From: "Ted Ts'o" <tytso@mit.edu>
To: Dave Young <hidave.darkstar@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-ext4@vger.kernel.org
Subject: Re: [BUG] copy file result with zero
Date: Sat, 1 Oct 2011 10:39:00 -0400 [thread overview]
Message-ID: <20111001143900.GH28234@thunk.org> (raw)
In-Reply-To: <CABqxG0feuZCmx=RfxU-50uFK9-P2vNbAMqJUdWM5RhuJifD5Ow@mail.gmail.com>
On Sat, Oct 01, 2011 at 10:01:35PM +0800, Dave Young wrote:
> Hi,
>
> Weird problem, when I build app from source,
> make; make install
> run the command, but got "cannot execute binary file"
>
> hexdump shows the installed binary is full of zero
>
> Is it related to ext4 fiemap problem described below?
> http://lwn.net/Articles/429349/
There is general agreement that /bin/cp should not have been relying
on FIEMAP, and I believe the more recent versions of /bin/cp have
removed that code by default pending implementation of
SEEK_HOLE/SEEK_DATA. That being said, ext4 had a workaround to its
FIEMAP implementation that landed in 2.6.39, and you're using
3.1.0-rc6.
> I finally managed to find the way to reproduce this:
> just cp a elf binary A to file B, then cp B to file C, then you will get:
> A == B != C
>
> ie.
> cp /bin/ls ls1
> cp ls1 ls2
>
> ls2 will be filled with zero
If you add a "sync" between the two copies, does that work around the
problem? I bet it will...
My suggestion is to upgrade to a newer version of coreutils that
doesn't try to use FIEMAP.
- Ted
next prev parent reply other threads:[~2011-10-01 14:39 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-01 14:01 [BUG] copy file result with zero Dave Young
2011-10-01 14:39 ` Ted Ts'o [this message]
2011-10-01 23:37 ` Dave Young
2011-10-02 6:41 ` Jeff liu
2011-10-02 7:59 ` Andreas Dilger
2011-10-02 7:14 ` Jeff liu
2011-10-02 8:46 ` Dave Young
2011-10-02 11:54 ` Christoph Hellwig
2011-10-03 9:26 ` Yongqiang Yang
2011-10-03 13:11 ` Lukas Czerner
2011-10-03 14:18 ` Ted Ts'o
2011-10-03 15:51 ` Lukas Czerner
2011-10-02 8:02 ` Andreas Dilger
2011-10-02 8:43 ` Dave Young
2011-10-03 11:08 ` Pádraig Brady
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