conn); + + session->tt->terminate_conn(conn); + } + + spin_lock_bh(&session->lock); + conn->c_stage = ISCSI_CONN_CLEANUP_WAIT; + if (session->leadconn == conn) { + /* + * leading connection? then give up on recovery. + */ + session->state = ISCSI_STATE_TERMINATE; + wake_up(&conn->ehwait); + } + spin_unlock_bh(&session->lock); + + mutex_unlock(&conn->xmitmutex); + + /* + * Block until all in-progress commands for this connection + * time out or fail. + */ + for (;;) { + spin_lock_irqsave(session->host->host_lock, flags); + if (!session->host->host_busy) { /* OK for ERL == 0 */ + spin_unlock_irqrestore(session->host->host_lock, flags); + break; + } + spin_unlock_irqrestore(session->host->host_lock, flags); + msleep_interruptible(500); + printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d " + "host_failed %d\n", session->host->host_busy, + session->host->host_failed); + /* + * force eh_abort() to unblock + */ + wake_up(&conn->ehwait); + } + + spin_lock_bh(&session->lock); + kfree(conn->login_mtask->data); + __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask, + sizeof(void*)); + list_del(&conn->item); + if (list_empty(&session->connections)) + session->leadconn = NULL; + if (session->leadconn && session->leadconn == conn) + session->leadconn = container_of(session->connections.next, + struct iscsi_conn, item); + + if (session->leadconn == NULL) + /* no connections exits.. reset sequencing */ + session->cmdsn = session->max_cmdsn = session->exp_cmdsn = 1; + spin_unlock_bh(&session->lock); + + kfifo_free(conn->xmitqueue); + kfifo_free(conn->immqueue); + kfifo_free(conn->mgmtqueue); + + iscsi_destroy_conn(cls_conn); +} +EXPORT_SYMBOL_GPL(iscsi_conn_teardown); + +int iscsi_conn_start(struct iscsi_cls_conn *cls_conn) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_session *session = conn->session; + + if (session == NULL) { + printk(KERN_ERR "iscsi: can't start unbound connection\n"); + return -EPERM; + } + + spin_lock_bh(&session->lock); + conn->c_stage = ISCSI_CONN_STARTED; + session->state = ISCSI_STATE_LOGGED_IN; + + switch(conn->stop_stage) { + case STOP_CONN_RECOVER: + /* + * unblock eh_abort() if it is blocked. re-try all + * commands after successful recovery + */ + conn->stop_stage = 0; + conn->tmabort_state = TMABORT_INITIAL; + session->age++; + spin_unlock_bh(&session->lock); + + iscsi_unblock_session(session_to_cls(session)); + wake_up(&conn->ehwait); + return 0; + case STOP_CONN_TERM: + conn->stop_stage = 0; + break; + default: + break; + } + spin_unlock_bh(&session->lock); + + return 0; +} +EXPORT_SYMBOL_GPL(iscsi_conn_start); + +static void +flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn) +{ + struct iscsi_mgmt_task *mtask, *tmp; + + /* handle pending */ + while (__kfifo_get(conn->immqueue, (void*)&mtask, sizeof(void*)) || + __kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) { + if (mtask == conn->login_mtask) + continue; + debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt); + __kfifo_put(session->mgmtpool.queue, (void*)&mtask, + sizeof(void*)); + } + + /* handle running */ + list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) { + debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt); + list_del(&mtask->running); + + if (mtask == conn->login_mtask) + continue; + __kfifo_put(session->mgmtpool.queue, (void*)&mtask, + sizeof(void*)); + } + + conn->mtask = NULL; +} + +/* Fail commands. Mutex and session lock held and recv side suspended */ +static void fail_all_commands(struct iscsi_conn *conn) +{ + struct iscsi_cmd_task *ctask, *tmp; + + /* flush pending */ + while (__kfifo_get(conn->xmitqueue, (void*)&ctask, sizeof(void*))) { + debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc, + ctask->itt); + fail_command(conn, ctask, DID_BUS_BUSY << 16); + } + + /* fail all other running */ + list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) { + debug_scsi("failing in progress sc %p itt 0x%x\n", + ctask->sc, ctask->itt); + fail_command(conn, ctask, DID_BUS_BUSY << 16); + } + + conn->ctask = NULL; +} + +static void iscsi_start_session_recovery(struct iscsi_session *session, + struct iscsi_conn *conn, int flag) +{ + int old_stop_stage; + + spin_lock_bh(&session->lock); + if (conn->stop_stage == STOP_CONN_TERM) { + spin_unlock_bh(&session->lock); + return; + } + + /* + * When this is called for the in_login state, we only want to clean + * up the login task and connection. We do not need to block and set + * the recovery state again + */ + if (flag == STOP_CONN_TERM) + session->state = ISCSI_STATE_TERMINATE; + else if (conn->stop_stage != STOP_CONN_RECOVER) + session->state = ISCSI_STATE_IN_RECOVERY; + + old_stop_stage = conn->stop_stage; + conn->stop_stage = flag; + conn->c_stage = ISCSI_CONN_STOPPED; + set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx); + spin_unlock_bh(&session->lock); + + if (session->tt->suspend_conn_recv) + session->tt->suspend_conn_recv(conn); + + mutex_lock(&conn->xmitmutex); + /* + * for connection level recovery we should not calculate + * header digest. conn->hdr_size used for optimization + * in hdr_extract() and will be re-negotiated at + * set_param() time. + */ + if (flag == STOP_CONN_RECOVER) { + conn->hdrdgst_en = 0; + conn->datadgst_en = 0; + if (session->state == ISCSI_STATE_IN_RECOVERY && + old_stop_stage != STOP_CONN_RECOVER) { + debug_scsi("blocking session\n"); + iscsi_block_session(session_to_cls(session)); + } + } + + session->tt->terminate_conn(conn); + /* + * flush queues. + */ + spin_lock_bh(&session->lock); + fail_all_commands(conn); + flush_control_queues(session, conn); + spin_unlock_bh(&session->lock); + + mutex_unlock(&conn->xmitmutex); +} + +void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_session *session = conn->session; + + switch (flag) { + case STOP_CONN_RECOVER: + case STOP_CONN_TERM: + iscsi_start_session_recovery(session, conn, flag); + break; + default: + printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag); + } +} +EXPORT_SYMBOL_GPL(iscsi_conn_stop); + +int iscsi_conn_bind(struct iscsi_cls_session *cls_session, + struct iscsi_cls_conn *cls_conn, int is_leading) +{ + struct iscsi_session *session = class_to_transport_session(cls_session); + struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = cls_conn->dd_data; + + /* lookup for existing connection */ + spin_lock_bh(&session->lock); + list_for_each_entry(tmp, &session->connections, item) { + if (tmp == conn) { + if (conn->c_stage != ISCSI_CONN_STOPPED || + conn->stop_stage == STOP_CONN_TERM) { + printk(KERN_ERR "iscsi: can't bind " + "non-stopped connection (%d:%d)\n", + conn->c_stage, conn->stop_stage); + spin_unlock_bh(&session->lock); + return -EIO; + } + break; + } + } + if (tmp != conn) { + /* bind new iSCSI connection to session */ + conn->session = session; + list_add(&conn->item, &session->connections); + } + spin_unlock_bh(&session->lock); + + if (is_leading) + session->leadconn = conn; + + /* + * Unblock xmitworker(), Login Phase will pass through. + */ + clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx); + clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx); + return 0; +} +EXPORT_SYMBOL_GPL(iscsi_conn_bind); + +MODULE_AUTHOR("Mike Christie"); +MODULE_DESCRIPTION("iSCSI library functions"); +MODULE_LICENSE("GPL"); |
