diff options
Diffstat (limited to 'drivers/scsi/iscsi_tcp.c')
| -rw-r--r-- | drivers/scsi/iscsi_tcp.c | 3642 |
1 files changed, 3642 insertions, 0 deletions
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c new file mode 100644 index 000000000000..4fea3e4edaa7 --- /dev/null +++ b/drivers/scsi/iscsi_tcp.c @@ -0,0 +1,3642 @@ +/* + * iSCSI Initiator over TCP/IP Data-Path + * + * Copyright (C) 2004 Dmitry Yusupov + * Copyright (C) 2004 Alex Aizman + * Copyright (C) 2005 Mike Christie + * 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. + * + * See the file COPYING included with this distribution for more details. + * + * Credits: + * Christoph Hellwig + * FUJITA Tomonori + * Arne Redlich + * Zhenyu Wang + */ + +#include <linux/types.h> +#include <linux/list.h> +#include <linux/inet.h> +#include <linux/blkdev.h> +#include <linux/crypto.h> +#include <linux/delay.h> +#include <linux/kfifo.h> +#include <linux/scatterlist.h> +#include <net/tcp.h> +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_device.h> +#include <scsi/scsi_eh.h> +#include <scsi/scsi_request.h> +#include <scsi/scsi_tcq.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi.h> +#include <scsi/scsi_transport_iscsi.h> + +#include "iscsi_tcp.h" + +MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, " + "Alex Aizman <itn780@yahoo.com>"); +MODULE_DESCRIPTION("iSCSI/TCP data-path"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("0:4.409"); +/* #define DEBUG_TCP */ +/* #define DEBUG_SCSI */ +#define DEBUG_ASSERT + +#ifdef DEBUG_TCP +#define debug_tcp(fmt...) printk(KERN_DEBUG "tcp: " fmt) +#else +#define debug_tcp(fmt...) +#endif + +#ifdef DEBUG_SCSI +#define debug_scsi(fmt...) printk(KERN_DEBUG "scsi: " fmt) +#else +#define debug_scsi(fmt...) +#endif + +#ifndef DEBUG_ASSERT +#ifdef BUG_ON +#undef BUG_ON +#endif +#define BUG_ON(expr) +#endif + +#define INVALID_SN_DELTA 0xffff + +static unsigned int iscsi_max_lun = 512; +module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); + +/* global data */ +static kmem_cache_t *taskcache; + +static inline void +iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size) +{ + sg_init_one(&ibuf->sg, (u8 *)vbuf, size); + ibuf->sent = 0; +} + +static inline void +iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size) +{ + ibuf->sg.page = (void*)vbuf; + ibuf->sg.offset = (unsigned int)-1; + ibuf->sg.length = size; + ibuf->sent = 0; +} + +static inline void* +iscsi_buf_iov_base(struct iscsi_buf *ibuf) +{ + return (char*)ibuf->sg.page + ibuf->sent; +} + +static inline void +iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg) +{ + /* + * Fastpath: sg element fits into single page + */ + if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2) { + ibuf->sg.page = sg->page; + ibuf->sg.offset = sg->offset; + ibuf->sg.length = sg->length; + } else + iscsi_buf_init_iov(ibuf, page_address(sg->page), sg->length); + ibuf->sent = 0; +} + +static inline int +iscsi_buf_left(struct iscsi_buf *ibuf) +{ + int rc; + + rc = ibuf->sg.length - ibuf->sent; + BUG_ON(rc < 0); + return rc; +} + +static inline void +iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf, + u8* crc) +{ + crypto_digest_digest(conn->tx_tfm, &buf->sg, 1, crc); + buf->sg.length += sizeof(uint32_t); +} + +static 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->conn_cnt == 1 || session->leadconn == conn) + session->state = ISCSI_STATE_FAILED; + spin_unlock_irqrestore(&session->lock, flags); + set_bit(SUSPEND_BIT, &conn->suspend_tx); + set_bit(SUSPEND_BIT, &conn->suspend_rx); + iscsi_conn_error(iscsi_handle(conn), err); +} + +static inline 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; +} + +static inline int +iscsi_hdr_extract(struct iscsi_conn *conn) +{ + struct sk_buff *skb = conn->in.skb; + + if (conn->in.copy >= conn->hdr_size && + conn->in_progress == IN_PROGRESS_WAIT_HEADER) { + /* + * Zero-copy PDU Header: using connection context + * to store header pointer. + */ + if (skb_shinfo(skb)->frag_list == NULL && + !skb_shinfo(skb)->nr_frags) + conn->in.hdr = (struct iscsi_hdr *) + ((char*)skb->data + conn->in.offset); + else { + /* ignoring return code since we checked + * in.copy before */ + skb_copy_bits(skb, conn->in.offset, + &conn->hdr, conn->hdr_size); + conn->in.hdr = &conn->hdr; + } + conn->in.offset += conn->hdr_size; + conn->in.copy -= conn->hdr_size; + } else { + int hdr_remains; + int copylen; + + /* + * PDU header scattered across SKB's, + * copying it... This'll happen quite rarely. + */ + + if (conn->in_progress == IN_PROGRESS_WAIT_HEADER) + conn->in.hdr_offset = 0; + + hdr_remains = conn->hdr_size - conn->in.hdr_offset; + BUG_ON(hdr_remains <= 0); + + copylen = min(conn->in.copy, hdr_remains); + skb_copy_bits(skb, conn->in.offset, + (char*)&conn->hdr + conn->in.hdr_offset, copylen); + + debug_tcp("PDU gather offset %d bytes %d in.offset %d " + "in.copy %d\n", conn->in.hdr_offset, copylen, + conn->in.offset, conn->in.copy); + + conn->in.offset += copylen; + conn->in.copy -= copylen; + if (copylen < hdr_remains) { + conn->in_progress = IN_PROGRESS_HEADER_GATHER; + conn->in.hdr_offset += copylen; + return -EAGAIN; + } + conn->in.hdr = &conn->hdr; + conn->discontiguous_hdr_cnt++; + conn->in_progress = IN_PROGRESS_WAIT_HEADER; + } + + return 0; +} + +static inline void +iscsi_ctask_cleanup(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct scsi_cmnd *sc = ctask->sc; + struct iscsi_session *session = conn->session; + + spin_lock(&session->lock); + if (unlikely(!sc)) { + spin_unlock(&session->lock); + return; + } + if (sc->sc_data_direction == DMA_TO_DEVICE) { + struct iscsi_data_task *dtask, *n; + /* WRITE: cleanup Data-Out's if any */ + spin_lock(&conn->lock); + list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) { + list_del(&dtask->item); + mempool_free(dtask, ctask->datapool); + } + spin_unlock(&conn->lock); + } + ctask->xmstate = XMSTATE_IDLE; + ctask->r2t = NULL; + ctask->sc = NULL; + __kfifo_put(session->cmdpool.queue, (void*)&ctask, sizeof(void*)); + spin_unlock(&session->lock); +} + +/** + * iscsi_cmd_rsp - SCSI Command Response processing + * @conn: iscsi connection + * @ctask: scsi command task + **/ +static int +iscsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + int rc; + struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)conn->in.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 && conn->senselen) { + int sensecopy = min(conn->senselen, SCSI_SENSE_BUFFERSIZE); + + memcpy(sc->sense_buffer, conn->data + 2, sensecopy); + debug_scsi("copied %d bytes of sense\n", sensecopy); + } + + 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_ctask_cleanup(conn, ctask); + sc->scsi_done(sc); + return rc; +} + +/** + * iscsi_data_rsp - SCSI Data-In Response processing + * @conn: iscsi connection + * @ctask: scsi command task + **/ +static int +iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + int rc; + struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)conn->in.hdr; + struct iscsi_session *session = conn->session; + int datasn = be32_to_cpu(rhdr->datasn); + + rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr); + if (rc) + return rc; + /* + * setup Data-In byte counter (gets decremented..) + */ + ctask->data_count = conn->in.datalen; + + if (conn->in.datalen == 0) + return 0; + + if (ctask->datasn != datasn) + return ISCSI_ERR_DATASN; + + ctask->datasn++; + + ctask->data_offset = be32_to_cpu(rhdr->offset); + if (ctask->data_offset + conn->in.datalen > ctask->total_length) + return ISCSI_ERR_DATA_OFFSET; + + if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) { + struct scsi_cmnd *sc = ctask->sc; + + conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1; + 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; + sc->result = (DID_OK << 16) | rhdr->cmd_status; + } 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); + sc->result = (DID_OK << 16) | rhdr->cmd_status; + } else + sc->result = (DID_OK << 16) | rhdr->cmd_status; + } + + conn->datain_pdus_cnt++; + return 0; +} + +/** + * iscsi_solicit_data_init - initialize first Data-Out + * @conn: iscsi connection + * @ctask: scsi command task + * @r2t: R2T info + * + * Notes: + * Initialize first Data-Out within this R2T sequence and finds + * proper data_offset within this SCSI command. + * + * This function is called with connection lock taken. + **/ +static void +iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, + struct iscsi_r2t_info *r2t) +{ + struct iscsi_data *hdr; + struct iscsi_data_task *dtask; + struct scsi_cmnd *sc = ctask->sc; + + dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC); + BUG_ON(!dtask); + hdr = &dtask->hdr; + memset(hdr, 0, sizeof(struct iscsi_data)); + hdr->ttt = r2t->ttt; + hdr->datasn = cpu_to_be32(r2t->solicit_datasn); + r2t->solicit_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 = r2t->exp_statsn; + hdr->offset = cpu_to_be32(r2t->data_offset); + if (r2t->data_length > conn->max_xmit_dlength) { + hton24(hdr->dlength, conn->max_xmit_dlength); + r2t->data_count = conn->max_xmit_dlength; + hdr->flags = 0; + } else { + hton24(hdr->dlength, r2t->data_length); + r2t->data_count = r2t->data_length; + hdr->flags = ISCSI_FLAG_CMD_FINAL; + } + conn->dataout_pdus_cnt++; + + r2t->sent = 0; + + iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr, + sizeof(struct iscsi_hdr)); + + r2t->dtask = dtask; + + if (sc->use_sg) { + int i, sg_count = 0; + struct scatterlist *sg = sc->request_buffer; + + r2t->sg = NULL; + for (i = 0; i < sc->use_sg; i++, sg += 1) { + /* FIXME: prefetch ? */ + if (sg_count + sg->length > r2t->data_offset) { + int page_offset; + + /* sg page found! */ + + /* offset within this page */ + page_offset = r2t->data_offset - sg_count; + + /* fill in this buffer */ + iscsi_buf_init_sg(&r2t->sendbuf, sg); + r2t->sendbuf.sg.offset += page_offset; + r2t->sendbuf.sg.length -= page_offset; + + /* xmit logic will continue with next one */ + r2t->sg = sg + 1; + break; + } + sg_count += sg->length; + } + BUG_ON(r2t->sg == NULL); + } else + iscsi_buf_init_iov(&ctask->sendbuf, + (char*)sc->request_buffer + r2t->data_offset, + r2t->data_count); + + list_add(&dtask->item, &ctask->dataqueue); +} + +/** + * iscsi_r2t_rsp - iSCSI R2T Response processing + * @conn: iscsi connection + * @ctask: scsi command task + **/ +static int +iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct iscsi_r2t_info *r2t; + struct iscsi_session *session = conn->session; + struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)conn->in.hdr; + int r2tsn = be32_to_cpu(rhdr->r2tsn); + int rc; + + if (conn->in.ahslen) + return ISCSI_ERR_AHSLEN; + + if (conn->in.datalen) + return ISCSI_ERR_DATALEN; + + if (ctask->exp_r2tsn && ctask->exp_r2tsn != r2tsn) + return ISCSI_ERR_R2TSN; + + rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr); + if (rc) + return rc; + + /* FIXME: use R2TSN to detect missing R2T */ + + /* fill-in new R2T associated with the task */ + spin_lock(&session->lock); + if (!ctask->sc || ctask->mtask || + session->state != ISCSI_STATE_LOGGED_IN) { + printk(KERN_INFO "iscsi_tcp: dropping R2T itt %d in " + "recovery...\n", ctask->itt); + spin_unlock(&session->lock); + return 0; + } + rc = __kfifo_get(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); + BUG_ON(!rc); + + r2t->exp_statsn = rhdr->statsn; + r2t->data_length = be32_to_cpu(rhdr->data_length); + if (r2t->data_length == 0 || + r2t->data_length > session->max_burst) { + spin_unlock(&session->lock); + return ISCSI_ERR_DATALEN; + } + + r2t->data_offset = be32_to_cpu(rhdr->data_offset); + if (r2t->data_offset + r2t->data_length > ctask->total_length) { + spin_unlock(&session->lock); + return ISCSI_ERR_DATALEN; + } + + r2t->ttt = rhdr->ttt; /* no flip */ + r2t->solicit_datasn = 0; + + iscsi_solicit_data_init(conn, ctask, r2t); + + ctask->exp_r2tsn = r2tsn + 1; + ctask->xmstate |= XMSTATE_SOL_HDR; + __kfifo_put(ctask->r2tqueue, (void*)&r2t, sizeof(void*)); + __kfifo_put(conn->writequeue, (void*)&ctask, sizeof(void*)); + + schedule_work(&conn->xmitwork); + conn->r2t_pdus_cnt++; + spin_unlock(&session->lock); + + return 0; +} + +static int +iscsi_hdr_recv(struct iscsi_conn *conn) +{ + int rc = 0; + struct iscsi_hdr *hdr; + struct iscsi_cmd_task *ctask; + struct iscsi_session *session = conn->session; + uint32_t cdgst, rdgst = 0; + + hdr = conn->in.hdr; + + /* verify PDU length */ + conn->in.datalen = ntoh24(hdr->dlength); + if (conn->in.datalen > conn->max_recv_dlength) { + printk(KERN_ERR "iscsi_tcp: datalen %d > %d\n", + conn->in.datalen, conn->max_recv_dlength); + return ISCSI_ERR_DATALEN; + } + conn->data_copied = 0; + + /* read AHS */ + conn->in.ahslen = hdr->hlength * 4; + conn->in.offset += conn->in.ahslen; + conn->in.copy -= conn->in.ahslen; + if (conn->in.copy < 0) { + printk(KERN_ERR "iscsi_tcp: can't handle AHS with length " + "%d bytes\n", conn->in.ahslen); + return ISCSI_ERR_AHSLEN; + } + + /* calculate read padding */ + conn->in.padding = conn->in.datalen & (ISCSI_PAD_LEN-1); + if (conn->in.padding) { + conn->in.padding = ISCSI_PAD_LEN - conn->in.padding; + debug_scsi("read padding %d bytes\n", conn->in.padding); + } + + if (conn->hdrdgst_en) { + struct scatterlist sg; + + sg_init_one(&sg, (u8 *)hdr, + sizeof(struct iscsi_hdr) + conn->in.ahslen); + crypto_digest_digest(conn->rx_tfm, &sg, 1, (u8 *)&cdgst); + rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) + + conn->in.ahslen); + } + + /* save opcode for later */ + conn->in.opcode = hdr->opcode; + + /* verify itt (itt encoding: age+cid+itt) */ + if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) { + if ((hdr->itt & AGE_MASK) != + (session->age << AGE_SHIFT)) { + printk(KERN_ERR "iscsi_tcp: received itt %x expected " + "session age (%x)\n", hdr->itt, + session->age & AGE_MASK); + return ISCSI_ERR_BAD_ITT; + } + + if ((hdr->itt & CID_MASK) != (conn->id << CID_SHIFT)) { + printk(KERN_ERR "iscsi_tcp: received itt %x, expected " + "CID (%x)\n", hdr->itt, conn->id); + return ISCSI_ERR_BAD_ITT; + } + conn->in.itt = hdr->itt & ITT_MASK; + } else + conn->in.itt = hdr->itt; + + debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n", + hdr->opcode, conn->in.offset, conn->in.copy, + conn->in.ahslen, conn->in.datalen); + + if (conn->in.itt < session->cmds_max) { + if (conn->hdrdgst_en && cdgst != rdgst) { + printk(KERN_ERR "iscsi_tcp: itt %x: hdrdgst error " + "recv 0x%x calc 0x%x\n", conn->in.itt, rdgst, + cdgst); + return ISCSI_ERR_HDR_DGST; + } + + ctask = (struct iscsi_cmd_task *)session->cmds[conn->in.itt]; + + if (!ctask->sc) { + printk(KERN_INFO "iscsi_tcp: dropping ctask with " + "itt 0x%x\n", ctask->itt); + conn->in.datalen = 0; /* force drop */ + return 0; + } + + if (ctask->sc->SCp.phase != session->age) { + printk(KERN_ERR "iscsi_tcp: ctask's session age %d, " + "expected %d\n", ctask->sc->SCp.phase, + session->age); + return ISCSI_ERR_SESSION_FAILED; + } + + conn->in.ctask = ctask; + + debug_scsi("rsp [op 0x%x cid %d sc %lx itt 0x%x len %d]\n", + hdr->opcode, conn->id, (long)ctask->sc, + ctask->itt, conn->in.datalen); + + switch(conn->in.opcode) { + case ISCSI_OP_SCSI_CMD_RSP: + BUG_ON((void*)ctask != ctask->sc->SCp.ptr); + if (ctask->hdr.flags & ISCSI_FLAG_CMD_WRITE) + rc = iscsi_cmd_rsp(conn, ctask); + else if (!conn->in.datalen) + rc = iscsi_cmd_rsp(conn, ctask); + else + /* + * got sense or response data; copying PDU + * Header to the connection's header + * placeholder + */ + memcpy(&conn->hdr, hdr, + sizeof(struct iscsi_hdr)); + break; + case ISCSI_OP_SCSI_DATA_IN: + BUG_ON((void*)ctask != ctask->sc->SCp.ptr); + /* save flags for non-exceptional status */ + conn->in.flags = hdr->flags; + /* save cmd_status for sense data */ + conn->in.cmd_status = + ((struct iscsi_data_rsp*)hdr)->cmd_status; + rc = iscsi_data_rsp(conn, ctask); + break; + case ISCSI_OP_R2T: + BUG_ON((void*)ctask != ctask->sc->SCp.ptr); + if (ctask->hdr.flags & ISCSI_FLAG_CMD_WRITE && + ctask->sc->sc_data_direction == DMA_TO_DEVICE) + rc = iscsi_r2t_rsp(conn, ctask); + else + rc = ISCSI_ERR_PROTO; + break; + default: + rc = ISCSI_ERR_BAD_OPCODE; + break; + } + } else if (conn->in.itt >= ISCSI_MGMT_ITT_OFFSET && + conn->in.itt < ISCSI_MGMT_ITT_OFFSET + + session->mgmtpool_max) { + struct iscsi_mgmt_task *mtask = (struct iscsi_mgmt_task *) + session->mgmt_cmds[conn->in.itt - + ISCSI_MGMT_ITT_OFFSET]; + + debug_scsi("immrsp [op 0x%x cid %d itt 0x%x len %d]\n", + conn->in.opcode, conn->id, mtask->itt, + conn->in.datalen); + + switch(conn->in.opcode) { + case ISCSI_OP_LOGIN_RSP: + case ISCSI_OP_TEXT_RSP: + case ISCSI_OP_LOGOUT_RSP: + rc = iscsi_check_assign_cmdsn(session, + (struct iscsi_nopin*)hdr); + if (rc) + break; + + if (!conn->in.datalen) { + rc = iscsi_recv_pdu(iscsi_handle(conn), hdr, + NULL, 0); + if (conn->login_mtask != mtask) { + spin_lock(&session->lock); + __kfifo_put(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*)); + spin_unlock(&session->lock); + } + } + break; + case ISCSI_OP_SCSI_TMFUNC_RSP: + rc = iscsi_check_assign_cmdsn(session, + (struct iscsi_nopin*)hdr); + if (rc) + break; + + if (conn->in.datalen || conn->in.ahslen) { + rc = ISCSI_ERR_PROTO; + break; + } + conn->tmfrsp_pdus_cnt++; + spin_lock(&session->lock); + if (conn->tmabort_state == TMABORT_INITIAL) { + __kfifo_put(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*)); + conn->tmabort_state = + ((struct iscsi_tm_rsp *)hdr)-> + response == ISCSI_TMF_RSP_COMPLETE ? + TMABORT_SUCCESS:TMABORT_FAILED; + /* unblock eh_abort() */ + wake_up(&conn->ehwait); + } + spin_unlock(&session->lock); + break; + case ISCSI_OP_NOOP_IN: + if (hdr->ttt != ISCSI_RESERVED_TAG) { + rc = ISCSI_ERR_PROTO; + break; + } + rc = iscsi_check_assign_cmdsn(session, + (struct iscsi_nopin*)hdr); + if (rc) + break; + conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1; + + if (!conn->in.datalen) { + struct iscsi_mgmt_task *mtask; + + rc = iscsi_recv_pdu(iscsi_handle(conn), hdr, + NULL, 0); + mtask = (struct iscsi_mgmt_task *) + session->mgmt_cmds[conn->in.itt - + ISCSI_MGMT_ITT_OFFSET]; + if (conn->login_mtask != mtask) { + spin_lock(&session->lock); + __kfifo_put(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*)); + spin_unlock(&session->lock); + } + } + break; + default: + rc = ISCSI_ERR_BAD_OPCODE; + break; + } + } else if (conn->in.itt == ISCSI_RESERVED_TAG) { + switch(conn->in.opcode) { + case ISCSI_OP_NOOP_IN: + if (!conn->in.datalen) { + rc = iscsi_check_assign_cmdsn(session, + (struct iscsi_nopin*)hdr); + if (!rc && hdr->ttt != ISCSI_RESERVED_TAG) + rc = iscsi_recv_pdu(iscsi_handle(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: + /* 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; + + return rc; +} + +/** + * iscsi_ctask_copy - copy skb bits to the destanation cmd task + * @conn: iscsi connection + * @ctask: scsi command task + * @buf: buffer to copy to + * @buf_size: size of buffer + * @offset: offset within the buffer + * + * Notes: + * The function calls skb_copy_bits() and updates per-connection and + * per-cmd byte counters. + * + * Read counters (in bytes): + * + * conn->in.offset offset within in progress SKB + * conn->in.copy left to copy from in progress SKB + * including padding + * conn->in.copied copied already from in progress SKB + * conn->data_copied copied already from in progress buffer + * ctask->sent total bytes sent up to the MidLayer + * ctask->data_count left to copy from in progress Data-In + * buf_left left to copy from in progress buffer + **/ +static inline int +iscsi_ctask_copy(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, + void *buf, int buf_size, int offset) +{ + int buf_left = buf_size - (conn->data_copied + offset); + int size = min(conn->in.copy, buf_left); + int rc; + + size = min(size, ctask->data_count); + + debug_tcp("ctask_copy %d bytes at offset %d copied %d\n", + size, conn->in.offset, conn->in.copied); + + BUG_ON(size <= 0); + BUG_ON(ctask->sent + size > ctask->total_length); + + rc = skb_copy_bits(conn->in.skb, conn->in.offset, + (char*)buf + (offset + conn->data_copied), size); + /* must fit into skb->len */ + BUG_ON(rc); + + conn->in.offset += size; + conn->in.copy -= size; + conn->in.copied += size; + conn->data_copied += size; + ctask->sent += size; + ctask->data_count -= size; + + BUG_ON(conn->in.copy < 0); + BUG_ON(ctask->data_count < 0); + + if (buf_size != (conn->data_copied + offset)) { + if (!ctask->data_count) { + BUG_ON(buf_size - conn->data_copied < 0); + /* done with this PDU */ + return buf_size - conn->data_copied; + } + return -EAGAIN; + } + + /* done with this buffer or with both - PDU and buffer */ + conn->data_copied = 0; + return 0; +} + +/** + * iscsi_tcp_copy - copy skb bits to the destanation buffer + * @conn: iscsi connection + * @buf: buffer to copy to + * @buf_size: number of bytes to copy + * + * Notes: + * The function calls skb_copy_bits() and updates per-connection + * byte counters. + **/ +static inline int +iscsi_tcp_copy(struct iscsi_conn *conn, void *buf, int buf_size) +{ + int buf_left = buf_size - conn->data_copied; + int size = min(conn->in.copy, buf_left); + int rc; + + debug_tcp("tcp_copy %d bytes at offset %d copied %d\n", + size, conn->in.offset, conn->data_copied); + BUG_ON(size <= 0); + + rc = skb_copy_bits(conn->in.skb, conn->in.offset, + (char*)buf + conn->data_copied, size); + BUG_ON(rc); + + conn->in.offset += size; + conn->in.copy -= size; + conn->in.copied += size; + conn->data_copied += size; + + if (buf_size != conn->data_copied) + return -EAGAIN; + + return 0; +} + +static inline void +partial_sg_digest_update(struct iscsi_conn *conn, struct scatterlist *sg, + int offset, int length) +{ + struct scatterlist temp; + + memcpy(&temp, sg, sizeof(struct scatterlist)); + temp.offset = offset; + temp.length = length; + crypto_digest_update(conn->data_rx_tfm, &temp, 1); +} + +static int iscsi_scsi_data_in(struct iscsi_conn *conn) +{ + struct iscsi_cmd_task *ctask = conn->in.ctask; + struct scsi_cmnd *sc = ctask->sc; + struct scatterlist tmp, *sg; + int i, offset, rc = 0; + + BUG_ON((void*)ctask != sc->SCp.ptr); + + /* + * copying Data-In into the Scsi_Cmnd + */ + if (!sc->use_sg) { + i = ctask->data_count; + rc = iscsi_ctask_copy(conn, ctask, sc->request_buffer, + sc->request_bufflen, ctask->data_offset); + if (rc == -EAGAIN) + return rc; + if (conn->datadgst_en) { + sg_init_one(&tmp, sc->request_buffer, i); + crypto_digest_update(conn->data_rx_tfm, &tmp, 1); + } + rc = 0; + goto done; + } + + offset = ctask->data_offset; + sg = sc->request_buffer; + + if (ctask->data_offset) + for (i = 0; i < ctask->sg_count; i++) + offset -= sg[i].length; + /* we've passed through partial sg*/ + if (offset < 0) + offset = 0; + + for (i = ctask->sg_count; i < sc->use_sg; i++) { + char *dest; + + dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0); + rc = iscsi_ctask_copy(conn, ctask, dest + sg[i].offset, + sg[i].length, offset); + kunmap_atomic(dest, KM_SOFTIRQ0); + if (rc == -EAGAIN) + /* continue with the next SKB/PDU */ + return rc; + if (!rc) { + if (conn->datadgst_en) { + if (!offset) + crypto_digest_update(conn->data_rx_tfm, + &sg[i], 1); + else + partial_sg_digest_update(conn, &sg[i], + sg[i].offset + offset, + sg[i].length - offset); + } + offset = 0; + ctask->sg_count++; + } + + if (!ctask->data_count) { + if (rc && conn->datadgst_en) + /* + * data-in is complete, but buffer not... + */ + partial_sg_digest_update(conn, &sg[i], + sg[i].offset, sg[i].length-rc); + rc = 0; + break; + } + + if (!conn->in.copy) + return -EAGAIN; + } + BUG_ON(ctask->data_count); + +done: + /* check for non-exceptional status */ + if (conn->in.flags & ISCSI_FLAG_DATA_STATUS) { + debug_scsi("done [sc %lx res %d itt 0x%x]\n", + (long)sc, sc->result, ctask->itt); + conn->scsirsp_pdus_cnt++; + iscsi_ctask_cleanup(conn, ctask); + sc->scsi_done(sc); + } + + return rc; +} + +static int +iscsi_data_recv(struct iscsi_conn *conn) +{ + struct iscsi_session *session = conn->session; + int rc = 0; + + switch(conn->in.opcode) { + case ISCSI_OP_SCSI_DATA_IN: + rc = iscsi_scsi_data_in(conn); + break; + case ISCSI_OP_SCSI_CMD_RSP: { + /* + * SCSI Sense Data: + * copying the entire Data Segment. + */ + if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) { + rc = -EAGAIN; + goto exit; + } + + /* + * check for sense + */ + conn->in.hdr = &conn->hdr; + conn->senselen = (conn->data[0] << 8) | conn->data[1]; + rc = iscsi_cmd_rsp(conn, conn->in.ctask); + } + break; + case ISCSI_OP_TEXT_RSP: + case ISCSI_OP_LOGIN_RSP: + case ISCSI_OP_NOOP_IN: { + struct iscsi_mgmt_task *mtask = NULL; + + if (conn->in.itt != ISCSI_RESERVED_TAG) + mtask = (struct iscsi_mgmt_task *) + session->mgmt_cmds[conn->in.itt - + ISCSI_MGMT_ITT_OFFSET]; + + /* + * Collect data segment to the connection's data + * placeholder + */ + if (iscsi_tcp_copy(conn, conn->data, conn->in.datalen)) { + rc = -EAGAIN; + goto exit; + } + + rc = iscsi_recv_pdu(iscsi_handle(conn), conn->in.hdr, + conn->data, conn->in.datalen); + + if (mtask && conn->login_mtask != mtask) { + spin_lock(&session->lock); + __kfifo_put(session->mgmtpool.queue, (void*)&mtask, + sizeof(void*)); + spin_unlock(&session->lock); + } + } + break; + default: + BUG_ON(1); + } +exit: + return rc; +} + +/** + * iscsi_tcp_data_recv - TCP receive in sendfile fashion + * @rd_desc: read descriptor + * @skb: socket buffer + * @offset: offset in skb + * @len: skb->len - offset + **/ +static int +iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, + unsigned int offset, size_t len) +{ + int rc; + struct iscsi_conn *conn = rd_desc->arg.data; + int processed; + char pad[ISCSI_PAD_LEN]; + struct scatterlist sg; + + /* + * Save current SKB and its offset in the corresponding + * connection context. + */ + conn->in.copy = skb->len - offset; + conn->in.offset = offset; + conn->in.skb = skb; + conn->in.len = conn->in.copy; + BUG_ON(conn->in.copy <= 0); + debug_tcp("in %d bytes\n", conn->in.copy); + +more: + conn->in.copied = 0; + rc = 0; + + if (unlikely(conn->suspend_rx)) { + debug_tcp("conn %d Rx suspended!\n", conn->id); + return 0; + } + + if (conn->in_progress == IN_PROGRESS_WAIT_HEADER || + conn->in_progress == IN_PROGRESS_HEADER_GATHER) { + rc = iscsi_hdr_extract(conn); + if (rc) { + if (rc == -EAGAIN) + goto nomore; + else { + iscsi_conn_failure(conn, rc); + return 0; + } + } + + /* + * Verify and process incoming PDU header. + */ + rc = iscsi_hdr_recv(conn); + if (!rc && conn->in.datalen) { + if (conn->datadgst_en && + conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) { + BUG_ON(!conn->data_rx_tfm); + crypto_digest_init(conn->data_rx_tfm); + } + conn->in_progress = IN_PROGRESS_DATA_RECV; + } else if (rc) { + iscsi_conn_failure(conn, rc); + return 0; + } + } + + if (conn->in_progress == IN_PROGRESS_DDIGEST_RECV) { + debug_tcp("extra data_recv offset %d copy %d\n", + conn->in.offset, conn->in.copy); + if (conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) { + uint32_t recv_digest; + skb_copy_bits(conn->in.skb, conn->in.offset, + &recv_digest, 4); + conn->in.offset += 4; + conn->in.copy -= 4; + if (recv_digest != conn->in.datadgst) { + debug_tcp("iscsi_tcp: data digest error!" + "0x%x != 0x%x\n", recv_digest, + conn->in.datadgst); + iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST); + return 0; + } else { + debug_tcp("iscsi_tcp: data digest match!" + "0x%x == 0x%x\n", recv_digest, + conn->in.datadgst); + conn->in_progress = IN_PROGRESS_WAIT_HEADER; + } + } + } + + if (conn->in_progress == IN_PROGRESS_DATA_RECV && conn->in.copy) { + + debug_tcp("data_recv offset %d copy %d\n", + conn->in.offset, conn->in.copy); + + rc = iscsi_data_recv(conn); + if (rc) { + if (rc == -EAGAIN) { + rd_desc->count = conn->in.datalen - + conn->in.ctask->data_count; + goto again; + } + iscsi_conn_failure(conn, rc); + return 0; + } + conn->in.copy -= conn->in.padding; + conn->in.offset += conn->in.padding; + if (conn->datadgst_en && + conn->in.opcode == ISCSI_OP_SCSI_DATA_IN) { + if (conn->in.padding) { + debug_tcp("padding -> %d\n", conn->in.padding); + memset(pad, 0, conn->in.padding); + sg_init_one(&sg, pad, conn->in.padding); + crypto_digest_update(conn->data_rx_tfm, &sg, 1); + } + crypto_digest_final(conn->data_rx_tfm, + (u8 *) & conn->in.datadgst); + debug_tcp("rx digest 0x%x\n", conn->in.datadgst); + conn->in_progress = IN_PROGRESS_DDIGEST_RECV; + } else + conn->in_progress = IN_PROGRESS_WAIT_HEADER; + } + + debug_tcp("f, processed %d from out of %d padding %d\n", + conn->in.offset - offset, (int)len, conn->in.padding); + BUG_ON(conn->in.offset - offset > len); + + if (conn->in.offset - offset != len) { + debug_tcp("continue to process %d bytes\n", + (int)len - (conn->in.offset - offset)); + goto more; + } + +nomore: + processed = conn->in.offset - offset; + BUG_ON(processed == 0); + return processed; + +again: + processed = conn->in.offset - offset; + debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n", + processed, (int)len, (int)rd_desc->count); + BUG_ON(processed == 0); + BUG_ON(processed > len); + + conn->rxdata_octets += processed; + return processed; +} + +static void +iscsi_tcp_data_ready(struct sock *sk, int flag) +{ + struct iscsi_conn *conn = sk->sk_user_data; + read_descriptor_t rd_desc; + + read_lock(&sk->sk_callback_lock); + + /* use rd_desc to pass 'conn' to iscsi_tcp_data_recv */ + rd_desc.arg.data = conn; + rd_desc.count = 0; + tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv); + + read_unlock(&sk->sk_callback_lock); +} + +static void +iscsi_tcp_state_change(struct sock *sk) +{ + struct iscsi_conn *conn; + struct iscsi_session *session; + void (*old_state_change)(struct sock *); + + read_lock(&sk->sk_callback_lock); + + conn = (struct iscsi_conn*)sk->sk_user_data; + session = conn->session; + + if (sk->sk_state == TCP_CLOSE_WAIT || + sk->sk_state == TCP_CLOSE) { + debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n"); + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + } + + old_state_change = conn->old_state_change; + + read_unlock(&sk->sk_callback_lock); + + old_state_change(sk); +} + +/** + * iscsi_write_space - Called when more output buffer space is available + * @sk: socket space is available for + **/ +static void +iscsi_write_space(struct sock *sk) +{ + struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data; + conn->old_write_space(sk); + debug_tcp("iscsi_write_space: cid %d\n", conn->id); + clear_bit(SUSPEND_BIT, &conn->suspend_tx); + schedule_work(&conn->xmitwork); +} + +static void +iscsi_conn_set_callbacks(struct iscsi_conn *conn) +{ + struct sock *sk = conn->sock->sk; + + /* assign new callbacks */ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_user_data = conn; + conn->old_data_ready = sk->sk_data_ready; + conn->old_state_change = sk->sk_state_change; + conn->old_write_space = sk->sk_write_space; + sk->sk_data_ready = iscsi_tcp_data_ready; + sk->sk_state_change = iscsi_tcp_state_change; + sk->sk_write_space = iscsi_write_space; + write_unlock_bh(&sk->sk_callback_lock); +} + +static void +iscsi_conn_restore_callbacks(struct iscsi_conn *conn) +{ + struct sock *sk = conn->sock->sk; + + /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_user_data = NULL; + sk->sk_data_ready = conn->old_data_ready; + sk->sk_state_change = conn->old_state_change; + sk->sk_write_space = conn->old_write_space; + sk->sk_no_check = 0; + write_unlock_bh(&sk->sk_callback_lock); +} + +/** + * iscsi_send - generic send routine + * @sk: kernel's socket + * @buf: buffer to write from + * @size: actual size to write + * @flags: socket's flags + * + * Notes: + * depending on buffer will use tcp_sendpage() or tcp_sendmsg(). + * buf->sg.offset == -1 tells us that buffer is non S/G and forces + * to use tcp_sendmsg(). + */ +static inline int +iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags) +{ + int res; + + if ((int)buf->sg.offset >= 0) { + int offset = buf->sg.offset + buf->sent; + + /* tcp_sendpage */ + res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags); + } else { + struct msghdr msg; + + buf->iov.iov_base = iscsi_buf_iov_base(buf); + buf->iov.iov_len = size; + + memset(&msg, 0, sizeof(struct msghdr)); + + /* tcp_sendmsg */ + res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size); + } + + return res; +} + +/** + * iscsi_sendhdr - send PDU Header via tcp_sendpage() + * @conn: iscsi connection + * @buf: buffer to write from + * @datalen: lenght of data to be sent after the header + * + * Notes: + * (Tx, Fast Path) + **/ +static inline int +iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen) +{ + struct socket *sk = conn->sock; + int flags = 0; /* MSG_DONTWAIT; */ + int res, size; + + size = buf->sg.length - buf->sent; + BUG_ON(buf->sent + size > buf->sg.length); + if (buf->sent + size != buf->sg.length || datalen) + flags |= MSG_MORE; + + res = iscsi_send(sk, buf, size, flags); + debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res); + if (res >= 0) { + conn->txdata_octets += res; + buf->sent += res; + if (size != res) + return -EAGAIN; + return 0; + } else if (res == -EAGAIN) { + conn->sendpage_failures_cnt++; + set_bit(SUSPEND_BIT, &conn->suspend_tx); + } else if (res == -EPIPE) + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + + return res; +} + +/** + * iscsi_sendpage - send one page of iSCSI Data-Out. + * @conn: iscsi connection + * @buf: buffer to write from + * @count: remaining data + * @sent: number of bytes sent + * + * Notes: + * (Tx, Fast Path) + **/ +static inline int +iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf, + int *count, int *sent) +{ + struct socket *sk = conn->sock; + int flags = 0; /* MSG_DONTWAIT; */ + int res, size; + + size = buf->sg.length - buf->sent; + BUG_ON(buf->sent + size > buf->sg.length); + if (size > *count) + size = *count; + if (buf->sent + size != buf->sg.length || *count != size) + flags |= MSG_MORE; + + res = iscsi_send(sk, buf, size, flags); + debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n", + size, buf->sent, *count, *sent, res); + if (res >= 0) { + conn->txdata_octets += res; + buf->sent += res; + *count -= res; + *sent += res; + if (size != res) + return -EAGAIN; + return 0; + } else if (res == -EAGAIN) { + conn->sendpage_failures_cnt++; + set_bit(SUSPEND_BIT, &conn->suspend_tx); + } else if (res == -EPIPE) + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + + return res; +} + +static inline void +iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + BUG_ON(!conn->data_tx_tfm); + crypto_digest_init(conn->data_tx_tfm); + ctask->digest_count = 4; +} + +static inline void +iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf) +{ + struct scatterlist sg; + + if (buf->sg.offset != -1) + crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1); + else { + sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length); + crypto_digest_update(conn->data_tx_tfm, &sg, 1); + } +} + +static inline int +iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, + struct iscsi_buf *buf, uint32_t *digest, int final) +{ + int rc = 0; + int sent = 0; + + if (final) + crypto_digest_final(conn->data_tx_tfm, (u8*)digest); + + iscsi_buf_init_virt(buf, (char*)digest, 4); + rc = iscsi_sendpage(conn, buf, &ctask->digest_count, &sent); + if (rc) { + ctask->datadigest = *digest; + ctask->xmstate |= XMSTATE_DATA_DIGEST; + } else + ctask->digest_count = 4; + return rc; +} + +/** + * iscsi_solicit_data_cont - initialize next Data-Out + * @conn: iscsi connection + * @ctask: scsi command task + * @r2t: R2T info + * @left: bytes left to transfer + * + * Notes: + * Initialize next Data-Out within this R2T sequence and continue + * to process next Scatter-Gather element(if any) of this SCSI command. + * + * Called under connection lock. + **/ +static void +iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, + struct iscsi_r2t_info *r2t, int left) +{ + struct iscsi_data *hdr; + struct iscsi_data_task *dtask; + struct scsi_cmnd *sc = ctask->sc; + int new_offset; + + dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC); + BUG_ON(!dtask); + hdr = &dtask->hdr; + memset(hdr, 0, sizeof(struct iscsi_data)); + hdr->ttt = r2t->ttt; + hdr->datasn = cpu_to_be32(r2t->solicit_datasn); + r2t->solicit_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 = r2t->exp_statsn; + new_offset = r2t->data_offset + r2t->sent; + hdr->offset = cpu_to_be32(new_offset); + if (left > conn->max_xmit_dlength) { + hton24(hdr->dlength, conn->max_xmit_dlength); + r2t->data_count = conn->max_xmit_dlength; + } else { + hton24(hdr->dlength, left); + r2t->data_count = left; + hdr->flags = ISCSI_FLAG_CMD_FINAL; + } + conn->dataout_pdus_cnt++; + + iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr, + sizeof(struct iscsi_hdr)); + + r2t->dtask = dtask; + + if (sc->use_sg && !iscsi_buf_left(&r2t->sendbuf)) { + BUG_ON(ctask->bad_sg == r2t->sg); + iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg); + r2t->sg += 1; + } else + iscsi_buf_init_iov(&ctask->sendbuf, + (char*)sc->request_buffer + new_offset, + r2t->data_count); + + list_add(&dtask->item, &ctask->dataqueue); +} + +static void +iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct iscsi_data *hdr; + struct iscsi_data_task *dtask; + + dtask = mempool_alloc(ctask->datapool, GFP_ATOMIC); + BUG_ON(!dtask); + hdr = &dtask->hdr; + 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 - + ctask->r2t_data_count - + 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; + } + + iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr, + sizeof(struct iscsi_hdr)); + + list_add(&dtask->item, &ctask->dataqueue); + + ctask->dtask = dtask; +} + +/** + * iscsi_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands + * @conn: iscsi connection + * @ctask: scsi command task + * @sc: scsi command + **/ +static void +iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, + struct scsi_cmnd *sc) +{ + struct iscsi_session *session = conn->session; + + BUG_ON(__kfifo_len(ctask->r2tqueue)); + + ctask->sc = sc; + ctask->conn = conn; + ctask->hdr.opcode = ISCSI_OP_SCSI_CMD; + ctask->hdr.flags = ISCSI_ATTR_SIMPLE; + int_to_scsilun(sc->device->lun, (struct scsi_lun *)ctask->hdr.lun); + ctask->hdr.itt = ctask->itt | (conn->id << CID_SHIFT) | + (session->age << AGE_SHIFT); + ctask->hdr.data_length = cpu_to_be32(sc->request_bufflen); + ctask->hdr.cmdsn = cpu_to_be32(session->cmdsn); session->cmdsn++; + ctask->hdr.exp_statsn = cpu_to_be32(conn->exp_statsn); + memcpy(ctask->hdr.cdb, sc->cmnd, sc->cmd_len); + memset(&ctask->hdr.cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len); + + ctask->mtask = NULL; + ctask->sent = 0; + ctask->sg_count = 0; + + ctask->total_length = sc->request_bufflen; + + if (sc->sc_data_direction == DMA_TO_DEVICE) { + ctask->exp_r2tsn = 0; + ctask->hdr.flags |= ISCSI_FLAG_CMD_WRITE; + BUG_ON(ctask->total_length == 0); + if (sc->use_sg) { + struct scatterlist *sg = sc->request_buffer; + + iscsi_buf_init_sg(&ctask->sendbuf, + &sg[ctask->sg_count++]); + ctask->sg = sg; + ctask->bad_sg = sg + sc->use_sg; + } else { + iscsi_buf_init_iov(&ctask->sendbuf, sc->request_buffer, + sc->request_bufflen); + } + + /* + * 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; + ctask->xmstate = XMSTATE_W_HDR; + /* calculate write padding */ + ctask->pad_count = ctask->total_length & (ISCSI_PAD_LEN-1); + if (ctask->pad_count) { + ctask->pad_count = ISCSI_PAD_LEN - ctask->pad_count; + debug_scsi("write padding %d bytes\n", + ctask->pad_count); + ctask->xmstate |= XMSTATE_W_PAD; + } + 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); + ctask->xmstate |= XMSTATE_IMM_DATA; + } 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->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT; + + ctask->r2t_data_count = ctask->total_length - + ctask->imm_count - + ctask->unsol_count; + + debug_scsi("cmd [itt %x total %d imm %d imm_data %d " + "r2t_data %d]\n", + ctask->itt, ctask->total_length, ctask->imm_count, + ctask->unsol_count, ctask->r2t_data_count); + } else { + ctask->hdr.flags |= ISCSI_FLAG_CMD_FINAL; + if (sc->sc_data_direction == DMA_FROM_DEVICE) + ctask->hdr.flags |= ISCSI_FLAG_CMD_READ; + ctask->datasn = 0; + ctask->xmstate = XMSTATE_R_HDR; + zero_data(ctask->hdr.dlength); + } + + iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr, + sizeof(struct iscsi_hdr)); + conn->scsicmd_pdus_cnt++; +} + +/** + * iscsi_mtask_xmit - xmit management(immediate) task + * @conn: iscsi connection + * @mtask: task management task + * + * Notes: + * The function can return -EAGAIN in which case caller must + * call it again later, or recover. '0' return code means successful + * xmit. + * + * Management xmit state machine consists of two states: + * IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress + * IN_PROGRESS_IMM_DATA - PDU Data xmit in progress + **/ +static int +iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask) +{ + + debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n", + conn->id, mtask->xmstate, mtask->itt); + + if (mtask->xmstate & XMSTATE_IMM_HDR) { + mtask->xmstate &= ~XMSTATE_IMM_HDR; + if (mtask->data_count) + mtask->xmstate |= XMSTATE_IMM_DATA; + if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE && + conn->stop_stage != STOP_CONN_RECOVER && + conn->hdrdgst_en) + iscsi_hdr_digest(conn, &mtask->headbuf, + (u8*)mtask->hdrext); + if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) { + mtask->xmstate |= XMSTATE_IMM_HDR; + if (mtask->data_count) + mtask->xmstate &= ~XMSTATE_IMM_DATA; + return -EAGAIN; + } + } + + if (mtask->xmstate & XMSTATE_IMM_DATA) { + BUG_ON(!mtask->data_count); + mtask->xmstate &= ~XMSTATE_IMM_DATA; + /* FIXME: implement. + * Virtual buffer could be spreaded across multiple pages... + */ + do { + if (iscsi_sendpage(conn, &mtask->sendbuf, + &mtask->data_count, &mtask->sent)) { + mtask->xmstate |= XMSTATE_IMM_DATA; + return -EAGAIN; + } + } while (mtask->data_count); + } + + BUG_ON(mtask->xmstate != XMSTATE_IDLE); + return 0; +} + +static inline int +handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + ctask->xmstate &= ~XMSTATE_R_HDR; + if (conn->hdrdgst_en) + iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext); + if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) { + BUG_ON(ctask->xmstate != XMSTATE_IDLE); + return 0; /* wait for Data-In */ + } + ctask->xmstate |= XMSTATE_R_HDR; + return -EAGAIN; +} + +static inline int +handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + ctask->xmstate &= ~XMSTATE_W_HDR; + if (conn->hdrdgst_en) + iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext); + if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) { + ctask->xmstate |= XMSTATE_W_HDR; + return -EAGAIN; + } + return 0; +} + +static inline int +handle_xmstate_data_digest(struct iscsi_conn *conn, + struct iscsi_cmd_task *ctask) +{ + ctask->xmstate &= ~XMSTATE_DATA_DIGEST; + debug_tcp("resent data digest 0x%x\n", ctask->datadigest); + if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf, + &ctask->datadigest, 0)) { + ctask->xmstate |= XMSTATE_DATA_DIGEST; + debug_tcp("resent data digest 0x%x fail!\n", + ctask->datadigest); + return -EAGAIN; + } + return 0; +} + +static inline int +handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + BUG_ON(!ctask->imm_count); + ctask->xmstate &= ~XMSTATE_IMM_DATA; + + if (conn->datadgst_en) { + iscsi_data_digest_init(conn, ctask); + ctask->immdigest = 0; + } + + for (;;) { + if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->imm_count, + &ctask->sent)) { + ctask->xmstate |= XMSTATE_IMM_DATA; + if (conn->datadgst_en) { + crypto_digest_final(conn->data_tx_tfm, + (u8*)&ctask->immdigest); + debug_tcp("tx imm sendpage fail 0x%x\n", + ctask->datadigest); + } + return -EAGAIN; + } + if (conn->datadgst_en) + iscsi_buf_data_digest_update(conn, &ctask->sendbuf); + + if (!ctask->imm_count) + break; + iscsi_buf_init_sg(&ctask->sendbuf, + &ctask->sg[ctask->sg_count++]); + } + + if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) { + if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf, + &ctask->immdigest, 1)) { + debug_tcp("sending imm digest 0x%x fail!\n", + ctask->immdigest); + return -EAGAIN; + } + debug_tcp("sending imm digest 0x%x\n", ctask->immdigest); + } + + return 0; +} + +static inline int +handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct iscsi_data_task *dtask; + + ctask->xmstate |= XMSTATE_UNS_DATA; + if (ctask->xmstate & XMSTATE_UNS_INIT) { + iscsi_unsolicit_data_init(conn, ctask); + BUG_ON(!ctask->dtask); + dtask = ctask->dtask; + if (conn->hdrdgst_en) + iscsi_hdr_digest(conn, &ctask->headbuf, + (u8*)dtask->hdrext); + ctask->xmstate &= ~XMSTATE_UNS_INIT; + } + if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) { + ctask->xmstate &= ~XMSTATE_UNS_DATA; + ctask->xmstate |= XMSTATE_UNS_HDR; + return -EAGAIN; + } + + debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n", + ctask->itt, ctask->unsol_count, ctask->sent); + return 0; +} + +static inline int +handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct iscsi_data_task *dtask = ctask->dtask; + + BUG_ON(!ctask->data_count); + ctask->xmstate &= ~XMSTATE_UNS_DATA; + + if (conn->datadgst_en) { + iscsi_data_digest_init(conn, ctask); + dtask->digest = 0; + } + + for (;;) { + int start = ctask->sent; + + if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->data_count, + &ctask->sent)) { + ctask->unsol_count -= ctask->sent - start; + ctask->xmstate |= XMSTATE_UNS_DATA; + /* will continue with this ctask later.. */ + if (conn->datadgst_en) { + crypto_digest_final(conn->data_tx_tfm, + (u8 *)&dtask->digest); + debug_tcp("tx uns data fail 0x%x\n", + dtask->digest); + } + return -EAGAIN; + } + + BUG_ON(ctask->sent > ctask->total_length); + ctask->unsol_count -= ctask->sent - start; + + /* + * XXX:we may run here with un-initial sendbuf. + * so pass it + */ + if (conn->datadgst_en && ctask->sent - start > 0) + iscsi_buf_data_digest_update(conn, &ctask->sendbuf); + + if (!ctask->data_count) + break; + iscsi_buf_init_sg(&ctask->sendbuf, + &ctask->sg[ctask->sg_count++]); + } + BUG_ON(ctask->unsol_count < 0); + + /* + * Done with the Data-Out. Next, check if we need + * to send another unsolicited Data-Out. + */ + if (ctask->unsol_count) { + if (conn->datadgst_en) { + if (iscsi_digest_final_send(conn, ctask, + &dtask->digestbuf, + &dtask->digest, 1)) { + debug_tcp("send uns digest 0x%x fail\n", + dtask->digest); + return -EAGAIN; + } + debug_tcp("sending uns digest 0x%x, more uns\n", + dtask->digest); + } + ctask->xmstate |= XMSTATE_UNS_INIT; + return 1; + } + + if (conn->datadgst_en && !(ctask->xmstate & XMSTATE_W_PAD)) { + if (iscsi_digest_final_send(conn, ctask, + &dtask->digestbuf, + &dtask->digest, 1)) { + debug_tcp("send last uns digest 0x%x fail\n", + dtask->digest); + return -EAGAIN; + } + debug_tcp("sending uns digest 0x%x\n",dtask->digest); + } + + return 0; +} + +static inline int +handle_xmstate_sol_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct iscsi_session *session = conn->session; + struct iscsi_r2t_info *r2t = ctask->r2t; + struct iscsi_data_task *dtask = r2t->dtask; + int left; + + ctask->xmstate &= ~XMSTATE_SOL_DATA; + ctask->dtask = dtask; + + if (conn->datadgst_en) { + iscsi_data_digest_init(conn, ctask); + dtask->digest = 0; + } +solicit_again: + /* + * send Data-Out whitnin this R2T sequence. + */ + if (!r2t->data_count) + goto data_out_done; + + if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) { + ctask->xmstate |= XMSTATE_SOL_DATA; + /* will continue with this ctask later.. */ + if (conn->datadgst_en) { + crypto_digest_final(conn->data_tx_tfm, + (u8 *)&dtask->digest); + debug_tcp("r2t data send fail 0x%x\n", dtask->digest); + } + return -EAGAIN; + } + + BUG_ON(r2t->data_count < 0); + if (conn->datadgst_en) + iscsi_buf_data_digest_update(conn, &r2t->sendbuf); + + if (r2t->data_count) { + BUG_ON(ctask->sc->use_sg == 0); + if (!iscsi_buf_left(&r2t->sendbuf)) { + BUG_ON(ctask->bad_sg == r2t->sg); + iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg); + r2t->sg += 1; + } + goto solicit_again; + } + +data_out_done: + /* + * Done with this Data-Out. Next, check if we have + * to send another Data-Out for this R2T. + */ + BUG_ON(r2t->data_length - r2t->sent < 0); + left = r2t->data_length - r2t->sent; + if (left) { + if (conn->datadgst_en) { + if (iscsi_digest_final_send(conn, ctask, + &dtask->digestbuf, + &dtask->digest, 1)) { + debug_tcp("send r2t data digest 0x%x" + "fail\n", dtask->digest); + return -EAGAIN; + } + debug_tcp("r2t data send digest 0x%x\n", + dtask->digest); + } + iscsi_solicit_data_cont(conn, ctask, r2t, left); + ctask->xmstate |= XMSTATE_SOL_DATA; + ctask->xmstate &= ~XMSTATE_SOL_HDR; + return 1; + } + + /* + * Done with this R2T. Check if there are more + * outstanding R2Ts ready to be processed. + */ + BUG_ON(ctask->r2t_data_count - r2t->data_length < 0); + if (conn->datadgst_en) { + if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf, + &dtask->digest, 1)) { + debug_tcp("send last r2t data digest 0x%x" + "fail\n", dtask->digest); + return -EAGAIN; + } + debug_tcp("r2t done dout digest 0x%x\n", dtask->digest); + } + + ctask->r2t_data_count -= r2t->data_length; + ctask->r2t = NULL; + spin_lock_bh(&session->lock); + __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); + spin_unlock_bh(&session->lock); + if (__kfifo_get(ctask->r2tqueue, (void*)&r2t, sizeof(void*))) { + ctask->r2t = r2t; + ctask->xmstate |= XMSTATE_SOL_DATA; + ctask->xmstate &= ~XMSTATE_SOL_HDR; + return 1; + } + + return 0; +} + +static inline int +handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + struct iscsi_data_task *dtask = ctask->dtask; + int sent; + + ctask->xmstate &= ~XMSTATE_W_PAD; + iscsi_buf_init_virt(&ctask->sendbuf, (char*)&ctask->pad, + ctask->pad_count); + if (iscsi_sendpage(conn, &ctask->sendbuf, &ctask->pad_count, &sent)) { + ctask->xmstate |= XMSTATE_W_PAD; + return -EAGAIN; + } + + if (conn->datadgst_en) { + iscsi_buf_data_digest_update(conn, &ctask->sendbuf); + /* imm data? */ + if (!dtask) { + if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf, + &ctask->immdigest, 1)) { + debug_tcp("send padding digest 0x%x" + "fail!\n", ctask->immdigest); + return -EAGAIN; + } + debug_tcp("done with padding, digest 0x%x\n", + ctask->datadigest); + } else { + if (iscsi_digest_final_send(conn, ctask, + &dtask->digestbuf, + &dtask->digest, 1)) { + debug_tcp("send padding digest 0x%x" + "fail\n", dtask->digest); + return -EAGAIN; + } + debug_tcp("done with padding, digest 0x%x\n", + dtask->digest); + } + } + + return 0; +} + +static int +iscsi_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) +{ + int rc = 0; + + debug_scsi("ctask deq [cid %d xmstate %x itt 0x%x]\n", + conn->id, ctask->xmstate, ctask->itt); + + /* + * serialize with TMF AbortTask + */ + if (ctask->mtask) + return rc; + + if (ctask->xmstate & XMSTATE_R_HDR) { + rc = handle_xmstate_r_hdr(conn, ctask); + return rc; + } + + if (ctask->xmstate & XMSTATE_W_HDR) { + rc = handle_xmstate_w_hdr(conn, ctask); + if (rc) + return rc; + } + + /* XXX: for data digest xmit recover */ + if (ctask->xmstate & XMSTATE_DATA_DIGEST) { + rc = handle_xmstate_data_digest(conn, ctask); + if (rc) + return rc; + } + + if (ctask->xmstate & XMSTATE_IMM_DATA) { + rc = handle_xmstate_imm_data(conn, ctask); + if (rc) + return rc; + } + + if (ctask->xmstate & XMSTATE_UNS_HDR) { + BUG_ON(!ctask->unsol_count); + ctask->xmstate &= ~XMSTATE_UNS_HDR; +unsolicit_head_again: + rc = handle_xmstate_uns_hdr(conn, ctask); + if (rc) + return rc; + } + + if (ctask->xmstate & XMSTATE_UNS_DATA) { + rc = handle_xmstate_uns_data(conn, ctask); + if (rc == 1) + goto unsolicit_head_again; + else if (rc) + return rc; + goto done; + } + + if (ctask->xmstate & XMSTATE_SOL_HDR) { + struct iscsi_r2t_info *r2t; + + ctask->xmstate &= ~XMSTATE_SOL_HDR; + ctask->xmstate |= XMSTATE_SOL_DATA; + if (!ctask->r2t) + __kfifo_get(ctask->r2tqueue, (void*)&ctask->r2t, + sizeof(void*)); +solicit_head_again: + r2t = ctask->r2t; + if (conn->hdrdgst_en) + iscsi_hdr_digest(conn, &r2t->headbuf, + (u8*)r2t->dtask->hdrext); + if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) { + ctask->xmstate &= ~XMSTATE_SOL_DATA; + ctask->xmstate |= XMSTATE_SOL_HDR; + return -EAGAIN; + } + + debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n", + r2t->solicit_datasn - 1, ctask->itt, r2t->data_count, + r2t->sent); + } + + if (ctask->xmstate & XMSTATE_SOL_DATA) { + rc = handle_xmstate_sol_data(conn, ctask); + if (rc == 1) + goto solicit_head_again; + if (rc) + return rc; + } + +done: + /* + * Last thing to check is whether we need to send write + * padding. Note that we check for xmstate equality, not just the bit. + */ + if (ctask->xmstate == XMSTATE_W_PAD) + rc = handle_xmstate_w_pad(conn, ctask); + + return rc; +} + +/** + * 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) +{ + if (unlikely(conn->suspend_tx)) { + debug_tcp("conn %d Tx suspended!\n", conn->id); + return 0; + } + + /* + * 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) { + if (iscsi_ctask_xmit(conn, conn->ctask)) + goto again; + /* done with this in-progress ctask */ + conn->ctask = NULL; + } + if (conn->mtask) { + if (iscsi_mtask_xmit(conn, conn->mtask)) + goto again; + /* done with this in-progress mtask */ + conn->mtask = NULL; + } + + /* process immediate first */ + if (unlikely(__kfifo_len(conn->immqueue))) { + struct iscsi_session *session = conn->session; + while (__kfifo_get(conn->immqueue, (void*)&conn->mtask, + sizeof(void*))) { + if (iscsi_mtask_xmit(conn, conn->mtask)) + goto again; + + if (conn->mtask->hdr.itt == + cpu_to_be32(ISCSI_RESERVED_TAG)) { + spin_lock_bh(&session->lock); + __kfifo_put(session->mgmtpool.queue, + (void*)&conn->mtask, sizeof(void*)); + spin_unlock_bh(&session->lock); + } + } + /* done with this mtask */ + conn->mtask = NULL; + } + + /* process write queue */ + while (__kfifo_get(conn->writequeue, (void*)&conn->ctask, + sizeof(void*))) { + if (iscsi_ctask_xmit(conn, conn->ctask)) + goto again; + } + + /* process command queue */ + while (__kfifo_get(conn->xmitqueue, (void*)&conn->ctask, + sizeof(void*))) { + if (iscsi_ctask_xmit(conn, conn->ctask)) + goto again; + } + /* done with this ctask */ + conn->ctask = NULL; + + /* process the rest control plane PDUs, if any */ + if (unlikely(__kfifo_len(conn->mgmtqueue))) { + struct iscsi_session *session = conn->session; + + while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask, + sizeof(void*))) { + if (iscsi_mtask_xmit(conn, conn->mtask)) + goto again; + + if (conn->mtask->hdr.itt == + cpu_to_be32(ISCSI_RESERVED_TAG)) { + spin_lock_bh(&session->lock); + __kfifo_put(session->mgmtpool.queue, + (void*)&conn->mtask, + sizeof(void*)); + spin_unlock_bh(&session->lock); + } + } + /* done with this mtask */ + conn->mtask = NULL; + } + + return 0; + +again: + if (unlikely(conn->suspend_tx)) + return 0; + + return -EAGAIN; +} + +static void +iscsi_xmitworker(void *data) +{ + struct iscsi_conn *conn = data; + + /* + * serialize Xmit worker on a per-connection basis. + */ + down(&conn->xmitsema); + if (iscsi_data_xmit(conn)) + schedule_work(&conn->xmitwork); + up(&conn->xmitsema); +} + +#define FAILURE_BAD_HOST 1 +#define FAILURE_SESSION_FAILED 2 +#define FAILURE_SESSION_FREED 3 +#define FAILURE_WINDOW_CLOSED 4 +#define FAILURE_SESSION_TERMINATE 5 + +static 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 = NULL; + struct iscsi_cmd_task *ctask = NULL; + + sc->scsi_done = done; + sc->result = 0; + + host = sc->device->host; + session = iscsi_hostdata(host->hostdata); + BUG_ON(host != session->host); + + spin_lock(&session->lock); + + if (session->state != ISCSI_STATE_LOGGED_IN) { + if (session->state == ISCSI_STATE_FAILED) { + reason = FAILURE_SESSION_FAILED; + goto reject; + } else if (session->state == ISCSI_STATE_TERMINATE) { + reason = FAILURE_SESSION_TERMINATE; + goto fault; + } + 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*)); + BUG_ON(ctask->sc); + + sc->SCp.phase = session->age; + sc->SCp.ptr = (char*)ctask; + iscsi_cmd_init(conn, ctask, sc); + + __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); + + if (!in_interrupt() && !down_trylock(&conn->xmitsema)) { + spin_unlock_irq(host->host_lock); + if (iscsi_data_xmit(conn)) + schedule_work(&conn->xmitwork); + up(&conn->xmitsema); + spin_lock_irq(host->host_lock); + } else + schedule_work(&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_tcp: cmd 0x%x is not queued (%d)\n", + sc->cmnd[0], reason); + sc->sense_buffer[0] = 0x70; + sc->sense_buffer[2] = NOT_READY; + sc->sense_buffer[7] = 0x6; + sc->sense_buffer[12] = 0x08; + sc->sense_buffer[13] = 0x00; + sc->result = (DID_NO_CONNECT << 16); + sc->resid = sc->request_bufflen; + sc->scsi_done(sc); + return 0; +} + +static 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; +} + +static 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); +} + +static iscsi_connh_t +iscsi_conn_create(iscsi_sessionh_t sessionh, uint32_t conn_idx) +{ + struct iscsi_session *session = iscsi_ptr(sessionh); + struct iscsi_conn *conn = NULL; + + conn = kmalloc(sizeof(struct iscsi_conn), GFP_KERNEL); + if (conn == NULL) + goto conn_alloc_fail; + memset(conn, 0, sizeof(struct iscsi_conn)); + + conn->c_stage = ISCSI_CONN_INITIAL_STAGE; + conn->in_progress = IN_PROGRESS_WAIT_HEADER; + conn->id = conn_idx; + conn->exp_statsn = 0; + conn->tmabort_state = TMABORT_INITIAL; + + /* initial operational parameters */ + conn->hdr_size = sizeof(struct iscsi_hdr); + conn->data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH; + conn->max_recv_dlength = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH; + + spin_lock_init(&conn->lock); + + /* 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 write response PDU commands queue */ + conn->writequeue = kfifo_alloc(session->cmds_max * sizeof(void*), + GFP_KERNEL, NULL); + if (conn->writequeue == ERR_PTR(-ENOMEM)) + goto writequeue_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); + + /* allocate initial PDU receive place holder */ + if (conn->data_size <= PAGE_SIZE) + conn->data = kmalloc(conn->data_size, GFP_KERNEL); + else + conn->data = (void*)__get_free_pages(GFP_KERNEL, + get_order(conn->data_size)); + if (!conn->data) + goto max_recv_dlenght_alloc_fail; + + init_timer(&conn->tmabort_timer); + init_MUTEX(&conn->xmitsema); + init_waitqueue_head(&conn->ehwait); + + return iscsi_handle(conn); + +max_recv_dlenght_alloc_fail: + spin_lock_bh(&session->lock); + __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask, + sizeof(void*)); + spin_unlock_bh(&session->lock); +login_mtask_alloc_fail: + kfifo_free(conn->mgmtqueue); +mgmtqueue_alloc_fail: + kfifo_free(conn->immqueue); +immqueue_alloc_fail: + kfifo_free(conn->writequeue); +writequeue_alloc_fail: + kfifo_free(conn->xmitqueue); +xmitqueue_alloc_fail: + kfree(conn); +conn_alloc_fail: + return iscsi_handle(NULL); +} + +static void +iscsi_conn_destroy(iscsi_connh_t connh) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + struct iscsi_session *session = conn->session; + + down(&conn->xmitsema); + set_bit(SUSPEND_BIT, &conn->suspend_tx); + if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE && conn->sock) { + struct sock *sk = conn->sock->sk; + + /* + * conn_start() has never been called! + * need to cleanup the socket. + */ + write_lock_bh(&sk->sk_callback_lock); + set_bit(SUSPEND_BIT, &conn->suspend_rx); + write_unlock_bh(&sk->sk_callback_lock); + + sock_hold(conn->sock->sk); + iscsi_conn_restore_callbacks(conn); + sock_put(conn->sock->sk); + sock_release(conn->sock); + conn->sock = NULL; + } + + 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); + + up(&conn->xmitsema); + + /* + * Block until all in-progress commands for this connection + * time out or fail. + */ + for (;;) { + spin_lock_bh(&conn->lock); + if (!session->host->host_busy) { /* OK for ERL == 0 */ + spin_unlock_bh(&conn->lock); + break; + } + spin_unlock_bh(&conn->lock); + msleep_interruptible(500); + printk("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); + } + + /* now free crypto */ + if (conn->hdrdgst_en || conn->datadgst_en) { + if (conn->tx_tfm) + crypto_free_tfm(conn->tx_tfm); + if (conn->rx_tfm) + crypto_free_tfm(conn->rx_tfm); + if (conn->data_tx_tfm) + crypto_free_tfm(conn->data_tx_tfm); + if (conn->data_rx_tfm) + crypto_free_tfm(conn->data_rx_tfm); + } + + /* free conn->data, size = MaxRecvDataSegmentLength */ + if (conn->data_size <= PAGE_SIZE) + kfree(conn->data); + else + free_pages((unsigned long)conn->data, + get_order(conn->data_size)); + + spin_lock_bh(&session->lock); + __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) + /* none 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->writequeue); + kfifo_free(conn->immqueue); + kfifo_free(conn->mgmtqueue); + kfree(conn); +} + +static int +iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh, + uint32_t transport_fd, int is_leading) +{ + struct iscsi_session *session = iscsi_ptr(sessionh); + struct iscsi_conn *tmp = ERR_PTR(-EEXIST), *conn = iscsi_ptr(connh); + struct sock *sk; + struct socket *sock; + int err; + + /* lookup for existing socket */ + sock = sockfd_lookup(transport_fd, &err); + if (!sock) { + printk(KERN_ERR "iscsi_tcp: sockfd_lookup failed %d\n", err); + return -EEXIST; + } + + /* 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_tcp: 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 (conn->stop_stage != STOP_CONN_SUSPEND) { + /* bind iSCSI connection and socket */ + conn->sock = sock; + + /* setup Socket parameters */ + sk = sock->sk; + sk->sk_reuse = 1; + sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ + sk->sk_allocation = GFP_ATOMIC; + + /* FIXME: disable Nagle's algorithm */ + + /* + * Intercept TCP callbacks for sendfile like receive + * processing. + */ + iscsi_conn_set_callbacks(conn); + + /* + * set receive state machine into initial state + */ + conn->in_progress = IN_PROGRESS_WAIT_HEADER; + } + + if (is_leading) + session->leadconn = conn; + + /* + * Unblock xmitworker(), Login Phase will pass through. + */ + clear_bit(SUSPEND_BIT, &conn->suspend_rx); + clear_bit(SUSPEND_BIT, &conn->suspend_tx); + + return 0; +} + +static int +iscsi_conn_start(iscsi_connh_t connh) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + struct iscsi_session *session = conn->session; + struct sock *sk; + + /* FF phase warming up... */ + + if (session == NULL) { + printk(KERN_ERR "iscsi_tcp: can't start unbound connection\n"); + return -EPERM; + } + + sk = conn->sock->sk; + + write_lock_bh(&sk->sk_callback_lock); + 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 + */ + session->conn_cnt++; + conn->stop_stage = 0; + conn->tmabort_state = TMABORT_INITIAL; + session->age++; + wake_up(&conn->ehwait); + break; + case STOP_CONN_TERM: + session->conn_cnt++; + conn->stop_stage = 0; + break; + case STOP_CONN_SUSPEND: + conn->stop_stage = 0; + clear_bit(SUSPEND_BIT, &conn->suspend_rx); + clear_bit(SUSPEND_BIT, &conn->suspend_tx); + break; + default: + break; + } + spin_unlock_bh(&session->lock); + write_unlock_bh(&sk->sk_callback_lock); + + return 0; +} + +static void +iscsi_conn_stop(iscsi_connh_t connh, int flag) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + struct iscsi_session *session = conn->session; + struct sock *sk; + unsigned long flags; + + BUG_ON(!conn->sock); + sk = conn->sock->sk; + write_lock_bh(&sk->sk_callback_lock); + set_bit(SUSPEND_BIT, &conn->suspend_rx); + write_unlock_bh(&sk->sk_callback_lock); + + down(&conn->xmitsema); + + spin_lock_irqsave(session->host->host_lock, flags); + spin_lock(&session->lock); + conn->stop_stage = flag; + conn->c_stage = ISCSI_CONN_STOPPED; + set_bit(SUSPEND_BIT, &conn->suspend_tx); + + if (flag != STOP_CONN_SUSPEND) + session->conn_cnt--; + + if (session->conn_cnt == 0 || session->leadconn == conn) + session->state = ISCSI_STATE_FAILED; + + spin_unlock(&session->lock); + spin_unlock_irqrestore(session->host->host_lock, flags); + + if (flag == STOP_CONN_TERM || flag == STOP_CONN_RECOVER) { + struct iscsi_cmd_task *ctask; + struct iscsi_mgmt_task *mtask; + + /* + * Socket must go now. + */ + sock_hold(conn->sock->sk); + iscsi_conn_restore_callbacks(conn); + sock_put(conn->sock->sk); + + /* + * flush xmit queues. + */ + spin_lock_bh(&session->lock); + while (__kfifo_get(conn->writequeue, (void*)&ctask, + sizeof(void*)) || + __kfifo_get(conn->xmitqueue, (void*)&ctask, + sizeof(void*))) { + struct iscsi_r2t_info *r2t; + + /* + * flush ctask's r2t queues + */ + while (__kfifo_get(ctask->r2tqueue, (void*)&r2t, + sizeof(void*))) + __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, + sizeof(void*)); + + spin_unlock_bh(&session->lock); + local_bh_disable(); + iscsi_ctask_cleanup(conn, ctask); + local_bh_enable(); + spin_lock_bh(&session->lock); + } + conn->ctask = NULL; + while (__kfifo_get(conn->immqueue, (void*)&mtask, + sizeof(void*)) || + __kfifo_get(conn->mgmtqueue, (void*)&mtask, + sizeof(void*))) { + __kfifo_put(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*)); + } + conn->mtask = NULL; + spin_unlock_bh(&session->lock); + + /* + * release socket only after we stopped data_xmit() + * activity and flushed all outstandings + */ + sock_release(conn->sock); + conn->sock = NULL; + + /* + * 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->hdr_size = sizeof(struct iscsi_hdr); + } + up(&conn->xmitsema); +} + +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); + + if (!__kfifo_get(session->mgmtpool.queue, + (void*)&mtask, sizeof(void*))) { + spin_unlock_bh(&session->lock); + return -ENOSPC; + } + } + + /* + * pre-format CmdSN and ExpStatSN for outgoing PDU. + */ + if (hdr->itt != cpu_to_be32(ISCSI_RESERVED_TAG)) { + hdr->itt = mtask->itt | (conn->id << CID_SHIFT) | + (session->age << 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); + + nop->exp_statsn = cpu_to_be32(conn->exp_statsn); + + memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr)); + + iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr, + sizeof(struct iscsi_hdr)); + + spin_unlock_bh(&session->lock); + + if (data_size) { + memcpy(mtask->data, data, data_size); + mtask->data_count = data_size; + } else + mtask->data_count = 0; + + mtask->xmstate = XMSTATE_IMM_HDR; + + if (mtask->data_count) { + iscsi_buf_init_iov(&mtask->sendbuf, (char*)mtask->data, + mtask->data_count); + } + + 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*)); + + schedule_work(&conn->xmitwork); + + return 0; +} + +static int +iscsi_eh_host_reset(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; + + spin_lock_bh(&session->lock); + if (session->state == ISCSI_STATE_TERMINATE) { + debug_scsi("failing host reset: session terminated " + "[CID %d age %d]", conn->id, session->age); + spin_unlock_bh(&session->lock); + return FAILED; + } + spin_unlock_bh(&session->lock); + + debug_scsi("failing connection CID %d due to SCSI host reset " + "[itt 0x%x age %d]", conn->id, ctask->itt, + session->age); + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + + return SUCCESS; +} + +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) { + __kfifo_put(session->mgmtpool.queue, + (void*)&ctask->mtask, sizeof(void*)); + conn->tmabort_state = TMABORT_TIMEDOUT; + debug_scsi("tmabort timedout [sc %lx itt 0x%x]\n", + (long)ctask->sc, ctask->itt); + /* unblock eh_abort() */ + wake_up(&conn->ehwait); + } + spin_unlock(&session->lock); +} + +static int +iscsi_eh_abort(struct scsi_cmnd *sc) +{ + int rc; + struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)sc->SCp.ptr; + struct iscsi_conn *conn = ctask->conn; + struct iscsi_session *session = conn->session; + + conn->eh_abort_cnt++; + debug_scsi("aborting [sc %lx itt 0x%x]\n", (long)sc, ctask->itt); + + /* + * two cases for ERL=0 here: + * + * 1) connection-level failure; + * 2) recovery due protocol error; + */ + down(&conn->xmitsema); + spin_lock_bh(&session->lock); + if (session->state != ISCSI_STATE_LOGGED_IN) { + if (session->state == ISCSI_STATE_TERMINATE) { + spin_unlock_bh(&session->lock); + up(&conn->xmitsema); + goto failed; + } + spin_unlock_bh(&session->lock); + } else { + struct iscsi_tm *hdr = &conn->tmhdr; + + /* + * Still LOGGED_IN... + */ + + if (!ctask->sc || sc->SCp.phase != session->age) { + /* + * 1) ctask completed before time out. But session + * is still ok => Happy Retry. + * 2) session was re-open during time out of ctask. + */ + spin_unlock_bh(&session->lock); + up(&conn->xmitsema); + goto success; + } + conn->tmabort_state = TMABORT_INITIAL; + spin_unlock_bh(&session->lock); + + /* + * ctask timed out but session is OK + * ERL=0 requires task mgmt abort to be issued on each + * failed command. 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]", ctask->itt); + } else { + struct iscsi_r2t_info *r2t; + + /* + * TMF abort vs. TMF response race logic + */ + spin_lock_bh(&session->lock); + ctask->mtask = (struct iscsi_mgmt_task *) + session->mgmt_cmds[(hdr->itt & ITT_MASK) - + ISCSI_MGMT_ITT_OFFSET]; + /* + * have to flush r2tqueue to avoid r2t leaks + */ + while (__kfifo_get(ctask->r2tqueue, (void*)&r2t, + sizeof(void*))) { + __kfifo_put(ctask->r2tpool.queue, (void*)&r2t, + sizeof(void*)); + } + if (conn->tmabort_state == TMABORT_INITIAL) { + conn->tmfcmd_pdus_cnt++; + conn->tmabort_timer.expires = 3*HZ + jiffies; + conn->tmabort_timer.function = + iscsi_tmabort_timedout; + conn->tmabort_timer.data = (unsigned long)ctask; + add_timer(&conn->tmabort_timer); + debug_scsi("abort sent [itt 0x%x]", ctask->itt); + } else { + if (!ctask->sc || + conn->tmabort_state == TMABORT_SUCCESS) { + conn->tmabort_state = TMABORT_INITIAL; + spin_unlock_bh(&session->lock); + up(&conn->xmitsema); + goto success; + } + conn->tmabort_state = TMABORT_INITIAL; + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + } + spin_unlock_bh(&session->lock); + } + } + up(&conn->xmitsema); + + + /* + * block eh thread until: + * + * 1) abort response; + * 2) abort timeout; + * 3) session re-opened; + * 4) session terminated; + */ + for (;;) { + int p_state = session->state; + + rc = wait_event_interruptible(conn->ehwait, + (p_state == ISCSI_STATE_LOGGED_IN ? + (session->state == ISCSI_STATE_TERMINATE || + conn->tmabort_state != TMABORT_INITIAL) : + (session->state == ISCSI_STATE_TERMINATE || + session->state == ISCSI_STATE_LOGGED_IN))); + if (rc) { + /* shutdown.. */ + session->state = ISCSI_STATE_TERMINATE; + goto failed; + } + + if (signal_pending(current)) + flush_signals(current); + + if (session->state == ISCSI_STATE_TERMINATE) + goto failed; + + spin_lock_bh(&session->lock); + if (sc->SCp.phase == session->age && + (conn->tmabort_state == TMABORT_TIMEDOUT || + conn->tmabort_state == TMABORT_FAILED)) { + conn->tmabort_state = TMABORT_INITIAL; + if (!ctask->sc) { + /* + * ctask completed before tmf abort response or + * time out. + * But session is still ok => Happy Retry. + */ + spin_unlock_bh(&session->lock); + break; + } + spin_unlock_bh(&session->lock); + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + continue; + } + spin_unlock_bh(&session->lock); + break; + } + +success: + debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt); + rc = SUCCESS; + goto exit; + +failed: + debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt); + rc = FAILED; + +exit: + del_timer_sync(&conn->tmabort_timer); + + down(&conn->xmitsema); + if (conn->sock) { + struct sock *sk = conn->sock->sk; + + write_lock_bh(&sk->sk_callback_lock); + iscsi_ctask_cleanup(conn, ctask); + write_unlock_bh(&sk->sk_callback_lock); + } + up(&conn->xmitsema); + return rc; +} + +static int +iscsi_r2tpool_alloc(struct iscsi_session *session) +{ + int i; + int cmd_i; + + /* + * initialize per-task: R2T pool and xmit queue + */ + for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) { + struct iscsi_cmd_task *ctask = session->cmds[cmd_i]; + + /* + * pre-allocated x4 as much r2ts to handle race when + * target acks DataOut faster than we data_xmit() queues + * could replenish r2tqueue. + */ + + /* R2T pool */ + if (iscsi_pool_init(&ctask->r2tpool, session->max_r2t * 4, + (void***)&ctask->r2ts, sizeof(struct iscsi_r2t_info))) { + goto r2t_alloc_fail; + } + + /* R2T xmit queue */ + ctask->r2tqueue = kfifo_alloc( + session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL); + if (ctask->r2tqueue == ERR_PTR(-ENOMEM)) { + iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts); + goto r2t_alloc_fail; + } + + /* + * number of + * Data-Out PDU's within R2T-sequence can be quite big; + * using mempool + */ + ctask->datapool = mempool_create(ISCSI_DTASK_DEFAULT_MAX, + mempool_alloc_slab, mempool_free_slab, taskcache); + if (ctask->datapool == NULL) { + kfifo_free(ctask->r2tqueue); + iscsi_pool_free(&ctask->r2tpool, (void**)ctask->r2ts); + goto r2t_alloc_fail; + } + INIT_LIST_HEAD(&ctask->dataqueue); + } + + return 0; + +r2t_alloc_fail: + for (i = 0; i < cmd_i; i++) { + mempool_destroy(session->cmds[i]->datapool); + kfifo_free(session->cmds[i]->r2tqueue); + iscsi_pool_free(&session->cmds[i]->r2tpool, + (void**)session->cmds[i]->r2ts); + } + return -ENOMEM; +} + +static void +iscsi_r2tpool_free(struct iscsi_session *session) +{ + int i; + + for (i = 0; i < session->cmds_max; i++) { + mempool_destroy(session->cmds[i]->datapool); + kfifo_free(session->cmds[i]->r2tqueue); + iscsi_pool_free(&session->cmds[i]->r2tpool, + (void**)session->cmds[i]->r2ts); + } +} + +static struct scsi_host_template iscsi_sht = { + .name = "iSCSI Initiator over TCP/IP, v." + ISCSI_VERSION_STR, + .queuecommand = iscsi_queuecommand, + .can_queue = ISCSI_XMIT_CMDS_MAX - 1, + .sg_tablesize = ISCSI_SG_TABLESIZE, + .cmd_per_lun = ISCSI_CMD_PER_LUN, + .eh_abort_handler = iscsi_eh_abort, + .eh_host_reset_handler = iscsi_eh_host_reset, + .use_clustering = DISABLE_CLUSTERING, + .proc_name = "iscsi_tcp", + .this_id = -1, +}; + +static iscsi_sessionh_t +iscsi_session_create(uint32_t initial_cmdsn, struct Scsi_Host *host) +{ + int cmd_i; + struct iscsi_session *session; + + session = iscsi_hostdata(host->hostdata); + memset(session, 0, sizeof(struct iscsi_session)); + + session->host = host; + session->id = host->host_no; + session->state = ISCSI_STATE_LOGGED_IN; + 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; + + /* initialize SCSI PDU commands pool */ + if (iscsi_pool_init(&session->cmdpool, session->cmds_max, + (void***)&session->cmds, 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++) + session->cmds[cmd_i]->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, 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++) { + session->mgmt_cmds[cmd_i]->itt = ISCSI_MGMT_ITT_OFFSET + cmd_i; + session->mgmt_cmds[cmd_i]->data = kmalloc( + DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH, GFP_KERNEL); + if (!session->mgmt_cmds[cmd_i]->data) { + int j; + + for (j = 0; j < cmd_i; j++) + kfree(session->mgmt_cmds[j]->data); + goto immdata_alloc_fail; + } + } + + if (iscsi_r2tpool_alloc(session)) + goto r2tpool_alloc_fail; + + return iscsi_handle(session); + +r2tpool_alloc_fail: + for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) + kfree(session->mgmt_cmds[cmd_i]->data); + iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds); +immdata_alloc_fail: +mgmtpool_alloc_fail: + iscsi_pool_free(&session->cmdpool, (void**)session->cmds); +cmdpool_alloc_fail: + return iscsi_handle(NULL); +} + +static void +iscsi_session_destroy(iscsi_sessionh_t sessionh) +{ + int cmd_i; + struct iscsi_data_task *dtask, *n; + struct iscsi_session *session = iscsi_ptr(sessionh); + + for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) { + struct iscsi_cmd_task *ctask = session->cmds[cmd_i]; + list_for_each_entry_safe(dtask, n, &ctask->dataqueue, item) { + list_del(&dtask->item); + mempool_free(dtask, ctask->datapool); + } + } + + for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) + kfree(session->mgmt_cmds[cmd_i]->data); + + iscsi_r2tpool_free(session); + iscsi_pool_free(&session->mgmtpool, (void**)session->mgmt_cmds); + iscsi_pool_free(&session->cmdpool, (void**)session->cmds); +} + +static int +iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param, + uint32_t value) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + struct iscsi_session *session = conn->session; + + spin_lock_bh(&session->lock); + if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE && + conn->stop_stage != STOP_CONN_RECOVER) { + printk(KERN_ERR "iscsi_tcp: can not change parameter [%d]\n", + param); + spin_unlock_bh(&session->lock); + return 0; + } + spin_unlock_bh(&session->lock); + + switch(param) { + case ISCSI_PARAM_MAX_RECV_DLENGTH: { + char *saveptr = conn->data; + int flags = GFP_KERNEL; + + if (conn->data_size >= value) { + conn->max_recv_dlength = value; + break; + } + + spin_lock_bh(&session->lock); + if (conn->stop_stage == STOP_CONN_RECOVER) + flags = GFP_ATOMIC; + spin_unlock_bh(&session->lock); + + if (value <= PAGE_SIZE) + conn->data = kmalloc(value, flags); + else + conn->data = (void*)__get_free_pages(flags, + get_order(value)); + if (conn->data == NULL) { + conn->data = saveptr; + return -ENOMEM; + } + if (conn->data_size <= PAGE_SIZE) + kfree(saveptr); + else + free_pages((unsigned long)saveptr, + get_order(conn->data_size)); + conn->max_recv_dlength = value; + conn->data_size = value; + } + break; + case ISCSI_PARAM_MAX_XMIT_DLENGTH: + conn->max_xmit_dlength = value; + break; + case ISCSI_PARAM_HDRDGST_EN: + conn->hdrdgst_en = value; + conn->hdr_size = sizeof(struct iscsi_hdr); + if (conn->hdrdgst_en) { + conn->hdr_size += sizeof(__u32); + if (!conn->tx_tfm) + conn->tx_tfm = crypto_alloc_tfm("crc32c", 0); + if (!conn->tx_tfm) + return -ENOMEM; + if (!conn->rx_tfm) + conn->rx_tfm = crypto_alloc_tfm("crc32c", 0); + if (!conn->rx_tfm) { + crypto_free_tfm(conn->tx_tfm); + return -ENOMEM; + } + } else { + if (conn->tx_tfm) + crypto_free_tfm(conn->tx_tfm); + if (conn->rx_tfm) + crypto_free_tfm(conn->rx_tfm); + } + break; + case ISCSI_PARAM_DATADGST_EN: + conn->datadgst_en = value; + if (conn->datadgst_en) { + if (!conn->data_tx_tfm) + conn->data_tx_tfm = + crypto_alloc_tfm("crc32c", 0); + if (!conn->data_tx_tfm) + return -ENOMEM; + if (!conn->data_rx_tfm) + conn->data_rx_tfm = + crypto_alloc_tfm("crc32c", 0); + if (!conn->data_rx_tfm) { + crypto_free_tfm(conn->data_tx_tfm); + return -ENOMEM; + } + } else { + if (conn->data_tx_tfm) + crypto_free_tfm(conn->data_tx_tfm); + if (conn->data_rx_tfm) + crypto_free_tfm(conn->data_rx_tfm); + } + break; + case ISCSI_PARAM_INITIAL_R2T_EN: + session->initial_r2t_en = value; + break; + case ISCSI_PARAM_MAX_R2T: + if (session->max_r2t == roundup_pow_of_two(value)) + break; + iscsi_r2tpool_free(session); + session->max_r2t = value; + if (session->max_r2t & (session->max_r2t - 1)) + session->max_r2t = roundup_pow_of_two(session->max_r2t); + if (iscsi_r2tpool_alloc(session)) + return -ENOMEM; + break; + case ISCSI_PARAM_IMM_DATA_EN: + session->imm_data_en = value; + break; + case ISCSI_PARAM_FIRST_BURST: + session->first_burst = value; + break; + case ISCSI_PARAM_MAX_BURST: + session->max_burst = value; + break; + case ISCSI_PARAM_PDU_INORDER_EN: + session->pdu_inorder_en = value; + break; + case ISCSI_PARAM_DATASEQ_INORDER_EN: + session->dataseq_inorder_en = value; + break; + case ISCSI_PARAM_ERL: + session->erl = value; + break; + case ISCSI_PARAM_IFMARKER_EN: + BUG_ON(value); + session->ifmarker_en = value; + break; + case ISCSI_PARAM_OFMARKER_EN: + BUG_ON(value); + session->ofmarker_en = value; + break; + default: + break; + } + + return 0; +} + +static int +iscsi_conn_get_param(iscsi_connh_t connh, enum iscsi_param param, + uint32_t *value) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + struct iscsi_session *session = conn->session; + + switch(param) { + case ISCSI_PARAM_MAX_RECV_DLENGTH: + *value = conn->max_recv_dlength; + break; + case ISCSI_PARAM_MAX_XMIT_DLENGTH: + *value = conn->max_xmit_dlength; + break; + case ISCSI_PARAM_HDRDGST_EN: + *value = conn->hdrdgst_en; + break; + case ISCSI_PARAM_DATADGST_EN: + *value = conn->datadgst_en; + break; + case ISCSI_PARAM_INITIAL_R2T_EN: + *value = session->initial_r2t_en; + break; + case ISCSI_PARAM_MAX_R2T: + *value = session->max_r2t; + break; + case ISCSI_PARAM_IMM_DATA_EN: + *value = session->imm_data_en; + break; + case ISCSI_PARAM_FIRST_BURST: + *value = session->first_burst; + break; + case ISCSI_PARAM_MAX_BURST: + *value = session->max_burst; + break; + case ISCSI_PARAM_PDU_INORDER_EN: + *value = session->pdu_inorder_en; + break; + case ISCSI_PARAM_DATASEQ_INORDER_EN: + *value = session->dataseq_inorder_en; + break; + case ISCSI_PARAM_ERL: + *value = session->erl; + break; + case ISCSI_PARAM_IFMARKER_EN: + *value = session->ifmarker_en; + break; + case ISCSI_PARAM_OFMARKER_EN: + *value = session->ofmarker_en; + break; + default: + return ISCSI_ERR_PARAM_NOT_FOUND; + } + + return 0; +} + +static void +iscsi_conn_get_stats(iscsi_connh_t connh, struct iscsi_stats *stats) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + + stats->txdata_octets = conn->txdata_octets; + stats->rxdata_octets = conn->rxdata_octets; + stats->scsicmd_pdus = conn->scsicmd_pdus_cnt; + stats->dataout_pdus = conn->dataout_pdus_cnt; + stats->scsirsp_pdus = conn->scsirsp_pdus_cnt; + stats->datain_pdus = conn->datain_pdus_cnt; + stats->r2t_pdus = conn->r2t_pdus_cnt; + stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt; + stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt; + stats->custom_length = 3; + strcpy(stats->custom[0].desc, "tx_sendpage_failures"); + stats->custom[0].value = conn->sendpage_failures_cnt; + strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); + stats->custom[1].value = conn->discontiguous_hdr_cnt; + strcpy(stats->custom[2].desc, "eh_abort_cnt"); + stats->custom[2].value = conn->eh_abort_cnt; +} + +static int +iscsi_conn_send_pdu(iscsi_connh_t connh, struct iscsi_hdr *hdr, char *data, + uint32_t data_size) +{ + struct iscsi_conn *conn = iscsi_ptr(connh); + int rc; + + down(&conn->xmitsema); + rc = iscsi_conn_send_generic(conn, hdr, data, data_size); + up(&conn->xmitsema); + + return rc; +} + +static struct iscsi_transport iscsi_tcp_transport = { + .owner = THIS_MODULE, + .name = "tcp", + .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST + | CAP_DATADGST, + .host_template = &iscsi_sht, + .hostdata_size = sizeof(struct iscsi_session), + .max_conn = 1, + .max_cmd_len = ISCSI_TCP_MAX_CMD_LEN, + .create_session = iscsi_session_create, + .destroy_session = iscsi_session_destroy, + .create_conn = iscsi_conn_create, + .bind_conn = iscsi_conn_bind, + .destroy_conn = iscsi_conn_destroy, + .set_param = iscsi_conn_set_param, + .get_param = iscsi_conn_get_param, + .start_conn = iscsi_conn_start, + .stop_conn = iscsi_conn_stop, + .send_pdu = iscsi_conn_send_pdu, + .get_stats = iscsi_conn_get_stats, +}; + +static int __init +iscsi_tcp_init(void) +{ + int error; + + if (iscsi_max_lun < 1) { + printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun); + return -EINVAL; + } + iscsi_tcp_transport.max_lun = iscsi_max_lun; + + taskcache = kmem_cache_create("iscsi_taskcache", + sizeof(struct iscsi_data_task), 0, + SLAB_HWCACHE_ALIGN | SLAB_NO_REAP, NULL, NULL); + if (!taskcache) + return -ENOMEM; + + error = iscsi_register_transport(&iscsi_tcp_transport); + if (error) + kmem_cache_destroy(taskcache); + + return error; +} + +static void __exit +iscsi_tcp_exit(void) +{ + iscsi_unregister_transport(&iscsi_tcp_transport); + kmem_cache_destroy(taskcache); +} + +module_init(iscsi_tcp_init); +module_exit(iscsi_tcp_exit); |