[PATCH 1/2] scsi_dh: Return SCSI_DH_XX error code from ->attach()

[Hannes Reinecke <hare@xxxxxxx>]

Rather than having each device handler implementing their own
error mapping have the ->attach() call return a SCSI_DH_XXX
error code and implement the mapping in scsi_dh_handler_attach().

Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
---
 drivers/scsi/device_handler/scsi_dh_alua.c  | 10 ++++------
 drivers/scsi/device_handler/scsi_dh_emc.c   |  6 +++---
 drivers/scsi/device_handler/scsi_dh_hp_sw.c | 12 ++++++++----
 drivers/scsi/device_handler/scsi_dh_rdac.c  |  6 +++---
 drivers/scsi/scsi_dh.c                      | 17 ++++++++++++++---
 5 files changed, 32 insertions(+), 19 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 0962fd544401..fd22dc6ab5d9 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -1085,11 +1085,11 @@ static void alua_rescan(struct scsi_device *sdev)
 static int alua_bus_attach(struct scsi_device *sdev)
 {
 	struct alua_dh_data *h;
-	int err, ret = -EINVAL;
+	int err;
 
 	h = kzalloc(sizeof(*h) , GFP_KERNEL);
 	if (!h)
-		return -ENOMEM;
+		return SCSI_DH_NOMEM;
 	spin_lock_init(&h->pg_lock);
 	rcu_assign_pointer(h->pg, NULL);
 	h->init_error = SCSI_DH_OK;
@@ -1098,16 +1098,14 @@ static int alua_bus_attach(struct scsi_device *sdev)
 
 	mutex_init(&h->init_mutex);
 	err = alua_initialize(sdev, h);
-	if (err == SCSI_DH_NOMEM)
-		ret = -ENOMEM;
 	if (err != SCSI_DH_OK && err != SCSI_DH_DEV_OFFLINED)
 		goto failed;
 
 	sdev->handler_data = h;
-	return 0;
+	return SCSI_DH_OK;
 failed:
 	kfree(h);
-	return ret;
+	return err;
 }
 
 /*
diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index 8654e940e1a8..6a2792f3a37e 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -490,7 +490,7 @@ static int clariion_bus_attach(struct scsi_device *sdev)
 
 	h = kzalloc(sizeof(*h) , GFP_KERNEL);
 	if (!h)
-		return -ENOMEM;
+		return SCSI_DH_NOMEM;
 	h->lun_state = CLARIION_LUN_UNINITIALIZED;
 	h->default_sp = CLARIION_UNBOUND_LU;
 	h->current_sp = CLARIION_UNBOUND_LU;
@@ -510,11 +510,11 @@ static int clariion_bus_attach(struct scsi_device *sdev)
 		    h->default_sp + 'A');
 
 	sdev->handler_data = h;
-	return 0;
+	return SCSI_DH_OK;
 
 failed:
 	kfree(h);
-	return -EINVAL;
+	return err;
 }
 
 static void clariion_bus_detach(struct scsi_device *sdev)
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index 62d314e07d11..e65a0ebb4b54 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -218,24 +218,28 @@ static int hp_sw_bus_attach(struct scsi_device *sdev)
 
 	h = kzalloc(sizeof(*h), GFP_KERNEL);
 	if (!h)
-		return -ENOMEM;
+		return SCSI_DH_NOMEM;
 	h->path_state = HP_SW_PATH_UNINITIALIZED;
 	h->retries = HP_SW_RETRIES;
 	h->sdev = sdev;
 
 	ret = hp_sw_tur(sdev, h);
-	if (ret != SCSI_DH_OK || h->path_state == HP_SW_PATH_UNINITIALIZED)
+	if (ret != SCSI_DH_OK)
 		goto failed;
+	if (h->path_state == HP_SW_PATH_UNINITIALIZED) {
+		ret = SCSI_DH_NOSYS;
+		goto failed;
+	}
 
 	sdev_printk(KERN_INFO, sdev, "%s: attached to %s path\n",
 		    HP_SW_NAME, h->path_state == HP_SW_PATH_ACTIVE?
 		    "active":"passive");
 
 	sdev->handler_data = h;
-	return 0;
+	return SCSI_DH_OK;
 failed:
 	kfree(h);
-	return -EINVAL;
+	return ret;
 }
 
 static void hp_sw_bus_detach( struct scsi_device *sdev )
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 2ceff585f189..7af31a1247ee 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -729,7 +729,7 @@ static int rdac_bus_attach(struct scsi_device *sdev)
 
 	h = kzalloc(sizeof(*h) , GFP_KERNEL);
 	if (!h)
-		return -ENOMEM;
+		return SCSI_DH_NOMEM;
 	h->lun = UNINITIALIZED_LUN;
 	h->state = RDAC_STATE_ACTIVE;
 
@@ -755,7 +755,7 @@ static int rdac_bus_attach(struct scsi_device *sdev)
 		    lun_state[(int)h->lun_state]);
 
 	sdev->handler_data = h;
-	return 0;
+	return SCSI_DH_OK;
 
 clean_ctlr:
 	spin_lock(&list_lock);
@@ -764,7 +764,7 @@ static int rdac_bus_attach(struct scsi_device *sdev)
 
 failed:
 	kfree(h);
-	return -EINVAL;
+	return err;
 }
 
 static void rdac_bus_detach( struct scsi_device *sdev )
diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
index 84addee05be6..ac798d284a7e 100644
--- a/drivers/scsi/scsi_dh.c
+++ b/drivers/scsi/scsi_dh.c
@@ -126,20 +126,31 @@ static struct scsi_device_handler *scsi_dh_lookup(const char *name)
 static int scsi_dh_handler_attach(struct scsi_device *sdev,
 				  struct scsi_device_handler *scsi_dh)
 {
-	int error;
+	int error, ret = 0;
 
 	if (!try_module_get(scsi_dh->module))
 		return -EINVAL;
 
 	error = scsi_dh->attach(sdev);
-	if (error) {
+	if (error != SCSI_DH_OK) {
+		switch (error) {
+		case SCSI_DH_NOMEM:
+			ret = -ENOMEM;
+			break;
+		case SCSI_DH_RES_TEMP_UNAVAIL:
+			ret = -EAGAIN;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
 		sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
 			    scsi_dh->name, error);
 		module_put(scsi_dh->module);
 	} else
 		sdev->handler = scsi_dh;
 
-	return error;
+	return ret;
 }
 
 /*
-- 
2.12.3