From nobody Tue Sep 16 21:46:32 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 475DBC53210 for ; Thu, 29 Dec 2022 08:14:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233156AbiL2IOM (ORCPT ); Thu, 29 Dec 2022 03:14:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233106AbiL2INU (ORCPT ); Thu, 29 Dec 2022 03:13:20 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B26711183E for ; Thu, 29 Dec 2022 00:13:06 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id h7-20020a17090aa88700b00225f3e4c992so9628305pjq.1 for ; Thu, 29 Dec 2022 00:13:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; 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=97i6P/h7b+1gvIVRYO+DX34CDfR4Yqv0wh8jpsVN6uA=; b=J3UxtnO0lRODuALIZIbXFjggUs9csqzYnLWy6fCUhVcEssVoXOgvKDKzSKMFzlyrjx IAcfKrnfFQdpsDZbxkBzRb3HsHRv4Zx0R+LRjDqk5C1MorbFDuEtB4dQo6e2wnJcboJU lOoPqaeq28xjwQUyT3StdCsVbKKsSKUNoIs8A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=97i6P/h7b+1gvIVRYO+DX34CDfR4Yqv0wh8jpsVN6uA=; b=PAynIa6SN0H4NkhA+ZMsriGtNsrwSSh6Jc0rUcmolON4NBbncvV4525+NeX2zCgqG4 M62fS/y6WYpFTMaaKav26iLo4IYqVnDmmPhJ2gJ3amOpNJfxfW89riZL7HBCu2InzQY8 d52xRtUQhxV7PlniNvCUuNfGyvNAPBpUMYuIj55jhOIqosjfVxP6PciepgLOJgEyh9/n Z+0aXiYwwK3xp/Jnj5BWsWO2EWxQWL5A0ObGt6wrFXlwRluMNkVUQiU47JYtooK9sGbK SNufCK1xC1mfZz5WMCYE6aBnAsZNlW0i0zK7wrrToBqT0+fOIEJtx63yIZTCbhvW/hTf 2trA== X-Gm-Message-State: AFqh2koZGl7fI4jIgrXoQqR4Dc8XO3ajMwbJ2bJkJdSK7L65Yc0xKZ8K VqPzAMbhiQ/x6iiNotV1PFY7sg== X-Google-Smtp-Source: AMrXdXuG8djGml0FmIoeHtIQvCDtglHyJ1RnAJ0w5NvdgLWhnB8c6w6P+S+xrI2iEBZecvFqN4EojA== X-Received: by 2002:a17:902:9687:b0:192:9ab2:fd1c with SMTP id n7-20020a170902968700b001929ab2fd1cmr2910136plp.26.1672301586179; Thu, 29 Dec 2022 00:13:06 -0800 (PST) Received: from sarthakkukreti-glaptop.hsd1.ca.comcast.net ([2601:647:4200:b5b0:75ff:1277:3d7b:d67a]) by smtp.gmail.com with ESMTPSA id 12-20020a170902e9cc00b00192820d00d0sm6496325plk.120.2022.12.29.00.13.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Dec 2022 00:13:05 -0800 (PST) From: Sarthak Kukreti To: sarthakkukreti@google.com, dm-devel@redhat.com, linux-block@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Jens Axboe , "Michael S. Tsirkin" , Jason Wang , Stefan Hajnoczi , Alasdair Kergon , Mike Snitzer , Christoph Hellwig , Brian Foster , Theodore Ts'o , Andreas Dilger , Bart Van Assche , Daniil Lunev , "Darrick J. Wong" Subject: [PATCH v2 3/7] fs: Introduce FALLOC_FL_PROVISION Date: Thu, 29 Dec 2022 00:12:48 -0800 Message-Id: <20221229081252.452240-4-sarthakkukreti@chromium.org> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog In-Reply-To: <20221229081252.452240-1-sarthakkukreti@chromium.org> References: <20221229081252.452240-1-sarthakkukreti@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" FALLOC_FL_PROVISION is a new fallocate() allocation mode that sends a hint to (supported) thinly provisioned block devices to allocate space for the given range of sectors via REQ_OP_PROVISION. The man pages for both fallocate(2) and posix_fallocate(3) describe the default allocation mode as: ``` The default operation (i.e., mode is zero) of fallocate() allocates the disk space within the range specified by offset and len. ... subsequent writes to bytes in the specified range are guaranteed not to fail because of lack of disk space. ``` For thinly provisioned storage constructs (dm-thin, filesystems on sparse files), the term 'disk space' is overloaded and can either mean the apparent disk space in the filesystem/thin logical volume or the true disk space that will be utilized on the underlying non-sparse allocation layer. The use of a separate mode allows us to cleanly disambiguate whether falloc= ate() causes allocation only at the current layer (default mode) or whether it pr= opagates allocations to underlying layers (provision mode) for thinly provisioned fi= lesystems/ block devices. For devices that do not support REQ_OP_PROVISION, both these allocation modes will be equivalent. Given the performance cost of sending = provision requests to the underlying layers, keeping the default mode as-is allows us= ers to preserve existing behavior. Signed-off-by: Sarthak Kukreti --- block/fops.c | 15 +++++++++++---- include/linux/falloc.h | 3 ++- include/uapi/linux/falloc.h | 8 ++++++++ 3 files changed, 21 insertions(+), 5 deletions(-) diff --git a/block/fops.c b/block/fops.c index 50d245e8c913..01bde561e1e2 100644 --- a/block/fops.c +++ b/block/fops.c @@ -598,7 +598,8 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, str= uct iov_iter *to) =20 #define BLKDEV_FALLOC_FL_SUPPORTED \ (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ - FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) + FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE | \ + FALLOC_FL_PROVISION) =20 static long blkdev_fallocate(struct file *file, int mode, loff_t start, loff_t len) @@ -634,9 +635,11 @@ static long blkdev_fallocate(struct file *file, int mo= de, loff_t start, filemap_invalidate_lock(inode->i_mapping); =20 /* Invalidate the page cache, including dirty pages. */ - error =3D truncate_bdev_range(bdev, file->f_mode, start, end); - if (error) - goto fail; + if (mode !=3D FALLOC_FL_PROVISION) { + error =3D truncate_bdev_range(bdev, file->f_mode, start, end); + if (error) + goto fail; + } =20 switch (mode) { case FALLOC_FL_ZERO_RANGE: @@ -654,6 +657,10 @@ static long blkdev_fallocate(struct file *file, int mo= de, loff_t start, error =3D blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, len >> SECTOR_SHIFT, GFP_KERNEL); break; + case FALLOC_FL_PROVISION: + error =3D blkdev_issue_provision(bdev, start >> SECTOR_SHIFT, + len >> SECTOR_SHIFT, GFP_KERNEL); + break; default: error =3D -EOPNOTSUPP; } diff --git a/include/linux/falloc.h b/include/linux/falloc.h index f3f0b97b1675..b9a40a61a59b 100644 --- a/include/linux/falloc.h +++ b/include/linux/falloc.h @@ -30,7 +30,8 @@ struct space_resv { FALLOC_FL_COLLAPSE_RANGE | \ FALLOC_FL_ZERO_RANGE | \ FALLOC_FL_INSERT_RANGE | \ - FALLOC_FL_UNSHARE_RANGE) + FALLOC_FL_UNSHARE_RANGE | \ + FALLOC_FL_PROVISION) =20 /* on ia32 l_start is on a 32-bit boundary */ #if defined(CONFIG_X86_64) diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h index 51398fa57f6c..2d323d113eed 100644 --- a/include/uapi/linux/falloc.h +++ b/include/uapi/linux/falloc.h @@ -77,4 +77,12 @@ */ #define FALLOC_FL_UNSHARE_RANGE 0x40 =20 +/* + * FALLOC_FL_PROVISION acts as a hint for thinly provisioned devices to al= locate + * blocks for the range/EOF. + * + * FALLOC_FL_PROVISION can only be used with allocate-mode fallocate. + */ +#define FALLOC_FL_PROVISION 0x80 + #endif /* _UAPI_FALLOC_H_ */ --=20 2.37.3