Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 430 insertions, 0 deletions

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
new file mode 100644
index 000000000..4718db628
--- /dev/null
+++ b/drivers/target/target_core_tmr.c
@@ -0,0 +1,430 @@
+// 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 <nab@kernel.org>
+ *
+ ******************************************************************************/
+
+#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)
+{
+	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;
+
+	lockdep_assert_held(&sess->sess_cmd_lock);
+
+	/*
+	 * 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)
+{
+	LIST_HEAD(aborted_list);
+	struct se_cmd *se_cmd, *next;
+	unsigned long flags;
+	bool rc;
+	u64 ref_tag;
+	int i;
+
+	for (i = 0; i < dev->queue_cnt; i++) {
+		flush_work(&dev->queues[i].sq.work);
+
+		spin_lock_irqsave(&dev->queues[i].lock, flags);
+		list_for_each_entry_safe(se_cmd, next, &dev->queues[i].state_list,
+					 state_list) {
+			if (se_sess != se_cmd->se_sess)
+				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;
+
+			pr_err("ABORT_TASK: Found referenced %s task_tag: %llu\n",
+			       se_cmd->se_tfo->fabric_name, ref_tag);
+
+			spin_lock(&se_sess->sess_cmd_lock);
+			rc = __target_check_io_state(se_cmd, se_sess, 0);
+			spin_unlock(&se_sess->sess_cmd_lock);
+			if (!rc)
+				continue;
+
+			list_move_tail(&se_cmd->state_list, &aborted_list);
+			se_cmd->state_active = false;
+			spin_unlock_irqrestore(&dev->queues[i].lock, flags);
+
+			if (dev->transport->tmr_notify)
+				dev->transport->tmr_notify(dev, TMR_ABORT_TASK,
+							   &aborted_list);
+
+			list_del_init(&se_cmd->state_list);
+			target_put_cmd_and_wait(se_cmd);
+
+			pr_err("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(&dev->queues[i].lock, flags);
+	}
+
+	if (dev->transport->tmr_notify)
+		dev->transport->tmr_notify(dev, TMR_ABORT_TASK, &aborted_list);
+
+	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);
+	list_for_each_entry_safe(tmr_p, tmr_pp, &dev->dev_tmr_list, tmr_list) {
+		if (tmr_p == tmr)
+			continue;
+
+		cmd = tmr_p->task_cmd;
+		if (!cmd) {
+			pr_err("Unable to locate struct se_cmd for TMR\n");
+			continue;
+		}
+
+		/*
+		 * We only execute one LUN_RESET at a time so we can't wait
+		 * on them below.
+		 */
+		if (tmr_p->function == TMR_LUN_RESET)
+			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);
+		tmr_p->tmr_dev = NULL;
+	}
+	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, i;
+
+	/*
+	 * 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.
+	 */
+	for (i = 0; i < dev->queue_cnt; i++) {
+		flush_work(&dev->queues[i].sq.work);
+
+		spin_lock_irqsave(&dev->queues[i].lock, flags);
+		list_for_each_entry_safe(cmd, next, &dev->queues[i].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->queues[i].lock, flags);
+	}
+
+	if (dev->transport->tmr_notify)
+		dev->transport->tmr_notify(dev, preempt_and_abort_list ?
+					   TMR_LUN_RESET_PRO : TMR_LUN_RESET,
+					   &drain_task_list);
+
+	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);
+		}
+	}
+
+
+	/*
+	 * We only allow one reset or preempt and abort to execute at a time
+	 * to prevent one call from claiming all the cmds causing a second
+	 * call from returning while cmds it should have waited on are still
+	 * running.
+	 */
+	mutex_lock(&dev->lun_reset_mutex);
+
+	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);
+
+	mutex_unlock(&dev->lun_reset_mutex);
+
+	/*
+	 * 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;
+}
+