Relax ScopedFD close() error checking

base/files/scoped_file.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/files/scoped_file.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
@@ skipping 15 matching lines @@
   // There are security implications to not closing a file descriptor
   // properly. As file descriptors are "capabilities", keeping them open
   // would make the current process keep access to a resource. Much of
   // Chrome relies on being able to "drop" such access.
   // It's especially problematic on Linux with the setuid sandbox, where
   // a single open directory would bypass the entire security model.
   int ret = IGNORE_EINTR(close(fd));
 
   // TODO(davidben): Remove this once it's been determined whether
   // https://crbug.com/603354 is caused by EBADF or a network filesystem
   // returning some other error.

[davidben, 2017/01/18 20:38:26]

Probably want to remove both the code and the TODO or neither. ;-)

If we're making it OS_LINUX-only, the base::debug::Alias isn't totally useless,
so I guess we can keep it around until the bugs are closed? (Though I think we
know the ones we were looking at were EBADF.)

-  int close_errno = errno;
-  base::debug::Alias(&close_errno);
-
+#if defined(OS_LINUX)
+  // NB: Some file descriptors can return errors from close() e.g. network
+  // filesystems such as NFS and Linux input devices. On Linux, errors from
+  // close other than EBADF do not indicate failure to actually close the fd.
+  if (errno != EBADF)
+    ret = 0;
+#endif
   PCHECK(0 == ret);
 }
 
 #endif  // OS_POSIX
 
 }  // namespace internal
 }  // namespace base