When DAX calls _ext4_get_block() and the file offset points to a hole we currently don't set bh->b_size. This is current worked around via buffer_size_valid() in fs/dax.c. _ext4_get_block() has the hole size information from ext4_map_blocks(), so populate bh->b_size so we can remove buffer_size_valid() in a later patch. Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> --- fs/ext4/inode.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 0900cb4..9075fac 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -759,6 +759,9 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock, ext4_update_bh_state(bh, map.m_flags); bh->b_size = inode->i_sb->s_blocksize * map.m_len; ret = 0; + } else if (ret == 0) { + /* hole case, need to fill in bh->b_size */ + bh->b_size = inode->i_sb->s_blocksize * map.m_len; } return ret; } -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>