ocfs2: Local alloc window size changeable via mount option

Local alloc is a performance optimization in ocfs2 in which a node
takes a window of bits from the global bitmap and then uses that for
all small local allocations. This window size is fixed to 8MB currently.
This patch allows users to specify the window size in MB including
disabling it by passing in 0. If the number specified is too large,
the fs will use the default value of 8MB.

mount -o localalloc=X /dev/sdX /mntpoint

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 82802f5672a1..d12bd7036da7 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -231,6 +231,7 @@ struct ocfs2_super
         struct ocfs2_journal *journal;
         unsigned long osb_commit_interval;
 
+        int local_alloc_size;
         enum ocfs2_local_alloc_state local_alloc_state;
         struct buffer_head *local_alloc_bh;
         u64 la_last_gd;