Re: [PATCH] thread wakeup fix for 2.4.0-test7

From: kuznet@ms2.inr.ac.ru
Date: Sun Aug 27 2000 - 14:10:29 EST


Hello!

> normal UNIX semantics. close(dup(fd)) should have _no_ effect.

Grrr... No doubts!

File is closed, when all the references from user disappear.

I have already tried to clean this issue times in the past.

File must have two refcounts: f_users and f_count.
f_users counts references from user i.e. from file descriptor
tables (and from a few of descriptor-less files inside kernel).

fget() and fput() work on f_count.

When f_users becomes zero, file is closed, but not destroyed.
Method fops->flush() is called to shutdown it. It wakes up
processes holding f_count on this file, particualry.

When f_count becomes zero, it is destroyed. Method fos->close()
is called before destruction.

Alexey
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