Re-attempt to delete temporary upload if the file is locked by another process (#12447)

Replace all calls to os.Remove/os.RemoveAll by retrying util.Remove/util.RemoveAll and remove circular dependencies from util.

Fix #12339

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: silverwind <me@silverwind.io>

1 files changed, 57 insertions, 0 deletions

diff --git a/modules/util/remove.go b/modules/util/remove.go
new file mode 100644
index 0000000000..f2bbbc30b9
--- /dev/null
+++ b/modules/util/remove.go
@@ -0,0 +1,57 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package util
+
+import (
+	"os"
+	"syscall"
+	"time"
+)
+
+// Remove removes the named file or (empty) directory with at most 5 attempts.
+func Remove(name string) error {
+	var err error
+	for i := 0; i < 5; i++ {
+		err = os.Remove(name)
+		if err == nil {
+			break
+		}
+		unwrapped := err.(*os.PathError).Err
+		if unwrapped == syscall.EBUSY || unwrapped == syscall.ENOTEMPTY || unwrapped == syscall.EPERM || unwrapped == syscall.EMFILE || unwrapped == syscall.ENFILE {
+			// try again
+			<-time.After(100 * time.Millisecond)
+			continue
+		}
+
+		if unwrapped == syscall.ENOENT {
+			// it's already gone
+			return nil
+		}
+	}
+	return err
+}
+
+// RemoveAll removes the named file or (empty) directory with at most 5 attempts.Remove
+func RemoveAll(name string) error {
+	var err error
+	for i := 0; i < 5; i++ {
+		err = os.RemoveAll(name)
+		if err == nil {
+			break
+		}
+		unwrapped := err.(*os.PathError).Err
+		if unwrapped == syscall.EBUSY || unwrapped == syscall.ENOTEMPTY || unwrapped == syscall.EPERM || unwrapped == syscall.EMFILE || unwrapped == syscall.ENFILE {
+			// try again
+			<-time.After(100 * time.Millisecond)
+			continue
+		}
+
+		if unwrapped == syscall.ENOENT {
+			// it's already gone
+			return nil
+		}
+	}
+	return err
+}