* get_vnode() did not decrease the sUnusedVnodes counter when taking one node

of that list.
* Added a vfs_free_unused_vnodes() function that calls the low memory handler
  directly.
* create_sem_etc() now calls the above function in case there are no semaphores
  available anymore; this usually frees up to 2 semaphores per node (one from
  the cache if there is a file cache attached, and eventually one from the
  file system).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16610 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/vfs.h

@@ -96,6 +96,7 @@ status_t vfs_get_fs_node_from_path(mount_id mountID, const char *path,
 status_t vfs_stat_vnode(void *_vnode, struct stat *stat);
 status_t vfs_get_vnode_name(void *vnode, char *name, size_t nameSize);
 status_t vfs_get_cwd(mount_id *_mountID, vnode_id *_vnodeID);
+void vfs_free_unused_vnodes(int32 level);
 
 /* special module convenience call */
 status_t vfs_get_module_path(const char *basePath, const char *moduleName,