X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;ds=sidebyside;f=cmd%2Fsafcm-remote%2Fsync%2Ffiles.go;h=119a3534239f68e2e5d10aee08ec2559590ada87;hb=5d6cc7f14a4bacc36bf3a23cd735a75ad4a90f1d;hp=12508ce08c2f7e7d2c17b74dca980285ec01f334;hpb=713cde4bd701dd53ed46d01f43c9e9e7b82dc514;p=safcm%2Fsafcm.git

diff --git a/cmd/safcm-remote/sync/files.go b/cmd/safcm-remote/sync/files.go
index 12508ce..119a353 100644
--- a/cmd/safcm-remote/sync/files.go
+++ b/cmd/safcm-remote/sync/files.go
@@ -113,7 +113,7 @@ reopen:
 	oldFh, err := OpenFileNoFollow(file.Path)
 	if err != nil {
 		err := err.(*fs.PathError)
-		if err.Err == syscall.ELOOP {
+		if err.Err == syscall.ELOOP || err.Err == syscall.EMLINK {
 			// Check if ELOOP was caused not by O_NOFOLLOW but by
 			// too many nested symlinks before the final path
 			// component.
@@ -149,6 +149,15 @@ reopen:
 	if !change.Created {
 		// Compare permissions
 		change.Old.Mode = oldStat.Mode()
+		if change.Old.Mode.Type() == fs.ModeSymlink {
+			// Some BSD systems permit changing permissions of
+			// symlinks but ignore them on traversal. To keep it
+			// simple we don't support that and always use 0777
+			// for symlink permissions (the value on GNU/Linux).
+			//
+			// TODO: Add proper support for symlinks on BSD
+			change.Old.Mode |= 0777
+		}
 		if change.Old.Mode != file.Mode {
 			if change.Old.Mode.Type() != file.Mode.Type() {
 				changeType = true
@@ -258,7 +267,7 @@ reopen:
 		}
 	}
 
-	// Directory: create new directory (also type change to directory)
+	// Directory: create new directory, also type change to directory
 	if file.Mode.IsDir() && (change.Created || changeType) {
 		debugf("creating directory")
 		err := os.Mkdir(file.Path, 0700)
@@ -328,52 +337,20 @@ reopen:
 	}
 
 	dir := filepath.Dir(file.Path)
-	base := filepath.Base(file.Path)
+	// Create hidden file which should be ignored by most other tools and
+	// thus not affect anything during creation
+	base := "." + filepath.Base(file.Path)
 
 	var tmpPath string
 	switch file.Mode.Type() {
 	case 0: // regular file
 		debugf("creating temporary file %q",
-			filepath.Join(dir, "."+base+"*"))
-		// Create hidden file which should be ignored by most other
-		// tools and thus not affect anything during creation
-		newFh, err := os.CreateTemp(dir, "."+base)
+			filepath.Join(dir, base+"*"))
+		tmpPath, err = WriteTemp(dir, base, file.Data,
+			file.Uid, file.Gid, file.Mode)
 		if err != nil {
 			return err
 		}
-		tmpPath = newFh.Name()
-
-		_, err = newFh.Write(file.Data)
-		if err != nil {
-			newFh.Close()
-			os.Remove(tmpPath)
-			return err
-		}
-		// CreateTemp() creates the file with 0600
-		err = newFh.Chown(file.Uid, file.Gid)
-		if err != nil {
-			newFh.Close()
-			os.Remove(tmpPath)
-			return err
-		}
-		err = newFh.Chmod(file.Mode)
-		if err != nil {
-			newFh.Close()
-			os.Remove(tmpPath)
-			return err
-		}
-		err = newFh.Sync()
-		if err != nil {
-			newFh.Close()
-			os.Remove(tmpPath)
-			return err
-		}
-		err = newFh.Close()
-		if err != nil {
-			newFh.Close()
-			os.Remove(tmpPath)
-			return err
-		}
 
 	case fs.ModeSymlink:
 		i := 0
@@ -381,7 +358,7 @@ reopen:
 		// Similar to os.CreateTemp() but for symlinks which we cannot
 		// open as file
 		tmpPath = filepath.Join(dir,
-			"."+base+strconv.Itoa(rand.Int()))
+			base+strconv.Itoa(rand.Int()))
 		debugf("creating temporary symlink %q", tmpPath)
 		err := os.Symlink(string(file.Data), tmpPath)
 		if err != nil {
@@ -396,7 +373,7 @@ reopen:
 			os.Remove(tmpPath)
 			return err
 		}
-		// Permissions are irrelevant for symlinks
+		// Permissions are irrelevant for symlinks (on most systems)
 
 	default:
 		panic(fmt.Sprintf("invalid file type %s", file.Mode))
@@ -408,7 +385,7 @@ reopen:
 		os.Remove(tmpPath)
 		return err
 	}
-	err = syncPath(dir)
+	err = SyncPath(dir)
 	if err != nil {
 		return err
 	}
@@ -505,7 +482,51 @@ func OpenFileNoFollow(path string) (*os.File, error) {
 		os.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
 }
 
-// syncPath syncs path, which should be a directory. To guarantee durability
+func WriteTemp(dir, base string, data []byte, uid, gid int, mode fs.FileMode) (
+	string, error) {
+
+	fh, err := os.CreateTemp(dir, base)
+	if err != nil {
+		return "", err
+	}
+	tmpPath := fh.Name()
+
+	_, err = fh.Write(data)
+	if err != nil {
+		fh.Close()
+		os.Remove(tmpPath)
+		return "", err
+	}
+	// CreateTemp() creates the file with 0600
+	err = fh.Chown(uid, gid)
+	if err != nil {
+		fh.Close()
+		os.Remove(tmpPath)
+		return "", err
+	}
+	err = fh.Chmod(mode)
+	if err != nil {
+		fh.Close()
+		os.Remove(tmpPath)
+		return "", err
+	}
+	err = fh.Sync()
+	if err != nil {
+		fh.Close()
+		os.Remove(tmpPath)
+		return "", err
+	}
+	err = fh.Close()
+	if err != nil {
+		fh.Close()
+		os.Remove(tmpPath)
+		return "", err
+	}
+
+	return tmpPath, nil
+}
+
+// SyncPath syncs path, which should be a directory. To guarantee durability
 // it must be called on a parent directory after adding, renaming or removing
 // files therein.
 //
@@ -513,7 +534,7 @@ func OpenFileNoFollow(path string) (*os.File, error) {
 // fsync: "Calling fsync() does not necessarily ensure that the entry in the
 // directory containing the file has also reached disk. For that an explicit
 // fsync() on a file descriptor for the directory is also needed."
-func syncPath(path string) error {
+func SyncPath(path string) error {
 	x, err := os.Open(path)
 	if err != nil {
 		return err