iomap: add a flag to report shared extents

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

2 files changed, 3 insertions, 0 deletions

diff --git a/fs/iomap.c b/fs/iomap.c
index e9b3f991c2d8..ec411a6b9edc 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -512,6 +512,8 @@ static int iomap_to_fiemap(struct fiemap_extent_info *fi,
 
         if (iomap->flags & IOMAP_F_MERGED)
                 flags |= FIEMAP_EXTENT_MERGED;
+        if (iomap->flags & IOMAP_F_SHARED)
+                flags |= FIEMAP_EXTENT_SHARED;
 
         return fiemap_fill_next_extent(fi, iomap->offset,
                         iomap->blkno != IOMAP_NULL_BLOCK ? iomap->blkno << 9: 0,
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 3a56212a0a8d..c74226a738a3 100644
--- a/include/linux/iomap.h
+++ b/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_SHARED  0x02    /* block shared with another file */
 
 /*
  * Magic value for blkno: