generic: Add SEEK_DATA tests for offsets in the middle of holes

ext4 had a bug for files with indirect extents where it wrongly
reported a size of a hole in some cases and thus SEEK_DATA
implementation could skip some data in a file. Test for that. The
problem is fixed by patch "ext4: Fix hole length detection in
ext4_ind_map_blocks()".

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
4 files changed