In message <[EMAIL PROTECTED]>, Warner Losh writes:
>In message <[EMAIL PROTECTED]> Luigi Rizzo writes:
>: > In message <[EMAIL PROTECTED]> David Rufino writes:
>: > : I'm writing a character device driver in which each minor device can be
>: > : opened more than once. When a device is opened is there a way to associate
>: > : some private data for each opened instance ? Thanks.
>: >
>: > No. You only get one close call and in the kernel all instances of a
>: > minor device are treated identically.
>:
>: this is not true anymore, there is some special flag you can
>: specify in cdevsw or so which passes all close calls to the driver.
>
>It is only half untrue. There's a special flag to get all calls to
>close, but you have no way of knowing which instance of the minor
>device is being closed because they are all identical in the kernel's
>eyes.
And you actually cannot know how many filedescriptors are open in
how many processes because neither dup(2) nor fork(2) result in
a (pseudo-)open call.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
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