On Tue, Aug 22, 2017 at 06:15:27PM -0400, Theodore Ts'o wrote:
> On Sat, Feb 18, 2017 at 06:13:53PM +0100, G.raud wrote:
> > Package: e2fsprogs
> > Version: 1.42.12-2+b1
> > Severity: normal
> >
> > e2image tries to seek into an ouput to stdout ("-"), even when it is a
> > pipe:
> >
> > ------
> > # LC_ALL=C e2image /dev/mapper/debian-var - | cat >test
> > e2image 1.42.12 (29-Aug-2014)
> > seek_set: Illegal seek
> > ------
> >
> > According the manpage, only the raw and qcow2 formats require seeking
> > into the output.
>
> Actually, the manage states that only the raw mode supports using
> stdout:
>
> If image-file is -, then the output of e2image will be sent to
> standard output, so that the output can be piped to another
> program, such as gzip(1). (Note that this is currently only
> supported when creating a raw image file using the -r option, since
> the process of creating a normal image file, or QCOW2 image
> currently requires random access to the file, which cannot be done
> using a pipe. This restriction will hopefully be lifted in a
> future version of e2image.)
Either I misread that part or the manpage in jessie was erroneous.
> The fact that e2image doesn't work on "normal" e2image files is a
> long-standing short-coming. But note that it's really an obsolete
> format. The raw or qcow image formats are actually far more useful,
> and the primary use cases of e2image today. The only reason why
> "normal" is still used to describe the original e2image format is for
> historical reasons.
To avoid that someone else makes the same mistake, I suggest to put a
warning message to stderr in case such a combination of options is
selected, because "seek_set: Illegal seek" implies a programming error.
Regards
--
G.raud
