[PATCH] ses: Handle non-unique element descriptors

Ankit Jain
2011-07-04T15:14:31Z

Some SES devices give non-unique Element Descriptors as part of the
Element Descriptor diag page. Since we use these for creating sysfs
entries, they need to be unique.

Eg:
$ sg_ses -p 7 /dev/sg0
FTS CORP TXS6_SAS20BPX12 0500
enclosure services device
Element descriptor In diagnostic page:
generation code: 0x0
element descriptor by type list
Element type: Array device, subenclosure id: 0
Overall descriptor: ArrayDevicesInSubEnclsr0
Element 1 descriptor: ArrayDevice00
Element 2 descriptor: ArrayDevice01
Element 3 descriptor: ArrayDevice02
Element 4 descriptor: ArrayDevice03
Element 5 descriptor: ArrayDevice03
Element 6 descriptor: ArrayDevice03
Element 7 descriptor: ArrayDevice03
Element 8 descriptor: ArrayDevice03
Element 9 descriptor: ArrayDevice03
Element 10 descriptor: ArrayDevice03
Element 11 descriptor: ArrayDevice03
Element 12 descriptor: ArrayDevice03

Based on scsi-misc

Signed-off-by: Ankit Jain <jankit@suse.de>

---
diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index 00e5fca..8087055 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -239,6 +239,24 @@ static void enclosure_component_release(struct device *dev)
put_device(dev->parent);
}

+struct enclosure_component *
+enclosure_component_find_by_name(struct enclosure_device *edev,
+ const char *name)
+{
+ int i;
+ if (!edev || !name || !name[0])
+ return NULL;
+
+ for (i=0; i<edev->components; i++) {
+ struct enclosure_component *ecomp = &edev->component[i];
+ if (ecomp->number != -1 && !strcmp(dev_name(&ecomp->cdev), name))
+ return ecomp;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(enclosure_component_find_by_name);
+
static const struct attribute_group *enclosure_groups[];

/**
diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index eba183c..abfd962 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -421,12 +421,17 @@ static void ses_enclosure_data_process(struct enclosure_device *edev,
if (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE) {

- if (create)
+ if (create) {
+ if (enclosure_component_find_by_name(edev, name))
+ /* name is not unique, already used
+ * set to NULL, so that enclosure_component_register
+ * will assign us a new one */
+ name = NULL;
ecomp = enclosure_component_register(edev,
components++,
type_ptr[0],
name);
- else
+ } else
ecomp = &edev->component[components++];

if (!IS_ERR(ecomp) && addl_desc_ptr)
diff --git a/include/linux/enclosure.h b/include/linux/enclosure.h
index 9a33c5f..7e48ba9 100644
--- a/include/linux/enclosure.h
+++ b/include/linux/enclosure.h
@@ -122,6 +122,8 @@ void enclosure_unregister(struct enclosure_device *);
struct enclosure_component *
enclosure_component_register(struct enclosure_device *, unsigned int,
enum enclosure_component_type, const char *);
+struct enclosure_component *
+enclosure_component_find_by_name(struct enclosure_device *, const char *);
int enclosure_add_device(struct enclosure_device *enclosure, int component,
struct device *dev);
int enclosure_remove_device(struct enclosure_device *, struct device *);
--
Ankit Jain
SUSE Labs