[SCSI] target: Add LIO target core v4.0.0-rc6
LIO target is a full featured in-kernel target framework with the
following feature set:
High-performance, non-blocking, multithreaded architecture with SIMD
support.
Advanced SCSI feature set:
* Persistent Reservations (PRs)
* Asymmetric Logical Unit Assignment (ALUA)
* Protocol and intra-nexus multiplexing, load-balancing and failover (MC/S)
* Full Error Recovery (ERL=0,1,2)
* Active/active task migration and session continuation (ERL=2)
* Thin LUN provisioning (UNMAP and WRITE_SAMExx)
Multiprotocol target plugins
Storage media independence:
* Virtualization of all storage media; transparent mapping of IO to LUNs
* No hard limits on number of LUNs per Target; maximum LUN size ~750 TB
* Backstores: SATA, SAS, SCSI, BluRay, DVD, FLASH, USB, ramdisk, etc.
Standards compliance:
* Full compliance with IETF (RFC 3720)
* Full implementation of SPC-4 PRs and ALUA
Significant code cleanups done by Christoph Hellwig.
[jejb: fix up for new block bdev exclusive interface. Minor fixes from
Randy Dunlap and Dan Carpenter.]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
new file mode 100644
index 0000000..158cecb
--- /dev/null
+++ b/drivers/target/target_core_tmr.c
@@ -0,0 +1,404 @@
+/*******************************************************************************
+ * Filename: target_core_tmr.c
+ *
+ * This file contains SPC-3 task management infrastructure
+ *
+ * Copyright (c) 2009,2010 Rising Tide Systems
+ * Copyright (c) 2009,2010 Linux-iSCSI.org
+ *
+ * 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/version.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_device.h>
+#include <target/target_core_tmr.h>
+#include <target/target_core_transport.h>
+#include <target/target_core_fabric_ops.h>
+#include <target/target_core_configfs.h>
+
+#include "target_core_alua.h"
+#include "target_core_pr.h"
+
+#define DEBUG_LUN_RESET
+#ifdef DEBUG_LUN_RESET
+#define DEBUG_LR(x...) printk(KERN_INFO x)
+#else
+#define DEBUG_LR(x...)
+#endif
+
+struct se_tmr_req *core_tmr_alloc_req(
+ struct se_cmd *se_cmd,
+ void *fabric_tmr_ptr,
+ u8 function)
+{
+ struct se_tmr_req *tmr;
+
+ tmr = kmem_cache_zalloc(se_tmr_req_cache, GFP_KERNEL);
+ if (!(tmr)) {
+ printk(KERN_ERR "Unable to allocate struct se_tmr_req\n");
+ return ERR_PTR(-ENOMEM);
+ }
+ tmr->task_cmd = se_cmd;
+ tmr->fabric_tmr_ptr = fabric_tmr_ptr;
+ tmr->function = function;
+ INIT_LIST_HEAD(&tmr->tmr_list);
+
+ return tmr;
+}
+EXPORT_SYMBOL(core_tmr_alloc_req);
+
+void core_tmr_release_req(
+ struct se_tmr_req *tmr)
+{
+ struct se_device *dev = tmr->tmr_dev;
+
+ spin_lock(&dev->se_tmr_lock);
+ list_del(&tmr->tmr_list);
+ kmem_cache_free(se_tmr_req_cache, tmr);
+ spin_unlock(&dev->se_tmr_lock);
+}
+
+static void core_tmr_handle_tas_abort(
+ struct se_node_acl *tmr_nacl,
+ struct se_cmd *cmd,
+ int tas,
+ int fe_count)
+{
+ if (!(fe_count)) {
+ transport_cmd_finish_abort(cmd, 1);
+ return;
+ }
+ /*
+ * TASK ABORTED status (TAS) bit support
+ */
+ if (((tmr_nacl != NULL) &&
+ (tmr_nacl == cmd->se_sess->se_node_acl)) || tas)
+ transport_send_task_abort(cmd);
+
+ transport_cmd_finish_abort(cmd, 0);
+}
+
+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_cmd *cmd;
+ struct se_queue_req *qr, *qr_tmp;
+ struct se_node_acl *tmr_nacl = NULL;
+ struct se_portal_group *tmr_tpg = NULL;
+ struct se_queue_obj *qobj = dev->dev_queue_obj;
+ struct se_tmr_req *tmr_p, *tmr_pp;
+ struct se_task *task, *task_tmp;
+ unsigned long flags;
+ int fe_count, state, 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_ATTRIB(dev)->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) {
+ DEBUG_LR("LUN_RESET: TMR caller fabric: %s"
+ " initiator port %s\n",
+ TPG_TFO(tmr_tpg)->get_fabric_name(),
+ tmr_nacl->initiatorname);
+ }
+ }
+ DEBUG_LR("LUN_RESET: %s starting for [%s], tas: %d\n",
+ (preempt_and_abort_list) ? "Preempt" : "TMR",
+ TRANSPORT(dev)->name, tas);
+ /*
+ * Release all pending and outgoing TMRs aside from the received
+ * LUN_RESET tmr..
+ */
+ spin_lock(&dev->se_tmr_lock);
+ 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 && (tmr_p == tmr))
+ continue;
+
+ cmd = tmr_p->task_cmd;
+ if (!(cmd)) {
+ printk(KERN_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 ((preempt_and_abort_list != NULL) &&
+ (core_scsi3_check_cdb_abort_and_preempt(
+ preempt_and_abort_list, cmd) != 0))
+ continue;
+ spin_unlock(&dev->se_tmr_lock);
+
+ spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
+ if (!(atomic_read(&T_TASK(cmd)->t_transport_active))) {
+ spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
+ spin_lock(&dev->se_tmr_lock);
+ continue;
+ }
+ if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
+ spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
+ spin_lock(&dev->se_tmr_lock);
+ continue;
+ }
+ DEBUG_LR("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);
+ spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
+
+ transport_cmd_finish_abort_tmr(cmd);
+ spin_lock(&dev->se_tmr_lock);
+ }
+ spin_unlock(&dev->se_tmr_lock);
+ /*
+ * Complete outstanding struct se_task CDBs 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(task, task_tmp, &dev->state_task_list,
+ t_state_list) {
+ if (!(TASK_CMD(task))) {
+ printk(KERN_ERR "TASK_CMD(task) is NULL!\n");
+ continue;
+ }
+ cmd = TASK_CMD(task);
+
+ if (!T_TASK(cmd)) {
+ printk(KERN_ERR "T_TASK(cmd) is NULL for task: %p cmd:"
+ " %p ITT: 0x%08x\n", task, cmd,
+ CMD_TFO(cmd)->get_task_tag(cmd));
+ continue;
+ }
+ /*
+ * For PREEMPT_AND_ABORT usage, only process commands
+ * with a matching reservation key.
+ */
+ if ((preempt_and_abort_list != NULL) &&
+ (core_scsi3_check_cdb_abort_and_preempt(
+ preempt_and_abort_list, cmd) != 0))
+ continue;
+ /*
+ * Not aborting PROUT PREEMPT_AND_ABORT CDB..
+ */
+ if (prout_cmd == cmd)
+ continue;
+
+ list_del(&task->t_state_list);
+ atomic_set(&task->task_state_active, 0);
+ spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+
+ spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
+ DEBUG_LR("LUN_RESET: %s cmd: %p task: %p"
+ " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state/"
+ "def_t_state: %d/%d cdb: 0x%02x\n",
+ (preempt_and_abort_list) ? "Preempt" : "", cmd, task,
+ CMD_TFO(cmd)->get_task_tag(cmd), 0,
+ CMD_TFO(cmd)->get_cmd_state(cmd), cmd->t_state,
+ cmd->deferred_t_state, T_TASK(cmd)->t_task_cdb[0]);
+ DEBUG_LR("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
+ " t_task_cdbs: %d t_task_cdbs_left: %d"
+ " t_task_cdbs_sent: %d -- t_transport_active: %d"
+ " t_transport_stop: %d t_transport_sent: %d\n",
+ CMD_TFO(cmd)->get_task_tag(cmd), cmd->pr_res_key,
+ T_TASK(cmd)->t_task_cdbs,
+ atomic_read(&T_TASK(cmd)->t_task_cdbs_left),
+ atomic_read(&T_TASK(cmd)->t_task_cdbs_sent),
+ atomic_read(&T_TASK(cmd)->t_transport_active),
+ atomic_read(&T_TASK(cmd)->t_transport_stop),
+ atomic_read(&T_TASK(cmd)->t_transport_sent));
+
+ if (atomic_read(&task->task_active)) {
+ atomic_set(&task->task_stop, 1);
+ spin_unlock_irqrestore(
+ &T_TASK(cmd)->t_state_lock, flags);
+
+ DEBUG_LR("LUN_RESET: Waiting for task: %p to shutdown"
+ " for dev: %p\n", task, dev);
+ wait_for_completion(&task->task_stop_comp);
+ DEBUG_LR("LUN_RESET Completed task: %p shutdown for"
+ " dev: %p\n", task, dev);
+ spin_lock_irqsave(&T_TASK(cmd)->t_state_lock, flags);
+ atomic_dec(&T_TASK(cmd)->t_task_cdbs_left);
+
+ atomic_set(&task->task_active, 0);
+ atomic_set(&task->task_stop, 0);
+ }
+ __transport_stop_task_timer(task, &flags);
+
+ if (!(atomic_dec_and_test(&T_TASK(cmd)->t_task_cdbs_ex_left))) {
+ spin_unlock_irqrestore(
+ &T_TASK(cmd)->t_state_lock, flags);
+ DEBUG_LR("LUN_RESET: Skipping task: %p, dev: %p for"
+ " t_task_cdbs_ex_left: %d\n", task, dev,
+ atomic_read(&T_TASK(cmd)->t_task_cdbs_ex_left));
+
+ spin_lock_irqsave(&dev->execute_task_lock, flags);
+ continue;
+ }
+ fe_count = atomic_read(&T_TASK(cmd)->t_fe_count);
+
+ if (atomic_read(&T_TASK(cmd)->t_transport_active)) {
+ DEBUG_LR("LUN_RESET: got t_transport_active = 1 for"
+ " task: %p, t_fe_count: %d dev: %p\n", task,
+ fe_count, dev);
+ spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock,
+ flags);
+ core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
+
+ spin_lock_irqsave(&dev->execute_task_lock, flags);
+ continue;
+ }
+ DEBUG_LR("LUN_RESET: Got t_transport_active = 0 for task: %p,"
+ " t_fe_count: %d dev: %p\n", task, fe_count, dev);
+ spin_unlock_irqrestore(&T_TASK(cmd)->t_state_lock, flags);
+ core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
+
+ spin_lock_irqsave(&dev->execute_task_lock, flags);
+ }
+ spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+ /*
+ * Release all commands remaining in the struct se_device cmd queue.
+ *
+ * This follows the same logic as above for the struct se_device
+ * struct se_task state list, where commands are returned with
+ * TASK_ABORTED status, if there is an outstanding $FABRIC_MOD
+ * reference, otherwise the struct se_cmd is released.
+ */
+ spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
+ list_for_each_entry_safe(qr, qr_tmp, &qobj->qobj_list, qr_list) {
+ cmd = (struct se_cmd *)qr->cmd;
+ if (!(cmd)) {
+ /*
+ * Skip these for non PREEMPT_AND_ABORT usage..
+ */
+ if (preempt_and_abort_list != NULL)
+ continue;
+
+ atomic_dec(&qobj->queue_cnt);
+ list_del(&qr->qr_list);
+ kfree(qr);
+ continue;
+ }
+ /*
+ * For PREEMPT_AND_ABORT usage, only process commands
+ * with a matching reservation key.
+ */
+ if ((preempt_and_abort_list != NULL) &&
+ (core_scsi3_check_cdb_abort_and_preempt(
+ preempt_and_abort_list, cmd) != 0))
+ continue;
+ /*
+ * Not aborting PROUT PREEMPT_AND_ABORT CDB..
+ */
+ if (prout_cmd == cmd)
+ continue;
+
+ atomic_dec(&T_TASK(cmd)->t_transport_queue_active);
+ atomic_dec(&qobj->queue_cnt);
+ list_del(&qr->qr_list);
+ spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
+
+ state = qr->state;
+ kfree(qr);
+
+ DEBUG_LR("LUN_RESET: %s from Device Queue: cmd: %p t_state:"
+ " %d t_fe_count: %d\n", (preempt_and_abort_list) ?
+ "Preempt" : "", cmd, state,
+ atomic_read(&T_TASK(cmd)->t_fe_count));
+ /*
+ * Signal that the command has failed via cmd->se_cmd_flags,
+ * and call TFO->new_cmd_failure() to wakeup any fabric
+ * dependent code used to wait for unsolicited data out
+ * allocation to complete. The fabric module is expected
+ * to dump any remaining unsolicited data out for the aborted
+ * command at this point.
+ */
+ transport_new_cmd_failure(cmd);
+
+ core_tmr_handle_tas_abort(tmr_nacl, cmd, tas,
+ atomic_read(&T_TASK(cmd)->t_fe_count));
+ spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
+ }
+ spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
+ /*
+ * Clear any legacy SPC-2 reservation when called during
+ * LOGICAL UNIT RESET
+ */
+ if (!(preempt_and_abort_list) &&
+ (dev->dev_flags & DF_SPC2_RESERVATIONS)) {
+ spin_lock(&dev->dev_reservation_lock);
+ dev->dev_reserved_node_acl = NULL;
+ dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
+ spin_unlock(&dev->dev_reservation_lock);
+ printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
+ }
+
+ spin_lock(&dev->stats_lock);
+ dev->num_resets++;
+ spin_unlock(&dev->stats_lock);
+
+ DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
+ (preempt_and_abort_list) ? "Preempt" : "TMR",
+ TRANSPORT(dev)->name);
+ return 0;
+}