set btree_node_size for the cache_sb based on bucket_size

Change-Id: I98dab6e9a221cd8781095039d653ace84ffae806
Signed-off-by: Jacob Malevich <jam@daterainc.com>

1 files changed, 26 insertions, 2 deletions

diff --git a/bcache.c b/bcache.c
index fbaaa0ef..7e061649 100644
--- a/bcache.c
+++ b/bcache.c
@@ -530,12 +530,34 @@ int dev_open(const char *dev, bool wipe_bcache)
 	return fd;
 }
 
+static unsigned min_bucket_size(int num_bucket_sizes, unsigned *bucket_sizes)
+{
+	int i;
+	unsigned min = bucket_sizes[0];
+
+	for (i = 0; i < num_bucket_sizes; i++)
+		min = bucket_sizes[i] < min ? bucket_sizes[i] : min;
+
+	return min;
+}
+
+static unsigned node_size(unsigned bucket_size) {
+
+	if (bucket_size <= 256)
+		return bucket_size;
+	else if (bucket_size <= 512)
+		return bucket_size / 2;
+	else
+		return bucket_size / 4;
+}
+
 void write_cache_sbs(int *fds, struct cache_sb *sb,
 			    unsigned block_size, unsigned *bucket_sizes,
 				int num_bucket_sizes)
 {
 	char uuid_str[40], set_uuid_str[40];
 	size_t i;
+	unsigned min_size = min_bucket_size(num_bucket_sizes, bucket_sizes);
 
 	sb->offset	= SB_SECTOR;
 	sb->version	= BCACHE_SB_VERSION_CDEV_V3;
@@ -552,11 +574,13 @@ void write_cache_sbs(int *fds, struct cache_sb *sb,
 	for (i = 0; i < sb->nr_in_set; i++) {
 		struct cache_member *m = sb->members + i;
 
-		sb->uuid = m->uuid;
-		if(num_bucket_sizes <= 1)
+		if (num_bucket_sizes <= 1)
 			sb->bucket_size = bucket_sizes[0];
 		else
 			sb->bucket_size	= bucket_sizes[i];
+		SET_CACHE_BTREE_NODE_SIZE(sb, node_size(min_size));
+
+		sb->uuid = m->uuid;
 		sb->nbuckets		= getblocks(fds[i]) / sb->bucket_size;
 		sb->nr_this_dev		= i;
 		sb->first_bucket	= (23 / sb->bucket_size) + 1;