--- /dev/null
+/*******************************************************************************
+ * This file contains error recovery level two functions used by
+ * the iSCSI Target driver.
+ *
+ * (c) Copyright 2007-2013 Datera, Inc.
+ *
+ * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
+ *
+ * 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.
+ ******************************************************************************/
+
+#include <scsi/iscsi_proto.h>
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+
+#include <target/iscsi/iscsi_target_core.h>
+#include "iscsi_target_datain_values.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target_erl0.h"
+#include "iscsi_target_erl1.h"
+#include "iscsi_target_erl2.h"
+#include "iscsi_target.h"
+
+/*
+ * FIXME: Does RData SNACK apply here as well?
+ */
+void iscsit_create_conn_recovery_datain_values(
+ struct iscsi_cmd *cmd,
+ __be32 exp_data_sn)
+{
+ u32 data_sn = 0;
+ struct iscsi_conn *conn = cmd->conn;
+
+ cmd->next_burst_len = 0;
+ cmd->read_data_done = 0;
+
+ while (be32_to_cpu(exp_data_sn) > data_sn) {
+ if ((cmd->next_burst_len +
+ conn->conn_ops->MaxRecvDataSegmentLength) <
+ conn->sess->sess_ops->MaxBurstLength) {
+ cmd->read_data_done +=
+ conn->conn_ops->MaxRecvDataSegmentLength;
+ cmd->next_burst_len +=
+ conn->conn_ops->MaxRecvDataSegmentLength;
+ } else {
+ cmd->read_data_done +=
+ (conn->sess->sess_ops->MaxBurstLength -
+ cmd->next_burst_len);
+ cmd->next_burst_len = 0;
+ }
+ data_sn++;
+ }
+}
+
+void iscsit_create_conn_recovery_dataout_values(
+ struct iscsi_cmd *cmd)
+{
+ u32 write_data_done = 0;
+ struct iscsi_conn *conn = cmd->conn;
+
+ cmd->data_sn = 0;
+ cmd->next_burst_len = 0;
+
+ while (cmd->write_data_done > write_data_done) {
+ if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
+ cmd->write_data_done)
+ write_data_done += conn->sess->sess_ops->MaxBurstLength;
+ else
+ break;
+ }
+
+ cmd->write_data_done = write_data_done;
+}
+
+static int iscsit_attach_active_connection_recovery_entry(
+ struct iscsi_session *sess,
+ struct iscsi_conn_recovery *cr)
+{
+ spin_lock(&sess->cr_a_lock);
+ list_add_tail(&cr->cr_list, &sess->cr_active_list);
+ spin_unlock(&sess->cr_a_lock);
+
+ return 0;
+}
+
+static int iscsit_attach_inactive_connection_recovery_entry(
+ struct iscsi_session *sess,
+ struct iscsi_conn_recovery *cr)
+{
+ spin_lock(&sess->cr_i_lock);
+ list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
+
+ sess->conn_recovery_count++;
+ pr_debug("Incremented connection recovery count to %u for"
+ " SID: %u\n", sess->conn_recovery_count, sess->sid);
+ spin_unlock(&sess->cr_i_lock);
+
+ return 0;
+}
+
+struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
+ struct iscsi_session *sess,
+ u16 cid)
+{
+ struct iscsi_conn_recovery *cr;
+
+ spin_lock(&sess->cr_i_lock);
+ list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
+ if (cr->cid == cid) {
+ spin_unlock(&sess->cr_i_lock);
+ return cr;
+ }
+ }
+ spin_unlock(&sess->cr_i_lock);
+
+ return NULL;
+}
+
+void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
+{
+ struct iscsi_cmd *cmd, *cmd_tmp;
+ struct iscsi_conn_recovery *cr, *cr_tmp;
+
+ spin_lock(&sess->cr_a_lock);
+ list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
+ list_del(&cr->cr_list);
+ spin_unlock(&sess->cr_a_lock);
+
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ list_for_each_entry_safe(cmd, cmd_tmp,
+ &cr->conn_recovery_cmd_list, i_conn_node) {
+
+ list_del_init(&cmd->i_conn_node);
+ cmd->conn = NULL;
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+ iscsit_free_cmd(cmd, true);
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ }
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+ spin_lock(&sess->cr_a_lock);
+
+ kfree(cr);
+ }
+ spin_unlock(&sess->cr_a_lock);
+
+ spin_lock(&sess->cr_i_lock);
+ list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
+ list_del(&cr->cr_list);
+ spin_unlock(&sess->cr_i_lock);
+
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ list_for_each_entry_safe(cmd, cmd_tmp,
+ &cr->conn_recovery_cmd_list, i_conn_node) {
+
+ list_del_init(&cmd->i_conn_node);
+ cmd->conn = NULL;
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+ iscsit_free_cmd(cmd, true);
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ }
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+ spin_lock(&sess->cr_i_lock);
+
+ kfree(cr);
+ }
+ spin_unlock(&sess->cr_i_lock);
+}
+
+int iscsit_remove_active_connection_recovery_entry(
+ struct iscsi_conn_recovery *cr,
+ struct iscsi_session *sess)
+{
+ spin_lock(&sess->cr_a_lock);
+ list_del(&cr->cr_list);
+
+ sess->conn_recovery_count--;
+ pr_debug("Decremented connection recovery count to %u for"
+ " SID: %u\n", sess->conn_recovery_count, sess->sid);
+ spin_unlock(&sess->cr_a_lock);
+
+ kfree(cr);
+
+ return 0;
+}
+
+static void iscsit_remove_inactive_connection_recovery_entry(
+ struct iscsi_conn_recovery *cr,
+ struct iscsi_session *sess)
+{
+ spin_lock(&sess->cr_i_lock);
+ list_del(&cr->cr_list);
+ spin_unlock(&sess->cr_i_lock);
+}
+
+/*
+ * Called with cr->conn_recovery_cmd_lock help.
+ */
+int iscsit_remove_cmd_from_connection_recovery(
+ struct iscsi_cmd *cmd,
+ struct iscsi_session *sess)
+{
+ struct iscsi_conn_recovery *cr;
+
+ if (!cmd->cr) {
+ pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
+ " is NULL!\n", cmd->init_task_tag);
+ BUG();
+ }
+ cr = cmd->cr;
+
+ list_del_init(&cmd->i_conn_node);
+ return --cr->cmd_count;
+}
+
+void iscsit_discard_cr_cmds_by_expstatsn(
+ struct iscsi_conn_recovery *cr,
+ u32 exp_statsn)
+{
+ u32 dropped_count = 0;
+ struct iscsi_cmd *cmd, *cmd_tmp;
+ struct iscsi_session *sess = cr->sess;
+
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ list_for_each_entry_safe(cmd, cmd_tmp,
+ &cr->conn_recovery_cmd_list, i_conn_node) {
+
+ if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
+ (cmd->deferred_i_state != ISTATE_REMOVE)) ||
+ (cmd->stat_sn >= exp_statsn)) {
+ continue;
+ }
+
+ dropped_count++;
+ pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
+ " 0x%08x, CID: %hu.\n", cmd->init_task_tag,
+ cmd->stat_sn, cr->cid);
+
+ iscsit_remove_cmd_from_connection_recovery(cmd, sess);
+
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+ iscsit_free_cmd(cmd, true);
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ }
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+
+ pr_debug("Dropped %u total acknowledged commands on"
+ " CID: %hu less than old ExpStatSN: 0x%08x\n",
+ dropped_count, cr->cid, exp_statsn);
+
+ if (!cr->cmd_count) {
+ pr_debug("No commands to be reassigned for failed"
+ " connection CID: %hu on SID: %u\n",
+ cr->cid, sess->sid);
+ iscsit_remove_inactive_connection_recovery_entry(cr, sess);
+ iscsit_attach_active_connection_recovery_entry(sess, cr);
+ pr_debug("iSCSI connection recovery successful for CID:"
+ " %hu on SID: %u\n", cr->cid, sess->sid);
+ iscsit_remove_active_connection_recovery_entry(cr, sess);
+ } else {
+ iscsit_remove_inactive_connection_recovery_entry(cr, sess);
+ iscsit_attach_active_connection_recovery_entry(sess, cr);
+ }
+}
+
+int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
+{
+ u32 dropped_count = 0;
+ struct iscsi_cmd *cmd, *cmd_tmp;
+ struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
+ struct iscsi_session *sess = conn->sess;
+
+ mutex_lock(&sess->cmdsn_mutex);
+ list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
+ &sess->sess_ooo_cmdsn_list, ooo_list) {
+
+ if (ooo_cmdsn->cid != conn->cid)
+ continue;
+
+ dropped_count++;
+ pr_debug("Dropping unacknowledged CmdSN:"
+ " 0x%08x during connection recovery on CID: %hu\n",
+ ooo_cmdsn->cmdsn, conn->cid);
+ iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
+ }
+ mutex_unlock(&sess->cmdsn_mutex);
+
+ spin_lock_bh(&conn->cmd_lock);
+ list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
+ if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
+ continue;
+
+ list_del_init(&cmd->i_conn_node);
+
+ spin_unlock_bh(&conn->cmd_lock);
+ iscsit_free_cmd(cmd, true);
+ spin_lock_bh(&conn->cmd_lock);
+ }
+ spin_unlock_bh(&conn->cmd_lock);
+
+ pr_debug("Dropped %u total unacknowledged commands on CID:"
+ " %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
+ sess->exp_cmd_sn);
+ return 0;
+}
+
+int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
+{
+ u32 cmd_count = 0;
+ struct iscsi_cmd *cmd, *cmd_tmp;
+ struct iscsi_conn_recovery *cr;
+
+ /*
+ * Allocate an struct iscsi_conn_recovery for this connection.
+ * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
+ * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
+ * connection's command list for connection recovery.
+ */
+ cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
+ if (!cr) {
+ pr_err("Unable to allocate memory for"
+ " struct iscsi_conn_recovery.\n");
+ return -1;
+ }
+ INIT_LIST_HEAD(&cr->cr_list);
+ INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
+ spin_lock_init(&cr->conn_recovery_cmd_lock);
+ /*
+ * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
+ * ISCSI_OP_NOOP_OUT opcodes. For all other opcodes call
+ * list_del_init(&cmd->i_conn_node); to release the command to the
+ * session pool and remove it from the connection's list.
+ *
+ * Also stop the DataOUT timer, which will be restarted after
+ * sending the TMR response.
+ */
+ spin_lock_bh(&conn->cmd_lock);
+ list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_conn_node) {
+
+ if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
+ (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
+ pr_debug("Not performing realligence on"
+ " Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
+ " CID: %hu\n", cmd->iscsi_opcode,
+ cmd->init_task_tag, cmd->cmd_sn, conn->cid);
+
+ list_del_init(&cmd->i_conn_node);
+ spin_unlock_bh(&conn->cmd_lock);
+ iscsit_free_cmd(cmd, true);
+ spin_lock_bh(&conn->cmd_lock);
+ continue;
+ }
+
+ /*
+ * Special case where commands greater than or equal to
+ * the session's ExpCmdSN are attached to the connection
+ * list but not to the out of order CmdSN list. The one
+ * obvious case is when a command with immediate data
+ * attached must only check the CmdSN against ExpCmdSN
+ * after the data is received. The special case below
+ * is when the connection fails before data is received,
+ * but also may apply to other PDUs, so it has been
+ * made generic here.
+ */
+ if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
+ iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) {
+ list_del_init(&cmd->i_conn_node);
+ spin_unlock_bh(&conn->cmd_lock);
+ iscsit_free_cmd(cmd, true);
+ spin_lock_bh(&conn->cmd_lock);
+ continue;
+ }
+
+ cmd_count++;
+ pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
+ " CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
+ " realligence.\n", cmd->iscsi_opcode,
+ cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
+ conn->cid);
+
+ cmd->deferred_i_state = cmd->i_state;
+ cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
+
+ if (cmd->data_direction == DMA_TO_DEVICE)
+ iscsit_stop_dataout_timer(cmd);
+
+ cmd->sess = conn->sess;
+
+ list_del_init(&cmd->i_conn_node);
+ spin_unlock_bh(&conn->cmd_lock);
+
+ iscsit_free_all_datain_reqs(cmd);
+
+ transport_wait_for_tasks(&cmd->se_cmd);
+ /*
+ * Add the struct iscsi_cmd to the connection recovery cmd list
+ */
+ spin_lock(&cr->conn_recovery_cmd_lock);
+ list_add_tail(&cmd->i_conn_node, &cr->conn_recovery_cmd_list);
+ spin_unlock(&cr->conn_recovery_cmd_lock);
+
+ spin_lock_bh(&conn->cmd_lock);
+ cmd->cr = cr;
+ cmd->conn = NULL;
+ }
+ spin_unlock_bh(&conn->cmd_lock);
+ /*
+ * Fill in the various values in the preallocated struct iscsi_conn_recovery.
+ */
+ cr->cid = conn->cid;
+ cr->cmd_count = cmd_count;
+ cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
+ cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
+ cr->sess = conn->sess;
+
+ iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
+
+ return 0;
+}
+
+int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
+{
+ atomic_set(&conn->connection_recovery, 1);
+
+ if (iscsit_close_connection(conn) < 0)
+ return -1;
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff