| /******************************************************************************* |
| * 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 <linux/slab.h> |
| #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_entries(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_reallegiance(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 reallegiance 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" |
| " reallegiance.\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; |
| } |