Merge branch '19362-all-webdav-via-sitefs'

[arvados.git] / sdk / go / arvados / fs_base.go

diff --git a/sdk/go/arvados/fs_base.go b/sdk/go/arvados/fs_base.go
index 2ad4d1f859f1141035c04cb4180c5ef623d1fa04..5569554ab883b2b9f31748bf983f592b43f96b65 100644 (file)
--- a/sdk/go/arvados/fs_base.go
+++ b/sdk/go/arvados/fs_base.go
@@ -420,10 +420,20 @@ func (n *treenode) Sync() error {
 }
 
 func (n *treenode) MemorySize() (size int64) {
+       // To avoid making other callers wait while we count the
+       // entire filesystem size, we lock the node only long enough
+       // to copy the list of children. We accept that the resulting
+       // size will sometimes be misleading (e.g., we will
+       // double-count an item that moves from A to B after we check
+       // A's size but before we check B's size).
        n.RLock()
-       defer n.RUnlock()
        debugPanicIfNotLocked(n, false)
+       todo := make([]inode, 0, len(n.inodes))
        for _, inode := range n.inodes {
+               todo = append(todo, inode)
+       }
+       n.RUnlock()
+       for _, inode := range todo {
                size += inode.MemorySize()
        }
        return 64 + size
@@ -631,7 +641,15 @@ func (fs *fileSystem) Rename(oldname, newname string) error {
        }
        locked := map[sync.Locker]bool{}
        for i := len(needLock) - 1; i >= 0; i-- {
-               if n := needLock[i]; !locked[n] {
+               n := needLock[i]
+               if fs, ok := n.(FileSystem); ok {
+                       // Lock the fs's root dir directly, not
+                       // through the fs. Otherwise our "locked" map
+                       // would not reliably prevent double-locking
+                       // the fs's root dir.
+                       n = fs.rootnode()
+               }
+               if !locked[n] {
                        n.Lock()
                        defer n.Unlock()
                        locked[n] = true