From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B383C43219 for ; Tue, 30 Apr 2019 15:26:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C5B02147A for ; Tue, 30 Apr 2019 15:26:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="ux2QZJeZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725950AbfD3P05 (ORCPT ); Tue, 30 Apr 2019 11:26:57 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:60876 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725930AbfD3P05 (ORCPT ); Tue, 30 Apr 2019 11:26:57 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3UFOXkW110533; Tue, 30 Apr 2019 15:26:29 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=GP7BtA84ivQNMdsMKZBYVXe+9V8f4N3iqEFhAXP+9sU=; b=ux2QZJeZOV2RwfeCOt5Fwitbzg65YB8PWWvqo9Gr3+uBYd8grAQ1RMoW2rlaXtTH/O41 zB3a+7FNt5/wiSJCTceiIFJIEULrchwFxJwyStBfhrRszrF0cx9zHgUVb6n9+uAkkG4r 5RutasAnvK9RuB0rKnNV60OyDWD4m6hhpXx8H20HTSVBRNnbYKzigBx3HeFFpnb/k12s g3dqpNChdgl72zsXUT5F3GxpvMlkMRNM5J9YuDcX3ctkOI0YENEr9dkRtF3oOQEj81cw 0n5n85my190UTUHLg8SmvHDHJvFHcyNlBU9XleRytWhmploJFcJX4vBvDzn6gMrnjnKg EQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 2s5j5u207g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Apr 2019 15:26:29 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3UFOkof124244; Tue, 30 Apr 2019 15:26:28 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 2s4ew1aach-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Apr 2019 15:26:28 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x3UFQRom010154; Tue, 30 Apr 2019 15:26:27 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 30 Apr 2019 08:26:27 -0700 Date: Tue, 30 Apr 2019 08:26:25 -0700 From: "Darrick J. Wong" To: Andreas Gruenbacher Cc: cluster-devel@redhat.com, Christoph Hellwig , Bob Peterson , Jan Kara , Dave Chinner , Ross Lagerwall , Mark Syms , Edwin =?iso-8859-1?B?VPZy9ms=?= , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v7 4/5] iomap: Add a page_prepare callback Message-ID: <20190430152625.GE5200@magnolia> References: <20190429220934.10415-1-agruenba@redhat.com> <20190429220934.10415-5-agruenba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190429220934.10415-5-agruenba@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9243 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904300095 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9243 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904300095 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Apr 30, 2019 at 12:09:33AM +0200, Andreas Gruenbacher wrote: > 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 Looks fine, assuming you've done the appropriate QA/testing on the gfs2 side. :) Reviewed-by: Darrick J. Wong --D > --- > fs/gfs2/bmap.c | 15 ++++++++++----- > fs/iomap.c | 36 ++++++++++++++++++++++++++---------- > include/linux/iomap.h | 22 +++++++++++++++++----- > 3 files changed, 53 insertions(+), 20 deletions(-) > > diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c > index 5da4ca9041c0..aa014725f84a 100644 > --- a/fs/gfs2/bmap.c > +++ b/fs/gfs2/bmap.c > @@ -991,15 +991,20 @@ 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 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_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 +1082,7 @@ 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 62e3461704ce..a3ffc83134ee 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, > } > > __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) > + 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); > }; > -- > 2.20.1 >