linux-kernel - Re: Finding hardlinks

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Date:	Fri, 29 Dec 2006 10:02:23 +0000
From:	Pavel Machek <pavel@...e.cz>
To:	Mikulas Patocka <mikulas@...ax.karlin.mff.cuni.cz>
Subject: Re: Finding hardlinks

Hi!

> >>If user (or script) doesn't specify that flag, it 
> >>doesn't help. I think
> >>the best solution for these filesystems would be 
> >>either to add new syscall
> >> 	int is_hardlink(char *filename1, char *filename2)
> >>(but I know adding syscall bloat may be objectionable)
> >
> >it's also the wrong api; the filenames may have been 
> >changed under you
> >just as you return from this call, so it really is a
> >"was_hardlink_at_some_point()" as you specify it.
> >If you make it work on fd's.. it has a chance at least.
> 
> Yes, but it doesn't matter --- if the tree changes under 
> "cp -a" command, no one guarantees you what you get.
> 	int fis_hardlink(int handle1, int handle 2);
> Is another possibility but it can't detect hardlinked 
> symlinks.

Ugh. Is it even legal to hardlink symlinks?

Anyway, cp -a is not the only application that wants to do hardlink
detection.
						Pavel
-- 
Thanks for all the (sleeping) penguins.
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