static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
int num_blocks, int wait)
{
struct btrfs_trans_handle *h =
kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
int ret;
mutex_lock(&root->fs_info->trans_mutex);
if (!root->fs_info->log_root_recovering &&
((wait == 1 && !root->fs_info->open_ioctl_trans) || wait == 2))
wait_current_trans(root);
ret = join_transaction(root);
BUG_ON(ret);
h->transid = root->fs_info->running_transaction->transid;
h->transaction = root->fs_info->running_transaction;
h->blocks_reserved = num_blocks;
h->blocks_used = 0;
h->block_group = 0;
h->alloc_exclude_nr = 0;
h->alloc_exclude_start = 0;
h->delayed_ref_updates = 0;
if (!current->journal_info)
current->journal_info = h;
root->fs_info->running_transaction->use_count++;
record_root_in_trans(h, root);
mutex_unlock(&root->fs_info->trans_mutex);
return h;
}
static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
u64 num_items, int type)
{
struct btrfs_trans_handle *h;
struct btrfs_transaction *cur_trans;
int retries = 0;
int ret;
again:
h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
if (!h)
return ERR_PTR(-ENOMEM);
mutex_lock(&root->fs_info->trans_mutex);
if (may_wait_transaction(root, type))
wait_current_trans(root);
ret = join_transaction(root);
BUG_ON(ret);
cur_trans = root->fs_info->running_transaction;
cur_trans->use_count++;
mutex_unlock(&root->fs_info->trans_mutex);
h->transid = cur_trans->transid;
h->transaction = cur_trans;
h->blocks_used = 0;
h->block_group = 0;
h->bytes_reserved = 0;
h->delayed_ref_updates = 0;
h->block_rsv = NULL;
smp_mb();
if (cur_trans->blocked && may_wait_transaction(root, type)) {
btrfs_commit_transaction(h, root);
goto again;
}
if (num_items > 0) {
ret = btrfs_trans_reserve_metadata(h, root, num_items,
&retries);
if (ret == -EAGAIN) {
btrfs_commit_transaction(h, root);
goto again;
}
if (ret < 0) {
btrfs_end_transaction(h, root);
return ERR_PTR(ret);
}
}
mutex_lock(&root->fs_info->trans_mutex);
record_root_in_trans(h, root);
mutex_unlock(&root->fs_info->trans_mutex);
if (!current->journal_info && type != TRANS_USERSPACE)
current->journal_info = h;
return h;
}