open-iscsi 源码包

/* * iSCSI lib functions * * Copyright (C) 2006 Red Hat, Inc. All rights reserved. * Copyright (C) 2004 - 2006 Mike Christie * Copyright (C) 2004 - 2005 Dmitry Yusupov * Copyright (C) 2004 - 2005 Alex Aizman * maintained by open-iscsi@googlegroups.com * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <linux/types.h> #include <linux/kfifo.h> #include <linux/delay.h> #include <linux/log2.h> #include <asm/unaligned.h> #include <net/tcp.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_device.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_tcq.h> #include <scsi/scsi_host.h> #include <scsi/scsi.h> #include <scsi/scsi_transport.h> #include "iscsi_proto.h" #include "scsi_transport_iscsi.h" #include "libiscsi.h" static int iscsi_dbg_lib_conn; module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug_libiscsi_conn, "Turn on debugging for connections in libiscsi module. " "Set to 1 to turn on, and zero to turn off. Default is off."); static int iscsi_dbg_lib_session; module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug_libiscsi_session, "Turn on debugging for sessions in libiscsi module. " "Set to 1 to turn on, and zero to turn off. Default is off."); static int iscsi_dbg_lib_eh; module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug_libiscsi_eh, "Turn on debugging for error handling in libiscsi module. " "Set to 1 to turn on, and zero to turn off. Default is off."); #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...) \ do { \ if (iscsi_dbg_lib_conn) \ iscsi_conn_printk(KERN_INFO, _conn, \ "%s " dbg_fmt, \ __func__, ##arg); \ } while (0); #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...) \ do { \ if (iscsi_dbg_lib_session) \ iscsi_session_printk(KERN_INFO, _session, \ "%s " dbg_fmt, \ __func__, ##arg); \ } while (0); #define ISCSI_DBG_EH(_session, dbg_fmt, arg...) \ do { \ if (iscsi_dbg_lib_eh) \ iscsi_session_printk(KERN_INFO, _session, \ "%s " dbg_fmt, \ __func__, ##arg); \ } while (0); /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */ #define SNA32_CHECK 2147483648UL static int iscsi_sna_lt(u32 n1, u32 n2) { return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) || (n1 > n2 && (n2 - n1 < SNA32_CHECK))); } /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */ static int iscsi_sna_lte(u32 n1, u32 n2) { return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) || (n1 > n2 && (n2 - n1 < SNA32_CHECK))); } inline void iscsi_conn_queue_work(struct iscsi_conn *conn) { struct Scsi_Host *shost = conn->session->host; struct iscsi_host *ihost = shost_priv(shost); if (ihost->workq) queue_work(ihost->workq, &conn->xmitwork); } EXPORT_SYMBOL_GPL(iscsi_conn_queue_work); void iscsi_update_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); /* * standard specifies this check for when to update expected and * max sequence numbers */ if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1)) return; if (exp_cmdsn != session->exp_cmdsn && !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn)) session->exp_cmdsn = exp_cmdsn; if (max_cmdsn != session->max_cmdsn && !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) { session->max_cmdsn = max_cmdsn; /* * if the window closed with IO queued, then kick the * xmit thread */ if (!list_empty(&session->leadconn->cmdqueue) || !list_empty(&session->leadconn->mgmtqueue)) iscsi_conn_queue_work(session->leadconn); } } EXPORT_SYMBOL_GPL(iscsi_update_cmdsn); /** * iscsi_prep_data_out_pdu - initialize Data-Out * @task: scsi command task * @r2t: R2T info * @hdr: iscsi data in pdu * * Notes: * Initialize Data-Out within this R2T sequence and finds * proper data_offset within this SCSI command. * * This function is called with connection lock taken. **/ void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t, struct iscsi_data *hdr) { struct iscsi_conn *conn = task->conn; unsigned int left = r2t->data_length - r2t->sent; task->hdr_len = sizeof(struct iscsi_data); memset(hdr, 0, sizeof(struct iscsi_data)); hdr->ttt = r2t->ttt; hdr->datasn = cpu_to_be32(r2t->datasn); r2t->datasn++; hdr->opcode = ISCSI_OP_SCSI_DATA_OUT; memcpy(hdr->lun, task->lun, sizeof(hdr->lun)); hdr->itt = task->hdr_itt; hdr->exp_statsn = r2t->exp_statsn; hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent); if (left > 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, left); r2t->data_count = left; hdr->flags = ISCSI_FLAG_CMD_FINAL; } conn->dataout_pdus_cnt++; } EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu); static int iscsi_add_hdr(struct iscsi_task *task, unsigned len) { unsigned exp_len = task->hdr_len + len; if (exp_len > task->hdr_max) { WARN_ON(1); return -EINVAL; } WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */ task->hdr_len = exp_len; return 0; } /* * make an extended cdb AHS */ static int iscsi_prep_ecdb_ahs(struct iscsi_task *task) { struct scsi_cmnd *cmd = task->sc; unsigned rlen, pad_len; unsigned short ahslength; struct iscsi_ecdb_ahdr *ecdb_ahdr; int rc; ecdb_ahdr = iscsi_next_hdr(task); rlen = cmd->cmd_len - ISCSI_CDB_SIZE; BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb)); ahslength = rlen + sizeof(ecdb_ahdr->reserved); pad_len = iscsi_padding(rlen); rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) + sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len); if (rc) return rc; if (pad_len) memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len); ecdb_ahdr->ahslength = cpu_to_be16(ahslength); ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB; ecdb_ahdr->reserved = 0; memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen); ISCSI_DBG_SESSION(task->conn->session, "iscsi_prep_ecdb_ahs: varlen_cdb_len %d " "rlen %d pad_len %d ahs_length %d iscsi_headers_size " "%u\n", cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len); return 0; } static int iscsi_prep_bidi_ahs(struct iscsi_task *task) { struct scsi_cmnd *sc = task->sc; struct iscsi_rlength_ahdr *rlen_ahdr; int rc; rlen_ahdr = iscsi_next_hdr(task); rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr)); if (rc) return rc; rlen_ahdr->ahslength = cpu_to_be16(sizeof(rlen_ahdr->read_length) + sizeof(rlen_ahdr->reserved)); rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH; rlen_ahdr->reserved = 0; rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length); ISCSI_DBG_SESSION(task->conn->session, "bidi-in rlen_ahdr->read_length(%d) " "rlen_ahdr->ahslength(%d)\n", be32_to_cpu(rlen_ahdr->read_length), be16_to_cpu(rlen_ahdr->ahslength)); return 0; } /** * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu * @task: iscsi task * * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set * fields like dlength or final based on h