diff options
Diffstat (limited to 'drivers/target/target_core_tmr.c')
| -rw-r--r-- | drivers/target/target_core_tmr.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c new file mode 100644 index 00000000000..f7cd95e8111 --- /dev/null +++ b/drivers/target/target_core_tmr.c @@ -0,0 +1,395 @@ +/******************************************************************************* + * Filename: target_core_tmr.c + * + * This file contains SPC-3 task management infrastructure + * + * (c) Copyright 2009-2013 Datera, Inc. + * + * Nicholas A. Bellinger <nab@kernel.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. + * + * 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/slab.h> +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/export.h> +#include <scsi/scsi.h> +#include <scsi/scsi_cmnd.h> + +#include <target/target_core_base.h> +#include <target/target_core_backend.h> +#include <target/target_core_fabric.h> +#include <target/target_core_configfs.h> + +#include "target_core_internal.h" +#include "target_core_alua.h" +#include "target_core_pr.h" + +int core_tmr_alloc_req( + struct se_cmd *se_cmd, + void *fabric_tmr_ptr, + u8 function, + gfp_t gfp_flags) +{ + struct se_tmr_req *tmr; + + tmr = kzalloc(sizeof(struct se_tmr_req), gfp_flags); + if (!tmr) { + pr_err("Unable to allocate struct se_tmr_req\n"); + return -ENOMEM; + } + + se_cmd->se_cmd_flags |= SCF_SCSI_TMR_CDB; + se_cmd->se_tmr_req = tmr; + tmr->task_cmd = se_cmd; + tmr->fabric_tmr_ptr = fabric_tmr_ptr; + tmr->function = function; + INIT_LIST_HEAD(&tmr->tmr_list); + + return 0; +} +EXPORT_SYMBOL(core_tmr_alloc_req); + +void core_tmr_release_req( + struct se_tmr_req *tmr) +{ + struct se_device *dev = tmr->tmr_dev; + unsigned long flags; + + if (!dev) { + kfree(tmr); + return; + } + + spin_lock_irqsave(&dev->se_tmr_lock, flags); + list_del(&tmr->tmr_list); + spin_unlock_irqrestore(&dev->se_tmr_lock, flags); + + kfree(tmr); +} + +static void core_tmr_handle_tas_abort( + struct se_node_acl *tmr_nacl, + struct se_cmd *cmd, + int tas) +{ + bool remove = true; + /* + * TASK ABORTED status (TAS) bit support + */ + if ((tmr_nacl && + (tmr_nacl != cmd->se_sess->se_node_acl)) && tas) { + remove = false; + transport_send_task_abort(cmd); + } + + transport_cmd_finish_abort(cmd, remove); +} + +static int target_check_cdb_and_preempt(struct list_head *list, + struct se_cmd *cmd) +{ + struct t10_pr_registration *reg; + + if (!list) + return 0; + list_for_each_entry(reg, list, pr_reg_abort_list) { + if (reg->pr_res_key == cmd->pr_res_key) + return 0; + } + + return 1; +} + +void core_tmr_abort_task( + struct se_device *dev, + struct se_tmr_req *tmr, + struct se_session *se_sess) +{ + struct se_cmd *se_cmd, *tmp_cmd; + unsigned long flags; + int ref_tag; + + spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); + list_for_each_entry_safe(se_cmd, tmp_cmd, + &se_sess->sess_cmd_list, se_cmd_list) { + + if (dev != se_cmd->se_dev) + continue; + + /* skip se_cmd associated with tmr */ + if (tmr->task_cmd == se_cmd) + continue; + + ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd); + if (tmr->ref_task_tag != ref_tag) + continue; + + printk("ABORT_TASK: Found referenced %s task_tag: %u\n", + se_cmd->se_tfo->get_fabric_name(), ref_tag); + + spin_lock(&se_cmd->t_state_lock); + if (se_cmd->transport_state & CMD_T_COMPLETE) { + printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag); + spin_unlock(&se_cmd->t_state_lock); + spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + goto out; + } + se_cmd->transport_state |= CMD_T_ABORTED; + spin_unlock(&se_cmd->t_state_lock); + + list_del_init(&se_cmd->se_cmd_list); + kref_get(&se_cmd->cmd_kref); + spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + + cancel_work_sync(&se_cmd->work); + transport_wait_for_tasks(se_cmd); + + target_put_sess_cmd(se_sess, se_cmd); + transport_cmd_finish_abort(se_cmd, true); + + printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" + " ref_tag: %d\n", ref_tag); + tmr->response = TMR_FUNCTION_COMPLETE; + return; + } + spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); + +out: + printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n", + tmr->ref_task_tag); + tmr->response = TMR_TASK_DOES_NOT_EXIST; +} + +static void core_tmr_drain_tmr_list( + struct se_device *dev, + struct se_tmr_req *tmr, + struct list_head *preempt_and_abort_list) +{ + LIST_HEAD(drain_tmr_list); + struct se_tmr_req *tmr_p, *tmr_pp; + struct se_cmd *cmd; + unsigned long flags; + /* + * Release all pending and outgoing TMRs aside from the received + * LUN_RESET tmr.. + */ + spin_lock_irqsave(&dev->se_tmr_lock, flags); + list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { + /* + * Allow the received TMR to return with FUNCTION_COMPLETE. + */ + if (tmr_p == tmr) + continue; + + cmd = tmr_p->task_cmd; + if (!cmd) { + pr_err("Unable to locate struct se_cmd for TMR\n"); + continue; + } + /* + * If this function was called with a valid pr_res_key + * parameter (eg: for PROUT PREEMPT_AND_ABORT service action + * skip non regisration key matching TMRs. + */ + if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) + continue; + + spin_lock(&cmd->t_state_lock); + if (!(cmd->transport_state & CMD_T_ACTIVE)) { + spin_unlock(&cmd->t_state_lock); + continue; + } + if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) { + spin_unlock(&cmd->t_state_lock); + continue; + } + spin_unlock(&cmd->t_state_lock); + + list_move_tail(&tmr_p->tmr_list, &drain_tmr_list); + } + spin_unlock_irqrestore(&dev->se_tmr_lock, flags); + + list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) { + list_del_init(&tmr_p->tmr_list); + cmd = tmr_p->task_cmd; + + pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x," + " Response: 0x%02x, t_state: %d\n", + (preempt_and_abort_list) ? "Preempt" : "", tmr_p, + tmr_p->function, tmr_p->response, cmd->t_state); + + transport_cmd_finish_abort(cmd, 1); + } +} + +static void core_tmr_drain_state_list( + struct se_device *dev, + struct se_cmd *prout_cmd, + struct se_node_acl *tmr_nacl, + int tas, + struct list_head *preempt_and_abort_list) +{ + LIST_HEAD(drain_task_list); + struct se_cmd *cmd, *next; + unsigned long flags; + + /* + * Complete outstanding commands with TASK_ABORTED SAM status. + * + * This is following sam4r17, section 5.6 Aborting commands, Table 38 + * for TMR LUN_RESET: + * + * a) "Yes" indicates that each command that is aborted on an I_T nexus + * other than the one that caused the SCSI device condition is + * completed with TASK ABORTED status, if the TAS bit is set to one in + * the Control mode page (see SPC-4). "No" indicates that no status is + * returned for aborted commands. + * + * d) If the logical unit reset is caused by a particular I_T nexus + * (e.g., by a LOGICAL UNIT RESET task management function), then "yes" + * (TASK_ABORTED status) applies. + * + * Otherwise (e.g., if triggered by a hard reset), "no" + * (no TASK_ABORTED SAM status) applies. + * + * Note that this seems to be independent of TAS (Task Aborted Status) + * in the Control Mode Page. + */ + spin_lock_irqsave(&dev->execute_task_lock, flags); + list_for_each_entry_safe(cmd, next, &dev->state_list, state_list) { + /* + * For PREEMPT_AND_ABORT usage, only process commands + * with a matching reservation key. + */ + if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) + continue; + + /* + * Not aborting PROUT PREEMPT_AND_ABORT CDB.. + */ + if (prout_cmd == cmd) + continue; + + list_move_tail(&cmd->state_list, &drain_task_list); + cmd->state_active = false; + } + spin_unlock_irqrestore(&dev->execute_task_lock, flags); + + while (!list_empty(&drain_task_list)) { + cmd = list_entry(drain_task_list.next, struct se_cmd, state_list); + list_del(&cmd->state_list); + + pr_debug("LUN_RESET: %s cmd: %p" + " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d" + "cdb: 0x%02x\n", + (preempt_and_abort_list) ? "Preempt" : "", cmd, + cmd->se_tfo->get_task_tag(cmd), 0, + cmd->se_tfo->get_cmd_state(cmd), cmd->t_state, + cmd->t_task_cdb[0]); + pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx" + " -- CMD_T_ACTIVE: %d" + " CMD_T_STOP: %d CMD_T_SENT: %d\n", + cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key, + (cmd->transport_state & CMD_T_ACTIVE) != 0, + (cmd->transport_state & CMD_T_STOP) != 0, + (cmd->transport_state & CMD_T_SENT) != 0); + + /* + * If the command may be queued onto a workqueue cancel it now. + * + * This is equivalent to removal from the execute queue in the + * loop above, but we do it down here given that + * cancel_work_sync may block. + */ + if (cmd->t_state == TRANSPORT_COMPLETE) + cancel_work_sync(&cmd->work); + + spin_lock_irqsave(&cmd->t_state_lock, flags); + target_stop_cmd(cmd, &flags); + + cmd->transport_state |= CMD_T_ABORTED; + spin_unlock_irqrestore(&cmd->t_state_lock, flags); + + core_tmr_handle_tas_abort(tmr_nacl, cmd, tas); + } +} + +int core_tmr_lun_reset( + struct se_device *dev, + struct se_tmr_req *tmr, + struct list_head *preempt_and_abort_list, + struct se_cmd *prout_cmd) +{ + struct se_node_acl *tmr_nacl = NULL; + struct se_portal_group *tmr_tpg = NULL; + int tas; + /* + * TASK_ABORTED status bit, this is configurable via ConfigFS + * struct se_device attributes. spc4r17 section 7.4.6 Control mode page + * + * A task aborted status (TAS) bit set to zero specifies that aborted + * tasks shall be terminated by the device server without any response + * to the application client. A TAS bit set to one specifies that tasks + * aborted by the actions of an I_T nexus other than the I_T nexus on + * which the command was received shall be completed with TASK ABORTED + * status (see SAM-4). + */ + tas = dev->dev_attrib.emulate_tas; + /* + * Determine if this se_tmr is coming from a $FABRIC_MOD + * or struct se_device passthrough.. + */ + if (tmr && tmr->task_cmd && tmr->task_cmd->se_sess) { + tmr_nacl = tmr->task_cmd->se_sess->se_node_acl; + tmr_tpg = tmr->task_cmd->se_sess->se_tpg; + if (tmr_nacl && tmr_tpg) { + pr_debug("LUN_RESET: TMR caller fabric: %s" + " initiator port %s\n", + tmr_tpg->se_tpg_tfo->get_fabric_name(), + tmr_nacl->initiatorname); + } + } + pr_debug("LUN_RESET: %s starting for [%s], tas: %d\n", + (preempt_and_abort_list) ? "Preempt" : "TMR", + dev->transport->name, tas); + + core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list); + core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas, + preempt_and_abort_list); + + /* + * Clear any legacy SPC-2 reservation when called during + * LOGICAL UNIT RESET + */ + if (!preempt_and_abort_list && + (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)) { + spin_lock(&dev->dev_reservation_lock); + dev->dev_reserved_node_acl = NULL; + dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS; + spin_unlock(&dev->dev_reservation_lock); + pr_debug("LUN_RESET: SCSI-2 Released reservation\n"); + } + + atomic_long_inc(&dev->num_resets); + + pr_debug("LUN_RESET: %s for [%s] Complete\n", + (preempt_and_abort_list) ? "Preempt" : "TMR", + dev->transport->name); + return 0; +} + |