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 3E796C636CA for ; Thu, 15 Jul 2021 21:28:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C4F1A61374 for ; Thu, 15 Jul 2021 21:27:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4F1A61374 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2EDE28D00F5; Thu, 15 Jul 2021 17:28:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 29D598D00EC; Thu, 15 Jul 2021 17:28:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1655A8D00F5; Thu, 15 Jul 2021 17:28:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0027.hostedemail.com [216.40.44.27]) by kanga.kvack.org (Postfix) with ESMTP id E5F288D00EC for ; Thu, 15 Jul 2021 17:27:59 -0400 (EDT) Received: from smtpin37.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id CB8D026829 for ; Thu, 15 Jul 2021 21:27:58 +0000 (UTC) X-FDA: 78366109836.37.1B01006 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf02.hostedemail.com (Postfix) with ESMTP id 6A8C87001A23 for ; Thu, 15 Jul 2021 21:26:58 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 845EE611F1; Thu, 15 Jul 2021 21:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626384417; bh=u8MbHkVCv8WZ+jb8DX1ndBE18b6PN59H67U6iNz0TW0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RxzBUVRGx+C9eR9+nT1mJwlIuUq/tPqF85xSh00juUARMwIF0UkewUSWNAiRjK5/z 86ckHRCu6bZWaHd2HHh39ow24q41+wIjI/kdYkmk13c8inswC0o84TIwTpQiFj6wZO x5/PG980+eZVVy8vo0mvTxyUByT8Xrd9rBibhDNS7YFbFbZTrFoEFTflg7BLQOS7uL +a69jcb9Op3dJjHVDvC/eroypcMEmzBVinOrE0qAuedWDaOHq/VikKYV0kckFxR3cX vmw21+JNtmMIV6xvMW8g8R5Fnd51ermq7E5GU1WmWKeLab+l1r5qysW744c2bNRnav eCrmvyQ9xN7ow== Date: Thu, 15 Jul 2021 14:26:57 -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 098/138] iomap: Use folio offsets instead of page offsets Message-ID: <20210715212657.GI22357@magnolia> References: <20210715033704.692967-1-willy@infradead.org> <20210715033704.692967-99-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210715033704.692967-99-willy@infradead.org> Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=RxzBUVRG; spf=pass (imf02.hostedemail.com: domain of djwong@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=djwong@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam02 X-Stat-Signature: rjwgp1afj55q3q7k6s6d8yhodhcyan3g X-Rspamd-Queue-Id: 6A8C87001A23 X-HE-Tag: 1626384418-446975 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jul 15, 2021 at 04:36:24AM +0100, Matthew Wilcox (Oracle) wrote: > Pass a folio around instead of the page, and make sure the offset > is relative to the start of the folio instead of the start of a page. > Also use size_t for offset & length to make it clear that these are byte > counts, and to support >2GB folios in the future. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > fs/iomap/buffered-io.c | 85 ++++++++++++++++++++++-------------------- > 1 file changed, 44 insertions(+), 41 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index fbe4ebc074ce..707a96e36651 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -75,18 +75,18 @@ static void iomap_page_release(struct folio *folio) > } > > /* > - * Calculate the range inside the page that we actually need to read. > + * Calculate the range inside the folio that we actually need to read. > */ > -static void > -iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > - loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp) > +static void iomap_adjust_read_range(struct inode *inode, struct folio *folio, > + loff_t *pos, loff_t length, size_t *offp, size_t *lenp) > { > + struct iomap_page *iop = to_iomap_page(folio); > loff_t orig_pos = *pos; > loff_t isize = i_size_read(inode); > unsigned block_bits = inode->i_blkbits; > unsigned block_size = (1 << block_bits); > - unsigned poff = offset_in_page(*pos); > - unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length); > + size_t poff = offset_in_folio(folio, *pos); > + size_t plen = min_t(loff_t, folio_size(folio) - poff, length); I'm confused about 'size_t poff' here vs. 'unsigned end' later -- why do we need a 64-bit quantity for poff? I suppose some day we might want to have folios larger than 4GB or so, but so far we don't need that large of a byte offset within a page/folio, right? Or are you merely moving the codebase towards using size_t for all byte offsets? The rest of the conversion code looked ok though. --D > unsigned first = poff >> block_bits; > unsigned last = (poff + plen - 1) >> block_bits; > > @@ -124,7 +124,7 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > * page cache for blocks that are entirely outside of i_size. > */ > if (orig_pos <= isize && orig_pos + length > isize) { > - unsigned end = offset_in_page(isize - 1) >> block_bits; > + unsigned end = offset_in_folio(folio, isize - 1) >> block_bits; > > if (first <= end && last > end) > plen -= (last - end) * block_size; > @@ -134,31 +134,31 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > *lenp = plen; > } > > -static void iomap_iop_set_range_uptodate(struct page *page, > - struct iomap_page *iop, unsigned off, unsigned len) > +static void iomap_iop_set_range_uptodate(struct folio *folio, > + struct iomap_page *iop, size_t off, size_t len) > { > - struct inode *inode = page->mapping->host; > + struct inode *inode = folio->mapping->host; > unsigned first = off >> inode->i_blkbits; > unsigned last = (off + len - 1) >> inode->i_blkbits; > unsigned long flags; > > spin_lock_irqsave(&iop->uptodate_lock, flags); > bitmap_set(iop->uptodate, first, last - first + 1); > - if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page))) > - SetPageUptodate(page); > + if (bitmap_full(iop->uptodate, i_blocks_per_folio(inode, folio))) > + folio_mark_uptodate(folio); > spin_unlock_irqrestore(&iop->uptodate_lock, flags); > } > > -static void iomap_set_range_uptodate(struct page *page, > - struct iomap_page *iop, unsigned off, unsigned len) > +static void iomap_set_range_uptodate(struct folio *folio, > + struct iomap_page *iop, size_t off, size_t len) > { > - if (PageError(page)) > + if (folio_test_error(folio)) > return; > > if (iop) > - iomap_iop_set_range_uptodate(page, iop, off, len); > + iomap_iop_set_range_uptodate(folio, iop, off, len); > else > - SetPageUptodate(page); > + folio_mark_uptodate(folio); > } > > static void > @@ -169,15 +169,17 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error) > struct iomap_page *iop = to_iomap_page(folio); > > if (unlikely(error)) { > - ClearPageUptodate(page); > - SetPageError(page); > + folio_clear_uptodate(folio); > + folio_set_error(folio); > } else { > - iomap_set_range_uptodate(page, iop, bvec->bv_offset, > - bvec->bv_len); > + size_t off = (page - &folio->page) * PAGE_SIZE + > + bvec->bv_offset; > + > + iomap_set_range_uptodate(folio, iop, off, bvec->bv_len); > } > > if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending)) > - unlock_page(page); > + folio_unlock(folio); > } > > static void > @@ -237,7 +239,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > struct iomap_page *iop = iomap_page_create(inode, folio); > bool same_page = false, is_contig = false; > loff_t orig_pos = pos; > - unsigned poff, plen; > + size_t poff, plen; > sector_t sector; > > if (iomap->type == IOMAP_INLINE) { > @@ -246,14 +248,14 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > return PAGE_SIZE; > } > > - /* zero post-eof blocks as the page may be mapped */ > - iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); > + /* zero post-eof blocks as the folio may be mapped */ > + iomap_adjust_read_range(inode, folio, &pos, length, &poff, &plen); > if (plen == 0) > goto done; > > if (iomap_block_needs_zeroing(inode, iomap, pos)) { > - zero_user(page, poff, plen); > - iomap_set_range_uptodate(page, iop, poff, plen); > + zero_user(&folio->page, poff, plen); > + iomap_set_range_uptodate(folio, iop, poff, plen); > goto done; > } > > @@ -264,7 +266,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > /* Try to merge into a previous segment if we can */ > sector = iomap_sector(iomap, pos); > if (ctx->bio && bio_end_sector(ctx->bio) == sector) { > - if (__bio_try_merge_page(ctx->bio, page, plen, poff, > + if (__bio_try_merge_page(ctx->bio, &folio->page, plen, poff, > &same_page)) > goto done; > is_contig = true; > @@ -296,7 +298,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > ctx->bio->bi_end_io = iomap_read_end_io; > } > > - bio_add_page(ctx->bio, page, plen, poff); > + bio_add_folio(ctx->bio, folio, plen, poff); > done: > /* > * Move the caller beyond our range so that it keeps making progress. > @@ -531,9 +533,8 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len) > truncate_pagecache_range(inode, max(pos, i_size), pos + len); > } > > -static int > -iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, > - unsigned plen, struct iomap *iomap) > +static int iomap_read_folio_sync(loff_t block_start, struct folio *folio, > + size_t poff, size_t plen, struct iomap *iomap) > { > struct bio_vec bvec; > struct bio bio; > @@ -542,7 +543,7 @@ iomap_read_page_sync(loff_t block_start, struct page *page, unsigned poff, > bio.bi_opf = REQ_OP_READ; > bio.bi_iter.bi_sector = iomap_sector(iomap, block_start); > bio_set_dev(&bio, iomap->bdev); > - __bio_add_page(&bio, page, plen, poff); > + bio_add_folio(&bio, folio, plen, poff); > return submit_bio_wait(&bio); > } > > @@ -555,14 +556,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > loff_t block_size = i_blocksize(inode); > loff_t block_start = round_down(pos, block_size); > loff_t block_end = round_up(pos + len, block_size); > - unsigned from = offset_in_page(pos), to = from + len, poff, plen; > + size_t from = offset_in_folio(folio, pos), to = from + len; > + size_t poff, plen; > > - if (PageUptodate(page)) > + if (folio_test_uptodate(folio)) > return 0; > - ClearPageError(page); > + folio_clear_error(folio); > > do { > - iomap_adjust_read_range(inode, iop, &block_start, > + iomap_adjust_read_range(inode, folio, &block_start, > block_end - block_start, &poff, &plen); > if (plen == 0) > break; > @@ -575,14 +577,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > if (iomap_block_needs_zeroing(inode, srcmap, block_start)) { > if (WARN_ON_ONCE(flags & IOMAP_WRITE_F_UNSHARE)) > return -EIO; > - zero_user_segments(page, poff, from, to, poff + plen); > + zero_user_segments(&folio->page, poff, from, to, > + poff + plen); > } else { > - int status = iomap_read_page_sync(block_start, page, > + int status = iomap_read_folio_sync(block_start, folio, > poff, plen, srcmap); > if (status) > return status; > } > - iomap_set_range_uptodate(page, iop, poff, plen); > + iomap_set_range_uptodate(folio, iop, poff, plen); > } while ((block_start += plen) < block_end); > > return 0; > @@ -661,7 +664,7 @@ static size_t __iomap_write_end(struct inode *inode, loff_t pos, size_t len, > */ > if (unlikely(copied < len && !PageUptodate(page))) > return 0; > - iomap_set_range_uptodate(page, iop, offset_in_page(pos), len); > + iomap_set_range_uptodate(folio, iop, offset_in_folio(folio, pos), len); > __set_page_dirty_nobuffers(page); > return copied; > } > -- > 2.30.2 >