From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="MyZfR5+S" Received: from mail-lf1-x14a.google.com (mail-lf1-x14a.google.com [IPv6:2a00:1450:4864:20::14a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 883511707 for ; Fri, 1 Dec 2023 03:47:53 -0800 (PST) Received: by mail-lf1-x14a.google.com with SMTP id 2adb3069b0e04-50bd3ac2a8aso1722096e87.3 for ; Fri, 01 Dec 2023 03:47:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701431272; x=1702036072; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=6g1GqQ4TrIojcjyDirpeDTGx+n3XD+xjD29/oGpLNfI=; b=MyZfR5+SGN0FhAH/+aiSSa5Fxv2pKfXcJ+75yqnXxvQjqbNBeRDcQcievpFYglujkc DhXM1fo4edTrakiCOx0FM97hNtPZ2d3TUjRlBcWqMTBlNK/4vsxmoZySEsnRr/lIbh0o u13iyIyylhncz+mzUvZwCrjXs/UfStO5j6AhlIKNWYz42BpacRM98h6iUwOnQglafX7W GAOwVQGkKhXO/IieXBopZMOZFizm3nmcYWuhdnIU+tIqdfdw17KzDTYq5s5QV8bCEyoc SPyvuLP+6BEN9O+/33w0xAM3ikaYuwNxU1t2+J1Z4htSXGgZ+ufmSa90DdR6GLXR/fFD 0xdw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701431272; x=1702036072; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6g1GqQ4TrIojcjyDirpeDTGx+n3XD+xjD29/oGpLNfI=; b=WOYFEHyITc3yY3Q9eP353njffemilQY72aA4MKB9gR/+QyhNTfQuGoQpoC4OQ3/Hio xWAaovARGmBPT/ZKSVSYNwXn5pTDt1/CSqZOoCUEEuKqHxClZTka3DhRzYDRqatc+Sji wILEQOFWAG3ao1GYDOTMHcdj9wpMVpl5blSSxDtN27p8h29dLvl9ZADMYgYGa1/sTmb0 t1+Hz7y814GSLhmZeTm+Bb9ELyCtZzNTgg1bAFNf50wb63mLdI09p9iUPbkVq/YZpIcX rL+MCYgOgvexOIIwfK0epD1JmwMA/lEcPfYCItt/NvMeUoaX+/IL8HUYAD7pJqq84zko 9ZRA== X-Gm-Message-State: AOJu0YwZwYDmDZ2eNUcJLPVovuxqxL9HgjUymGYPsEcPihl5Ccqa525B uiDD+Xa3PgbQZGUd/ITl5EwnfXMCLjNCrRc= X-Google-Smtp-Source: AGHT+IGmdHD9ndeAoG99U6CjjEVBhoGpQPpovxP6HXHrU+LrFLBMj6V3Szk+lEYNslRiUnlO96T3DeFoBd52niY= X-Received: from aliceryhl2.c.googlers.com ([fda3:e722:ac3:cc00:68:949d:c0a8:572]) (user=aliceryhl job=sendgmr) by 2002:a19:c207:0:b0:509:440f:3c5 with SMTP id l7-20020a19c207000000b00509440f03c5mr41495lfc.1.1701431271741; Fri, 01 Dec 2023 03:47:51 -0800 (PST) Date: Fri, 1 Dec 2023 11:47:48 +0000 In-Reply-To: Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.43.0.rc2.451.g8631bc7472-goog Message-ID: <20231201114749.2207060-1-aliceryhl@google.com> Subject: Re: [PATCH 7/7] rust: file: add abstraction for `poll_table` From: Alice Ryhl To: benno.lossin@proton.me Cc: a.hindborg@samsung.com, alex.gaynor@gmail.com, aliceryhl@google.com, arve@android.com, bjorn3_gh@protonmail.com, boqun.feng@gmail.com, brauner@kernel.org, cmllamas@google.com, dan.j.williams@intel.com, dxu@dxuuu.xyz, gary@garyguo.net, gregkh@linuxfoundation.org, joel@joelfernandes.org, keescook@chromium.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, maco@android.com, ojeda@kernel.org, peterz@infradead.org, rust-for-linux@vger.kernel.org, surenb@google.com, tglx@linutronix.de, tkjos@android.com, viro@zeniv.linux.org.uk, wedsonaf@gmail.com, willy@infradead.org Content-Type: text/plain; charset="utf-8" Benno Lossin writes: >> +#[pinned_drop] >> +impl PinnedDrop for PollCondVar { >> + fn drop(self: Pin<&mut Self>) { >> + // Clear anything registered using `register_wait`. >> + self.inner.notify(1, bindings::POLLHUP | bindings::POLLFREE); > > Isn't notifying only a single thread problematic, since a user could > misuse the `PollCondVar` (since all functions of `CondVar` are also > accessible) and also `.wait()` on the condvar? When dropping a > `PollCondVar` it might notify only the user `.wait()`, but not the > `PollTable`. Or am I missing something? Using POLLFREE clears everything. However, this should probably be updated to use `wake_up_pollfree` instead. Note that calls to `.wait()` are definitely gone by the time the destructor runs, since such calls borrows the `PollCondVar`, preventing you from running the destructor. Alice