From a205aca6d272fa1cd070da6dc2d21008555bc8a5 Mon Sep 17 00:00:00 2001
From: Krishna Srinivas <krishna@minio.io>
Date: Sun, 8 May 2016 22:45:34 +0530
Subject: [PATCH] init: Cleanup .minio/tmp directories recursively. Also takes
 care of cleaning up of parts directory during abortMultipartUpload. (#1532)

---
 fs-objects-multipart.go    |  2 +-
 object-common-multipart.go | 21 +++------------------
 object-common.go           | 31 ++++++++++++++++++++++++++++++-
 object-utils.go            |  9 +++++++--
 4 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/fs-objects-multipart.go b/fs-objects-multipart.go
index f358a0477..0c042c84b 100644
--- a/fs-objects-multipart.go
+++ b/fs-objects-multipart.go
@@ -123,7 +123,7 @@ func (fs fsObjects) CompleteMultipartUpload(bucket string, object string, upload
 	}
 
 	// Cleanup all the parts if everything else has been safely committed.
-	if err = cleanupUploadedParts(fs.storage, mpartMetaPrefix, bucket, object, uploadID); err != nil {
+	if err = cleanupUploadedParts(fs.storage, bucket, object, uploadID); err != nil {
 		return "", err
 	}
 
diff --git a/object-common-multipart.go b/object-common-multipart.go
index 4f85512a1..e408abbf5 100644
--- a/object-common-multipart.go
+++ b/object-common-multipart.go
@@ -215,25 +215,10 @@ func putObjectPartCommon(storage StorageAPI, bucket string, object string, uploa
 	return newMD5Hex, nil
 }
 
-// Cleanup all temp entries inside tmpMetaPrefix directory, upon server initialization.
-func cleanupAllTmpEntries(storage StorageAPI) error {
-	return cleanupUploadedParts(storage, tmpMetaPrefix, "", "", "")
-}
-
 // Wrapper to which removes all the uploaded parts after a successful
 // complete multipart upload.
-func cleanupUploadedParts(storage StorageAPI, prefix, bucket, object, uploadID string) error {
-	multipartDir := path.Join(prefix, bucket, object, uploadID)
-	entries, err := storage.ListDir(minioMetaBucket, multipartDir)
-	if err != nil {
-		return err
-	}
-	for _, entry := range entries {
-		if err = storage.DeleteFile(minioMetaBucket, path.Join(multipartDir, entry)); err != nil {
-			return err
-		}
-	}
-	return nil
+func cleanupUploadedParts(storage StorageAPI, bucket, object, uploadID string) error {
+	return cleanupDir(storage, minioMetaBucket, path.Join(mpartMetaPrefix, bucket, object, uploadID))
 }
 
 // abortMultipartUploadCommon - aborts a multipart upload, common
@@ -253,7 +238,7 @@ func abortMultipartUploadCommon(storage StorageAPI, bucket, object, uploadID str
 	if !isUploadIDExists(storage, bucket, object, uploadID) {
 		return InvalidUploadID{UploadID: uploadID}
 	}
-	return cleanupUploadedParts(storage, mpartMetaPrefix, bucket, object, uploadID)
+	return cleanupUploadedParts(storage, bucket, object, uploadID)
 }
 
 // isIncompleteMultipart - is object incomplete multipart.
diff --git a/object-common.go b/object-common.go
index 22f83bd13..e437ed34c 100644
--- a/object-common.go
+++ b/object-common.go
@@ -38,13 +38,42 @@ func initObjectLayer(storage StorageAPI) error {
 		}
 	}
 	// Cleanup all temp entries upon start.
-	err := cleanupAllTmpEntries(storage)
+	err := cleanupDir(storage, minioMetaBucket, tmpMetaPrefix)
 	if err != nil {
 		return toObjectErr(err, minioMetaBucket, tmpMetaPrefix)
 	}
 	return nil
 }
 
+// Cleanup a directory recursively.
+func cleanupDir(storage StorageAPI, volume, dirPath string) error {
+	var delFunc func(string) error
+	// Function to delete entries recursively.
+	delFunc = func(entryPath string) error {
+		if !strings.HasSuffix(entryPath, slashSeparator) {
+			// No trailing "/" means that this is a file which can be deleted.
+			return storage.DeleteFile(volume, entryPath)
+		}
+		// If it's a directory, list and call delFunc() for each entry.
+		entries, err := storage.ListDir(volume, entryPath)
+		if err != nil {
+			if err == errFileNotFound {
+				// if dirPath prefix never existed.
+				return nil
+			}
+			return err
+		}
+		for _, entry := range entries {
+			err = delFunc(pathJoin(entryPath, entry))
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+	return delFunc(retainSlash(dirPath))
+}
+
 /// Common object layer functions.
 
 // makeBucket - create a bucket, is a common function for both object layers.
diff --git a/object-utils.go b/object-utils.go
index 583fca34c..9370c3161 100644
--- a/object-utils.go
+++ b/object-utils.go
@@ -22,6 +22,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"path"
 	"regexp"
 	"strings"
 	"unicode/utf8"
@@ -103,9 +104,13 @@ func retainSlash(s string) string {
 	return strings.TrimSuffix(s, slashSeparator) + slashSeparator
 }
 
-// pathJoin - path join.
+// pathJoin - like path.Join() but retains trailing "/" of the last element
 func pathJoin(s1 string, s2 string) string {
-	return retainSlash(s1) + s2
+	trailingSlash := ""
+	if strings.HasSuffix(s2, slashSeparator) {
+		trailingSlash = "/"
+	}
+	return path.Join(s1, s2) + trailingSlash
 }
 
 // Create an s3 compatible MD5sum for complete multipart transaction.