exofs:  Add SYSFS info for autologin/pNFS export

Introduce sysfs infrastructure for exofs cluster filesystem.

Each OSD target shows up as below in the sysfs hierarchy:
	/sys/fs/exofs/<osdname>_<partition_id>/devX

Where <osdname>_<partition_id> is the unique identification
of a Superblock.

Where devX: 0 <= X < device_table_size. They are ordered
in device-table order as specified to the mkfs.exofs command

Each OSD device  devX has following attributes :
	osdname - ReadOnly
	systemid - ReadOnly
	uri - Read/Write

It is up to user-mode to update devX/uri for support of
autologin.

These sysfs information are used both for autologin as well
as support for exporting exofs via a pNFSD server in user-mode.
(.eg NFS-Ganesha)

Signed-off-by: Sachin Bhamare <sbhamare@panasas.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/exofs/exofs.h b/fs/exofs/exofs.h
index ca9d496..fffe86f 100644
--- a/fs/exofs/exofs.h
+++ b/fs/exofs/exofs.h
@@ -56,6 +56,9 @@
 struct exofs_dev {
 	struct ore_dev ored;
 	unsigned did;
+	unsigned urilen;
+	uint8_t *uri;
+	struct kobject ed_kobj;
 };
 /*
  * our extension to the in-memory superblock
@@ -73,6 +76,7 @@
 	struct ore_layout	layout;		/* Default files layout       */
 	struct ore_comp one_comp;		/* id & cred of partition id=0*/
 	struct ore_components oc;		/* comps for the partition    */
+	struct kobject	s_kobj;			/* holds per-sbi kobject      */
 };
 
 /*
@@ -176,6 +180,16 @@
 			   const struct osd_obj_id *obj);
 int exofs_sbi_write_stats(struct exofs_sb_info *sbi);
 
+/* sys.c                 */
+int exofs_sysfs_init(void);
+void exofs_sysfs_uninit(void);
+int exofs_sysfs_sb_add(struct exofs_sb_info *sbi,
+		       struct exofs_dt_device_info *dt_dev);
+void exofs_sysfs_sb_del(struct exofs_sb_info *sbi);
+int exofs_sysfs_odev_add(struct exofs_dev *edev,
+			 struct exofs_sb_info *sbi);
+void exofs_sysfs_dbg_print(void);
+
 /*********************
  * operation vectors *
  *********************/