refactor: extract fs lock into go-fs-lock

License: MIT
Signed-off-by: dignifiedquire <dignifiedquire@gmail.com>

core/commands/repo.go

@@ -15,7 +15,6 @@ import (
 	corerepo "github.com/ipfs/go-ipfs/core/corerepo"
 	config "github.com/ipfs/go-ipfs/repo/config"
 	fsrepo "github.com/ipfs/go-ipfs/repo/fsrepo"
-	lockfile "github.com/ipfs/go-ipfs/repo/fsrepo/lock"
 
 	bstore "gx/ipfs/QmaG4DZ4JaqEfvPWt5nPPgoTzhc1tr1T3f4Nu9Jpdm8ymY/go-ipfs-blockstore"
 	cid "gx/ipfs/QmcZfnkapfECQGcLZaf9B79NRg7cRa9EnZh4LSbkCzwNvY/go-cid"
@@ -233,7 +232,7 @@ daemons are running.
 		}
 
 		dsLockFile := filepath.Join(dsPath, "LOCK") // TODO: get this lockfile programmatically
-		repoLockFile := filepath.Join(configRoot, lockfile.LockFile)
+		repoLockFile := filepath.Join(configRoot, fsrepo.LockFile)
 		apiFile := filepath.Join(configRoot, "api") // TODO: get this programmatically
 
 		log.Infof("Removing repo lockfile: %s", repoLockFile)

package.json

@@ -575,6 +575,12 @@
       "hash": "QmWLWmRVSiagqP15jczsGME1qpob6HDbtbHAY2he9W5iUo",
       "name": "opentracing-go",
       "version": "0.0.3"
+    },
+    {
+      "author": "dignifiedquire",
+      "hash": "QmPdqSMmiwtQCBC515gFtMW2mP14HsfgnyQ2k5xPQVxMge",
+      "name": "go-fs-lock",
+      "version": "0.1.2"
     }
   ],
   "gxVersion": "0.10.0",

repo/fsrepo/fsrepo.go

@@ -16,10 +16,10 @@ import (
 	repo "github.com/ipfs/go-ipfs/repo"
 	"github.com/ipfs/go-ipfs/repo/common"
 	config "github.com/ipfs/go-ipfs/repo/config"
-	lockfile "github.com/ipfs/go-ipfs/repo/fsrepo/lock"
 	mfsr "github.com/ipfs/go-ipfs/repo/fsrepo/migrations"
 	serialize "github.com/ipfs/go-ipfs/repo/fsrepo/serialize"
 	dir "github.com/ipfs/go-ipfs/thirdparty/dir"
+	lockfile "gx/ipfs/QmPdqSMmiwtQCBC515gFtMW2mP14HsfgnyQ2k5xPQVxMge/go-fs-lock"
 
 	"github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/mitchellh/go-homedir"
 
@@ -29,6 +29,10 @@ import (
 	measure "gx/ipfs/QmbJgZGRtkFeSdCxBCPaMKWRDYbqMxHyFfvjQGcWzpqsDe/go-ds-measure"
 )
 
+// LockFile is the filename of the repo lock, relative to config dir
+// TODO rename repo lock and hide name
+const LockFile = "repo.lock"
+
 var log = logging.Logger("fsrepo")
 
 // version number that we are currently expecting to see
@@ -126,7 +130,7 @@ func open(repoPath string) (repo.Repo, error) {
 		return nil, err
 	}
 
-	r.lockfile, err = lockfile.Lock(r.path)
+	r.lockfile, err = lockfile.Lock(r.path, LockFile)
 	if err != nil {
 		return nil, err
 	}
@@ -297,7 +301,7 @@ func Init(repoPath string, conf *config.Config) error {
 // process. If true, then the repo cannot be opened by this process.
 func LockedByOtherProcess(repoPath string) (bool, error) {
 	repoPath = filepath.Clean(repoPath)
-	locked, err := lockfile.Locked(repoPath)
+	locked, err := lockfile.Locked(repoPath, LockFile)
 	if locked {
 		log.Debugf("(%t)<->Lock is held at %s", locked, repoPath)
 	}

repo/fsrepo/lock/lock.go

@@ -1,70 +0,0 @@
-package lock
-
-import (
-	"fmt"
-	"io"
-	"os"
-	"path"
-	"strings"
-	"syscall"
-
-	"gx/ipfs/QmNiJuT8Ja3hMVpBHXv3Q6dwmperaQ6JjLtpMQgMCD7xvx/go-ipfs-util"
-	logging "gx/ipfs/QmRb5jh8z2E8hMGN2tkvs1yHynUanqnZ3UeKwgN1i9P1F8/go-log"
-	lock "gx/ipfs/QmVUAoR89E6KDBJmsfRVkAoBMEfgVfy8rRmvzf4y9rWp1d/go4-lock"
-)
-
-// LockFile is the filename of the repo lock, relative to config dir
-// TODO rename repo lock and hide name
-const LockFile = "repo.lock"
-
-// log is the fsrepo logger
-var log = logging.Logger("lock")
-
-func errPerm(path string) error {
-	return fmt.Errorf("failed to take lock at %s: permission denied", path)
-}
-
-func Lock(confdir string) (io.Closer, error) {
-	return lock.Lock(path.Join(confdir, LockFile))
-}
-
-func Locked(confdir string) (bool, error) {
-	log.Debugf("Checking lock")
-	if !util.FileExists(path.Join(confdir, LockFile)) {
-		log.Debugf("File doesn't exist: %s", path.Join(confdir, LockFile))
-		return false, nil
-	}
-	if lk, err := Lock(confdir); err != nil {
-		// EAGAIN == someone else has the lock
-		if err == syscall.EAGAIN {
-			log.Debugf("Someone else has the lock: %s", path.Join(confdir, LockFile))
-			return true, nil
-		}
-		if strings.Contains(err.Error(), "resource temporarily unavailable") {
-			log.Debugf("Can't lock file: %s.\n reason: %s", path.Join(confdir, LockFile), err.Error())
-			return true, nil
-		}
-
-		// lock fails on permissions error
-		if os.IsPermission(err) {
-			log.Debugf("Lock fails on permissions error")
-			return false, errPerm(confdir)
-		}
-		if isLockCreatePermFail(err) {
-			log.Debugf("Lock fails on permissions error")
-			return false, errPerm(confdir)
-		}
-
-		// otherwise, we cant guarantee anything, error out
-		return false, err
-	} else {
-		log.Debugf("No one has a lock")
-		lk.Close()
-		return false, nil
-	}
-}
-
-func isLockCreatePermFail(err error) bool {
-	s := err.Error()
-	return strings.Contains(s, "Lock Create of") && strings.Contains(s, "permission denied")
-}