These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / target / target_core_tmr.c
index 315ec34..46b1991 100644 (file)
 #include <linux/spinlock.h>
 #include <linux/list.h>
 #include <linux/export.h>
-#include <scsi/scsi.h>
-#include <scsi/scsi_cmnd.h>
 
 #include <target/target_core_base.h>
 #include <target/target_core_backend.h>
 #include <target/target_core_fabric.h>
-#include <target/target_core_configfs.h>
 
 #include "target_core_internal.h"
 #include "target_core_alua.h"
@@ -71,23 +68,25 @@ void core_tmr_release_req(struct se_tmr_req *tmr)
 
        if (dev) {
                spin_lock_irqsave(&dev->se_tmr_lock, flags);
-               list_del(&tmr->tmr_list);
+               list_del_init(&tmr->tmr_list);
                spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
        }
 
        kfree(tmr);
 }
 
-static void core_tmr_handle_tas_abort(
-       struct se_node_acl *tmr_nacl,
-       struct se_cmd *cmd,
-       int tas)
+static void core_tmr_handle_tas_abort(struct se_cmd *cmd, int tas)
 {
-       bool remove = true;
+       unsigned long flags;
+       bool remove = true, send_tas;
        /*
         * TASK ABORTED status (TAS) bit support
         */
-       if ((tmr_nacl && (tmr_nacl != cmd->se_sess->se_node_acl)) && tas) {
+       spin_lock_irqsave(&cmd->t_state_lock, flags);
+       send_tas = (cmd->transport_state & CMD_T_TAS);
+       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+       if (send_tas) {
                remove = false;
                transport_send_task_abort(cmd);
        }
@@ -110,6 +109,46 @@ static int target_check_cdb_and_preempt(struct list_head *list,
        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;
+       }
+       if (sess->sess_tearing_down || se_cmd->cmd_wait_set) {
+               pr_debug("Attempted to abort io tag: %llu already shutdown,"
+                       " 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,
@@ -117,7 +156,7 @@ void core_tmr_abort_task(
 {
        struct se_cmd *se_cmd;
        unsigned long flags;
-       int ref_tag;
+       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) {
@@ -129,42 +168,35 @@ void core_tmr_abort_task(
                if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
                        continue;
 
-               ref_tag = se_cmd->se_tfo->get_task_tag(se_cmd);
+               ref_tag = se_cmd->tag;
                if (tmr->ref_task_tag != ref_tag)
                        continue;
 
-               printk("ABORT_TASK: Found referenced %s task_tag: %u\n",
+               printk("ABORT_TASK: Found referenced %s task_tag: %llu\n",
                        se_cmd->se_tfo->get_fabric_name(), ref_tag);
 
-               spin_lock(&se_cmd->t_state_lock);
-               if (se_cmd->transport_state & CMD_T_COMPLETE) {
-                       printk("ABORT_TASK: ref_tag: %u already complete, skipping\n", ref_tag);
-                       spin_unlock(&se_cmd->t_state_lock);
+               if (!__target_check_io_state(se_cmd, se_sess, 0)) {
                        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
                        goto out;
                }
-               se_cmd->transport_state |= CMD_T_ABORTED;
-               spin_unlock(&se_cmd->t_state_lock);
-
                list_del_init(&se_cmd->se_cmd_list);
-               kref_get(&se_cmd->cmd_kref);
                spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 
                cancel_work_sync(&se_cmd->work);
                transport_wait_for_tasks(se_cmd);
 
-               target_put_sess_cmd(se_sess, se_cmd);
                transport_cmd_finish_abort(se_cmd, true);
+               target_put_sess_cmd(se_cmd);
 
                printk("ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for"
-                               " ref_tag: %d\n", ref_tag);
+                               " ref_tag: %llu\n", ref_tag);
                tmr->response = TMR_FUNCTION_COMPLETE;
                return;
        }
        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 
 out:
-       printk("ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: %d\n",
+       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;
 }
@@ -175,9 +207,11 @@ static void core_tmr_drain_tmr_list(
        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..
@@ -203,17 +237,39 @@ static void core_tmr_drain_tmr_list(
                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);
                spin_lock(&cmd->t_state_lock);
-               if (!(cmd->transport_state & CMD_T_ACTIVE)) {
+               if (!(cmd->transport_state & CMD_T_ACTIVE) ||
+                    (cmd->transport_state & CMD_T_FABRIC_STOP)) {
                        spin_unlock(&cmd->t_state_lock);
+                       spin_unlock(&sess->sess_cmd_lock);
                        continue;
                }
                if (cmd->t_state == TRANSPORT_ISTATE_PROCESSING) {
                        spin_unlock(&cmd->t_state_lock);
+                       spin_unlock(&sess->sess_cmd_lock);
+                       continue;
+               }
+               if (sess->sess_tearing_down || cmd->cmd_wait_set) {
+                       spin_unlock(&cmd->t_state_lock);
+                       spin_unlock(&sess->sess_cmd_lock);
                        continue;
                }
+               cmd->transport_state |= CMD_T_ABORTED;
                spin_unlock(&cmd->t_state_lock);
 
+               rc = kref_get_unless_zero(&cmd->cmd_kref);
+               if (!rc) {
+                       printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
+                       spin_unlock(&sess->sess_cmd_lock);
+                       continue;
+               }
+               spin_unlock(&sess->sess_cmd_lock);
+
                list_move_tail(&tmr_p->tmr_list, &drain_tmr_list);
        }
        spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
@@ -227,20 +283,26 @@ static void core_tmr_drain_tmr_list(
                        (preempt_and_abort_list) ? "Preempt" : "", tmr_p,
                        tmr_p->function, tmr_p->response, cmd->t_state);
 
+               cancel_work_sync(&cmd->work);
+               transport_wait_for_tasks(cmd);
+
                transport_cmd_finish_abort(cmd, 1);
+               target_put_sess_cmd(cmd);
        }
 }
 
 static void core_tmr_drain_state_list(
        struct se_device *dev,
        struct se_cmd *prout_cmd,
-       struct se_node_acl *tmr_nacl,
+       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.
@@ -279,6 +341,16 @@ static void core_tmr_drain_state_list(
                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;
        }
@@ -286,19 +358,19 @@ static void core_tmr_drain_state_list(
 
        while (!list_empty(&drain_task_list)) {
                cmd = list_entry(drain_task_list.next, struct se_cmd, state_list);
-               list_del(&cmd->state_list);
+               list_del_init(&cmd->state_list);
 
                pr_debug("LUN_RESET: %s cmd: %p"
-                       " ITT/CmdSN: 0x%08x/0x%08x, i_state: %d, t_state: %d"
+                       " ITT/CmdSN: 0x%08llx/0x%08x, i_state: %d, t_state: %d"
                        "cdb: 0x%02x\n",
                        (preempt_and_abort_list) ? "Preempt" : "", cmd,
-                       cmd->se_tfo->get_task_tag(cmd), 0,
+                       cmd->tag, 0,
                        cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
                        cmd->t_task_cdb[0]);
-               pr_debug("LUN_RESET: ITT[0x%08x] - pr_res_key: 0x%016Lx"
+               pr_debug("LUN_RESET: ITT[0x%08llx] - pr_res_key: 0x%016Lx"
                        " -- CMD_T_ACTIVE: %d"
                        " CMD_T_STOP: %d CMD_T_SENT: %d\n",
-                       cmd->se_tfo->get_task_tag(cmd), cmd->pr_res_key,
+                       cmd->tag, cmd->pr_res_key,
                        (cmd->transport_state & CMD_T_ACTIVE) != 0,
                        (cmd->transport_state & CMD_T_STOP) != 0,
                        (cmd->transport_state & CMD_T_SENT) != 0);
@@ -310,16 +382,11 @@ static void core_tmr_drain_state_list(
                 * loop above, but we do it down here given that
                 * cancel_work_sync may block.
                 */
-               if (cmd->t_state == TRANSPORT_COMPLETE)
-                       cancel_work_sync(&cmd->work);
-
-               spin_lock_irqsave(&cmd->t_state_lock, flags);
-               target_stop_cmd(cmd, &flags);
-
-               cmd->transport_state |= CMD_T_ABORTED;
-               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+               cancel_work_sync(&cmd->work);
+               transport_wait_for_tasks(cmd);
 
-               core_tmr_handle_tas_abort(tmr_nacl, cmd, tas);
+               core_tmr_handle_tas_abort(cmd, tas);
+               target_put_sess_cmd(cmd);
        }
 }
 
@@ -331,6 +398,7 @@ int core_tmr_lun_reset(
 {
        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
@@ -349,8 +417,9 @@ int core_tmr_lun_reset(
         * 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;
+               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",
@@ -363,7 +432,7 @@ int core_tmr_lun_reset(
                dev->transport->name, tas);
 
        core_tmr_drain_tmr_list(dev, tmr, preempt_and_abort_list);
-       core_tmr_drain_state_list(dev, prout_cmd, tmr_nacl, tas,
+       core_tmr_drain_state_list(dev, prout_cmd, tmr_sess, tas,
                                preempt_and_abort_list);
 
        /*