Btrfs: kill unused parts of block_rsv

The priority and refill_used flags are not used anymore, and neither is the
usage counter, so just remove them from btrfs_block_rsv.
Signed-off-by: Josef Bacik <josef@redhat.com>

fs/btrfs/ctree.h

@@ -774,9 +774,6 @@ struct btrfs_block_rsv {
 	u64 reserved;
 	struct btrfs_space_info *space_info;
 	spinlock_t lock;
-	atomic_t usage;
-	unsigned int priority:8;
-	unsigned int refill_used:1;
 	unsigned int full:1;
 };
 

fs/btrfs/extent-tree.c

@@ -3659,8 +3659,6 @@ void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
 {
 	memset(rsv, 0, sizeof(*rsv));
 	spin_lock_init(&rsv->lock);
-	atomic_set(&rsv->usage, 1);
-	rsv->priority = 6;
 }
 
 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
@@ -3681,10 +3679,8 @@ struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
 void btrfs_free_block_rsv(struct btrfs_root *root,
 			  struct btrfs_block_rsv *rsv)
 {
-	if (rsv && atomic_dec_and_test(&rsv->usage)) {
 	btrfs_block_rsv_release(root, rsv, (u64)-1);
 	kfree(rsv);
-	}
 }
 
 int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
@@ -3734,14 +3730,11 @@ int btrfs_block_rsv_check(struct btrfs_trans_handle *trans,
 	if (!ret)
 		return 0;
 
-	if (block_rsv->refill_used) {
-		ret = reserve_metadata_bytes(trans, root, block_rsv,
-					     num_bytes, 0);
+	ret = reserve_metadata_bytes(trans, root, block_rsv, num_bytes, 0);
 	if (!ret) {
 		block_rsv_add_bytes(block_rsv, num_bytes, 0);
 		return 0;
 	}
-	}
 
 	if (commit_trans) {
 		struct btrfs_space_info *sinfo = block_rsv->space_info;
@@ -3859,16 +3852,12 @@ static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
 
 	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 	fs_info->chunk_block_rsv.space_info = space_info;
-	fs_info->chunk_block_rsv.priority = 10;
 
 	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 	fs_info->global_block_rsv.space_info = space_info;
-	fs_info->global_block_rsv.priority = 10;
-	fs_info->global_block_rsv.refill_used = 1;
 	fs_info->delalloc_block_rsv.space_info = space_info;
 	fs_info->trans_block_rsv.space_info = space_info;
 	fs_info->empty_block_rsv.space_info = space_info;
-	fs_info->empty_block_rsv.priority = 10;
 
 	fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
 	fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;

fs/btrfs/relocation.c

@@ -3650,8 +3650,6 @@ int prepare_to_relocate(struct reloc_control *rc)
 	if (ret)
 		return ret;
 
-	rc->block_rsv->refill_used = 1;
-
 	memset(&rc->cluster, 0, sizeof(rc->cluster));
 	rc->search_start = rc->block_group->key.objectid;
 	rc->extents_found = 0;