From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
---
fs/btrfs/dax.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c
index d614bf73bf8e..5a297674adec 100644
--- a/fs/btrfs/dax.c
+++ b/fs/btrfs/dax.c
@@ -54,7 +54,12 @@ ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to)
BUG_ON(em->flags & EXTENT_FLAG_FS_MAPPING);
- ret = em_dax_rw(inode, em, pos, len, to);
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ u64 zero_len = min(em->len - (em->start - pos), len);
+ ret = iov_iter_zero(zero_len, to);
+ } else {
+ ret = em_dax_rw(inode, em, pos, len, to);
+ }
if (ret < 0)
goto out;
pos += ret;
--
2.16.4
