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linux-next/fs/btrfs/ref-cache.h
Eric Paris 6bef4d3171 Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULL
btrfs inialize rb trees in quite a number of places by settin rb_node =
NULL;  The problem with this is that 17d9ddc72f in the
linux-next tree adds a new field to that struct which needs to be NULL for
the new rbtree library code to work properly.  This patch uses RB_ROOT as
the intializer so all of the relevant fields will be NULL'd.  Without the
patch I get a panic.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-08 16:26:50 -05:00

77 lines
2.2 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.
*/
#ifndef __REFCACHE__
#define __REFCACHE__
struct btrfs_extent_info {
/* bytenr and num_bytes find the extent in the extent allocation tree */
u64 bytenr;
u64 num_bytes;
/* objectid and offset find the back reference for the file */
u64 objectid;
u64 offset;
};
struct btrfs_leaf_ref {
struct rb_node rb_node;
struct btrfs_leaf_ref_tree *tree;
int in_tree;
atomic_t usage;
u64 root_gen;
u64 bytenr;
u64 owner;
u64 generation;
int nritems;
struct list_head list;
struct btrfs_extent_info extents[];
};
static inline size_t btrfs_leaf_ref_size(int nr_extents)
{
return sizeof(struct btrfs_leaf_ref) +
sizeof(struct btrfs_extent_info) * nr_extents;
}
static inline void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree)
{
tree->root = RB_ROOT;
INIT_LIST_HEAD(&tree->list);
spin_lock_init(&tree->lock);
}
static inline int btrfs_leaf_ref_tree_empty(struct btrfs_leaf_ref_tree *tree)
{
return RB_EMPTY_ROOT(&tree->root);
}
void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree);
struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(struct btrfs_root *root,
int nr_extents);
void btrfs_free_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
u64 bytenr);
int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
int shared);
int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
int shared);
int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref);
#endif