linux/fs/btrfs/ordered-data.c

272 lines
6.5 KiB
C

/*
* Copyright (C) 2007 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/gfp.h>
#include <linux/slab.h>
#include "ctree.h"
#include "transaction.h"
#include "btrfs_inode.h"
struct tree_entry {
u64 root_objectid;
u64 objectid;
struct inode *inode;
struct rb_node rb_node;
};
/*
* returns > 0 if entry passed (root, objectid) is > entry,
* < 0 if (root, objectid) < entry and zero if they are equal
*/
static int comp_entry(struct tree_entry *entry, u64 root_objectid,
u64 objectid)
{
if (root_objectid < entry->root_objectid)
return -1;
if (root_objectid > entry->root_objectid)
return 1;
if (objectid < entry->objectid)
return -1;
if (objectid > entry->objectid)
return 1;
return 0;
}
static struct rb_node *tree_insert(struct rb_root *root, u64 root_objectid,
u64 objectid, struct rb_node *node)
{
struct rb_node ** p = &root->rb_node;
struct rb_node * parent = NULL;
struct tree_entry *entry;
int comp;
while(*p) {
parent = *p;
entry = rb_entry(parent, struct tree_entry, rb_node);
comp = comp_entry(entry, root_objectid, objectid);
if (comp < 0)
p = &(*p)->rb_left;
else if (comp > 0)
p = &(*p)->rb_right;
else
return parent;
}
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return NULL;
}
static struct rb_node *__tree_search(struct rb_root *root, u64 root_objectid,
u64 objectid, struct rb_node **prev_ret)
{
struct rb_node * n = root->rb_node;
struct rb_node *prev = NULL;
struct tree_entry *entry;
struct tree_entry *prev_entry = NULL;
int comp;
while(n) {
entry = rb_entry(n, struct tree_entry, rb_node);
prev = n;
prev_entry = entry;
comp = comp_entry(entry, root_objectid, objectid);
if (comp < 0)
n = n->rb_left;
else if (comp > 0)
n = n->rb_right;
else
return n;
}
if (!prev_ret)
return NULL;
while(prev && comp_entry(prev_entry, root_objectid, objectid) >= 0) {
prev = rb_next(prev);
prev_entry = rb_entry(prev, struct tree_entry, rb_node);
}
*prev_ret = prev;
return NULL;
}
static inline struct rb_node *tree_search(struct rb_root *root,
u64 root_objectid, u64 objectid)
{
struct rb_node *prev;
struct rb_node *ret;
ret = __tree_search(root, root_objectid, objectid, &prev);
if (!ret)
return prev;
return ret;
}
int btrfs_add_ordered_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 root_objectid = root->root_key.objectid;
u64 transid = root->fs_info->running_transaction->transid;
struct tree_entry *entry;
struct rb_node *node;
struct btrfs_ordered_inode_tree *tree;
if (transid <= BTRFS_I(inode)->ordered_trans)
return 0;
tree = &root->fs_info->running_transaction->ordered_inode_tree;
read_lock(&tree->lock);
node = __tree_search(&tree->tree, root_objectid, inode->i_ino, NULL);
read_unlock(&tree->lock);
if (node) {
return 0;
}
entry = kmalloc(sizeof(*entry), GFP_NOFS);
if (!entry)
return -ENOMEM;
write_lock(&tree->lock);
entry->objectid = inode->i_ino;
entry->root_objectid = root_objectid;
entry->inode = inode;
node = tree_insert(&tree->tree, root_objectid,
inode->i_ino, &entry->rb_node);
BTRFS_I(inode)->ordered_trans = transid;
write_unlock(&tree->lock);
if (node)
kfree(entry);
else
igrab(inode);
return 0;
}
int btrfs_find_first_ordered_inode(struct btrfs_ordered_inode_tree *tree,
u64 *root_objectid, u64 *objectid,
struct inode **inode)
{
struct tree_entry *entry;
struct rb_node *node;
write_lock(&tree->lock);
node = tree_search(&tree->tree, *root_objectid, *objectid);
if (!node) {
write_unlock(&tree->lock);
return 0;
}
entry = rb_entry(node, struct tree_entry, rb_node);
while(comp_entry(entry, *root_objectid, *objectid) >= 0) {
node = rb_next(node);
if (!node)
break;
entry = rb_entry(node, struct tree_entry, rb_node);
}
if (!node) {
write_unlock(&tree->lock);
return 0;
}
*root_objectid = entry->root_objectid;
*inode = entry->inode;
atomic_inc(&entry->inode->i_count);
*objectid = entry->objectid;
write_unlock(&tree->lock);
return 1;
}
int btrfs_find_del_first_ordered_inode(struct btrfs_ordered_inode_tree *tree,
u64 *root_objectid, u64 *objectid,
struct inode **inode)
{
struct tree_entry *entry;
struct rb_node *node;
write_lock(&tree->lock);
node = tree_search(&tree->tree, *root_objectid, *objectid);
if (!node) {
write_unlock(&tree->lock);
return 0;
}
entry = rb_entry(node, struct tree_entry, rb_node);
while(comp_entry(entry, *root_objectid, *objectid) >= 0) {
node = rb_next(node);
if (!node)
break;
entry = rb_entry(node, struct tree_entry, rb_node);
}
if (!node) {
write_unlock(&tree->lock);
return 0;
}
*root_objectid = entry->root_objectid;
*objectid = entry->objectid;
*inode = entry->inode;
atomic_inc(&entry->inode->i_count);
rb_erase(node, &tree->tree);
write_unlock(&tree->lock);
kfree(entry);
return 1;
}
static int __btrfs_del_ordered_inode(struct btrfs_ordered_inode_tree *tree,
struct inode *inode,
u64 root_objectid, u64 objectid)
{
struct tree_entry *entry;
struct rb_node *node;
struct rb_node *prev;
write_lock(&tree->lock);
node = __tree_search(&tree->tree, root_objectid, objectid, &prev);
if (!node) {
write_unlock(&tree->lock);
return 0;
}
rb_erase(node, &tree->tree);
BTRFS_I(inode)->ordered_trans = 0;
write_unlock(&tree->lock);
entry = rb_entry(node, struct tree_entry, rb_node);
kfree(entry);
return 1;
}
int btrfs_del_ordered_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 root_objectid = root->root_key.objectid;
int ret = 0;
spin_lock(&root->fs_info->new_trans_lock);
if (root->fs_info->running_transaction) {
struct btrfs_ordered_inode_tree *tree;
tree = &root->fs_info->running_transaction->ordered_inode_tree;
ret = __btrfs_del_ordered_inode(tree, inode, root_objectid,
inode->i_ino);
}
spin_unlock(&root->fs_info->new_trans_lock);
return ret;
}