From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [RFC][PATCH v5] readahead: introduce O_RANDOM for
	POSIX_FADV_RANDOM
Date: Tue, 5 Jan 2010 11:27:15 +0800
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Cc: Christoph Hellwig <hch@infradead.org>,
	Andi Kleen <andi@firstfloor.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Quentin Barnes <qbarnes+nfs@yahoo-inc.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	Nick Piggin <npiggin@suse.de>,
	Steven Whitehouse <swhiteho@redhat.com>,
	David Howells <dhowells@redhat.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Jonathan Corbet <corbet@lwn.net>,
	Eric Paris <eparis@redhat.com>
To: Stephen Rothwell <sfr@canb.auug.org.au>
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On Tue, Jan 05, 2010 at 11:18:01AM +0800, Wu Fengguang wrote:
>  
> +/*
> + * usage of open(O_RANDOM) is disabled: __dentry_open() will nuke this bit
> + */
> +#ifndef O_RANDOM
> +#define O_RANDOM	0200000000	/* random access pattern hint */
> +#endif
> +

Tested with this program, output is

        flags=0x9001 O_SYNC=0x1000 O_RANDOM=0

My user space O_SYNC is still the old O_DSYNC. But should be OK to
test the sparc O_SYNC.

------------------------------------------------------------------------------
#include <fcntl.h>
#include <stdio.h>

#define O_RANDOM       040000000       /* random access pattern hint */

int main (void)
{
	int fd, flags;

	fd = open("/tmp/fcntl-test",
		  O_WRONLY | O_CREAT | O_SYNC | O_RANDOM, 0666);
	flags = fcntl(fd, F_GETFL, 0);
	printf("flags=%#lx O_SYNC=%#lx O_RANDOM=%#lx\n",
	       flags, flags & O_SYNC, flags & O_RANDOM);
}
------------------------------------------------------------------------------

Thanks,
Fengguang