On Oct 29, 2013, at 7:10 AM, Pavel Raiskup <prais...@redhat.com> wrote:
>> To be clear, I can see that the fix to ST_IS_SPARSE should cause >> dump_regular_file to be called instead of sparse_dump_file, but I still >> wonder if it is wise to leave this logic in place. At the very last, >> I think a comment would be helpful to explain that this test is valid >> only because ST_IS_SPARSE has already succeeded. > > At least for the check for zero blocks in sparse file: It is intentional > because it makes the processing of completely sparse files to be done in > constant time (try to archive 'file' from `truncate -s 10G file`). This > could be documented possibly. Otherwise, I would not say that there is > unclear that sparse_dump_file is supposed to be called only against real > sparse files. What about this sparse file: $ truncate -s 10G file && echo hello >> file Are there filesystems where the 6 bytes here would be stored in the inode? That would give a large sparse file with zero allocated blocks but not zero content. Tim
