| /******************************************************************************* |
| * 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 <target/target_core_base.h> |
| #include <target/target_core_backend.h> |
| #include <target/target_core_fabric.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) { |
| spin_lock_irqsave(&dev->se_tmr_lock, flags); |
| list_del_init(&tmr->tmr_list); |
| spin_unlock_irqrestore(&dev->se_tmr_lock, flags); |
| } |
| |
| kfree(tmr); |
| } |
| |
| 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; |
| } |
| |
| static bool __target_check_io_state(struct se_cmd *se_cmd, |
| struct se_session *tmr_sess, int tas) |
| { |
| struct se_session *sess = se_cmd->se_sess; |
| |
| assert_spin_locked(&sess->sess_cmd_lock); |
| WARN_ON_ONCE(!irqs_disabled()); |
| /* |
| * If command already reached CMD_T_COMPLETE state within |
| * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown, |
| * this se_cmd has been passed to fabric driver and will |
| * not be aborted. |
| * |
| * Otherwise, obtain a local se_cmd->cmd_kref now for TMR |
| * ABORT_TASK + LUN_RESET for CMD_T_ABORTED processing as |
| * long as se_cmd->cmd_kref is still active unless zero. |
| */ |
| spin_lock(&se_cmd->t_state_lock); |
| if (se_cmd->transport_state & (CMD_T_COMPLETE | CMD_T_FABRIC_STOP)) { |
| pr_debug("Attempted to abort io tag: %llu already complete or" |
| " fabric stop, skipping\n", se_cmd->tag); |
| spin_unlock(&se_cmd->t_state_lock); |
| return false; |
| } |
| se_cmd->transport_state |= CMD_T_ABORTED; |
| |
| if ((tmr_sess != se_cmd->se_sess) && tas) |
| se_cmd->transport_state |= CMD_T_TAS; |
| |
| spin_unlock(&se_cmd->t_state_lock); |
| |
| return kref_get_unless_zero(&se_cmd->cmd_kref); |
| } |
| |
| void core_tmr_abort_task( |
| struct se_device *dev, |
| struct se_tmr_req *tmr, |
| struct se_session *se_sess) |
| { |
| struct se_cmd *se_cmd; |
| unsigned long flags; |
| u64 ref_tag; |
| |
| spin_lock_irqsave(&se_sess->sess_cmd_lock, flags); |
| list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list) { |
| |
| if (dev != se_cmd->se_dev) |
| continue; |
| |
| /* skip task management functions, including tmr->task_cmd */ |
| if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) |
| continue; |
| |
| ref_tag = se_cmd->tag; |
| if (tmr->ref_task_tag != ref_tag) |
| continue; |
| |
| printk("ABORT_TASK: Found referenced %s task_tag: %llu\n", |
| se_cmd->se_tfo->fabric_name, ref_tag); |
| |
| if (!__target_check_io_state(se_cmd, se_sess, |
| dev->dev_attrib.emulate_tas)) |
| continue; |
| |
| spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); |
| |
| /* |
| * Ensure that this ABORT request is visible to the LU RESET |
| * code. |
| */ |
| if (!tmr->tmr_dev) |
| WARN_ON_ONCE(transport_lookup_tmr_lun(tmr->task_cmd, |
| se_cmd->orig_fe_lun) < 0); |
| |
| target_put_cmd_and_wait(se_cmd); |
| |
| printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for" |
| " ref_tag: %llu\n", ref_tag); |
| tmr->response = TMR_FUNCTION_COMPLETE; |
| atomic_long_inc(&dev->aborts_complete); |
| return; |
| } |
| spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags); |
| |
| printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %lld\n", |
| tmr->ref_task_tag); |
| tmr->response = TMR_TASK_DOES_NOT_EXIST; |
| atomic_long_inc(&dev->aborts_no_task); |
| } |
| |
| 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_session *sess; |
| struct se_tmr_req *tmr_p, *tmr_pp; |
| struct se_cmd *cmd; |
| unsigned long flags; |
| bool rc; |
| /* |
| * Release all pending and outgoing TMRs aside from the received |
| * LUN_RESET tmr.. |
| */ |
| spin_lock_irqsave(&dev->se_tmr_lock, flags); |
| if (tmr) |
| list_del_init(&tmr->tmr_list); |
| list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) { |
| 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 registration key matching TMRs. |
| */ |
| if (target_check_cdb_and_preempt(preempt_and_abort_list, cmd)) |
| continue; |
| |
| sess = cmd->se_sess; |
| if (WARN_ON_ONCE(!sess)) |
| continue; |
| |
| spin_lock(&sess->sess_cmd_lock); |
| rc = __target_check_io_state(cmd, sess, 0); |
| spin_unlock(&sess->sess_cmd_lock); |
| |
| if (!rc) { |
| printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n"); |
| continue; |
| } |
| |
| 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); |
| |
| target_put_cmd_and_wait(cmd); |
| } |
| } |
| |
| /** |
| * core_tmr_drain_state_list() - abort SCSI commands associated with a device |
| * |
| * @dev: Device for which to abort outstanding SCSI commands. |
| * @prout_cmd: Pointer to the SCSI PREEMPT AND ABORT if this function is called |
| * to realize the PREEMPT AND ABORT functionality. |
| * @tmr_sess: Session through which the LUN RESET has been received. |
| * @tas: Task Aborted Status (TAS) bit from the SCSI control mode page. |
| * A quote from SPC-4, paragraph "7.5.10 Control mode page": |
| * "A task aborted status (TAS) bit set to zero specifies that |
| * aborted commands shall be terminated by the device server |
| * without any response to the application client. A TAS bit set |
| * to one specifies that commands 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." |
| * @preempt_and_abort_list: For the PREEMPT AND ABORT functionality, a list |
| * with registrations that will be preempted. |
| */ |
| static void core_tmr_drain_state_list( |
| struct se_device *dev, |
| struct se_cmd *prout_cmd, |
| struct se_session *tmr_sess, |
| int tas, |
| struct list_head *preempt_and_abort_list) |
| { |
| LIST_HEAD(drain_task_list); |
| struct se_session *sess; |
| struct se_cmd *cmd, *next; |
| unsigned long flags; |
| int rc; |
| |
| /* |
| * 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; |
| |
| sess = cmd->se_sess; |
| if (WARN_ON_ONCE(!sess)) |
| continue; |
| |
| spin_lock(&sess->sess_cmd_lock); |
| rc = __target_check_io_state(cmd, tmr_sess, tas); |
| spin_unlock(&sess->sess_cmd_lock); |
| if (!rc) |
| 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_init(&cmd->state_list); |
| |
| target_show_cmd("LUN_RESET: ", cmd); |
| pr_debug("LUN_RESET: ITT[0x%08llx] - %s pr_res_key: 0x%016Lx\n", |
| cmd->tag, (preempt_and_abort_list) ? "preempt" : "", |
| cmd->pr_res_key); |
| |
| target_put_cmd_and_wait(cmd); |
| } |
| } |
| |
| 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; |
| struct se_session *tmr_sess = 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_sess = tmr->task_cmd->se_sess; |
| tmr_nacl = tmr_sess->se_node_acl; |
| tmr_tpg = tmr_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->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_sess, 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; |
| } |
| |