Check disk space before trying a write from the downloader; don't make empty directories if we can't even write the file

router/downloader/downloader.go

@@ -66,10 +66,19 @@ func (dl *Download) Execute() error {
 		return errors.New("downloader: failed opening request to download file")
 	}
 	defer res.Body.Close()
-	if res.StatusCode >= 300 || res.StatusCode < 200 {
+	if res.StatusCode != http.StatusOK {
 		return errors.New("downloader: got bad response status from endpoint: " + res.Status)
 	}
 
+	// If there is a Content-Length header on this request go ahead and check that we can
+	// even write the whole file before beginning this process. If there is no header present
+	// we'll just have to give it a spin and see how it goes.
+	if res.ContentLength > 0 {
+		if err := dl.server.Filesystem().HasSpaceFor(res.ContentLength); err != nil {
+			return errors.WrapIf(err, "downloader: failed to write file: not enough space")
+		}
+	}
+
 	fnameparts := strings.Split(dl.req.URL.Path, "/")
 	p := filepath.Join(dl.req.Directory, fnameparts[len(fnameparts)-1])
 	dl.server.Log().WithField("path", p).Debug("writing remote file to disk")

server/filesystem/compress.go

@@ -150,7 +150,7 @@ func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, er
 		return nil, err
 	}
 
-	if err := fs.hasSpaceFor(f.Size()); err != nil {
+	if err := fs.HasSpaceFor(f.Size()); err != nil {
 		_ = os.Remove(d)
 
 		return nil, err

server/filesystem/disk_space.go

@@ -203,7 +203,7 @@ func (fs *Filesystem) DirectorySize(dir string) (int64, error) {
 // Helper function to determine if a server has space available for a file of a given size.
 // If space is available, no error will be returned, otherwise an ErrNotEnoughSpace error
 // will be raised.
-func (fs *Filesystem) hasSpaceFor(size int64) error {
+func (fs *Filesystem) HasSpaceFor(size int64) error {
 	if fs.MaxDisk() == 0 {
 		return nil
 	}

server/filesystem/filesystem.go

@@ -86,34 +86,36 @@ func (fs *Filesystem) Writefile(p string, r io.Reader) error {
 	var currentSize int64
 	// If the file does not exist on the system already go ahead and create the pathway
 	// to it and an empty file. We'll then write to it later on after this completes.
-	if stat, err := os.Stat(cleaned); err != nil {
-		if !os.IsNotExist(err) {
+	stat, err := os.Stat(cleaned)
+	if err != nil && !os.IsNotExist(err) {
 		return err
-		}
-
-		if err := os.MkdirAll(filepath.Dir(cleaned), 0755); err != nil {
-			return err
-		}
-
-		if err := fs.Chown(filepath.Dir(cleaned)); err != nil {
-			return err
-		}
-	} else {
+	} else if err == nil {
 		if stat.IsDir() {
 			return &Error{code: ErrCodeIsDirectory}
 		}
-
 		currentSize = stat.Size()
 	}
 
 	br := bufio.NewReader(r)
-	// Check that the new size we're writing to the disk can fit. If there is currently a file
-	// we'll subtract that current file size from the size of the buffer to determine the amount
-	// of new data we're writing (or amount we're removing if smaller).
-	if err := fs.hasSpaceFor(int64(br.Size()) - currentSize); err != nil {
+	// Check that the new size we're writing to the disk can fit. If there is currently
+	// a file we'll subtract that current file size from the size of the buffer to determine
+	// the amount of new data we're writing (or amount we're removing if smaller).
+	if err := fs.HasSpaceFor(int64(br.Size()) - currentSize); err != nil {
 		return err
 	}
 
+	// If we were unable to stat the location because it did not exist, go ahead and create
+	// it now. We do this after checking the disk space so that we do not just create empty
+	// directories at random.
+	if err != nil {
+		if err := os.MkdirAll(filepath.Dir(cleaned), 0755); err != nil {
+			return err
+		}
+		if err := fs.Chown(filepath.Dir(cleaned)); err != nil {
+			return err
+		}
+	}
+
 	o := &fileOpener{}
 	// This will either create the file if it does not already exist, or open and
 	// truncate the existing file.
@@ -298,7 +300,7 @@ func (fs *Filesystem) Copy(p string) error {
 	}
 
 	// Check that copying this file wouldn't put the server over its limit.
-	if err := fs.hasSpaceFor(s.Size()); err != nil {
+	if err := fs.HasSpaceFor(s.Size()); err != nil {
 		return err
 	}