// SPDX-License-Identifier: GPL-2.0-or-later /******************************************************************************* * Filename: target_core_tmr.c * * This file contains SPC-3 task management infrastructure * * (c) Copyright 2009-2013 Datera, Inc. * * Nicholas A. Bellinger * ******************************************************************************/ #include #include #include #include #include #include #include #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, bool 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) < 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, bool 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; bool 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->reservation_holder = 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; }