[SCSI] libosd: osd_dev_info: Unique Identification of an OSD device
Define an osd_dev_info structure that Uniquely identifies an OSD
device lun on the network. The identification is built from unique
target attributes and is the same for all network/SAN machines.
osduld_info_lookup() - NEW
New API that will lookup an osd_dev by its osd_dev_info.
This is used by pNFS-objects for cross network global device
identification. And by exofs multy-device support, the device
info is specified in the on-disk exofs device table.
osduld_device_info() - NEW
Given an osd_dev handle returns its associated osd_dev_info.
The ULD fetches this information at startup and hangs it on
each OSD device. (This is a fast operation that can be called
at any condition)
osduld_device_same() - NEW
With a given osd_dev at one hand and an osd_dev_info
at another, we would like to know if they are the same
device.
Two osd_dev handles can be checked by:
osduld_device_same(od1, osduld_device_info(od2));
osd_auto_detect_ver() - REVISED
Now returns an osd_dev_info structure. Is only called once
by ULD as before. See added comments for how to use.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c
index fc6fc1c..0a90702 100644
--- a/drivers/scsi/osd/osd_uld.c
+++ b/drivers/scsi/osd/osd_uld.c
@@ -84,6 +84,7 @@
struct device class_dev;
struct cdev cdev;
struct osd_dev od;
+ struct osd_dev_info odi;
struct gendisk *disk;
};
@@ -225,6 +226,72 @@
}
EXPORT_SYMBOL(osduld_path_lookup);
+static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
+ const u8 *a2, unsigned a2_len)
+{
+ if (!a2_len) /* User string is Empty means don't care */
+ return true;
+
+ if (a1_len != a2_len)
+ return false;
+
+ return 0 == memcmp(a1, a2, a1_len);
+}
+
+struct find_oud_t {
+ const struct osd_dev_info *odi;
+ struct device *dev;
+ struct osd_uld_device *oud;
+} ;
+
+int _mach_odi(struct device *dev, void *find_data)
+{
+ struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
+ class_dev);
+ struct find_oud_t *fot = find_data;
+ const struct osd_dev_info *odi = fot->odi;
+
+ if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
+ odi->systemid, odi->systemid_len) &&
+ _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
+ odi->osdname, odi->osdname_len)) {
+ OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
+ odi->systemid_len, odi->osdname_len);
+ fot->oud = oud;
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/* osduld_info_lookup - Loop through all devices, return the requested osd_dev.
+ *
+ * if @odi->systemid_len and/or @odi->osdname_len are zero, they act as a don't
+ * care. .e.g if they're both zero /dev/osd0 is returned.
+ */
+struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
+{
+ struct find_oud_t find = {.odi = odi};
+
+ find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
+ if (likely(find.dev)) {
+ struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
+
+ if (unlikely(!odh)) {
+ put_device(find.dev);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ odh->od = find.oud->od;
+ odh->oud = find.oud;
+
+ return &odh->od;
+ }
+
+ return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL(osduld_info_lookup);
+
void osduld_put_device(struct osd_dev *od)
{
if (od && !IS_ERR(od)) {
@@ -240,14 +307,39 @@
* is called after the fops->release. A get_/put_ pair makes
* sure we have a cdev for the duration of fput
*/
- get_device(&oud->class_dev);
- fput(odh->file);
+ if (odh->file) {
+ get_device(&oud->class_dev);
+ fput(odh->file);
+ }
put_device(&oud->class_dev);
kfree(odh);
}
}
EXPORT_SYMBOL(osduld_put_device);
+const struct osd_dev_info *osduld_device_info(struct osd_dev *od)
+{
+ struct osd_dev_handle *odh =
+ container_of(od, struct osd_dev_handle, od);
+ return &odh->oud->odi;
+}
+EXPORT_SYMBOL(osduld_device_info);
+
+bool osduld_device_same(struct osd_dev *od, const struct osd_dev_info *odi)
+{
+ struct osd_dev_handle *odh =
+ container_of(od, struct osd_dev_handle, od);
+ struct osd_uld_device *oud = odh->oud;
+
+ return (oud->odi.systemid_len == odi->systemid_len) &&
+ _the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
+ odi->systemid, odi->systemid_len) &&
+ (oud->odi.osdname_len == odi->osdname_len) &&
+ _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
+ odi->osdname, odi->osdname_len);
+}
+EXPORT_SYMBOL(osduld_device_same);
+
/*
* Scsi Device operations
*/
@@ -268,7 +360,7 @@
OSD_ERR("warning: scsi_test_unit_ready failed\n");
osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);
- if (osd_auto_detect_ver(&oud->od, caps))
+ if (osd_auto_detect_ver(&oud->od, caps, &oud->odi))
return -ENODEV;
return 0;
@@ -280,6 +372,8 @@
class_dev);
struct scsi_device *scsi_device = oud->od.scsi_device;
+ kfree(oud->odi.osdname);
+
if (oud->cdev.owner)
cdev_del(&oud->cdev);