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-rw-r--r--drivers/target/target_core_ua.c323
1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/target/target_core_ua.c b/drivers/target/target_core_ua.c
new file mode 100644
index 000000000..4276690fb
--- /dev/null
+++ b/drivers/target/target_core_ua.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*******************************************************************************
+ * Filename: target_core_ua.c
+ *
+ * This file contains logic for SPC-3 Unit Attention emulation
+ *
+ * (c) Copyright 2009-2013 Datera, Inc.
+ *
+ * Nicholas A. Bellinger <nab@kernel.org>
+ *
+ ******************************************************************************/
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <scsi/scsi_proto.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+
+#include "target_core_internal.h"
+#include "target_core_alua.h"
+#include "target_core_pr.h"
+#include "target_core_ua.h"
+
+sense_reason_t
+target_scsi3_ua_check(struct se_cmd *cmd)
+{
+ struct se_dev_entry *deve;
+ struct se_session *sess = cmd->se_sess;
+ struct se_node_acl *nacl;
+
+ if (!sess)
+ return 0;
+
+ nacl = sess->se_node_acl;
+ if (!nacl)
+ return 0;
+
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ return 0;
+ }
+ if (list_empty_careful(&deve->ua_list)) {
+ rcu_read_unlock();
+ return 0;
+ }
+ rcu_read_unlock();
+ /*
+ * From sam4r14, section 5.14 Unit attention condition:
+ *
+ * a) if an INQUIRY command enters the enabled command state, the
+ * device server shall process the INQUIRY command and shall neither
+ * report nor clear any unit attention condition;
+ * b) if a REPORT LUNS command enters the enabled command state, the
+ * device server shall process the REPORT LUNS command and shall not
+ * report any unit attention condition;
+ * e) if a REQUEST SENSE command enters the enabled command state while
+ * a unit attention condition exists for the SCSI initiator port
+ * associated with the I_T nexus on which the REQUEST SENSE command
+ * was received, then the device server shall process the command
+ * and either:
+ */
+ switch (cmd->t_task_cdb[0]) {
+ case INQUIRY:
+ case REPORT_LUNS:
+ case REQUEST_SENSE:
+ return 0;
+ default:
+ return TCM_CHECK_CONDITION_UNIT_ATTENTION;
+ }
+}
+
+int core_scsi3_ua_allocate(
+ struct se_dev_entry *deve,
+ u8 asc,
+ u8 ascq)
+{
+ struct se_ua *ua, *ua_p, *ua_tmp;
+
+ ua = kmem_cache_zalloc(se_ua_cache, GFP_ATOMIC);
+ if (!ua) {
+ pr_err("Unable to allocate struct se_ua\n");
+ return -ENOMEM;
+ }
+ INIT_LIST_HEAD(&ua->ua_nacl_list);
+
+ ua->ua_asc = asc;
+ ua->ua_ascq = ascq;
+
+ spin_lock(&deve->ua_lock);
+ list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
+ /*
+ * Do not report the same UNIT ATTENTION twice..
+ */
+ if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
+ spin_unlock(&deve->ua_lock);
+ kmem_cache_free(se_ua_cache, ua);
+ return 0;
+ }
+ /*
+ * Attach the highest priority Unit Attention to
+ * the head of the list following sam4r14,
+ * Section 5.14 Unit Attention Condition:
+ *
+ * POWER ON, RESET, OR BUS DEVICE RESET OCCURRED highest
+ * POWER ON OCCURRED or
+ * DEVICE INTERNAL RESET
+ * SCSI BUS RESET OCCURRED or
+ * MICROCODE HAS BEEN CHANGED or
+ * protocol specific
+ * BUS DEVICE RESET FUNCTION OCCURRED
+ * I_T NEXUS LOSS OCCURRED
+ * COMMANDS CLEARED BY POWER LOSS NOTIFICATION
+ * all others Lowest
+ *
+ * Each of the ASCQ codes listed above are defined in
+ * the 29h ASC family, see spc4r17 Table D.1
+ */
+ if (ua_p->ua_asc == 0x29) {
+ if ((asc == 0x29) && (ascq > ua_p->ua_ascq))
+ list_add(&ua->ua_nacl_list,
+ &deve->ua_list);
+ else
+ list_add_tail(&ua->ua_nacl_list,
+ &deve->ua_list);
+ } else if (ua_p->ua_asc == 0x2a) {
+ /*
+ * Incoming Family 29h ASCQ codes will override
+ * Family 2AHh ASCQ codes for Unit Attention condition.
+ */
+ if ((asc == 0x29) || (ascq > ua_p->ua_asc))
+ list_add(&ua->ua_nacl_list,
+ &deve->ua_list);
+ else
+ list_add_tail(&ua->ua_nacl_list,
+ &deve->ua_list);
+ } else
+ list_add_tail(&ua->ua_nacl_list,
+ &deve->ua_list);
+ spin_unlock(&deve->ua_lock);
+
+ return 0;
+ }
+ list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
+ spin_unlock(&deve->ua_lock);
+
+ pr_debug("Allocated UNIT ATTENTION, mapped LUN: %llu, ASC:"
+ " 0x%02x, ASCQ: 0x%02x\n", deve->mapped_lun,
+ asc, ascq);
+
+ return 0;
+}
+
+void target_ua_allocate_lun(struct se_node_acl *nacl,
+ u32 unpacked_lun, u8 asc, u8 ascq)
+{
+ struct se_dev_entry *deve;
+
+ if (!nacl)
+ return;
+
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, unpacked_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ return;
+ }
+
+ core_scsi3_ua_allocate(deve, asc, ascq);
+ rcu_read_unlock();
+}
+
+void core_scsi3_ua_release_all(
+ struct se_dev_entry *deve)
+{
+ struct se_ua *ua, *ua_p;
+
+ spin_lock(&deve->ua_lock);
+ list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
+ list_del(&ua->ua_nacl_list);
+ kmem_cache_free(se_ua_cache, ua);
+ }
+ spin_unlock(&deve->ua_lock);
+}
+
+/*
+ * Dequeue a unit attention from the unit attention list. This function
+ * returns true if the dequeuing succeeded and if *@key, *@asc and *@ascq have
+ * been set.
+ */
+bool core_scsi3_ua_for_check_condition(struct se_cmd *cmd, u8 *key, u8 *asc,
+ u8 *ascq)
+{
+ struct se_device *dev = cmd->se_dev;
+ struct se_dev_entry *deve;
+ struct se_session *sess = cmd->se_sess;
+ struct se_node_acl *nacl;
+ struct se_ua *ua = NULL, *ua_p;
+ int head = 1;
+ bool dev_ua_intlck_clear = (dev->dev_attrib.emulate_ua_intlck_ctrl
+ == TARGET_UA_INTLCK_CTRL_CLEAR);
+
+ if (WARN_ON_ONCE(!sess))
+ return false;
+
+ nacl = sess->se_node_acl;
+ if (WARN_ON_ONCE(!nacl))
+ return false;
+
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ *key = ILLEGAL_REQUEST;
+ *asc = 0x25; /* LOGICAL UNIT NOT SUPPORTED */
+ *ascq = 0;
+ return true;
+ }
+ *key = UNIT_ATTENTION;
+ /*
+ * The highest priority Unit Attentions are placed at the head of the
+ * struct se_dev_entry->ua_list, and will be returned in CHECK_CONDITION +
+ * sense data for the received CDB.
+ */
+ spin_lock(&deve->ua_lock);
+ list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
+ /*
+ * For ua_intlck_ctrl code not equal to 00b, only report the
+ * highest priority UNIT_ATTENTION and ASC/ASCQ without
+ * clearing it.
+ */
+ if (!dev_ua_intlck_clear) {
+ *asc = ua->ua_asc;
+ *ascq = ua->ua_ascq;
+ break;
+ }
+ /*
+ * Otherwise for the default 00b, release the UNIT ATTENTION
+ * condition. Return the ASC/ASCQ of the highest priority UA
+ * (head of the list) in the outgoing CHECK_CONDITION + sense.
+ */
+ if (head) {
+ *asc = ua->ua_asc;
+ *ascq = ua->ua_ascq;
+ head = 0;
+ }
+ list_del(&ua->ua_nacl_list);
+ kmem_cache_free(se_ua_cache, ua);
+ }
+ spin_unlock(&deve->ua_lock);
+ rcu_read_unlock();
+
+ pr_debug("[%s]: %s UNIT ATTENTION condition with"
+ " INTLCK_CTRL: %d, mapped LUN: %llu, got CDB: 0x%02x"
+ " reported ASC: 0x%02x, ASCQ: 0x%02x\n",
+ nacl->se_tpg->se_tpg_tfo->fabric_name,
+ dev_ua_intlck_clear ? "Releasing" : "Reporting",
+ dev->dev_attrib.emulate_ua_intlck_ctrl,
+ cmd->orig_fe_lun, cmd->t_task_cdb[0], *asc, *ascq);
+
+ return head == 0;
+}
+
+int core_scsi3_ua_clear_for_request_sense(
+ struct se_cmd *cmd,
+ u8 *asc,
+ u8 *ascq)
+{
+ struct se_dev_entry *deve;
+ struct se_session *sess = cmd->se_sess;
+ struct se_node_acl *nacl;
+ struct se_ua *ua = NULL, *ua_p;
+ int head = 1;
+
+ if (!sess)
+ return -EINVAL;
+
+ nacl = sess->se_node_acl;
+ if (!nacl)
+ return -EINVAL;
+
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+ if (list_empty_careful(&deve->ua_list)) {
+ rcu_read_unlock();
+ return -EPERM;
+ }
+ /*
+ * The highest priority Unit Attentions are placed at the head of the
+ * struct se_dev_entry->ua_list. The First (and hence highest priority)
+ * ASC/ASCQ will be returned in REQUEST_SENSE payload data for the
+ * matching struct se_lun.
+ *
+ * Once the returning ASC/ASCQ values are set, we go ahead and
+ * release all of the Unit Attention conditions for the associated
+ * struct se_lun.
+ */
+ spin_lock(&deve->ua_lock);
+ list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
+ if (head) {
+ *asc = ua->ua_asc;
+ *ascq = ua->ua_ascq;
+ head = 0;
+ }
+ list_del(&ua->ua_nacl_list);
+ kmem_cache_free(se_ua_cache, ua);
+ }
+ spin_unlock(&deve->ua_lock);
+ rcu_read_unlock();
+
+ pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
+ " LUN: %llu, got REQUEST_SENSE reported ASC: 0x%02x,"
+ " ASCQ: 0x%02x\n", nacl->se_tpg->se_tpg_tfo->fabric_name,
+ cmd->orig_fe_lun, *asc, *ascq);
+
+ return (head) ? -EPERM : 0;
+}
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