a61e6f29dc
This replaces the use of the page cache lock bit for locking, which wasn't suitable for block size < page size and couldn't be used recursively. The mutexes alone don't fix either problem, but they are the first step. Signed-off-by: Chris Mason <chris.mason@oracle.com>
59 lines
1.4 KiB
C
59 lines
1.4 KiB
C
/*
|
|
* 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 (mutex_trylock(&eb->mutex))
|
|
return 0;
|
|
for (i = 0; i < 512; i++) {
|
|
cpu_relax();
|
|
if (mutex_trylock(&eb->mutex))
|
|
return 0;
|
|
}
|
|
cpu_relax();
|
|
mutex_lock(&eb->mutex);
|
|
return 0;
|
|
}
|
|
|
|
int btrfs_try_tree_lock(struct extent_buffer *eb)
|
|
{
|
|
return mutex_trylock(&eb->mutex);
|
|
}
|
|
|
|
int btrfs_tree_unlock(struct extent_buffer *eb)
|
|
{
|
|
mutex_unlock(&eb->mutex);
|
|
return 0;
|
|
}
|
|
|
|
int btrfs_tree_locked(struct extent_buffer *eb)
|
|
{
|
|
return mutex_is_locked(&eb->mutex);
|
|
}
|
|
|