Re: [Bug-tar] GNU Tar 1.29/1.30: "file changed as we read it" warning when using --remove-files option in NTFS file systems

[Timothy Beryl Grahek]

Hi again,

I managed to reproduce the bug in GNU Tar 1.30. It appears to most
likely be affected by the NTFS-3G driver since I was not able to
reproduce this bug using Cygwin in Windows 10. To be clear, I received
the following output from the MATE-terminal in Arch Linux when inside
of my NTFS file system:

$ tar --remove-files -cf test.tar testing
tar: testing/New folder/New folder/New folder/New folder/New
folder/New folder/New folder (2)/New folder: file changed as we read
it
tar: testing/New folder/New folder/New folder/New folder/New
folder/New folder: file changed as we read it
tar: testing/New folder/New folder/New folder/New folder/New folder:
file changed as we read it
tar: testing/New folder/New folder/New folder/New folder: file changed
as we read it
tar: testing/New folder/New folder/New folder: file changed as we read it
tar: testing/New folder/New folder: file changed as we read it
tar: testing/New folder: file changed as we read it

I could not reproduce this when I used this exact same command in my
ext4 file system. I chose this as a test candidate because it had a
long path; using short paths doesn't seem to be affected by the bug.
Notice that it is only folders that exhibit this problem and not
files.

To summarize, the following reproduces the bug on two of my machines:

Using 'tar --remove-files -cf'
Using an NTFS file system in Arch Linux using the NTFS-3G driver
Attempting to archive a folder that contains many subfolders

Thank you,

Timothy Beryl Grahek

On Mon, Feb 26, 2018 at 10:29 AM, Timothy Beryl Grahek
<address@hidden> wrote:
> Hi,
>
> I wrote an email to help-tar about this and based on that, I have
> concluded that I may have found a bug. Essentially, occasionally when
> I use GNU Tar 1.29/1.30 in NTFS file systems with the --remove-files
> option, I run into "file changed as we read it" warnings on random
> folders. Is this a bug? Or is this GNU Tar's normal behavior when
> using this option? Should I be concerned about data loss based on
> these warnings?
>
> Thank you,
>
> Timothy Beryl Grahek