From patchwork Sun Dec 18 22:10:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 13076112 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 46B4BC3DA71 for ; Sun, 18 Dec 2022 22:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231224AbiLRWNa (ORCPT ); Sun, 18 Dec 2022 17:13:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231243AbiLRWN1 (ORCPT ); Sun, 18 Dec 2022 17:13:27 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E93C1173 for ; Sun, 18 Dec 2022 14:11:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671401472; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QloeDAWDhNne++m1CakCVHuvgCTtzpcI2+OpIgPLSTo=; b=DsY5+5urhqD4ejeCbgoY0VLZL9pLbSr2eNR2b3yKBRy1bAkpSdEgJBQArjIg+8BR0J81dm wm2UhRn6WzOf9qTFBhuFq2uTJcI2e6jWzIDOGZUapJtjoR0wzCSklZw3WsDFtNooe2d5b5 MrVzyQyO+3+SZhgoXTXBn6wTYSKJsAk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-453-Oww25riHNyC1a_58HxQhXg-1; Sun, 18 Dec 2022 17:11:09 -0500 X-MC-Unique: Oww25riHNyC1a_58HxQhXg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C70E12932486; Sun, 18 Dec 2022 22:11:08 +0000 (UTC) Received: from pasta.redhat.com (ovpn-192-22.brq.redhat.com [10.40.192.22]) by smtp.corp.redhat.com (Postfix) with ESMTP id D1F772166B26; Sun, 18 Dec 2022 22:11:06 +0000 (UTC) From: Andreas Gruenbacher To: Christoph Hellwig , "Darrick J . Wong" , Alexander Viro , Matthew Wilcox Cc: Andreas Gruenbacher , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, cluster-devel@redhat.com Subject: [RFC v4 5/7] iomap/gfs2: Get page in page_prepare handler Date: Sun, 18 Dec 2022 23:10:52 +0100 Message-Id: <20221218221054.3946886-6-agruenba@redhat.com> In-Reply-To: <20221216150626.670312-1-agruenba@redhat.com> References: <20221216150626.670312-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Change the iomap ->page_prepare() handler to get and return a locked folio instead of doing that in iomap_write_begin(). This allows to recover from out-of-memory situations in ->page_prepare(), which eliminates the corresponding error handling code in iomap_write_begin(). The ->page_done() handler is now not called with a NULL folio anymore. Filesystems are expected to use the iomap_folio_prepare() helper for getting locked folios in their ->page_prepare() handlers. Signed-off-by: Andreas Gruenbacher --- fs/gfs2/bmap.c | 16 +++++++++++++--- fs/iomap/buffered-io.c | 17 ++++++----------- include/linux/iomap.h | 9 +++++---- 3 files changed, 24 insertions(+), 18 deletions(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 11115fce68cb..ed8ceed64100 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -959,15 +959,25 @@ static int __gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length, goto out; } -static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, - unsigned len) +static struct folio * +gfs2_iomap_page_prepare(struct iomap_iter *iter, loff_t pos, unsigned len) { + struct inode *inode = iter->inode; unsigned int blockmask = i_blocksize(inode) - 1; struct gfs2_sbd *sdp = GFS2_SB(inode); unsigned int blocks; + struct folio *folio; + int status; blocks = ((pos & blockmask) + len + blockmask) >> inode->i_blkbits; - return gfs2_trans_begin(sdp, RES_DINODE + blocks, 0); + status = gfs2_trans_begin(sdp, RES_DINODE + blocks, 0); + if (status) + return ERR_PTR(status); + + folio = iomap_folio_prepare(iter, pos); + if (IS_ERR(folio)) + gfs2_trans_end(sdp); + return folio; } static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 93647dae934a..819562633998 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -607,7 +607,7 @@ static void iomap_folio_done(struct iomap_iter *iter, loff_t pos, size_t ret, if (page_ops && page_ops->page_done) { page_ops->page_done(iter->inode, pos, ret, folio); - } else if (folio) { + } else { folio_unlock(folio); folio_put(folio); } @@ -640,17 +640,12 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, if (!mapping_large_folio_support(iter->inode->i_mapping)) len = min_t(size_t, len, PAGE_SIZE - offset_in_page(pos)); - if (page_ops && page_ops->page_prepare) { - status = page_ops->page_prepare(iter->inode, pos, len); - if (status) - return status; - } - - folio = iomap_folio_prepare(iter, pos); - if (IS_ERR(folio)) { - iomap_folio_done(iter, pos, 0, NULL); + if (page_ops && page_ops->page_prepare) + folio = page_ops->page_prepare(iter, pos, len); + else + folio = iomap_folio_prepare(iter, pos); + if (IS_ERR(folio)) return PTR_ERR(folio); - } /* * Now we have a locked folio, before we do anything with it we need to diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 0bf16ef22d81..c74ab8c53b47 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -13,6 +13,7 @@ struct address_space; struct fiemap_extent_info; struct inode; +struct iomap_iter; struct iomap_dio; struct iomap_writepage_ctx; struct iov_iter; @@ -131,12 +132,12 @@ static inline bool iomap_inline_data_valid(const struct iomap *iomap) * associated with them. * * When page_prepare succeeds, page_done will always be called to do any - * cleanup work necessary. In that page_done call, @folio will be NULL if the - * associated folio could not be obtained. When folio is not NULL, page_done - * is responsible for unlocking and putting the folio. + * cleanup work necessary. page_done is responsible for unlocking and putting + * @folio. */ struct iomap_page_ops { - int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len); + struct folio *(*page_prepare)(struct iomap_iter *iter, loff_t pos, + unsigned len); void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, struct folio *folio);