jbd: clean up journal_try_to_free_buffers()

	return;

}

/*

 * journal_try_to_free_buffers() could race with journal_commit_transaction()

 * The latter might still hold the a count on buffers when inspecting

 * them on t_syncdata_list or t_locked_list.

 *

 * journal_try_to_free_buffers() will call this function to

 * wait for the current transaction to finish syncing data buffers, before

 * tryinf to free that buffer.

 *

 * Called with journal->j_state_lock held.

 */

static void journal_wait_for_transaction_sync_data(journal_t *journal)

{

	transaction_t *transaction = NULL;

	tid_t tid;

	spin_lock(&journal->j_state_lock);

	transaction = journal->j_committing_transaction;

	if (!transaction) {

		spin_unlock(&journal->j_state_lock);

		return;

	}

	tid = transaction->t_tid;

	spin_unlock(&journal->j_state_lock);

	log_wait_commit(journal, tid);

}

/**

 * int journal_try_to_free_buffers() - try to free page buffers.

 * @journal: journal for operation

	ret = try_to_free_buffers(page);

	/*

	 * There are a number of places where journal_try_to_free_buffers()

	 * could race with journal_commit_transaction(), the later still

	 * holds the reference to the buffers to free while processing them.

	 * try_to_free_buffers() failed to free those buffers. Some of the

	 * caller of releasepage() request page buffers to be dropped, otherwise

	 * treat the fail-to-free as errors (such as generic_file_direct_IO())

	 *

	 * So, if the caller of try_to_release_page() wants the synchronous

	 * behaviour(i.e make sure buffers are dropped upon return),

	 * let's wait for the current transaction to finish flush of

	 * dirty data buffers, then try to free those buffers again,

	 * with the journal locked.

	 */

	if (ret == 0 && (gfp_mask & __GFP_WAIT) && (gfp_mask & __GFP_FS)) {

		journal_wait_for_transaction_sync_data(journal);

		ret = try_to_free_buffers(page);

	}

busy:

	return ret;

}