From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f173.google.com (mail-pg1-f173.google.com [209.85.215.173]) (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 6CAEC12F375 for ; Sun, 10 Nov 2024 15:29:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731252565; cv=none; b=ru6/groeQ1xrm141Pa/79ON+/CiN56PftJ8Xtl4jtaZfw6GRFFiItYGjuOXsAVWxp1epcQB4DeZb/b5FRs8NWmYPIi0hk8apyrA63jzzVH6UZpio/3SlY0Vy+GAjVbU8a53ZNQdzZriKPbZ+PbAOAIk3yAESUT/1KHCLVFWcE1Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731252565; c=relaxed/simple; bh=QqsnT+PFB0stp1XOLxW6GR03t+Q+Rw9k/OtfDS+hMd8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gjc57iwA7sOyQDU4AugqjIBp8NxLKms9JE6P4Vh4VslYPorfY9TKa6lZHVjMu8IFmzfM4F4vTxyOk43N6u/hoBGeDFzAsy0Y5S6mJHivX5aIdaSRs718mGEH9tIPKt5gFgGpQsNxFIsSUGhrGxpjXCLVG2mT9yb/OJiAjW77ikA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=ITqFiO9j; arc=none smtp.client-ip=209.85.215.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="ITqFiO9j" Received: by mail-pg1-f173.google.com with SMTP id 41be03b00d2f7-7f3da2c2cb5so2733165a12.2 for ; Sun, 10 Nov 2024 07:29:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1731252564; x=1731857364; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=BpaeGG8sCxZf4JRh/p7NGjZl2gbHvBRPjf0TUvSvRrE=; b=ITqFiO9jdn5hfePmhO3CDfJ4/Dmi47iutuGrtDiahBPQhv0vuNt8DvJBOLO3Vxbm3j csJv0r53dA3Iw5r4Oyz+o8HNT+AnndUKoaQQv8Plso7XHK9X5ztaaObQL/PX9x5+v3AK svwxzNw08U3xQl9ftcmwmXj8N0SH1rhpCyajbwU9uOHps8jGHylvxgWT6cEhoORiWMSc DfWarKen3KehFQL5V0oQ4lXV4hOKfHYjbrxiU1wH/GwCNC9ZtZ/ylBhYS2sSgy4LlVIA 7iYkVAJkiGiVf6foE4lxi3B77XWykVOy6Ww0w2X40CY/7+KkhxAXQ/vRX8B39Zjr/M4y by3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731252564; x=1731857364; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=BpaeGG8sCxZf4JRh/p7NGjZl2gbHvBRPjf0TUvSvRrE=; b=N04fRwybkVOTDUAOl42XDoayXNEG51sjKXvZvV4a5Imk3/xn+8usDTLsulEFx22YS8 v/xVDw2D0AFDE8O1gvBgrKtpPCMSRBse9A5jJ9IPEMhncPb/gQEKVhKQkeyjebe0wzUV zTNPxqbyRjy8TJraSR9YhmEsQ/FQ3KW2Gk4+g+0xAu4QfAwJFtxDgLu3HHPBrFewKhls /TSnfCAbFyM86uFxbItizmCvyrq7oiq5FYsJByE38oZ+IZ2bu3nLhi/ML7U8cHGUtde1 66pbpjuGfBII3aBEGv19sv2efd+ei5p0O16W/jcnygMx6bJccyTTGhQANGCyXqvOBlea PVlw== X-Forwarded-Encrypted: i=1; AJvYcCUUYwAVuwOq/Ud+Xfj7vXNGDTZxmas2FIZgnsfFKs+PTwUpQEATBrUzZiqrE/2h48KHRbnOyIqEF5KGcc+w@vger.kernel.org X-Gm-Message-State: AOJu0YyBAnA4nQtPVeSEgbioBwEVjWw5fmhjslhiGimwhL+XmAISuiZU 0Z9YvkkfRKSqZ4/mc8+UdXNSxLo6VLdhr0FJN2tjnUVVF+njMLyuKx7QA4FdDLY= X-Google-Smtp-Source: AGHT+IGs3z/1IuRBhhgcQrQmIVWwPr43n/jctzILt+apLswhddJAGBym568yRqijFSP667Ww7gbDZA== X-Received: by 2002:a17:90b:1f8e:b0:2e0:d957:1b9d with SMTP id 98e67ed59e1d1-2e9b17163cbmr13877494a91.13.1731252563753; Sun, 10 Nov 2024 07:29:23 -0800 (PST) Received: from localhost.localdomain ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2e99a5f935dsm9940973a91.35.2024.11.10.07.29.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 10 Nov 2024 07:29:23 -0800 (PST) From: Jens Axboe To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Cc: hannes@cmpxchg.org, clm@meta.com, linux-kernel@vger.kernel.org, willy@infradead.org, Jens Axboe Subject: [PATCH 07/15] fs: add RWF_UNCACHED iocb and FOP_UNCACHED file_operations flag Date: Sun, 10 Nov 2024 08:27:59 -0700 Message-ID: <20241110152906.1747545-8-axboe@kernel.dk> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241110152906.1747545-1-axboe@kernel.dk> References: <20241110152906.1747545-1-axboe@kernel.dk> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If a file system supports uncached buffered IO, it may set FOP_UNCACHED and enable RWF_UNCACHED. If RWF_UNCACHED is attempted without the file system supporting it, it'll get errored with -EOPNOTSUPP. Signed-off-by: Jens Axboe --- include/linux/fs.h | 10 +++++++++- include/uapi/linux/fs.h | 6 +++++- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 3559446279c1..5abc53991cd0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -320,6 +320,7 @@ struct readahead_control; #define IOCB_NOWAIT (__force int) RWF_NOWAIT #define IOCB_APPEND (__force int) RWF_APPEND #define IOCB_ATOMIC (__force int) RWF_ATOMIC +#define IOCB_UNCACHED (__force int) RWF_UNCACHED /* non-RWF related bits - start at 16 */ #define IOCB_EVENTFD (1 << 16) @@ -354,7 +355,8 @@ struct readahead_control; { IOCB_SYNC, "SYNC" }, \ { IOCB_NOWAIT, "NOWAIT" }, \ { IOCB_APPEND, "APPEND" }, \ - { IOCB_ATOMIC, "ATOMIC"}, \ + { IOCB_ATOMIC, "ATOMIC" }, \ + { IOCB_UNCACHED, "UNCACHED" }, \ { IOCB_EVENTFD, "EVENTFD"}, \ { IOCB_DIRECT, "DIRECT" }, \ { IOCB_WRITE, "WRITE" }, \ @@ -2116,6 +2118,8 @@ struct file_operations { #define FOP_HUGE_PAGES ((__force fop_flags_t)(1 << 4)) /* Treat loff_t as unsigned (e.g., /dev/mem) */ #define FOP_UNSIGNED_OFFSET ((__force fop_flags_t)(1 << 5)) +/* File system supports uncached read/write buffered IO */ +#define FOP_UNCACHED ((__force fop_flags_t)(1 << 6)) /* Wrap a directory iterator that needs exclusive inode access */ int wrap_directory_iterator(struct file *, struct dir_context *, @@ -3532,6 +3536,10 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags, if (!(ki->ki_filp->f_mode & FMODE_CAN_ATOMIC_WRITE)) return -EOPNOTSUPP; } + if (flags & RWF_UNCACHED) { + if (!(ki->ki_filp->f_op->fop_flags & FOP_UNCACHED)) + return -EOPNOTSUPP; + } kiocb_flags |= (__force int) (flags & RWF_SUPPORTED); if (flags & RWF_SYNC) kiocb_flags |= IOCB_DSYNC; diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index 753971770733..dc77cd8ae1a3 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -332,9 +332,13 @@ typedef int __bitwise __kernel_rwf_t; /* Atomic Write */ #define RWF_ATOMIC ((__force __kernel_rwf_t)0x00000040) +/* buffered IO that drops the cache after reading or writing data */ +#define RWF_UNCACHED ((__force __kernel_rwf_t)0x00000080) + /* mask of flags supported by the kernel */ #define RWF_SUPPORTED (RWF_HIPRI | RWF_DSYNC | RWF_SYNC | RWF_NOWAIT |\ - RWF_APPEND | RWF_NOAPPEND | RWF_ATOMIC) + RWF_APPEND | RWF_NOAPPEND | RWF_ATOMIC |\ + RWF_UNCACHED) #define PROCFS_IOCTL_MAGIC 'f' -- 2.45.2