Remove fsrepo refcounting

No code attempts to open the same repo multiple times.

Error handling is still buggy, but it's starting to get clearer.

repo/fsrepo/counter/openers.go

-package counter
-
-import "path"
-
-// TODO this could be made into something more generic.
-
-type Openers struct {
-	// repos maps repo paths to the number of openers holding an FSRepo handle
-	// to it
-	repos map[string]int
-}
-
-func NewOpenersCounter() *Openers {
-	return &Openers{
-		repos: make(map[string]int),
-	}
-}
-
-// NumOpeners returns the number of FSRepos holding a handle to the repo at
-// this path. This method is not thread-safe. The caller must have this object
-// locked.
-func (l *Openers) NumOpeners(repoPath string) int {
-	return l.repos[key(repoPath)]
-}
-
-// AddOpener messages that an FSRepo holds a handle to the repo at this path.
-// This method is not thread-safe. The caller must have this object locked.
-func (l *Openers) AddOpener(repoPath string) error {
-	l.repos[key(repoPath)]++
-	return nil
-}
-
-// RemoveOpener messgaes that an FSRepo no longer holds a handle to the repo at
-// this path. This method is not thread-safe. The caller must have this object
-// locked.
-func (l *Openers) RemoveOpener(repoPath string) error {
-	l.repos[key(repoPath)]--
-	return nil
-}
-
-func key(repoPath string) string {
-	return path.Clean(repoPath)
-}

repo/fsrepo/fsrepo.go

@@ -14,7 +14,6 @@ import (
 	repo "github.com/jbenet/go-ipfs/repo"
 	"github.com/jbenet/go-ipfs/repo/common"
 	config "github.com/jbenet/go-ipfs/repo/config"
-	counter "github.com/jbenet/go-ipfs/repo/fsrepo/counter"
 	lockfile "github.com/jbenet/go-ipfs/repo/fsrepo/lock"
 	serialize "github.com/jbenet/go-ipfs/repo/fsrepo/serialize"
 	dir "github.com/jbenet/go-ipfs/thirdparty/dir"
@@ -33,14 +32,7 @@ var (
 
 	// packageLock must be held to while performing any operation that modifies an
 	// FSRepo's state field. This includes Init, Open, Close, and Remove.
-	packageLock sync.Mutex // protects openersCounter
-	// openersCounter ensures that the Init is atomic.
-	//
-	// packageLock also protects numOpenedRepos
-	//
-	// If an operation is used when repo is Open and the operation does not
-	// change the repo's state, the package lock does not need to be acquired.
-	openersCounter *counter.Openers
+	packageLock sync.Mutex
 
 	// onlyOne keeps track of open FSRepo instances.
 	//
@@ -57,10 +49,6 @@ var (
 	onlyOne repo.OnlyOne
 )
 
-func init() {
-	openersCounter = counter.NewOpenersCounter()
-}
-
 // FSRepo represents an IPFS FileSystem Repo. It is safe for use by multiple
 // callers.
 type FSRepo struct {
@@ -444,27 +432,20 @@ func isInitializedUnsynced(repoPath string) bool {
 // the package mutex.
 func (r *FSRepo) transitionToOpened() error {
 	r.state = opened
-	if countBefore := openersCounter.NumOpeners(r.path); countBefore == 0 { // #first
-		closer, err := lockfile.Lock(r.path)
-		if err != nil {
-			return err
-		}
-		r.lockfile = closer
+	closer, err := lockfile.Lock(r.path)
+	if err != nil {
+		return err
 	}
-	return openersCounter.AddOpener(r.path)
+	r.lockfile = closer
+	return nil
 }
 
 // transitionToClosed manages the state transition to |closed|. Caller must
 // hold the package mutex.
 func (r *FSRepo) transitionToClosed() error {
 	r.state = closed
-	if err := openersCounter.RemoveOpener(r.path); err != nil {
+	if err := r.lockfile.Close(); err != nil {
 		return err
 	}
-	if countAfter := openersCounter.NumOpeners(r.path); countAfter == 0 {
-		if err := r.lockfile.Close(); err != nil {
-			return err
-		}
-	}
 	return nil
 }