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To: linux-kernel@vger.kernel.org
From: Teemu Koponen <tkoponen@iki.fi>
Subject: Opening of blocking FIFOs not reliable?
Date: Fri, 12 Aug 2005 20:18:59 -0700
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Hi,

Opening a FIFO for WR_ONLY should release a previously blocked RD_ONLY 
open. I suspect this is not guaranteed on a heavily loaded Linux box.

Consider fs/fifo.c (of 2.6.13-rc6-git4) and its wait_for_partner() and 
wake_up_partner() functions. I think wait_for_partner()'s while loop 
never exits, *iff* the writer, after opening the FIFO, closes it before 
the reader gets scheduled. Shouldn't the writer's open() block until 
the reader's open() is done?

Teemu

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