Re: [PATCH/RFC 1/2] anon-inodes: Remove fd_install() from anon_inode_getfd()

Avi Kivity
2008-02-28T07:52:36Z

Roland Dreier wrote:
> > 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.
>

It makes is less usable, though (since the last step needs to be taken
by the caller.

We might add a int (*prepare_file)(...) parameter which
anon_inode_getfd() uses to munge the file before installing it.

--
error compiling committee.c: too many arguments to function