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scsi_dh: suppress errors from unsupported devices

PATCH Applied Hannes Reinecke 3 participants 6 messages Sep 20, 2017 – Sep 25, 2017 SCSI

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Hannes Reinecke

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#0 lore raw

cover scsi_dh: suppress errors from unsupported devices

From: Hannes Reinecke <[email protected]>

Hi all,

here's a small patchset to suppress errors from scsi_dh_attach() for unsupported devices.

As usual, comments and reviews are welcome.

Hannes Reinecke (2):
scsi_dh: Return SCSI_DH_XX error code from ->attach()
scsi_dh: suppress errors from unsupported devices

 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                      | 36 +++++++++++++++++++++--------
 drivers/scsi/scsi_priv.h                    |  4 ++--
 drivers/scsi/scsi_sysfs.c                   |  8 +------
 7 files changed, 48 insertions(+), 34 deletions(-)
Signature · 1 line
2.12.3
author
#1 lore raw

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

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 <[email protected]>
Signed-off-by Hannes Reinecke <[email protected]>
---
 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(-)
drivers/scsi/device_handler/scsi_dh_alua.c +4 -6
index 0962fd544401..fd22dc6ab5d9 100644
@@ -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;
 }
 
 /*
drivers/scsi/device_handler/scsi_dh_emc.c +3 -3
index 8654e940e1a8..6a2792f3a37e 100644
@@ -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)
drivers/scsi/device_handler/scsi_dh_hp_sw.c +8 -4
index 62d314e07d11..e65a0ebb4b54 100644
@@ -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 )
drivers/scsi/device_handler/scsi_dh_rdac.c +3 -3
index 2ceff585f189..7af31a1247ee 100644
@@ -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 )
drivers/scsi/scsi_dh.c +14 -3
index 84addee05be6..ac798d284a7e 100644
@@ -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;
 }
 
 /*
Signature · 1 line
2.12.3
Reviewed-by on v1 1/2
#2 lore raw

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

Reviewed-by Johannes Thumshirn <[email protected]>
Signature · 6 lines
Johannes Thumshirn                                          Storage
[email protected]                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
author
#3 lore raw

PATCH 2/2 scsi_dh: suppress errors from unsupported devices

In reply to Hannes Reinecke

Device handlers are optional, and for some handlers like ALUA only implemented for certain device types.
So suppress any errors for unsupported devices.

Signed-off-by Hannes Reinecke <[email protected]>
---
 drivers/scsi/scsi_dh.c    | 19 +++++++++++++------
 drivers/scsi/scsi_priv.h  |  4 ++--
 drivers/scsi/scsi_sysfs.c |  8 +-------
 3 files changed, 16 insertions(+), 15 deletions(-)
drivers/scsi/scsi_dh.c +13 -6
index ac798d284a7e..2b785d09d5bd 100644
@@ -140,12 +140,17 @@ static int scsi_dh_handler_attach(struct scsi_device *sdev,
 		case SCSI_DH_RES_TEMP_UNAVAIL:
 			ret = -EAGAIN;
 			break;
+		case SCSI_DH_DEV_UNSUPP:
+		case SCSI_DH_NOSYS:
+			ret = -ENODEV;
+			break;
 		default:
 			ret = -EINVAL;
 			break;
 		}
-		sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
-			    scsi_dh->name, error);
+		if (ret != -ENODEV)
+			sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
+				    scsi_dh->name, error);
 		module_put(scsi_dh->module);
 	} else
 		sdev->handler = scsi_dh;

@@ -164,18 +169,20 @@ static void scsi_dh_handler_detach(struct scsi_device *sdev)
 	module_put(sdev->handler->module);
 }
 
-int scsi_dh_add_device(struct scsi_device *sdev)
+void scsi_dh_add_device(struct scsi_device *sdev)
 {
 	struct scsi_device_handler *devinfo = NULL;
 	const char *drv;
-	int err = 0;
 
 	drv = scsi_dh_find_driver(sdev);
 	if (drv)
 		devinfo = __scsi_dh_lookup(drv);
+	/*
+	 * device_handler is optional, so ignore errors
+	 * from scsi_dh_handler_attach()
+	 */
 	if (devinfo)
-		err = scsi_dh_handler_attach(sdev, devinfo);
-	return err;
+		(void)scsi_dh_handler_attach(sdev, devinfo);
 }
 
 void scsi_dh_release_device(struct scsi_device *sdev)
drivers/scsi/scsi_priv.h +2 -2
index 5c6d016a5ae9..9125e0162eed 100644
@@ -176,10 +176,10 @@ extern struct async_domain scsi_sd_probe_domain;
 
 /* scsi_dh.c */
 #ifdef CONFIG_SCSI_DH
-int scsi_dh_add_device(struct scsi_device *sdev);
+void scsi_dh_add_device(struct scsi_device *sdev);
 void scsi_dh_release_device(struct scsi_device *sdev);
 #else
-static inline int scsi_dh_add_device(struct scsi_device *sdev) { return 0; }
+static inline void scsi_dh_add_device(struct scsi_device *sdev) { }
 static inline void scsi_dh_release_device(struct scsi_device *sdev) { }
 #endif
 static inline void scsi_dh_remove_device(struct scsi_device *sdev) { }
drivers/scsi/scsi_sysfs.c +1 -7
index bf53356f41f0..cfc5e316f6cb 100644
@@ -1234,13 +1234,7 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
 
 	scsi_autopm_get_device(sdev);
 
-	error = scsi_dh_add_device(sdev);
-	if (error)
-		/*
-		 * device_handler is optional, so any error can be ignored
-		 */
-		sdev_printk(KERN_INFO, sdev,
-				"failed to add device handler: %d\n", error);
+	scsi_dh_add_device(sdev);
 
 	error = device_add(&sdev->sdev_gendev);
 	if (error) {
Signature · 1 line
2.12.3
Applied
#5 lore raw
In reply to Hannes Reinecke

Hannes,

Quoted 2 lines

here's a small patchset to suppress errors from scsi_dh_attach() for unsupported devices.

Applied to 4.15/scsi-queue. Thank you!

Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering