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/*
* Copyright (C) 2008 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/gfp.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>
#include <linux/page-flags.h>
#include <linux/bug.h>
#include "ctree.h"
#include "extent_io.h"
#include "locking.h"
int btrfs_tree_lock(struct extent_buffer *eb)
{
int i;
if (!TestSetPageLocked(eb->first_page))
return 0;
for (i = 0; i < 512; i++) {
cpu_relax();
if (!TestSetPageLocked(eb->first_page))
return 0;
}
cpu_relax();
lock_page(eb->first_page);
return 0;
}
int btrfs_try_tree_lock(struct extent_buffer *eb)
{
return TestSetPageLocked(eb->first_page);
}
int btrfs_tree_unlock(struct extent_buffer *eb)
{
WARN_ON(!PageLocked(eb->first_page));
unlock_page(eb->first_page);
return 0;
}
int btrfs_tree_locked(struct extent_buffer *eb)
{
return PageLocked(eb->first_page);
}
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