Commit 425d8315 authored Nov 30, 2011 by Alexandre Oliva Committed by Chris Mason Nov 30, 2011

Btrfs: skip block groups without enough space for a cluster

We test whether a block group has enough free space to hold the
requested block, but when we're doing clustered allocation, we can
save some cycles by testing whether it has enough room for the cluster
upfront, otherwise we end up attempting to set up a cluster and
failing. Only in the NO_EMPTY_SIZE loop do we attempt an unclustered
allocation, and by then we'll have zeroed the cluster size, so this
patch won't stop us from using the block group as a last resort.

Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent 1b22bad7

fs/btrfs/extent-tree.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -5278,7 +5278,7 @@ alloc:
	spin_lock(&block_group->free_space_ctl->tree_lock);		spin_lock(&block_group->free_space_ctl->tree_lock);
	if (cached &&		if (cached &&
	block_group->free_space_ctl->free_space <		block_group->free_space_ctl->free_space <
	num_bytes + empty_size) {		num_bytes + empty_cluster + empty_size) {
	spin_unlock(&block_group->free_space_ctl->tree_lock);		spin_unlock(&block_group->free_space_ctl->tree_lock);
	goto loop;		goto loop;
	}		}

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