6 files changed, 167 insertions, 14 deletions

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index f2c5005f312a..c3ab093dd8a7 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -169,6 +169,7 @@ void scsi_remove_host(struct Scsi_Host *shost)
         spin_unlock_irqrestore(shost->host_lock, flags);
 
         scsi_autopm_get_host(shost);
+        flush_workqueue(shost->tmf_work_q);
         scsi_forget_host(shost);
         mutex_unlock(&shost->scan_mutex);
         scsi_proc_host_rm(shost);
@@ -294,6 +295,8 @@ static void scsi_host_dev_release(struct device *dev)
 
         scsi_proc_hostdir_rm(shost->hostt);
 
+        if (shost->tmf_work_q)
+                destroy_workqueue(shost->tmf_work_q);
         if (shost->ehandler)
                 kthread_stop(shost->ehandler);
         if (shost->work_q)
@@ -360,7 +363,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
         INIT_LIST_HEAD(&shost->eh_cmd_q);
         INIT_LIST_HEAD(&shost->starved_list);
         init_waitqueue_head(&shost->host_wait);
-
         mutex_init(&shost->scan_mutex);
 
         /*
@@ -444,9 +446,19 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
                 goto fail_kfree;
         }
 
+        shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
+                                            WQ_UNBOUND | WQ_MEM_RECLAIM,
+                                           1, shost->host_no);
+        if (!shost->tmf_work_q) {
+                printk(KERN_WARNING "scsi%d: failed to create tmf workq\n",
+                       shost->host_no);
+                goto fail_kthread;
+        }
         scsi_proc_hostdir_add(shost->hostt);
         return shost;
 
+ fail_kthread:
+        kthread_stop(shost->ehandler);
  fail_kfree:
         kfree(shost);
         return NULL;
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index fe0bcb18fb26..2b04a57e0f4f 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -297,6 +297,7 @@ struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
 
                 cmd->device = dev;
                 INIT_LIST_HEAD(&cmd->list);
+                INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
                 spin_lock_irqsave(&dev->list_lock, flags);
                 list_add_tail(&cmd->list, &dev->cmd_list);
                 spin_unlock_irqrestore(&dev->list_lock, flags);
@@ -353,6 +354,8 @@ void scsi_put_command(struct scsi_cmnd *cmd)
         list_del_init(&cmd->list);
         spin_unlock_irqrestore(&cmd->device->list_lock, flags);
 
+        cancel_delayed_work(&cmd->abort_work);
+
         __scsi_put_command(cmd->device->host, cmd, &sdev->sdev_gendev);
 }
 EXPORT_SYMBOL(scsi_put_command);
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 67c001457cb8..3dd04026d466 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -53,6 +53,8 @@ static void scsi_eh_done(struct scsi_cmnd *scmd);
 #define HOST_RESET_SETTLE_TIME  (10)
 
 static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
+static int scsi_try_to_abort_cmd(struct scsi_host_template *,
+                                 struct scsi_cmnd *);
 
 /* called with shost->host_lock held */
 void scsi_eh_wakeup(struct Scsi_Host *shost)
@@ -100,6 +102,116 @@ static int scsi_host_eh_past_deadline(struct Scsi_Host *shost)
 }
 
 /**
+ * scmd_eh_abort_handler - Handle command aborts
+ * @work:       command to be aborted.
+ */
+void
+scmd_eh_abort_handler(struct work_struct *work)
+{
+        struct scsi_cmnd *scmd =
+                container_of(work, struct scsi_cmnd, abort_work.work);
+        struct scsi_device *sdev = scmd->device;
+        unsigned long flags;
+        int rtn;
+
+        spin_lock_irqsave(sdev->host->host_lock, flags);
+        if (scsi_host_eh_past_deadline(sdev->host)) {
+                spin_unlock_irqrestore(sdev->host->host_lock, flags);
+                SCSI_LOG_ERROR_RECOVERY(3,
+                        scmd_printk(KERN_INFO, scmd,
+                                    "scmd %p eh timeout, not aborting\n",
+                                    scmd));
+        } else {
+                spin_unlock_irqrestore(sdev->host->host_lock, flags);
+                SCSI_LOG_ERROR_RECOVERY(3,
+                        scmd_printk(KERN_INFO, scmd,
+                                    "aborting command %p\n", scmd));
+                rtn = scsi_try_to_abort_cmd(sdev->host->hostt, scmd);
+                if (rtn == SUCCESS) {
+                        scmd->result |= DID_TIME_OUT << 16;
+                        if (!scsi_noretry_cmd(scmd) &&
+                            (++scmd->retries <= scmd->allowed)) {
+                                SCSI_LOG_ERROR_RECOVERY(3,
+                                        scmd_printk(KERN_WARNING, scmd,
+                                                    "scmd %p retry "
+                                                    "aborted command\n", scmd));
+                                scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
+                        } else {
+                                SCSI_LOG_ERROR_RECOVERY(3,
+                                        scmd_printk(KERN_WARNING, scmd,
+                                                    "scmd %p finish "
+                                                    "aborted command\n", scmd));
+                                scsi_finish_command(scmd);
+                        }
+                        return;
+                }
+                SCSI_LOG_ERROR_RECOVERY(3,
+                        scmd_printk(KERN_INFO, scmd,
+                                    "scmd %p abort failed, rtn %d\n",
+                                    scmd, rtn));
+        }
+
+        if (!scsi_eh_scmd_add(scmd, 0)) {
+                SCSI_LOG_ERROR_RECOVERY(3,
+                        scmd_printk(KERN_WARNING, scmd,
+                                    "scmd %p terminate "
+                                    "aborted command\n", scmd));
+                scmd->result |= DID_TIME_OUT << 16;
+                scsi_finish_command(scmd);
+        }
+}
+
+/**
+ * scsi_abort_command - schedule a command abort
+ * @scmd:       scmd to abort.
+ *
+ * We only need to abort commands after a command timeout
+ */
+static int
+scsi_abort_command(struct scsi_cmnd *scmd)
+{
+        struct scsi_device *sdev = scmd->device;
+        struct Scsi_Host *shost = sdev->host;
+        unsigned long flags;
+
+        if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
+                /*
+                 * Retry after abort failed, escalate to next level.
+                 */
+                SCSI_LOG_ERROR_RECOVERY(3,
+                        scmd_printk(KERN_INFO, scmd,
+                                    "scmd %p previous abort failed\n", scmd));
+                cancel_delayed_work(&scmd->abort_work);
+                return FAILED;
+        }
+
+        /*
+         * Do not try a command abort if
+         * SCSI EH has already started.
+         */
+        spin_lock_irqsave(shost->host_lock, flags);
+        if (scsi_host_in_recovery(shost)) {
+                spin_unlock_irqrestore(shost->host_lock, flags);
+                SCSI_LOG_ERROR_RECOVERY(3,
+                        scmd_printk(KERN_INFO, scmd,
+                                    "scmd %p not aborting, host in recovery\n",
+                                    scmd));
+                return FAILED;
+        }
+
+        if (shost->eh_deadline && !shost->last_reset)
+                shost->last_reset = jiffies;
+        spin_unlock_irqrestore(shost->host_lock, flags);
+
+        scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED;
+        SCSI_LOG_ERROR_RECOVERY(3,
+                scmd_printk(KERN_INFO, scmd,
+                            "scmd %p abort scheduled\n", scmd));
+        queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100);
+        return SUCCESS;
+}
+
+/**
  * scsi_eh_scmd_add - add scsi cmd to error handling.
  * @scmd:       scmd to run eh on.
  * @eh_flag:    optional SCSI_EH flag.
@@ -125,6 +237,8 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
                 shost->last_reset = jiffies;
 
         ret = 1;
+        if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
+                eh_flag &= ~SCSI_EH_CANCEL_CMD;
         scmd->eh_eflags |= eh_flag;
         list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
         shost->host_failed++;
@@ -161,6 +275,10 @@ enum blk_eh_timer_return scsi_times_out(struct request *req)
         else if (host->hostt->eh_timed_out)
                 rtn = host->hostt->eh_timed_out(scmd);
 
+        if (rtn == BLK_EH_NOT_HANDLED && !host->hostt->no_async_abort)
+                if (scsi_abort_command(scmd) == SUCCESS)
+                        return BLK_EH_NOT_HANDLED;
+
         scmd->result |= DID_TIME_OUT << 16;
 
         if (unlikely(rtn == BLK_EH_NOT_HANDLED &&
@@ -1577,7 +1695,7 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
 }
 
 /**
- * scsi_noretry_cmd - determinte if command should be failed fast
+ * scsi_noretry_cmd - determine if command should be failed fast
  * @scmd:       SCSI cmd to examine.
  */
 int scsi_noretry_cmd(struct scsi_cmnd *scmd)
@@ -1585,6 +1703,8 @@ int scsi_noretry_cmd(struct scsi_cmnd *scmd)
         switch (host_byte(scmd->result)) {
         case DID_OK:
                 break;
+        case DID_TIME_OUT:
+                goto check_type;
         case DID_BUS_BUSY:
                 return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
         case DID_PARITY:
@@ -1598,18 +1718,19 @@ int scsi_noretry_cmd(struct scsi_cmnd *scmd)
                 return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
         }
 
-        switch (status_byte(scmd->result)) {
-        case CHECK_CONDITION:
-                /*
-                 * assume caller has checked sense and determinted
-                 * the check condition was retryable.
-                 */
-                if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
-                    scmd->request->cmd_type == REQ_TYPE_BLOCK_PC)
-                        return 1;
-        }
+        if (status_byte(scmd->result) != CHECK_CONDITION)
+                return 0;
 
-        return 0;
+check_type:
+        /*
+         * assume caller has checked sense and determined
+         * the check condition was retryable.
+         */
+        if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
+            scmd->request->cmd_type == REQ_TYPE_BLOCK_PC)
+                return 1;
+        else
+                return 0;
 }
 
 /**
@@ -1659,9 +1780,13 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
                  * looks good.  drop through, and check the next byte.
                  */
                 break;
+        case DID_ABORT:
+                if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
+                        scmd->result |= DID_TIME_OUT << 16;
+                        return SUCCESS;
+                }
         case DID_NO_CONNECT:
         case DID_BAD_TARGET:
-        case DID_ABORT:
                 /*
                  * note - this means that we just report the status back
                  * to the top level driver, not that we actually think
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 8f9a0cadc296..f079a598bed4 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -19,6 +19,7 @@ struct scsi_nl_hdr;
  * Scsi Error Handler Flags
  */
 #define SCSI_EH_CANCEL_CMD      0x0001  /* Cancel this cmd */
+#define SCSI_EH_ABORT_SCHEDULED 0x0002  /* Abort has been scheduled */
 
 #define SCSI_SENSE_VALID(scmd) \
         (((scmd)->sense_buffer[0] & 0x70) == 0x70)
@@ -66,6 +67,7 @@ extern int __init scsi_init_devinfo(void);
 extern void scsi_exit_devinfo(void);
 
 /* scsi_error.c */
+extern void scmd_eh_abort_handler(struct work_struct *work);
 extern enum blk_eh_timer_return scsi_times_out(struct request *req);
 extern int scsi_error_handler(void *host);
 extern int scsi_decide_disposition(struct scsi_cmnd *cmd);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index de5f5d8f1f8a..91558a1f97f4 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -55,6 +55,7 @@ struct scsi_cmnd {
         struct scsi_device *device;
         struct list_head list;  /* scsi_cmnd participates in queue lists */
         struct list_head eh_entry; /* entry for the host eh_cmd_q */
+        struct delayed_work abort_work;
         int eh_eflags;          /* Used by error handlr */
 
         /*
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index fe3b58e836c8..53075e5039e6 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -479,6 +479,11 @@ struct scsi_host_template {
         unsigned no_write_same:1;
 
         /*
+         * True if asynchronous aborts are not supported
+         */
+        unsigned no_async_abort:1;
+
+        /*
          * Countdown for host blocking with no commands outstanding.
          */
         unsigned int max_host_blocked;
@@ -690,6 +695,11 @@ struct Scsi_Host {
         struct workqueue_struct *work_q;
 
         /*
+         * Task management function work queue
+         */
+        struct workqueue_struct *tmf_work_q;
+
+        /*
          * Host has rejected a command because it was busy.
          */
         unsigned int host_blocked;