linux-ext4.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Theodore Ts'o <tytso@mit.edu>
To: Phillip Susi <psusi@ubuntu.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [PATCH] e2fslibs: fix llseek on i386
Date: Thu, 24 Jan 2013 14:51:58 -0500	[thread overview]
Message-ID: <20130124195158.GC9477@thunk.org> (raw)
In-Reply-To: <1359044517-18243-1-git-send-email-psusi@ubuntu.com>

On Thu, Jan 24, 2013 at 11:21:56AM -0500, Phillip Susi wrote:
> ext2fs_llseek() was using lseek instead of lseek64.  The
> only time it would use lseek64 is if passed an offset that
> overflowed 32 bits.  This works for SEEK_SET, but not
> SEEK_CUR, which can apply a small offset to move the file
> pointer past the 32 bit limit.
> 
> The code has been changed to instead try lseek64 first, and
> fall back to lseek if that fails.  It also was doing a
> runtime check of the size of off_t.  This has been moved to
> compile time.
> 
> Signed-off-by: Phillip Susi <psusi@ubuntu.com>

How did you find this?  I've done a quick search for SEEK_CUR, and it
looks like only place where this could cause a problem is with
e2image.  And a quick test of a i386 version of e2image with a large
file system is that it does indeed blow up with an "Inappropriate
ioctl for device" error.

Is there any other potential problems that are caused by this bug?  I
like to explain the impacts of bug fixes in libext2fs for folks who
are doing bug fix / code archeology.

Thanks,


					- Ted

  reply	other threads:[~2013-01-24 19:52 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-24 16:21 [PATCH] e2fslibs: fix llseek on i386 Phillip Susi
2013-01-24 19:51 ` Theodore Ts'o [this message]
2013-01-24 20:22   ` Phillip Susi
2013-01-24 20:32     ` Theodore Ts'o
2013-01-25  2:25       ` Zheng Liu
2013-01-25  2:16         ` Theodore Ts'o
2013-01-25  2:48           ` Zheng Liu
2013-01-25  4:13 ` Theodore Ts'o
2013-01-25  4:14   ` [PATCH] libext2fs: fix ext2fs_llseek " Theodore Ts'o
2013-01-25  4:34     ` Phillip Susi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20130124195158.GC9477@thunk.org \
    --to=tytso@mit.edu \
    --cc=linux-ext4@vger.kernel.org \
    --cc=psusi@ubuntu.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).