FS-Cache: Fix lock misorder in fscache_write_op()
[safe/jmp/linux-2.6] / drivers / scsi / scsi_error.c
index 39ce3ab..1b0060b 100644 (file)
@@ -112,69 +112,8 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
 }
 
 /**
- * scsi_add_timer - Start timeout timer for a single scsi command.
- * @scmd:      scsi command that is about to start running.
- * @timeout:   amount of time to allow this command to run.
- * @complete:  timeout function to call if timer isn't canceled.
- *
- * Notes:
- *    This should be turned into an inline function.  Each scsi command
- *    has its own timer, and as it is added to the queue, we set up the
- *    timer.  When the command completes, we cancel the timer.
- */
-void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
-                   void (*complete)(struct scsi_cmnd *))
-{
-
-       /*
-        * If the clock was already running for this command, then
-        * first delete the timer.  The timer handling code gets rather
-        * confused if we don't do this.
-        */
-       if (scmd->eh_timeout.function)
-               del_timer(&scmd->eh_timeout);
-
-       scmd->eh_timeout.data = (unsigned long)scmd;
-       scmd->eh_timeout.expires = jiffies + timeout;
-       scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
-
-       SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
-                                         " %d, (%p)\n", __func__,
-                                         scmd, timeout, complete));
-
-       add_timer(&scmd->eh_timeout);
-}
-
-/**
- * scsi_delete_timer - Delete/cancel timer for a given function.
- * @scmd:      Cmd that we are canceling timer for
- *
- * Notes:
- *     This should be turned into an inline function.
- *
- * Return value:
- *     1 if we were able to detach the timer.  0 if we blew it, and the
- *     timer function has already started to run.
- */
-int scsi_delete_timer(struct scsi_cmnd *scmd)
-{
-       int rtn;
-
-       rtn = del_timer(&scmd->eh_timeout);
-
-       SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
-                                        " rtn: %d\n", __func__,
-                                        scmd, rtn));
-
-       scmd->eh_timeout.data = (unsigned long)NULL;
-       scmd->eh_timeout.function = NULL;
-
-       return rtn;
-}
-
-/**
  * scsi_times_out - Timeout function for normal scsi commands.
- * @scmd:      Cmd that is timing out.
+ * @req:       request that is timing out.
  *
  * Notes:
  *     We do not need to lock this.  There is the potential for a race
@@ -182,36 +121,25 @@ int scsi_delete_timer(struct scsi_cmnd *scmd)
  *     normal completion function determines that the timer has already
  *     fired, then it mustn't do anything.
  */
-void scsi_times_out(struct scsi_cmnd *scmd)
+enum blk_eh_timer_return scsi_times_out(struct request *req)
 {
-       enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+       struct scsi_cmnd *scmd = req->special;
+       enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
 
        scsi_log_completion(scmd, TIMEOUT_ERROR);
 
        if (scmd->device->host->transportt->eh_timed_out)
-               eh_timed_out = scmd->device->host->transportt->eh_timed_out;
+               rtn = scmd->device->host->transportt->eh_timed_out(scmd);
        else if (scmd->device->host->hostt->eh_timed_out)
-               eh_timed_out = scmd->device->host->hostt->eh_timed_out;
-       else
-               eh_timed_out = NULL;
-
-       if (eh_timed_out)
-               switch (eh_timed_out(scmd)) {
-               case EH_HANDLED:
-                       __scsi_done(scmd);
-                       return;
-               case EH_RESET_TIMER:
-                       scsi_add_timer(scmd, scmd->timeout_per_command,
-                                      scsi_times_out);
-                       return;
-               case EH_NOT_HANDLED:
-                       break;
-               }
+               rtn = scmd->device->host->hostt->eh_timed_out(scmd);
 
-       if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
+       if (unlikely(rtn == BLK_EH_NOT_HANDLED &&
+                    !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
                scmd->result |= DID_TIME_OUT << 16;
-               __scsi_done(scmd);
+               rtn = BLK_EH_HANDLED;
        }
+
+       return rtn;
 }
 
 /**
@@ -454,9 +382,13 @@ static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
                 * who knows?  FIXME(eric)
                 */
                return SUCCESS;
+       case RESERVATION_CONFLICT:
+               /*
+                * let issuer deal with this, it could be just fine
+                */
+               return SUCCESS;
        case BUSY:
        case QUEUE_FULL:
-       case RESERVATION_CONFLICT:
        default:
                return FAILED;
        }
@@ -713,9 +645,9 @@ EXPORT_SYMBOL(scsi_eh_prep_cmnd);
 /**
  * scsi_eh_restore_cmnd  - Restore a scsi command info as part of error recory
  * @scmd:       SCSI command structure to restore
- * @ses:        saved information from a coresponding call to scsi_prep_eh_cmnd
+ * @ses:        saved information from a coresponding call to scsi_eh_prep_cmnd
  *
- * Undo any damage done by above scsi_prep_eh_cmnd().
+ * Undo any damage done by above scsi_eh_prep_cmnd().
  */
 void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
 {
@@ -793,6 +725,9 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
                case NEEDS_RETRY:
                case FAILED:
                        break;
+               case ADD_TO_MLQUEUE:
+                       rtn = NEEDS_RETRY;
+                       break;
                default:
                        rtn = FAILED;
                        break;
@@ -993,8 +928,7 @@ static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
                int i, rtn = NEEDS_RETRY;
 
                for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
-                       rtn = scsi_send_eh_cmnd(scmd, stu_command, 6,
-                                               scmd->device->timeout, 0);
+                       rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
 
                if (rtn == SUCCESS)
                        return 0;
@@ -1126,10 +1060,10 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
                                struct list_head *done_q)
 {
        struct scsi_cmnd *scmd, *tgtr_scmd, *next;
-       unsigned int id;
+       unsigned int id = 0;
        int rtn;
 
-       for (id = 0; id <= shost->max_id; id++) {
+       do {
                tgtr_scmd = NULL;
                list_for_each_entry(scmd, work_q, eh_entry) {
                        if (id == scmd_id(scmd)) {
@@ -1137,8 +1071,18 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
                                break;
                        }
                }
+               if (!tgtr_scmd) {
+                       /* not one exactly equal; find the next highest */
+                       list_for_each_entry(scmd, work_q, eh_entry) {
+                               if (scmd_id(scmd) > id &&
+                                   (!tgtr_scmd ||
+                                    scmd_id(tgtr_scmd) > scmd_id(scmd)))
+                                               tgtr_scmd = scmd;
+                       }
+               }
                if (!tgtr_scmd)
-                       continue;
+                       /* no more commands, that's it */
+                       break;
 
                SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "
                                                  "to target %d\n",
@@ -1157,7 +1101,8 @@ static int scsi_eh_target_reset(struct Scsi_Host *shost,
                                                          " failed target: "
                                                          "%d\n",
                                                          current->comm, id));
-       }
+               id++;
+       } while(id != 0);
 
        return list_empty(work_q);
 }
@@ -1280,6 +1225,40 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
 }
 
 /**
+ * scsi_noretry_cmd - determinte if command should be failed fast
+ * @scmd:      SCSI cmd to examine.
+ */
+int scsi_noretry_cmd(struct scsi_cmnd *scmd)
+{
+       switch (host_byte(scmd->result)) {
+       case DID_OK:
+               break;
+       case DID_BUS_BUSY:
+               return blk_failfast_transport(scmd->request);
+       case DID_PARITY:
+               return blk_failfast_dev(scmd->request);
+       case DID_ERROR:
+               if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
+                   status_byte(scmd->result) == RESERVATION_CONFLICT)
+                       return 0;
+               /* fall through */
+       case DID_SOFT_ERROR:
+               return blk_failfast_driver(scmd->request);
+       }
+
+       switch (status_byte(scmd->result)) {
+       case CHECK_CONDITION:
+               /*
+                * assume caller has checked sense and determinted
+                * the check condition was retryable.
+                */
+               return blk_failfast_dev(scmd->request);
+       }
+
+       return 0;
+}
+
+/**
  * scsi_decide_disposition - Disposition a cmd on return from LLD.
  * @scmd:      SCSI cmd to examine.
  *
@@ -1351,7 +1330,21 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
 
        case DID_REQUEUE:
                return ADD_TO_MLQUEUE;
-
+       case DID_TRANSPORT_DISRUPTED:
+               /*
+                * LLD/transport was disrupted during processing of the IO.
+                * The transport class is now blocked/blocking,
+                * and the transport will decide what to do with the IO
+                * based on its timers and recovery capablilities if
+                * there are enough retries.
+                */
+               goto maybe_retry;
+       case DID_TRANSPORT_FAILFAST:
+               /*
+                * The transport decided to failfast the IO (most likely
+                * the fast io fail tmo fired), so send IO directly upwards.
+                */
+               return SUCCESS;
        case DID_ERROR:
                if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
                    status_byte(scmd->result) == RESERVATION_CONFLICT)
@@ -1408,8 +1401,9 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
                return ADD_TO_MLQUEUE;
        case GOOD:
        case COMMAND_TERMINATED:
-       case TASK_ABORTED:
                return SUCCESS;
+       case TASK_ABORTED:
+               goto maybe_retry;
        case CHECK_CONDITION:
                rtn = scsi_check_sense(scmd);
                if (rtn == NEEDS_RETRY)
@@ -1444,7 +1438,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
         * even if the request is marked fast fail, we still requeue
         * for queue congestion conditions (QUEUE_FULL or BUSY) */
        if ((++scmd->retries) <= scmd->allowed
-           && !blk_noretry_request(scmd->request)) {
+           && !scsi_noretry_cmd(scmd)) {
                return NEEDS_RETRY;
        } else {
                /*
@@ -1454,41 +1448,48 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
        }
 }
 
+static void eh_lock_door_done(struct request *req, int uptodate)
+{
+       __blk_put_request(req->q, req);
+}
+
 /**
  * scsi_eh_lock_door - Prevent medium removal for the specified device
  * @sdev:      SCSI device to prevent medium removal
  *
  * Locking:
- *     We must be called from process context; scsi_allocate_request()
- *     may sleep.
+ *     We must be called from process context.
  *
  * Notes:
  *     We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
  *     head of the devices request queue, and continue.
- *
- * Bugs:
- *     scsi_allocate_request() may sleep waiting for existing requests to
- *     be processed.  However, since we haven't kicked off any request
- *     processing for this host, this may deadlock.
- *
- *     If scsi_allocate_request() fails for what ever reason, we
- *     completely forget to lock the door.
  */
 static void scsi_eh_lock_door(struct scsi_device *sdev)
 {
-       unsigned char cmnd[MAX_COMMAND_SIZE];
+       struct request *req;
 
-       cmnd[0] = ALLOW_MEDIUM_REMOVAL;
-       cmnd[1] = 0;
-       cmnd[2] = 0;
-       cmnd[3] = 0;
-       cmnd[4] = SCSI_REMOVAL_PREVENT;
-       cmnd[5] = 0;
+       /*
+        * blk_get_request with GFP_KERNEL (__GFP_WAIT) sleeps until a
+        * request becomes available
+        */
+       req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
 
-       scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
-                          5, NULL, NULL, GFP_KERNEL);
-}
+       req->cmd[0] = ALLOW_MEDIUM_REMOVAL;
+       req->cmd[1] = 0;
+       req->cmd[2] = 0;
+       req->cmd[3] = 0;
+       req->cmd[4] = SCSI_REMOVAL_PREVENT;
+       req->cmd[5] = 0;
+
+       req->cmd_len = COMMAND_SIZE(req->cmd[0]);
 
+       req->cmd_type = REQ_TYPE_BLOCK_PC;
+       req->cmd_flags |= REQ_QUIET;
+       req->timeout = 10 * HZ;
+       req->retries = 5;
+
+       blk_execute_rq_nowait(req->q, NULL, req, 1, eh_lock_door_done);
+}
 
 /**
  * scsi_restart_operations - restart io operations to the specified host.
@@ -1569,7 +1570,7 @@ void scsi_eh_flush_done_q(struct list_head *done_q)
        list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
                list_del_init(&scmd->eh_entry);
                if (scsi_device_online(scmd->device) &&
-                   !blk_noretry_request(scmd->request) &&
+                   !scsi_noretry_cmd(scmd) &&
                    (++scmd->retries <= scmd->allowed)) {
                        SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
                                                          " retry cmd: %p\n",
@@ -1651,7 +1652,7 @@ int scsi_error_handler(void *data)
         * We use TASK_INTERRUPTIBLE so that the thread is not
         * counted against the load average as a running process.
         * We never actually get interrupted because kthread_run
-        * disables singal delivery for the created thread.
+        * disables signal delivery for the created thread.
         */
        set_current_state(TASK_INTERRUPTIBLE);
        while (!kthread_should_stop()) {
@@ -1793,7 +1794,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
 
        blk_rq_init(NULL, &req);
        scmd->request = &req;
-       memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
 
        scmd->cmnd = req.cmd;
 
@@ -1804,8 +1804,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
 
        scmd->sc_data_direction         = DMA_BIDIRECTIONAL;
 
-       init_timer(&scmd->eh_timeout);
-
        spin_lock_irqsave(shost->host_lock, flags);
        shost->tmf_in_progress = 1;
        spin_unlock_irqrestore(shost->host_lock, flags);