From 37a6b0ae5ff48137086532a28ac55ab195d5698f Mon Sep 17 00:00:00 2001
From: ston1th <ston1th@giftfish.de>
Date: Sat, 8 Oct 2022 10:34:16 +0200
Subject: [PATCH] fixed panic and quota

---
 cmd/cachefs/main.go  |  2 --
 pkg/config/config.go |  2 +-
 pkg/fs/metadata.go   | 62 ++++++++++++++++++++++++++++----------------
 3 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/cmd/cachefs/main.go b/cmd/cachefs/main.go
index b39a7bf..c2b6799 100644
--- a/cmd/cachefs/main.go
+++ b/cmd/cachefs/main.go
@@ -28,8 +28,6 @@ var (
 	log logr.Logger
 )
 
-const gib = 1024 * 1024 * 1024
-
 func main() {
 	klog.InitFlags(nil)
 	flag.StringVar(&cfg, "config", "", "path to config file")
diff --git a/pkg/config/config.go b/pkg/config/config.go
index c13b948..7f95139 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -74,7 +74,7 @@ func Validate(cfg *Config) error {
 	if cfg.Server.HTTP.Addr == "" {
 		cfg.Server.HTTP.Addr = defListenHTTP
 	}
-	c := cfg.Cache
+	c := &cfg.Cache
 	if c.Metadata == "" {
 		return errors.New("cache.metadata is empty")
 	}
diff --git a/pkg/fs/metadata.go b/pkg/fs/metadata.go
index b736110..bc2befa 100644
--- a/pkg/fs/metadata.go
+++ b/pkg/fs/metadata.go
@@ -199,7 +199,14 @@ func (mh *MetadataHandler) Metadata(name string, size int64) (md *Metadata) {
 		}
 		return md
 	}
-	md = &Metadata{Size: size, fs: mh.fs, name: name}
+	ctx, cancel := context.WithCancel(context.Background())
+	md = &Metadata{
+		Size:   size,
+		fs:     mh.fs,
+		name:   name,
+		ctx:    ctx,
+		cancel: cancel,
+	}
 	mh.md[name] = md
 	return
 }
@@ -221,6 +228,7 @@ func (mh *MetadataHandler) init() {
 			}
 			return true
 		}
+		v.ctx, v.cancel = context.WithCancel(context.Background())
 		v.fs = mh.fs
 		v.name = k
 		return false
@@ -352,6 +360,8 @@ type Metadata struct {
 	f      provider.File         `json:"-"`
 	wc     chan writeAt          `json:"-"`
 	done   chan struct{}         `json:"-"`
+	ctx    context.Context       `json:"-"`
+	cancel func()                `json:"-"`
 	err    atomic.Pointer[mdErr] `json:"-"`
 	name   string                `json:"-"`
 	Size   int64                 `json:"s"`
@@ -366,13 +376,8 @@ func (md *Metadata) Close() (err error) {
 }
 
 func (md *Metadata) close() (err error) {
-	if md.wc != nil {
-		close(md.wc)
-		if md.done != nil {
-			<-md.done
-		}
-		md.wc = nil
-	}
+	md.cancel()
+	md.wc = nil
 	if md.f != nil {
 		md.f.Sync()
 		err = md.f.Close()
@@ -439,31 +444,37 @@ type writeAt struct {
 
 func (md *Metadata) resetChans() {
 	md.wc = make(chan writeAt, 10)
-	md.done = make(chan struct{})
 }
 
 func (md *Metadata) writer() {
 	md.resetChans()
 	md.err.Store(nil)
 	go func() {
-		for wa := range md.wc {
-			atomic.StoreInt64(&md.Atime, now())
-			n, err := md.f.WriteAt(wa.data, wa.pos)
-			if err == nil {
-				md.addChunk(wa.pos, n)
-				md.fs.q.Add(n)
-			} else {
-				md.err.Store(&mdErr{err})
-			}
-			if wa.ret != nil {
-				streamingPool.Put(wa.ret)
+		for {
+			select {
+			case <-md.ctx.Done():
+				return
+			case wa := <-md.wc:
+				atomic.StoreInt64(&md.Atime, now())
+				n, err := md.f.WriteAt(wa.data, wa.pos)
+				if err == nil {
+					md.addChunk(wa.pos, n)
+					md.fs.q.Add(n)
+				} else {
+					md.err.Store(&mdErr{err})
+				}
+				if wa.ret != nil {
+					streamingPool.Put(wa.ret)
+				}
 			}
 		}
-		close(md.done)
 	}()
 }
 
 func (md *Metadata) WriteAt(data []byte, pos int64) (int, error) {
+	if md.ctx.Err() == context.Canceled {
+		return 0, context.Canceled
+	}
 	err := md.err.Load()
 	if err != nil && err.err != nil {
 		return 0, err.err
@@ -486,7 +497,10 @@ func (md *Metadata) WriteAt(data []byte, pos int64) (int, error) {
 	}
 	copy(buf, data)
 	wa.data = buf[:n]
-	md.wc <- wa
+	select {
+	case <-md.ctx.Done():
+	case md.wc <- wa:
+	}
 	return n, nil
 }
 
@@ -501,6 +515,10 @@ func (md *Metadata) openCacheFile() error {
 		return err
 	}
 	md.f = f
+	if md.ctx.Err() != nil {
+		md.cancel()
+		md.ctx, md.cancel = context.WithCancel(context.Background())
+	}
 	md.writer()
 	return nil
 }