exofs: Move layout related members to a layout structure

* Abstract away those members in exofs_sb_info that are related/needed
  by a layout into a new exofs_layout structure. Embed it in exofs_sb_info.

* At exofs_io_state receive/keep a pointer to an exofs_layout. No need for
  an exofs_sb_info pointer, all we need is at exofs_layout.

* Change any usage of above exofs_sb_info members to their new name.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index a1d1e77..fc88751 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -210,7 +210,7 @@
 	sbi = sb->s_fs_info;
 	fscb = &sbi->s_fscb;
 
-	ret = exofs_get_io_state(sbi, &ios);
+	ret = exofs_get_io_state(&sbi->layout, &ios);
 	if (ret)
 		goto out;
 
@@ -264,12 +264,12 @@
 
 void exofs_free_sbi(struct exofs_sb_info *sbi)
 {
-	while (sbi->s_numdevs) {
-		int i = --sbi->s_numdevs;
-		struct osd_dev *od = sbi->s_ods[i];
+	while (sbi->layout.s_numdevs) {
+		int i = --sbi->layout.s_numdevs;
+		struct osd_dev *od = sbi->layout.s_ods[i];
 
 		if (od) {
-			sbi->s_ods[i] = NULL;
+			sbi->layout.s_ods[i] = NULL;
 			osduld_put_device(od);
 		}
 	}
@@ -298,7 +298,8 @@
 				  msecs_to_jiffies(100));
 	}
 
-	_exofs_print_device("Unmounting", NULL, sbi->s_ods[0], sbi->s_pid);
+	_exofs_print_device("Unmounting", NULL, sbi->layout.s_ods[0],
+			    sbi->layout.s_pid);
 
 	exofs_free_sbi(sbi);
 	sb->s_fs_info = NULL;
@@ -361,7 +362,7 @@
 {
 	struct exofs_sb_info *sbi = *psbi;
 	struct osd_dev *fscb_od;
-	struct osd_obj_id obj = {.partition = sbi->s_pid,
+	struct osd_obj_id obj = {.partition = sbi->layout.s_pid,
 				 .id = EXOFS_DEVTABLE_ID};
 	struct exofs_device_table *dt;
 	unsigned table_bytes = table_count * sizeof(dt->dt_dev_table[0]) +
@@ -376,9 +377,9 @@
 		return -ENOMEM;
 	}
 
-	fscb_od = sbi->s_ods[0];
-	sbi->s_ods[0] = NULL;
-	sbi->s_numdevs = 0;
+	fscb_od = sbi->layout.s_ods[0];
+	sbi->layout.s_ods[0] = NULL;
+	sbi->layout.s_numdevs = 0;
 	ret = exofs_read_kern(fscb_od, sbi->s_cred, &obj, 0, dt, table_bytes);
 	if (unlikely(ret)) {
 		EXOFS_ERR("ERROR: reading device table\n");
@@ -397,14 +398,15 @@
 		goto out;
 
 	if (likely(numdevs > 1)) {
-		unsigned size = numdevs * sizeof(sbi->s_ods[0]);
+		unsigned size = numdevs * sizeof(sbi->layout.s_ods[0]);
 
 		sbi = krealloc(sbi, sizeof(*sbi) + size, GFP_KERNEL);
 		if (unlikely(!sbi)) {
 			ret = -ENOMEM;
 			goto out;
 		}
-		memset(&sbi->s_ods[1], 0, size - sizeof(sbi->s_ods[0]));
+		memset(&sbi->layout.s_ods[1], 0,
+		       size - sizeof(sbi->layout.s_ods[0]));
 		*psbi = sbi;
 	}
 
@@ -427,8 +429,8 @@
 		 * line. We always keep them in device-table order.
 		 */
 		if (fscb_od && osduld_device_same(fscb_od, &odi)) {
-			sbi->s_ods[i] = fscb_od;
-			++sbi->s_numdevs;
+			sbi->layout.s_ods[i] = fscb_od;
+			++sbi->layout.s_numdevs;
 			fscb_od = NULL;
 			continue;
 		}
@@ -441,8 +443,8 @@
 			goto out;
 		}
 
-		sbi->s_ods[i] = od;
-		++sbi->s_numdevs;
+		sbi->layout.s_ods[i] = od;
+		++sbi->layout.s_numdevs;
 
 		/* Read the fscb of the other devices to make sure the FS
 		 * partition is there.
@@ -499,9 +501,10 @@
 		goto free_sbi;
 	}
 
-	sbi->s_ods[0] = od;
-	sbi->s_numdevs = 1;
-	sbi->s_pid = opts->pid;
+	/* Default layout in case we do not have a device-table */
+	sbi->layout.s_ods[0] = od;
+	sbi->layout.s_numdevs = 1;
+	sbi->layout.s_pid = opts->pid;
 	sbi->s_timeout = opts->timeout;
 
 	/* fill in some other data by hand */
@@ -514,7 +517,7 @@
 	sb->s_bdev = NULL;
 	sb->s_dev = 0;
 
-	obj.partition = sbi->s_pid;
+	obj.partition = sbi->layout.s_pid;
 	obj.id = EXOFS_SUPER_ID;
 	exofs_make_credential(sbi->s_cred, &obj);
 
@@ -578,13 +581,13 @@
 		goto free_sbi;
 	}
 
-	_exofs_print_device("Mounting", opts->dev_name, sbi->s_ods[0],
-			    sbi->s_pid);
+	_exofs_print_device("Mounting", opts->dev_name, sbi->layout.s_ods[0],
+			    sbi->layout.s_pid);
 	return 0;
 
 free_sbi:
 	EXOFS_ERR("Unable to mount exofs on %s pid=0x%llx err=%d\n",
-		  opts->dev_name, sbi->s_pid, ret);
+		  opts->dev_name, sbi->layout.s_pid, ret);
 	exofs_free_sbi(sbi);
 	return ret;
 }
@@ -627,7 +630,7 @@
 	uint8_t cred_a[OSD_CAP_LEN];
 	int ret;
 
-	ret = exofs_get_io_state(sbi, &ios);
+	ret = exofs_get_io_state(&sbi->layout, &ios);
 	if (ret) {
 		EXOFS_DBGMSG("exofs_get_io_state failed.\n");
 		return ret;