From mboxrd@z Thu Jan  1 00:00:00 1970
From: Amerigo Wang <amwang@redhat.com>
Subject: Re: [patch 12/12] vfs: allow file truncations when both suid and
 write permissions set
Date: Fri, 07 Aug 2009 17:20:12 +0800
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To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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OGAWA Hirofumi wrote:
> I found the SuSv3 says for ftruncate():
>
> Upon successful completion, if fildes refers to a regular file,
> ftruncate() shall mark for update the last data modification and last
> file status change timestamps of the file and the S_ISUID and S_ISGID
> bits of the file mode may be cleared. If the ftruncate() function is
> unsuccessful, the file is unaffected.
>
> And vmtruncate() can return error easily with RLIMIT_FSIZE or
> ->s_maxbytes. So, I think clearing s[ug]id first may be bad behavior
> without good reason.
>   

Hmm, you mean we should clear suid after we do notify_change()?
Good point!

I will update the patch now...

Thanks for your review!