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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A328EC636C8 for ; Thu, 15 Jul 2021 22:01:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FCA361289 for ; Thu, 15 Jul 2021 22:01:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231701AbhGOWES (ORCPT ); Thu, 15 Jul 2021 18:04:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:49630 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231876AbhGOWEP (ORCPT ); Thu, 15 Jul 2021 18:04:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3780660FE7; Thu, 15 Jul 2021 22:01:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626386481; bh=EO40IYT9v1nClf3prfyuJT+UTB+r8LgL48MhF/4fssg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eNtxQy0yK0wxjrhikZjLEuchIkxicTL5XK5smE0JWADnB9mLTbXkIuWSVpk2xxXur nFjgm4p0i7KDm3PPzXWESR0708JMhln9ZQXjyn90ei1eVjiCf4Rn4S5uk4NcvlCVij ZZlQh8O0NJEA9vwOWZg6sAvHJx/9z53MmzKhPKEykiMyQzFVRO5dO4HGPWuA2u54CW WMshcTeOOvu5RD0Tpf81Bi3fvIpk5crPmmPtpXEe/btBfQvshXhQQHZNtXJLhbI3n8 8XKk5LdaSkL7DCKhGGlCGLGdiN6NaVQQBUzv1twHtP+yad7U/uCZYb6rIHOtVGF+dA SBOypKQ2uOFYg== Date: Thu, 15 Jul 2021 15:01:20 -0700 From: "Darrick J. Wong" To: "Matthew Wilcox (Oracle)" Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v14 105/138] iomap: Convert iomap_add_to_ioend to take a folio Message-ID: <20210715220120.GP22357@magnolia> References: <20210715033704.692967-1-willy@infradead.org> <20210715033704.692967-106-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210715033704.692967-106-willy@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 15, 2021 at 04:36:31AM +0100, Matthew Wilcox (Oracle) wrote: > We still iterate one block at a time, but now we call compound_head() > less often. Rename file_offset to pos to fit the rest of the file. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > fs/iomap/buffered-io.c | 66 +++++++++++++++++++----------------------- > 1 file changed, 30 insertions(+), 36 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index ac33f19325ab..8e767aec8d07 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -1252,36 +1252,29 @@ iomap_can_add_to_ioend(struct iomap_writepage_ctx *wpc, loff_t offset, > * first, otherwise finish off the current ioend and start another. > */ > static void > -iomap_add_to_ioend(struct inode *inode, loff_t offset, struct page *page, > +iomap_add_to_ioend(struct inode *inode, loff_t pos, struct folio *folio, > struct iomap_page *iop, struct iomap_writepage_ctx *wpc, > struct writeback_control *wbc, struct list_head *iolist) > { > - sector_t sector = iomap_sector(&wpc->iomap, offset); > + sector_t sector = iomap_sector(&wpc->iomap, pos); > unsigned len = i_blocksize(inode); > - unsigned poff = offset & (PAGE_SIZE - 1); > - bool merged, same_page = false; > + size_t poff = offset_in_folio(folio, pos); > > - if (!wpc->ioend || !iomap_can_add_to_ioend(wpc, offset, sector)) { > + if (!wpc->ioend || !iomap_can_add_to_ioend(wpc, pos, sector)) { > if (wpc->ioend) > list_add(&wpc->ioend->io_list, iolist); > - wpc->ioend = iomap_alloc_ioend(inode, wpc, offset, sector, wbc); > + wpc->ioend = iomap_alloc_ioend(inode, wpc, pos, sector, wbc); > } > > - merged = __bio_try_merge_page(wpc->ioend->io_bio, page, len, poff, > - &same_page); > if (iop) > atomic_add(len, &iop->write_bytes_pending); > - > - if (!merged) { > - if (bio_full(wpc->ioend->io_bio, len)) { > - wpc->ioend->io_bio = > - iomap_chain_bio(wpc->ioend->io_bio); > - } > - bio_add_page(wpc->ioend->io_bio, page, len, poff); > + if (!bio_add_folio(wpc->ioend->io_bio, folio, len, poff)) { > + wpc->ioend->io_bio = iomap_chain_bio(wpc->ioend->io_bio); > + bio_add_folio(wpc->ioend->io_bio, folio, len, poff); The paranoiac in me wonders if we ought to have some sort of error checking here just in case we encounter double failures? > } > > wpc->ioend->io_size += len; > - wbc_account_cgroup_owner(wbc, page, len); > + wbc_account_cgroup_owner(wbc, &folio->page, len); > } > > /* > @@ -1309,40 +1302,41 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > struct iomap_page *iop = to_iomap_page(folio); > struct iomap_ioend *ioend, *next; > unsigned len = i_blocksize(inode); > - u64 file_offset; /* file offset of page */ > + unsigned nblocks = i_blocks_per_folio(inode, folio); > + loff_t pos = folio_pos(folio); > int error = 0, count = 0, i; > LIST_HEAD(submit_list); > > - WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop); > + WARN_ON_ONCE(nblocks > 1 && !iop); > WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) != 0); > > /* > - * Walk through the page to find areas to write back. If we run off the > - * end of the current map or find the current map invalid, grab a new > - * one. > + * Walk through the folio to find areas to write back. If we > + * run off the end of the current map or find the current map > + * invalid, grab a new one. > */ > - for (i = 0, file_offset = page_offset(page); > - i < (PAGE_SIZE >> inode->i_blkbits) && file_offset < end_offset; > - i++, file_offset += len) { > + for (i = 0; i < nblocks; i++, pos += len) { > + if (pos >= end_offset) > + break; Any particular reason this isn't: for (i = 0; i < nblocks && pos < end_offset; i++, pos += len) { ? Everything from here on out looks decent to me. --D > if (iop && !test_bit(i, iop->uptodate)) > continue; > > - error = wpc->ops->map_blocks(wpc, inode, file_offset); > + error = wpc->ops->map_blocks(wpc, inode, pos); > if (error) > break; > if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE)) > continue; > if (wpc->iomap.type == IOMAP_HOLE) > continue; > - iomap_add_to_ioend(inode, file_offset, page, iop, wpc, wbc, > + iomap_add_to_ioend(inode, pos, folio, iop, wpc, wbc, > &submit_list); > count++; > } > > WARN_ON_ONCE(!wpc->ioend && !list_empty(&submit_list)); > - WARN_ON_ONCE(!PageLocked(page)); > - WARN_ON_ONCE(PageWriteback(page)); > - WARN_ON_ONCE(PageDirty(page)); > + WARN_ON_ONCE(!folio_test_locked(folio)); > + WARN_ON_ONCE(folio_test_writeback(folio)); > + WARN_ON_ONCE(folio_test_dirty(folio)); > > /* > * We cannot cancel the ioend directly here on error. We may have > @@ -1358,16 +1352,16 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > * now. > */ > if (wpc->ops->discard_page) > - wpc->ops->discard_page(page, file_offset); > + wpc->ops->discard_page(&folio->page, pos); > if (!count) { > - ClearPageUptodate(page); > - unlock_page(page); > + folio_clear_uptodate(folio); > + folio_unlock(folio); > goto done; > } > } > > - set_page_writeback(page); > - unlock_page(page); > + folio_start_writeback(folio); > + folio_unlock(folio); > > /* > * Preserve the original error if there was one, otherwise catch > @@ -1388,9 +1382,9 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > * with a partial page truncate on a sub-page block sized filesystem. > */ > if (!count) > - end_page_writeback(page); > + folio_end_writeback(folio); > done: > - mapping_set_error(page->mapping, error); > + mapping_set_error(folio->mapping, error); > return error; > } > > -- > 2.30.2 >