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AJvYcCX+vQV2xOMtB5AcXSfOirsr10m4v4qV6zGH1fn5trjrnN7Zjrh2mxeoeMMksHwInv7L+gcTohjL+g==@kvack.org X-Gm-Message-State: AOJu0Yx86IeBRkU/XRX4JQ+XRoCBzdsIb1iEnawaiF7qQue6fa2kld3Y dC4dYuXCyK/YdZqU9VipkqD0DpoRZPB5Y0DtneB7Vh9dOzsmymHW6qa1g1k9mtMJH6w2v1W+pHw qJscIQ50pL6pXCGTEVg== 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> 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" X-Rspamd-Queue-Id: 7652420002 X-Rspamd-Server: rspam07 X-Stat-Signature: nf1m414r8t1npik3binarirbx5kwahif X-Rspam-User: X-HE-Tag: 1773663255-831926 X-HE-Meta: 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 3C9WsB9I 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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