Btrfs: fix how we set max_size for free space clusters

This patch fixes a problem where max_size can be set to 0 even though we
filled the cluster properly.  We set max_size to 0 if we restart the cluster
window, but if the new start entry is big enough to be our new cluster then we
could return with a max_size set to 0, which will mean the next time we try to
allocate from this cluster it will fail.  So set max_extent to the entry's
size.  Tested this on my box and now we actually allocate from the cluster
after we fill it.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 5c2caad76212d2b5bfcc4329e255978525d6f5ed..cb2849f03251d081c6a6eca73f9372f0798517ac 100644 (file)
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1296,7 +1296,7 @@ again:
                        window_start = entry->offset;
                        window_free = entry->bytes;
                        last = entry;
-                       max_extent = 0;
+                       max_extent = entry->bytes;
                } else {
                        last = next;
                        window_free += next->bytes;