hfsplus: fix logic of alloc/free b-tree node

The hfs_bmap_alloc() and hfs_bmap_free() modify
the b-tree's counters and nodes' bitmap of b-tree.
However, hfs_btree_write() synchronizes the state of
in-core b-tree's counters and node's bitmap with
b-tree's descriptor in header node. Postponing this
synchronization could result in inconsistent state of
file system volume. This patch adds calling of
hfs_btree_write() in hfs_bmap_alloc() and hfs_bmap_free()
methods.

cc: John Paul Adrian Glaubitz <[email protected]>
cc: Yangtao Li <[email protected]>
cc: [email protected]
Signed-off-by: Viacheslav Dubeyko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Viacheslav Dubeyko <[email protected]>

Author: dubeyko

fs/hfsplus/btree.c

@@ -564,6 +564,7 @@ struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
 						set_page_dirty(page);
 						kunmap_local(data);
 						tree->free_nodes--;
+						hfs_btree_write(tree);
 						mark_inode_dirty(tree->inode);
 						hfs_bnode_put(node);
 						return hfs_bnode_create(tree,
@@ -585,6 +586,7 @@ struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
 		if (!nidx) {
 			hfs_dbg("create new bmap node\n");
 			next_node = hfs_bmap_new_bmap(node, idx);
+			hfs_btree_write(tree);
 		} else
 			next_node = hfs_bnode_find(tree, nidx);
 		hfs_bnode_put(node);
@@ -655,6 +657,7 @@ void hfs_bmap_free(struct hfs_bnode *node)
 			nidx, node->type);
 	} else {
 		tree->free_nodes++;
+		hfs_btree_write(tree);
 		mark_inode_dirty(tree->inode);
 	}