Messages in this thread | | | Date | Wed, 2 Dec 2009 20:48:28 +0000 | From | Alan Cox <> | Subject | Re: [PATCH v3] vfs: new O_NODE open flag |
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[Ridiculous cc list cleaned]
> > udev defends against it with the specific knowledge that any existing > > open means the device is open and cannot be unloaded. The combination is > > required (and some other happenstance properties). > > You're still missing the point. O_NODE is like a hard link, except > the reference doesn't come from the filesystem but from a file > descriptor. From udev's perspective there's no difference.
I don't think I am missing the point here. You have a reference to an object in the fs but you don't have a reference to the driver underneath s the driver can change on you *while* you have the O_NODE open and fd live. That cannot happen with a hard link and open.
It isn't the same thing as far as I can see. You don't have the barrier between the operations that occurs in the real open/close case because they lock the driver.
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