[PATCH 08/14] libata-hp-prep: add ata_hotplug_wq

[Tejun Heo <htejun@gmail.com>]

It's best to run ATA hotplug from EH but attaching SCSI devices needs
working EH.  ata_hotplug_wq is used to give SCSI hotplug operations a
separate context.

---

 drivers/scsi/libata-core.c |    9 +++++++++
 drivers/scsi/libata.h      |    1 +
 2 files changed, 10 insertions(+), 0 deletions(-)

60b0f9061e9ce6345e549a38d73f4759daae0339
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 6da1005..1f587aa 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -69,6 +69,8 @@ static void ata_dev_xfermask(struct ata_
 static unsigned int ata_unique_id = 1;
 static struct workqueue_struct *ata_wq;
 
+struct workqueue_struct *ata_hotplug_wq;
+
 int atapi_enabled = 1;
 module_param(atapi_enabled, int, 0444);
 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
@@ -5588,6 +5590,12 @@ static int __init ata_init(void)
 	if (!ata_wq)
 		return -ENOMEM;
 
+	ata_hotplug_wq = create_singlethread_workqueue("ata_hotplug");
+	if (!ata_hotplug_wq) {
+		destroy_workqueue(ata_wq);
+		return -ENOMEM;
+	}
+
 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
 	return 0;
 }
@@ -5595,6 +5603,7 @@ static int __init ata_init(void)
 static void __exit ata_exit(void)
 {
 	destroy_workqueue(ata_wq);
+	destroy_workqueue(ata_hotplug_wq);
 }
 
 module_init(ata_init);
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index 134cb4d..ff50442 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -39,6 +39,7 @@ struct ata_scsi_args {
 };
 
 /* libata-core.c */
+extern struct workqueue_struct *ata_hotplug_wq;
 extern int atapi_enabled;
 extern int atapi_dmadir;
 extern int libata_fua;
-- 
1.2.4