From patchwork Fri Dec 16 15:06:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 13075089 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 8A49FC3DA71 for ; Fri, 16 Dec 2022 15:08:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231370AbiLPPI1 (ORCPT ); Fri, 16 Dec 2022 10:08:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231347AbiLPPHk (ORCPT ); Fri, 16 Dec 2022 10:07:40 -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 C29D464D0 for ; Fri, 16 Dec 2022 07:06:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671203212; 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=Hx1hr3zVnpxfjUoh5oVvuyRaT+eEP0rAMA6HZN8X1gk=; b=Sbjq458Bho/9IccRb8LtqFiDVQkF5xzIAnXfyGxGNlomyZ8v6ppYG0SSXjZn9JFdgbyomT 6vVksRwXaBHNu0guv7l3AH44Hq0ibDKiWjjw0Y5X0lah/0AYBE46Vn7AGjUOAca5ffCa3M F386as0ZcHUjiA/Jd2+h2zepPZPvI6o= 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-323-u8Rdga8HO_uSQuxF1_tiZw-1; Fri, 16 Dec 2022 10:06:46 -0500 X-MC-Unique: u8Rdga8HO_uSQuxF1_tiZw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 370033C10ED8; Fri, 16 Dec 2022 15:06:45 +0000 (UTC) Received: from pasta.redhat.com (ovpn-192-182.brq.redhat.com [10.40.192.182]) by smtp.corp.redhat.com (Postfix) with ESMTP id 181A314171BE; Fri, 16 Dec 2022 15:06:42 +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 v3 6/7] iomap/xfs: Eliminate the iomap_valid handler Date: Fri, 16 Dec 2022 16:06:25 +0100 Message-Id: <20221216150626.670312-7-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 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Eliminate the ->iomap_valid() handler by switching to a ->page_prepare() handler and validating the mapping there. Signed-off-by: Andreas Gruenbacher --- fs/iomap/buffered-io.c | 24 ++++-------------------- fs/xfs/xfs_iomap.c | 38 +++++++++++++++++++++++++++----------- include/linux/iomap.h | 17 ----------------- 3 files changed, 31 insertions(+), 48 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 6b7c1a10b8ec..b73ff317da21 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -623,7 +623,7 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, const struct iomap_page_ops *page_ops = iter->iomap.page_ops; const struct iomap *srcmap = iomap_iter_srcmap(iter); struct folio *folio; - int status = 0; + int status; BUG_ON(pos + len > iter->iomap.offset + iter->iomap.length); if (srcmap != &iter->iomap) @@ -642,27 +642,11 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, if (IS_ERR_OR_NULL(folio)) { if (!folio) return (iter->flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOMEM; - return PTR_ERR(folio); - } - - /* - * Now we have a locked folio, before we do anything with it we need to - * check that the iomap we have cached is not stale. The inode extent - * mapping can change due to concurrent IO in flight (e.g. - * IOMAP_UNWRITTEN state can change and memory reclaim could have - * reclaimed a previously partially written page at this index after IO - * completion before this write reaches this file offset) and hence we - * could do the wrong thing here (zero a page range incorrectly or fail - * to zero) and corrupt data. - */ - if (page_ops && page_ops->iomap_valid) { - bool iomap_valid = page_ops->iomap_valid(iter->inode, - &iter->iomap); - if (!iomap_valid) { + if (folio == ERR_PTR(-ESTALE)) { iter->iomap.flags |= IOMAP_F_STALE; - status = 0; - goto out_unlock; + return 0; } + return PTR_ERR(folio); } if (pos + len > folio_pos(folio) + folio_size(folio)) diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 669c1bc5c3a7..2248ce7be2e3 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -62,29 +62,45 @@ xfs_iomap_inode_sequence( return cookie | READ_ONCE(ip->i_df.if_seq); } -/* - * Check that the iomap passed to us is still valid for the given offset and - * length. - */ -static bool -xfs_iomap_valid( - struct inode *inode, - const struct iomap *iomap) +static struct folio * +xfs_page_prepare( + struct iomap_iter *iter, + loff_t pos, + unsigned len) { + struct inode *inode = iter->inode; + struct iomap *iomap = &iter->iomap; struct xfs_inode *ip = XFS_I(inode); + struct folio *folio; + folio = iomap_folio_prepare(iter, pos); + if (!folio) + return NULL; + + /* + * Now we have a locked folio, before we do anything with it we need to + * check that the iomap we have cached is not stale. The inode extent + * mapping can change due to concurrent IO in flight (e.g. + * IOMAP_UNWRITTEN state can change and memory reclaim could have + * reclaimed a previously partially written page at this index after IO + * completion before this write reaches this file offset) and hence we + * could do the wrong thing here (zero a page range incorrectly or fail + * to zero) and corrupt data. + */ if (iomap->validity_cookie != xfs_iomap_inode_sequence(ip, iomap->flags)) { trace_xfs_iomap_invalid(ip, iomap); - return false; + folio_unlock(folio); + folio_put(folio); + return ERR_PTR(-ESTALE); } XFS_ERRORTAG_DELAY(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS); - return true; + return folio; } const struct iomap_page_ops xfs_iomap_page_ops = { - .iomap_valid = xfs_iomap_valid, + .page_prepare = xfs_page_prepare, }; int diff --git a/include/linux/iomap.h b/include/linux/iomap.h index c74ab8c53b47..1c8b9a04b0bb 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -140,23 +140,6 @@ struct iomap_page_ops { unsigned len); void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, struct folio *folio); - - /* - * Check that the cached iomap still maps correctly to the filesystem's - * internal extent map. FS internal extent maps can change while iomap - * is iterating a cached iomap, so this hook allows iomap to detect that - * the iomap needs to be refreshed during a long running write - * operation. - * - * The filesystem can store internal state (e.g. a sequence number) in - * iomap->validity_cookie when the iomap is first mapped to be able to - * detect changes between mapping time and whenever .iomap_valid() is - * called. - * - * This is called with the folio over the specified file position held - * locked by the iomap code. - */ - bool (*iomap_valid)(struct inode *inode, const struct iomap *iomap); }; /*