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/*
* 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 "kerncompat.h"
#include "disk-io.h"
#include "transaction.h"
#include "messages.h"
struct btrfs_trans_handle* btrfs_start_transaction(struct btrfs_root *root,
int num_blocks)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *h = kzalloc(sizeof(*h), GFP_NOFS);
if (fs_info->transaction_aborted)
return ERR_PTR(-EROFS);
if (!h)
return ERR_PTR(-ENOMEM);
if (root->commit_root) {
error("commit_root aleady set when starting transaction");
kfree(h);
return ERR_PTR(-EINVAL);
}
if (fs_info->running_transaction) {
error("attempt to start transaction over already running one");
kfree(h);
return ERR_PTR(-EINVAL);
}
h->fs_info = fs_info;
fs_info->running_transaction = h;
fs_info->generation++;
h->transid = fs_info->generation;
h->blocks_reserved = num_blocks;
h->reinit_extent_tree = false;
root->last_trans = h->transid;
root->commit_root = root->node;
extent_buffer_get(root->node);
return h;
}
static int update_cowonly_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
int ret;
u64 old_root_bytenr;
struct btrfs_root *tree_root = root->fs_info->tree_root;
while(1) {
old_root_bytenr = btrfs_root_bytenr(&root->root_item);
if (old_root_bytenr == root->node->start)
break;
btrfs_set_root_bytenr(&root->root_item,
root->node->start);
btrfs_set_root_generation(&root->root_item,
trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
if (ret < 0)
return ret;
btrfs_write_dirty_block_groups(trans);
}
return 0;
}
int commit_tree_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
struct btrfs_root *root;
struct list_head *next;
struct extent_buffer *eb;
int ret;
if (fs_info->readonly)
return 0;
eb = fs_info->tree_root->node;
extent_buffer_get(eb);
ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
free_extent_buffer(eb);
if (ret)
return ret;
/*
* If the above CoW is the first one to dirty the current tree_root,
* delayed refs for it won't be run until after this function has
* finished executing, meaning we won't process the extent tree root,
* which will have been added to ->dirty_cowonly_roots. So run
* delayed refs here as well.
*/
ret = btrfs_run_delayed_refs(trans, -1);
if (ret)
return ret;
while(!list_empty(&fs_info->dirty_cowonly_roots)) {
next = fs_info->dirty_cowonly_roots.next;
list_del_init(next);
root = list_entry(next, struct btrfs_root, dirty_list);
ret = update_cowonly_root(trans, root);
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
if (ret < 0)
return ret;
}
return 0;
}
int __commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 start;
u64 end;
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *eb;
struct extent_io_tree *tree = &fs_info->extent_cache;
int ret;
while(1) {
ret = find_first_extent_bit(tree, 0, &start, &end,
EXTENT_DIRTY);
if (ret)
break;
while(start <= end) {
eb = find_first_extent_buffer(tree, start);
BUG_ON(!eb || eb->start != start);
ret = write_tree_block(trans, fs_info, eb);
BUG_ON(ret);
start += eb->len;
clear_extent_buffer_dirty(eb);
free_extent_buffer(eb);
}
}
return 0;
}
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 transid = trans->transid;
int ret = 0;
struct btrfs_fs_info *fs_info = root->fs_info;
if (trans->fs_info->transaction_aborted)
return -EROFS;
/*
* Flush all accumulated delayed refs so that root-tree updates are
* consistent
*/
ret = btrfs_run_delayed_refs(trans, -1);
BUG_ON(ret);
if (root->commit_root == root->node)
goto commit_tree;
if (root == root->fs_info->tree_root)
goto commit_tree;
if (root == root->fs_info->chunk_root)
goto commit_tree;
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
btrfs_set_root_bytenr(&root->root_item, root->node->start);
btrfs_set_root_generation(&root->root_item, trans->transid);
root->root_item.level = btrfs_header_level(root->node);
ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
BUG_ON(ret);
commit_tree:
ret = commit_tree_roots(trans, fs_info);
BUG_ON(ret);
/*
* Ensure that all comitted roots are properly accounted in the
* extent tree
*/
ret = btrfs_run_delayed_refs(trans, -1);
BUG_ON(ret);
btrfs_write_dirty_block_groups(trans);
__commit_transaction(trans, root);
if (ret < 0)
goto out;
write_ctree_super(trans);
btrfs_finish_extent_commit(trans, fs_info->extent_root,
&fs_info->pinned_extents);
kfree(trans);
free_extent_buffer(root->commit_root);
root->commit_root = NULL;
fs_info->running_transaction = NULL;
fs_info->last_trans_committed = transid;
out:
return ret;
}
void btrfs_abort_transaction(struct btrfs_trans_handle *trans, int error)
{
trans->fs_info->transaction_aborted = error;
}
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