iomap: add IOMAP_F_NEW flag

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_iomap.c

@@ -1000,6 +1000,7 @@ xfs_file_iomap_begin(
 		if (error)
 			return error;
 
+		iomap->flags = IOMAP_F_NEW;
 		trace_xfs_iomap_alloc(ip, offset, length, 0, &imap);
 	} else {
 		ASSERT(nimaps);

include/linux/iomap.h

@@ -22,6 +22,7 @@ struct vm_fault;
  * Flags for iomap mappings:
  */
 #define IOMAP_F_MERGED	0x01	/* contains multiple blocks/extents */
+#define IOMAP_F_NEW	0x02	/* blocks have been newly allocated */
 
 /*
  * Magic value for blkno: