Re: Feature request: Add fibmap/SEEK_HOLE support to sha1sum.

[Jim Meyering]

On Thu, Sep 5, 2013 at 9:22 AM, Pádraig Brady <address@hidden> wrote:
> On 09/05/2013 04:58 PM, Chris Dew wrote:
>> Thanks Pádraig,
>>
>> I had avoided fiemap, due to the issue discussed at 
>> http://smackerelofopinion.blogspot.co.uk/2010/01/using-fiemap-ioctl-to-get-file-extents.html
>>  - I use fibmap instead, but it's only for root.
>>
>> Is fiemap now safe?
>
> The issue with fiemap is still there in that IMHO it returns useless data
...

s/The/One/ :-)

Please think very hard before adding new fiemap-using code to the
coreutils.  It is a poor interface.  Here is a data-corrupting bug
that made it into cp partly due to that poor interface:
https://plus.google.com/114228401647637059102/posts/FDV3JEaYsKD

In the long run, I would like to remove the FIEMAP-using code
altogether, for maintainability, but also partly out of spite.