tree 67b452d423dc64aa3896078a2f90066922bbf384
parent 1b22bad779be7fe07242be04749ec969164528b8
author Alexandre Oliva <oliva@lsd.ic.unicamp.br> 1322678580 -0500
committer Chris Mason <chris.mason@oracle.com> 1322678580 -0500

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>