[SCSI] libosd: osd_dev_info: Unique Identification of an OSD device

[net-next-2.6.git] / drivers / scsi / osd / osd_uld.c

diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c
index fc6fc1c4d4d1659629a7876a9df593cad33c8a4b..0a90702b3d710101904b73defb89a9a8d5580c67 100644 (file)
--- a/drivers/scsi/osd/osd_uld.c
+++ b/drivers/scsi/osd/osd_uld.c
@@ -84,6 +84,7 @@ struct osd_uld_device {
        struct device class_dev;
        struct cdev cdev;
        struct osd_dev od;
+       struct osd_dev_info odi;
        struct gendisk *disk;
 };
 
@@ -225,6 +226,72 @@ free_od:
 }
 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 @@ void osduld_put_device(struct osd_dev *od)
                 * 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 @@ static int __detect_osd(struct osd_uld_device *oud)
                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 @@ static void __remove(struct device *dev)
                                                  class_dev);
        struct scsi_device *scsi_device = oud->od.scsi_device;
 
+       kfree(oud->odi.osdname);
+
        if (oud->cdev.owner)
                cdev_del(&oud->cdev);