From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE4AD2594AA; Thu, 10 Jul 2025 13:34:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752154472; cv=none; b=gDU8QtKvE6aQS2du9PNiz9a0pAY3ofKPsnclLcDQwpPykU6he1QfFOqBfn53ST8vS28xBhzIkfK7S3wu8EVPCuBvq36NxgiKzShcI43a9u+xCH5uzrsgdLrBoLO1VKTMtLfiw7d+0lPzS3fUa3iZNntWFoCkQoxObz4YHJVsJBI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752154472; c=relaxed/simple; bh=1vY2SI/EU/p6f/MN0wtIAZuLaV0B+OamC3qSI48hGig=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qqKui+Leke2zJoIqO19VDqVRwoP6eHr/gm0wOESlFFRS6gXVbBfHgE0Bi3ysCYFRz3RHHEuX6xBbTbHb7Ks3zq13iJhT55mkVJHKer/7aYmlX6xPTTNvJnpo0iGMkhSf5Qd8xcqR6Zdv8qqMex66Naikw23a86xNOUi/SFDzOks= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=wEX3YJ21; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="wEX3YJ21" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=UhQeJkl5VSLEiGmrOdor8cRhYH50EWQ136HJ5CG2AWE=; b=wEX3YJ21eih3kF6luzyYju7zx7 INM7DQzg9lf7OU+/Dtun1zch0+nVDU70BAXBxE2jAPi1rYiBvOjuKtl0bDUGKNMM9Nckg9iIJhfUB A7LFPIraAuHjb9Aa41NAXSKtGihiB9hzzeejrPolshORcMt/VkOZORs6HhPb+/vrfeq0S0BOLVYu/ DFEom8lRz80dyrQz0Gi4voUKvyExVi9wrL/MMcPCJCRDwWVNOhgdMFabEfWu9mkw6NbY4H6PE5jh7 8KCQGlwYAxF9CSRpvLSc0EaThAe9fdfDJEkkeuo+lZ7tld9QWQx6egYBhc6gh9ISWvxIWRWDSI3Y/ Pv8ZWdiA==; Received: from 2a02-8389-2341-5b80-d601-7564-c2e0-491c.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:d601:7564:c2e0:491c] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uZrPy-0000000Bwck-0dPy; Thu, 10 Jul 2025 13:34:30 +0000 From: Christoph Hellwig To: Christian Brauner Cc: "Darrick J. Wong" , Joanne Koong , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-block@vger.kernel.org, gfs2@lists.linux.dev Subject: [PATCH 13/14] iomap: add read_folio_range() handler for buffered writes Date: Thu, 10 Jul 2025 15:33:37 +0200 Message-ID: <20250710133343.399917-14-hch@lst.de> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250710133343.399917-1-hch@lst.de> References: <20250710133343.399917-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Add a read_folio_range() handler for buffered writes that filesystems may pass in if they wish to provide a custom handler for synchronously reading in the contents of a folio. Signed-off-by: Joanne Koong [hch: renamed to read_folio_range, pass less arguments] Signed-off-by: Christoph Hellwig Reviewed-by: "Darrick J. Wong" --- Documentation/filesystems/iomap/operations.rst | 6 ++++++ fs/iomap/buffered-io.c | 13 +++++++++---- include/linux/iomap.h | 10 ++++++++++ 3 files changed, 25 insertions(+), 4 deletions(-) diff --git a/Documentation/filesystems/iomap/operations.rst b/Documentation/filesystems/iomap/operations.rst index a9b48ce4af92..067ed8e14ef3 100644 --- a/Documentation/filesystems/iomap/operations.rst +++ b/Documentation/filesystems/iomap/operations.rst @@ -68,6 +68,8 @@ The following address space operations can be wrapped easily: void (*put_folio)(struct inode *inode, loff_t pos, unsigned copied, struct folio *folio); bool (*iomap_valid)(struct inode *inode, const struct iomap *iomap); + int (*read_folio_range)(const struct iomap_iter *iter, + struct folio *folio, loff_t pos, size_t len); }; iomap calls these functions: @@ -123,6 +125,10 @@ iomap calls these functions: ``->iomap_valid``, then the iomap should considered stale and the validation failed. + - ``read_folio_range``: Called to synchronously read in the range that will + be written to. If this function is not provided, iomap will default to + submitting a bio read request. + These ``struct kiocb`` flags are significant for buffered I/O with iomap: * ``IOCB_NOWAIT``: Turns on ``IOMAP_NOWAIT``. diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 8a44f56a3a80..aed4fc30a849 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -671,7 +671,8 @@ static int iomap_read_folio_range(const struct iomap_iter *iter, return submit_bio_wait(&bio); } -static int __iomap_write_begin(const struct iomap_iter *iter, size_t len, +static int __iomap_write_begin(const struct iomap_iter *iter, + const struct iomap_write_ops *write_ops, size_t len, struct folio *folio) { struct iomap_folio_state *ifs; @@ -722,8 +723,12 @@ static int __iomap_write_begin(const struct iomap_iter *iter, size_t len, if (iter->flags & IOMAP_NOWAIT) return -EAGAIN; - status = iomap_read_folio_range(iter, folio, - block_start, plen); + if (write_ops && write_ops->read_folio_range) + status = write_ops->read_folio_range(iter, + folio, block_start, plen); + else + status = iomap_read_folio_range(iter, + folio, block_start, plen); if (status) return status; } @@ -839,7 +844,7 @@ static int iomap_write_begin(struct iomap_iter *iter, else if (srcmap->flags & IOMAP_F_BUFFER_HEAD) status = __block_write_begin_int(folio, pos, len, NULL, srcmap); else - status = __iomap_write_begin(iter, len, folio); + status = __iomap_write_begin(iter, write_ops, len, folio); if (unlikely(status)) goto out_unlock; diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 80f543cc4fe8..73dceabc21c8 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -166,6 +166,16 @@ struct iomap_write_ops { * locked by the iomap code. */ bool (*iomap_valid)(struct inode *inode, const struct iomap *iomap); + + /* + * Optional if the filesystem wishes to provide a custom handler for + * reading in the contents of a folio, otherwise iomap will default to + * submitting a bio read request. + * + * The read must be done synchronously. + */ + int (*read_folio_range)(const struct iomap_iter *iter, + struct folio *folio, loff_t pos, size_t len); }; /* -- 2.47.2