From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 74555396596 for ; Mon, 16 Mar 2026 12:14:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773663256; cv=none; b=HqSL7e1oX0ktVEf9w9u4Ss0hzDcfjaIHiJxvQtbPePfY9ZYqm/9yHkj5sRign1P4s4xaxDVjxn9jt5CZYgII8PGB3PvsYS22PNY/GCYLk29pF2yxwV1RhK3KbcBm9Pvr61fVIlUg9FxA9FEJE59UCYEQ/gPjaG3/YBJZSx0yxBw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773663256; c=relaxed/simple; bh=g8GaV3hlfBHoTjjCvqr/4Va/2jyatxk9/l1Nn+6OTaE=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=HzdOO/vTwa4QKKeSZ0Jg3X0sk6cWLrdKPwRqwuvKXLpMXYrOmmFRYML/xZN0nIWVH2Lxq33KWjoni7OtHgmFs1T+Qd1pu96Wl3AK6ZLsXkY6R+muuxIFFwIGzy9+XJfEy76oncd1wmPPvrV9Ti6SGYdXOtwDgD/kUo+JRVGqDoc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=MKzalTe5; arc=none smtp.client-ip=209.85.128.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="MKzalTe5" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-485389bf0daso30780995e9.0 for ; Mon, 16 Mar 2026 05:14:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1773663254; x=1774268054; 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=M7q2+A+kkZoyV3rsZQKFhC6jq2dbqO9RaZzFL/EKyo0=; b=MKzalTe5cMEJnDN5HAlmLI1ENwn4C99NhEkEXJP/9etqTjx8Psrj+LrUnOxl+ASIYy xaYpeb7SmEkxNgarhW2Obw4seQt+zikM4udWdv1WnrOVE0rAt7kdDvaIqmNotuMIaQsr uV+TUddQZLuZawdkzrMbcAU0A43yFs2kFVgYL9379qCobRQvs6WvdEor1sNijZluPl6H 2RM/Ck5YZURb5ZZzd+KI1Lmz9YxEB8z+dflOGZG0mL4bEXTrt7VQTCO1MRp2SoauD0NK MV6XJyuYb4yX5OeT2RI8VE1eoQl7pnwGloKz7rlbN+OG2fiXRNAFtcy15KnkdU4DyBGu q8PA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773663254; x=1774268054; 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=M7q2+A+kkZoyV3rsZQKFhC6jq2dbqO9RaZzFL/EKyo0=; b=mNoumiKuhgF6d+Ha0NskZFDBz6T4zDqNlTXFjURIcJE8sCEua3zrmZpA+SVOoPaN00 PbOL6ChfzxiHY6TcSFY7SQE/3Fl5Pv/mdlK2eppZNfkT76DiRUB08ga6LmGbsWJsVvYr 3Sc4d+jjD24FfkZVrTFdFc3AqVawd7Cr6je5qJN7SNxIxH0rKcQh8P/VjXbW7cgTymvJ VTDd6HnS2MMKjVz7Z+1GGkdxX2iThuKnaQJBFaz3aRlobWG2Hak2Ywalq4LgZdxflx5q dSQaWeBuMEOrBpgZaX94Era7+NvYcw62cW6n7IVlNANJZChj800nt8zkm2OKD3mJkTyW qlkw== X-Forwarded-Encrypted: i=1; AJvYcCVk+c5wf7gglzRvjbbm7IK6VvKDBgWhtebrTGA+YhHoHPwmn0Zs586Z/t5RMKqsnzJGHd3LNlHhsv2UViE=@vger.kernel.org X-Gm-Message-State: AOJu0Ywco23ApuiTNqTYShKx137avfq4uuMYY0562/kZ0PhHu5q/UDJG 7lroAdhjN7RHG7/k7njOnxIdti/aIa2Q846FS+xsUK+eYsqunTKZKUv2TKLjBcXJktSWOunq/lx pPNtmzCsJ2D8qm+cnag== X-Received: from wrs7.prod.google.com ([2002:a05:6000:647:b0:439:f5a6:f90f]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:45d5:b0:485:3ff1:d5c3 with SMTP id 5b1f17b1804b1-485566cfa3cmr204531455e9.5.1773663253523; Mon, 16 Mar 2026 05:14:13 -0700 (PDT) Date: Mon, 16 Mar 2026 12:14:12 +0000 In-Reply-To: <20260216-rnull-v6-19-rc5-send-v1-28-de9a7af4b469@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260216-rnull-v6-19-rc5-send-v1-0-de9a7af4b469@kernel.org> <20260216-rnull-v6-19-rc5-send-v1-28-de9a7af4b469@kernel.org> Message-ID: Subject: Re: [PATCH 28/79] block: rnull: add partial I/O support for bad blocks From: Alice Ryhl To: Andreas Hindborg Cc: Boqun Feng , Jens Axboe , Miguel Ojeda , Gary Guo , "=?utf-8?B?QmrDtnJu?= Roy Baron" , Benno Lossin , Trevor Gross , Danilo Krummrich , FUJITA Tomonori , Frederic Weisbecker , Lyude Paul , Thomas Gleixner , Anna-Maria Behnsen , John Stultz , Stephen Boyd , Lorenzo Stoakes , "Liam R. Howlett" , linux-block@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset="utf-8" On Mon, Feb 16, 2026 at 12:35:15AM +0100, Andreas Hindborg wrote: > Add bad_blocks_partial_io configuration option that allows partial I/O > completion when encountering bad blocks, rather than failing the entire > request. > > When enabled, requests are truncated to stop before the first bad block > range, allowing the valid portion to be processed successfully. This > improves compatibility with applications that can handle partial > reads/writes. > > Signed-off-by: Andreas Hindborg > -#[vtable] > -impl configfs::AttributeOperations<13> for DeviceConfig { > - type Data = DeviceConfig; > - > - fn show(this: &DeviceConfig, page: &mut [u8; PAGE_SIZE]) -> Result { > - let mut writer = kernel::str::Formatter::new(page); > - > - if this.data.lock().bad_blocks_once { > - writer.write_str("1\n")?; > - } else { > - writer.write_str("0\n")?; > - } > - > - Ok(writer.bytes_written()) > - } > - > - fn store(this: &DeviceConfig, page: &[u8]) -> Result { > - if this.data.lock().powered { > - return Err(EBUSY); > - } > - > - this.data.lock().bad_blocks_once = kstrtobool_bytes(page)?; > - > - Ok(()) > - } > -} > +configfs_simple_bool_field!(DeviceConfig, 13, bad_blocks_once); Squash this into previous patch. > +fn is_power_of_two(value: T) -> bool > +where > + T: core::ops::Sub, > + T: core::ops::BitAnd, > + T: core::cmp::PartialOrd, > + T: Copy, > + T: From, > +{ > + (value > 0u8.into()) && (value & (value - 1u8.into())) == 0u8.into() > +} This is in the standard library. > +fn align_down(value: T, to: T) -> T > +where > + T: core::ops::Sub, > + T: core::ops::Not, > + T: core::ops::BitAnd, > + T: core::cmp::PartialOrd, > + T: Copy, > + T: From, > +{ > + debug_assert!(is_power_of_two(to)); > + value & !(to - 1u8.into()) > +} Overlap with: https://lore.kernel.org/rust-for-linux/20260221020952.412352-22-jhubbard@nvidia.com/ Alice