Re: Problem with ISO9660 and files stored on multiple extents

[Vladimir 'phcoder' Serbinenko]

On Thu, Feb 16, 2017, 14:14 Carlo Caione <address@hidden> wrote:

On Thu, Feb 16, 2017 at 2:09 PM, Vladimir 'phcoder' Serbinenko
<address@hidden> wrote:
>
>
> On Thu, Feb 16, 2017, 14:04 Carlo Caione <address@hidden> wrote:
>>
>> On Thu, Feb 16, 2017 at 12:37 PM, Carlo Caione <address@hidden> wrote:
>> > On Thu, Feb 16, 2017 at 12:32 PM, Thomas Schmitt <address@hidden>
>> > wrote:
>> >> Hi,
>> >>
>> >> Carlo Caione wrote:
>> >>> > I think that the problem
>> >>> > here is that endless.squash has been stored in two extents in the
>> >>> > ISO9660 and GRUB doesn't deal fine with that (also according to this
>> >>> > comment
>> >>> >
>> >>> > http://git.savannah.gnu.org/cgit/grub.git/tree/grub-core/fs/iso9660.c#n960
>> >>
>> >> Andrei Borzenkov wrote:
>> >>> This comment could be stale and misleading.
>> >>
>> >> The code of read_node() in iso9660.c looks ready for multi-extent (aka
>> >> ISO
>> >> level 3).
>> >>
>> >> I have a very densely compressed test ISO for large file support
>> >>    http://scdbackup.webframe.org/large.iso.bz2
>> >> which bunzip2 inflates from 4.5 KiB to 4+ GiB.
>> >
>> > Yeah, I made some more tests and apparently the problem is not in the
>> > ISO9660 module but in the SQUASH4 module.
>> > To be perfectly honest I have already a patch that solves my problem
>> > but I'm having a hard time to understand WHY it solves the issue since
>> > I'm still not really familiar with squashfs (I casually found it
>> > during my debugging).
>> > Of course probably it is only masking a problem somewhere else. Still
>> > digging.
>> >
>> > diff --git a/grub-core/fs/squash4.c b/grub-core/fs/squash4.c
>> > index b97b344..4fef813 100644
>> > --- a/grub-core/fs/squash4.c
>> > +++ b/grub-core/fs/squash4.c
>> > @@ -895,7 +895,7 @@ grub_squash_read_data (struct grub_squash_data
>> > *data,
>> >        break;
>> >      }
>> >
>> > -  if (fragment == 0xffffffff)
>> > +  if (fragment == 0xffffffff || fragment == 0)
>> >      return direct_read (data, ino, off, buf, len);
>> >
>> >    err = read_chunk (data, &frag, sizeof (frag),
>>
>> Hey Vladimir,
>> Any idea about this?
>
> How big is the file in question? What is the squash tools version?

The squash image is 4564504576

I mean the size of file you try to access

mksquashfs version 4.3-git (2014/06/09)

No options are passed to mksquashfs when creating the image.

--
Carlo Caione  |  +39.340.80.30.096  |  Endless