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To: Davide Libenzi <davidel@xmailserver.org>
Cc: Christoph Hellwig <hch@lst.de>, linux-fsdevel@vger.kernel.org,
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Subject: Re: [PATCH/RFC 1/2] anon-inodes: Remove fd_install() from anon_inode_getfd()
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From: Roland Dreier <rdreier@cisco.com>
Date: Wed, 27 Feb 2008 15:42:42 -0800
In-Reply-To: <ada7igqyurw.fsf@cisco.com> (Roland Dreier's message of "Wed, 27 Feb 2008 13:05:55 -0800")
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 > http://git.kernel.org/?p=linux/kernel/git/viro/vfs-2.6.git;a=commit;h=49be4f8114e6ff0efdab10ebba2493fb67bc3034

Actually, looking closer at the kvm changes here, I think that
create_vcpu_fd() needs the same treatment as kvm_dev_ioctl_create_vm()
gets in the patch because of the race I mentioned in the changelog
for my patch: otherwise kvm_vcpu_release() could drop the last
reference to vcpu->kvm->filp before the get_file() gets an extra
reference.

I'm beginning to think that moving the fd_install() out of
anon_inode_getfd() really is worth it to make a safer interface.

 - R.