linux-kernel - Re: Deleting large files

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Date:	Sun, 11 May 2008 12:30:58 +0200 (CEST)
From:	Jan Engelhardt <jengelh@...ozas.de>
To:	Morten Welinder <mwelinder@...il.com>
cc:	"linux-os (Dick Johnson)" <linux-os@...logic.com>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: Deleting large files


On Thursday 2008-05-08 01:14, Morten Welinder wrote:

>>  Suppose you had an N GB file that just filled up the disk. You now
>>  delete it, but get control back before it is really deleted. You
>>  now start to write a new file that will eventually just fill up
>>  the disk. [...]
>
>NFS does not do that -- in fact, I don't believe any file system does that
>unless you can guarantee at least that no other process or the kernel has
>that file open;

Iff a process still has the file open, your unlink will succeed immediately
anyway, and the real deallocation takes place when the last process runs
close(). Which shows an interesting fact too: not only unlink can block.
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