iomap: add private pointer to struct iomap

Add a private pointer to struct iomap to allow filesystems to pass data
from iomap_begin to iomap_end.  Will be used by gfs2 for passing on the
on-disk inode buffer head.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 45f4386..1f36523 100644 (file)
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -57,6 +57,7 @@ struct iomap {
        struct block_device     *bdev;  /* block device for I/O */
        struct dax_device       *dax_dev; /* dax_dev for dax operations */
        void                    *inline_data;
+       void                    *private; /* filesystem private */
 
        /*
         * Called when finished processing a page in the mapping returned in