scsi: Only add commands to the device command list if required by the LLD

Just like for the scsi-mq code path, in the single queue SCSI code path
only add commands to the per-device command list if required by the SCSI
LLD. This patch will make it easier to merge the single-queue and
multiqueue command initialization code.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 61cdd99..1bf274e 100644 (file)
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -108,14 +108,7 @@ EXPORT_SYMBOL(scsi_sd_pm_domain);
  */
 void scsi_put_command(struct scsi_cmnd *cmd)
 {
-       unsigned long flags;
-
-       /* serious error if the command hasn't come from a device list */
-       spin_lock_irqsave(&cmd->device->list_lock, flags);
-       BUG_ON(list_empty(&cmd->list));
-       list_del_init(&cmd->list);
-       spin_unlock_irqrestore(&cmd->device->list_lock, flags);
-
+       scsi_del_cmd_from_list(cmd);
        BUG_ON(delayed_work_pending(&cmd->abort_work));
 }
 

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 0554a6a..1470c93 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -584,19 +584,9 @@ static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
 
 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
 {
-       struct scsi_device *sdev = cmd->device;
-       struct Scsi_Host *shost = sdev->host;
-       unsigned long flags;
-
        scsi_mq_free_sgtables(cmd);
        scsi_uninit_cmd(cmd);
-
-       if (shost->use_cmd_list) {
-               BUG_ON(list_empty(&cmd->list));
-               spin_lock_irqsave(&sdev->list_lock, flags);
-               list_del_init(&cmd->list);
-               spin_unlock_irqrestore(&sdev->list_lock, flags);
-       }
+       scsi_del_cmd_from_list(cmd);
 }
 
 /*
@@ -1134,12 +1124,40 @@ err_exit:
 }
 EXPORT_SYMBOL(scsi_init_io);
 
+/* Add a command to the list used by the aacraid and dpt_i2o drivers */
+void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
+{
+       struct scsi_device *sdev = cmd->device;
+       struct Scsi_Host *shost = sdev->host;
+       unsigned long flags;
+
+       if (shost->use_cmd_list) {
+               spin_lock_irqsave(&sdev->list_lock, flags);
+               list_add_tail(&cmd->list, &sdev->cmd_list);
+               spin_unlock_irqrestore(&sdev->list_lock, flags);
+       }
+}
+
+/* Remove a command from the list used by the aacraid and dpt_i2o drivers */
+void scsi_del_cmd_from_list(struct scsi_cmnd *cmd)
+{
+       struct scsi_device *sdev = cmd->device;
+       struct Scsi_Host *shost = sdev->host;
+       unsigned long flags;
+
+       if (shost->use_cmd_list) {
+               spin_lock_irqsave(&sdev->list_lock, flags);
+               BUG_ON(list_empty(&cmd->list));
+               list_del_init(&cmd->list);
+               spin_unlock_irqrestore(&sdev->list_lock, flags);
+       }
+}
+
 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 {
        void *buf = cmd->sense_buffer;
        void *prot = cmd->prot_sdb;
        unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
-       unsigned long flags;
 
        /* zero out the cmd, except for the embedded scsi_request */
        memset((char *)cmd + sizeof(cmd->req), 0,
@@ -1152,9 +1170,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
        INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
        cmd->jiffies_at_alloc = jiffies;
 
-       spin_lock_irqsave(&dev->list_lock, flags);
-       list_add_tail(&cmd->list, &dev->cmd_list);
-       spin_unlock_irqrestore(&dev->list_lock, flags);
+       scsi_add_cmd_to_list(cmd);
 }
 
 static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
@@ -1871,11 +1887,7 @@ static int scsi_mq_prep_fn(struct request *req)
        INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
        cmd->jiffies_at_alloc = jiffies;
 
-       if (shost->use_cmd_list) {
-               spin_lock_irq(&sdev->list_lock);
-               list_add_tail(&cmd->list, &sdev->cmd_list);
-               spin_unlock_irq(&sdev->list_lock);
-       }
+       scsi_add_cmd_to_list(cmd);
 
        sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
        cmd->sdb.table.sgl = sg;

diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index f860578..c11c1f9 100644 (file)
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -80,6 +80,8 @@ int scsi_eh_get_sense(struct list_head *work_q,
 int scsi_noretry_cmd(struct scsi_cmnd *scmd);
 
 /* scsi_lib.c */
+extern void scsi_add_cmd_to_list(struct scsi_cmnd *cmd);
+extern void scsi_del_cmd_from_list(struct scsi_cmnd *cmd);
 extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
 extern void scsi_device_unbusy(struct scsi_device *sdev);
 extern void scsi_queue_insert(struct scsi_cmnd *cmd, int reason);