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>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 22 insertions, 0 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c3fa19bd64df..4eeb69a88734 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -852,6 +852,27 @@ 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 02a9fb5a830c..d63461f97983 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1722,6 +1722,7 @@ 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_device(struct block_device *);
 extern int invalidate_partition(struct gendisk *, int);