Re: Bug in lrzip 0.631-1 (32 bit version) with -d -o - options

["David Balažic" <xerces9@gmail.com>]

I tried the  2.7.0-0.1  test release and now the behavior changed.

Before I got consistently a wrong MD5 sum of 8bd6ad48f2cea6a710af70b434d57673
With this release I get c43a02c309fa5e0abe778201e9ceec46.

So something changed.

Either the problem is in cygwin or lrzip, I guess.

Regards,
David


On 30 January 2017 at 16:23, David Balažic <xerces9@gmail.com> wrote:
> I tried in Ubuntu 32 bit (both the packaged lrzip  and a self compiled
> one) and there the problem does not happen, so it looks like either:
>  - bad lrzip in cygwin
>  - cygwin pipe issues?
>
> Regards,
> David
>
>
> On 25 January 2017 at 23:15, David Balažic <xerces9@gmail.com> wrote:
>> Hi!
>>
>> The 32 bit version of lrzip 0.631-1 contains a bug that corrupts the
>> decompressed dat in some circumstances.
>>
>> I reproduced the problem on 2 PCs (the md5sum of the broken output was
>> the same on both systems).
>>
>> I seems to happen when the (de)compressed file size is bigger than the
>> available RAM (note that the 32 bit version uses max 4GB in any case)
>> and lrzip resorts to using a temporary file.
>>
>> See below for reproducing:
>>
>> $ lrzip -i sda.img.lrz2
>> sda.img.lrz2:
>> lrzip version: 0.6 file
>> Compression: rzip + lzma
>> Decompressed file size: 64017212928
>> Compressed file size: 7210541304
>> Compression ratio: 8.878
>> MD5 used for integrity testing
>> MD5: 6594f5b0d22efd345003260054165842
>>
>> $ date; df -h ; TMP=/cygdrive/i/t/tmp/  lrzip -v  -d  -o -
>> sda.img.lrz2  | tee >(md5sum --tag) >(sha1sum --tag) > /dev/null   ;
>> date
>> Tue Jan 24 21:29:01 CET 2017
>> Filesystem      Size  Used Avail Use% Mounted on
>> C:/cygwin       114G   94G   21G  83% /
>> D:              541G  534G  7.1G  99% /cygdrive/d
>> I:              391G  279G  113G  72% /cygdrive/i
>> Q:               60G   57G  2.8G  96% /cygdrive/q
>> The following options are in effect for this DECOMPRESSION.
>> Threading is ENABLED. Number of CPUs detected: 4
>> Detected 17160601600 bytes ram
>> Compression level 7
>> Nice Value: 19
>> Show Progress
>> Verbose
>> Output Filename Specified: -
>> Temporary Directory set as: /cygdrive/i/t/tmp/
>> Outputting to stdout.
>> Detected lrzip version 0.6 file.
>> MD5 being used for integrity testing.
>> Decompressing...
>> Unable to decompress entirely in ram, will use physical files
>> Dumping temporary file to control->outFILE.
>>
>> [1]+  Stopped                 TMP=/cygdrive/i/t/tmp/ lrzip -v -d -o -
>> sda.img.lrz2 | tee >(md5sum --tag) >(sha1sum --tag) > /dev/null
>> Tue Jan 24 21:31:39 CET 2017
>>
>> stein@hofer8 /cygdrive/i/Zotac_bak
>> $ fg
>> TMP=/cygdrive/i/t/tmp/ lrzip -v -d -o - sda.img.lrz2 | tee >(md5sum
>> --tag) >(sha1sum --tag) > /dev/null
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>> Dumping temporary file to control->outFILE.
>>
>> Average DeCompression Speed:  0.668MB/s
>> Dumping temporary file to control->outFILE.
>> [OK] - 64017212928 bytes
>> Total time: 25:22:26.25
>> SHA1 (-) = 6c519210541eb128c03b7c0f803adb2b46ee2a72
>> MD5 (-) = 8bd6ad48f2cea6a710af70b434d57673
>>
>>
>> The correct md5sum is 6594f5b0d22efd345003260054165842.
>>
>>
>> Simply decompressing the file (lrzip -d -o sda.img sda.img.lrz2) to
>> filesystem works fine, only when piped to stdout the problem happens.
>>
>> The 64 bit version does not have this problem.
>>
>>
>> I will check if the same problem happens with the native linux build
>> of lrzip (it takes a day...).
>>
>>
>> I tried to reproduce the problem with a smaller file, but there it did
>> not happen. Maybe my first test file has some corruption that causes
>> this (unlikely).
>>
>> Some version information (complete cygcheck -s -v -r output attached):
>>
>> base-cygwin                           3.8-1
>> cygwin                                2.6.1-1
>> lrzip                                 0.631-1
>>
>> Regards,
>> David

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