20318: Close held-open filehandles when deleting cache files.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>

diff --git a/sdk/go/arvados/keep_cache.go b/sdk/go/arvados/keep_cache.go
index eb9d4607bf198248e74b764b3306fc95cdb0c690..6aed35a215c6d22691c0c547536710c2630b85dd 100644 (file)
--- a/sdk/go/arvados/keep_cache.go
+++ b/sdk/go/arvados/keep_cache.go
@@ -260,12 +260,33 @@ func (cache *DiskCache) ReadAt(locator string, dst []byte, offset int) (int, err
 
 var quickReadAtLostRace = errors.New("quickReadAt: lost race")
 
-func (cache *DiskCache) deleteHeldopen(cachefilename string, heldopen *openFileEnt) {
+// Remove the cache entry for the indicated cachefilename if it
+// matches expect (quickReadAt() usage), or if expect is nil (tidy()
+// usage).
+//
+// If expect is non-nil, close expect's filehandle.
+//
+// If expect is nil and a different cache entry is deleted, close its
+// filehandle.
+func (cache *DiskCache) deleteHeldopen(cachefilename string, expect *openFileEnt) {
+       needclose := expect
+
        cache.heldopenLock.Lock()
-       if cache.heldopen[cachefilename] == heldopen {
+       found := cache.heldopen[cachefilename]
+       if found != nil && (expect == nil || expect == found) {
                delete(cache.heldopen, cachefilename)
+               needclose = found
        }
        cache.heldopenLock.Unlock()
+
+       if needclose != nil {
+               needclose.Lock()
+               defer needclose.Unlock()
+               if needclose.f != nil {
+                       needclose.f.Close()
+                       needclose.f = nil
+               }
+       }
 }
 
 // quickReadAt attempts to use a cached-filehandle approach to read
@@ -522,6 +543,7 @@ func (cache *DiskCache) tidy() {
        deleted := 0
        for _, ent := range ents {
                os.Remove(ent.path)
+               go cache.deleteHeldopen(ent.path, nil)
                deleted++
                totalsize -= ent.size
                if totalsize <= maxsize {