xfs_alloc_space_available(
	struct xfs_alloc_arg	*args,
	xfs_extlen_t		min_free,
	int			flags)
{
	struct xfs_perag	*pag = args->pag;
	xfs_extlen_t		alloc_len, longest;
	xfs_extlen_t		reservation; /* blocks that are still reserved */
	int			available;
	xfs_extlen_t		agflcount;

	if (flags & XFS_ALLOC_FLAG_FREEING)
		return true;

	reservation = xfs_ag_resv_needed(pag, args->resv);

	/* do we have enough contiguous free space for the allocation? */
	alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop;
	longest = xfs_alloc_longest_free_extent(pag, min_free, reservation);
	if (longest < alloc_len)
		return false;

	/*
	 * Do we have enough free space remaining for the allocation? Don't
	 * account extra agfl blocks because we are about to defer free them,
	 * making them unavailable until the current transaction commits.
	 */
	agflcount = min_t(xfs_extlen_t, pag->pagf_flcount, min_free);
	available = (int)(pag->pagf_freeblks + agflcount -
			  reservation - min_free - args->minleft);
	if (available < (int)max(args->total, alloc_len))
		return false;

	/*
	 * Clamp maxlen to the amount of free space available for the actual
	 * extent allocation.
	 */
	if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) {
		args->maxlen = available;
		ASSERT(args->maxlen > 0);
		ASSERT(args->maxlen >= args->minlen);
	}

	return true;
}
Unknown