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    SubjectRe: [PATCH] kobject: make sure kobj->ktype is set before kobject_init
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    On Thu, 2007-11-29 at 12:06 -0500, Alan Stern wrote:
    > On Thu, 29 Nov 2007, Kay Sievers wrote:
    >
    > > > In fact, if we were designing the kobject API from scratch, I'd suggest
    > > > making the ktype value an argument to kobject_init() so that it
    > > > _couldn't_ be omitted.
    > >
    > > Sounds fine, maybe we should also pass the name along, so it will be
    > > obvious what happens here:
    > > int kobject_init(struct kobject *kobj, struct kobj_type *type, const char *fmt, ...)
    >
    > I don't know... Normally *_init() routines can't fail, but this could.
    > Then things like device_register() would run into trouble: The caller
    > wouldn't know whether a failure occurred before or after the
    > kobject_init() call, so it wouldn't know what sort of cleanup action
    > was needed: kfree() or device_put().

    But wouldn't device_register() do the kobject cleanup for you when it
    fails? Why would a caller of device_register() care about the state of
    the kobject?

    > > Oh, if you want to rewind on error and have an initialized but still
    > > unregistered kobject, and just want to free the allocated name by
    > > calling kobject_cleanup() or kobject_put() you might not expect, that
    > > your whole object that embeds the kobject will be gone. Just something
    > > we need to document ...
    >
    > When that sort of thing happens, the unwinding should be done by the
    > code responsible for whole object. For example, if device_add() fails
    > then the caller should go on to call device_put() rather than
    > kfree(dev).
    >
    > That's how you would expect things to work in most cases. There aren't
    > many bare kobjects in the kernel.
    >
    > I agree that documenting this behavior would be good.

    Ok, fine. Hope we will collect all that information in the end. :)

    Kay

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