From patchwork Mon Apr 29 16:32:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 10922083 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1F96A14C0 for ; Mon, 29 Apr 2019 16:32:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0ED8328161 for ; Mon, 29 Apr 2019 16:32:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 02C2228685; Mon, 29 Apr 2019 16:32:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7471928161 for ; Mon, 29 Apr 2019 16:32:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728645AbfD2Qcy (ORCPT ); Mon, 29 Apr 2019 12:32:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49092 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728524AbfD2Qcy (ORCPT ); Mon, 29 Apr 2019 12:32:54 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D55B459454; Mon, 29 Apr 2019 16:32:53 +0000 (UTC) Received: from max.home.com (unknown [10.40.205.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4F8DA17A64; Mon, 29 Apr 2019 16:32:51 +0000 (UTC) From: Andreas Gruenbacher To: cluster-devel@redhat.com, Christoph Hellwig Cc: Bob Peterson , Jan Kara , Dave Chinner , Ross Lagerwall , Mark Syms , =?utf-8?b?RWR3aW4gVMO2csO2aw==?= , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Andreas Gruenbacher Subject: [PATCH v6 3/4] iomap: Add a page_prepare callback Date: Mon, 29 Apr 2019 18:32:38 +0200 Message-Id: <20190429163239.4874-3-agruenba@redhat.com> In-Reply-To: <20190429163239.4874-1-agruenba@redhat.com> References: <20190429163239.4874-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 29 Apr 2019 16:32:53 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Move the page_done callback into a separate iomap_page_ops structure and add a page_prepare calback to be called before the next page is written to. In gfs2, we'll want to start a transaction in page_prepare and end it in page_done. Other filesystems that implement data journaling will require the same kind of mechanism. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara --- fs/gfs2/bmap.c | 22 +++++++++++++++++----- fs/iomap.c | 36 ++++++++++++++++++++++++++---------- include/linux/iomap.h | 22 +++++++++++++++++----- 3 files changed, 60 insertions(+), 20 deletions(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 5da4ca9041c0..6b980703bae7 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -991,15 +991,27 @@ static void gfs2_write_unlock(struct inode *inode) gfs2_glock_dq_uninit(&ip->i_gh); } -static void gfs2_iomap_journaled_page_done(struct inode *inode, loff_t pos, - unsigned copied, struct page *page, - struct iomap *iomap) +static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos, + unsigned len, struct iomap *iomap) +{ + return 0; +} + +static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, + unsigned copied, struct page *page, + struct iomap *iomap) { struct gfs2_inode *ip = GFS2_I(inode); - gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); + if (page) + gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); } +static const struct iomap_page_ops gfs2_iomap_page_ops = { + .page_prepare = gfs2_iomap_page_prepare, + .page_done = gfs2_iomap_page_done, +}; + static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, loff_t length, unsigned flags, struct iomap *iomap, @@ -1077,7 +1089,7 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, } } if (!gfs2_is_stuffed(ip) && gfs2_is_jdata(ip)) - iomap->page_done = gfs2_iomap_journaled_page_done; + iomap->page_ops = &gfs2_iomap_page_ops; return 0; out_trans_end: diff --git a/fs/iomap.c b/fs/iomap.c index b01ed5a28d2c..ee9ce7a06244 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -665,6 +665,7 @@ static int iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, struct page **pagep, struct iomap *iomap) { + const struct iomap_page_ops *page_ops = iomap->page_ops; pgoff_t index = pos >> PAGE_SHIFT; struct page *page; int status = 0; @@ -674,9 +675,17 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, if (fatal_signal_pending(current)) return -EINTR; + if (page_ops && page_ops->page_prepare) { + status = page_ops->page_prepare(inode, pos, len, iomap); + if (status) + return status; + } + page = grab_cache_page_write_begin(inode->i_mapping, index, flags); - if (!page) - return -ENOMEM; + if (!page) { + status = -ENOMEM; + goto out_no_page; + } if (iomap->type == IOMAP_INLINE) iomap_read_inline_data(inode, page, iomap); @@ -684,15 +693,21 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, status = __block_write_begin_int(page, pos, len, NULL, iomap); else status = __iomap_write_begin(inode, pos, len, page, iomap); - if (unlikely(status)) { - unlock_page(page); - put_page(page); - page = NULL; - iomap_write_failed(inode, pos, len); - } + if (unlikely(status)) + goto out_unlock; *pagep = page; + return 0; + +out_unlock: + unlock_page(page); + put_page(page); + iomap_write_failed(inode, pos, len); + +out_no_page: + if (page_ops && page_ops->page_done) + page_ops->page_done(inode, pos, 0, NULL, iomap); return status; } @@ -766,6 +781,7 @@ static int iomap_write_end(struct inode *inode, loff_t pos, unsigned len, unsigned copied, struct page *page, struct iomap *iomap) { + const struct iomap_page_ops *page_ops = iomap->page_ops; int ret; if (iomap->type == IOMAP_INLINE) { @@ -778,8 +794,8 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, } ret = __generic_write_end(inode, pos, ret, page); - if (iomap->page_done) - iomap->page_done(inode, pos, copied, page, iomap); + if (page_ops) + page_ops->page_done(inode, pos, copied, page, iomap); put_page(page); if (ret < len) diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 0fefb5455bda..2103b94cb1bf 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -53,6 +53,8 @@ struct vm_fault; */ #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ +struct iomap_page_ops; + struct iomap { u64 addr; /* disk offset of mapping, bytes */ loff_t offset; /* file offset of mapping, bytes */ @@ -63,12 +65,22 @@ struct iomap { struct dax_device *dax_dev; /* dax_dev for dax operations */ void *inline_data; void *private; /* filesystem private */ + const struct iomap_page_ops *page_ops; +}; - /* - * Called when finished processing a page in the mapping returned in - * this iomap. At least for now this is only supported in the buffered - * write path. - */ +/* + * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare + * and page_done will be called for each page written to. This only applies to + * buffered writes as unbuffered writes will not typically have pages + * associated with them. + * + * When page_prepare succeeds, page_done will always be called to do any + * cleanup work necessary. In that page_done call, @page will be NULL if the + * associated page could not be obtained. + */ +struct iomap_page_ops { + int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, + struct iomap *iomap); void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, struct page *page, struct iomap *iomap); };