From: Jeff Moyer <jmoyer@redhat.com>
Date: Mon, 8 Sep 2008 13:45:05 -0400
Subject: [fs] wrapper for lower-level revalidate_disk routines
Message-id: x49iqt6v8f2.fsf@segfault.boston.devel.redhat.com
O-Subject: [rhel5 patch 1/6 - v2] Wrapper for lower-level revalidate_disk routines.
Bugzilla: 444964
RH-Acked-by: Eric Sandeen <sandeen@redhat.com>
RH-Acked-by: Josef Bacik <jbacik@redhat.com>

OK, so I forgot to update the patch count in the header.  That last
message should have read 0/6.  ;)

Wrapper for lower-level revalidate_disk routines.

This is a wrapper for the lower-level revalidate_disk call-backs such
as sd_revalidate_disk(). It allows us to perform pre and post
operations when calling them.

We will use this wrapper in a later patch to adjust block device sizes
after an online resize (a _post_ operation).

Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>

diff --git a/fs/block_dev.c b/fs/block_dev.c
index d7b9a66..22e0aa8 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -824,6 +824,27 @@ struct block_device *open_by_devnum(dev_t dev, unsigned mode)
 
 EXPORT_SYMBOL(open_by_devnum);
 
+/**
+ * revalidate_disk - wrapper for lower-level driver's revalidate_disk
+ *                   call-back
+ *
+ * @disk: struct gendisk to be revalidated
+ *
+ * This routine is a wrapper for lower-level driver's revalidate_disk
+ * call-backs.  It is used to do common pre and post operations needed
+ * for all revalidate_disk operations.
+ */
+int revalidate_disk(struct gendisk *disk)
+{
+	int ret = 0;
+
+	if (disk->fops->revalidate_disk)
+		ret = disk->fops->revalidate_disk(disk);
+
+	return ret;
+}
+EXPORT_SYMBOL(revalidate_disk);
+
 /*
  * This routine checks whether a removable media has been changed,
  * and invalidates all buffer-cache-entries in that case. This
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 69813f5..bf709b7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1616,6 +1616,7 @@ extern int fs_may_remount_ro(struct super_block *);
  */
 #define bio_data_dir(bio)	((bio)->bi_rw & 1)
 
+extern int revalidate_disk(struct gendisk *);
 extern int check_disk_change(struct block_device *);
 extern int invalidate_inodes(struct super_block *);
 extern int __invalidate_device(struct block_device *);