handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
			      int revoke_records, gfp_t gfp_mask,
			      unsigned int type, unsigned int line_no)
{
	handle_t *handle = journal_current_handle();
	int err;

	if (!journal)
		return ERR_PTR(-EROFS);

	if (handle) {
		J_ASSERT(handle->h_transaction->t_journal == journal);
		handle->h_ref++;
		return handle;
	}

	nblocks += DIV_ROUND_UP(revoke_records,
				journal->j_revoke_records_per_block);
	handle = new_handle(nblocks);
	if (!handle)
		return ERR_PTR(-ENOMEM);
	if (rsv_blocks) {
		handle_t *rsv_handle;

		rsv_handle = new_handle(rsv_blocks);
		if (!rsv_handle) {
			jbd2_free_handle(handle);
			return ERR_PTR(-ENOMEM);
		}
		rsv_handle->h_reserved = 1;
		rsv_handle->h_journal = journal;
		handle->h_rsv_handle = rsv_handle;
	}
	handle->h_revoke_credits = revoke_records;

	err = start_this_handle(journal, handle, gfp_mask);
	if (err < 0) {
		if (handle->h_rsv_handle)
			jbd2_free_handle(handle->h_rsv_handle);
		jbd2_free_handle(handle);
		return ERR_PTR(err);
	}
	handle->h_type = type;
	handle->h_line_no = line_no;
	trace_jbd2_handle_start(journal->j_fs_dev->bd_dev,
				handle->h_transaction->t_tid, type,
				line_no, nblocks);

	return handle;
}
Unknown