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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 520BFC433DF for ; Thu, 21 May 2020 22:24:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1548B206F6 for ; Thu, 21 May 2020 22:24:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1548B206F6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9EC2C80008; Thu, 21 May 2020 18:24:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 99C9D80007; Thu, 21 May 2020 18:24:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8B2DD80008; Thu, 21 May 2020 18:24:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0236.hostedemail.com [216.40.44.236]) by kanga.kvack.org (Postfix) with ESMTP id 7154280007 for ; Thu, 21 May 2020 18:24:47 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 20457181AEF1F for ; Thu, 21 May 2020 22:24:47 +0000 (UTC) X-FDA: 76842157014.13.tiger03_80fe67a36a410 X-HE-Tag: tiger03_80fe67a36a410 X-Filterd-Recvd-Size: 4871 Received: from mail107.syd.optusnet.com.au (mail107.syd.optusnet.com.au [211.29.132.53]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Thu, 21 May 2020 22:24:46 +0000 (UTC) Received: from dread.disaster.area (pa49-195-157-175.pa.nsw.optusnet.com.au [49.195.157.175]) by mail107.syd.optusnet.com.au (Postfix) with ESMTPS id DD61ED585F3; Fri, 22 May 2020 08:24:42 +1000 (AEST) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1jbtcE-0000Wh-8K; Fri, 22 May 2020 08:24:38 +1000 Date: Fri, 22 May 2020 08:24:38 +1000 From: Dave Chinner To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 14/36] iomap: Support large pages in iomap_adjust_read_range Message-ID: <20200521222438.GT2005@dread.disaster.area> References: <20200515131656.12890-1-willy@infradead.org> <20200515131656.12890-15-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200515131656.12890-15-willy@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=QIgWuTDL c=1 sm=1 tr=0 a=ONQRW0k9raierNYdzxQi9Q==:117 a=ONQRW0k9raierNYdzxQi9Q==:17 a=kj9zAlcOel0A:10 a=sTwFKg_x9MkA:10 a=JfrnYn6hAAAA:8 a=7-415B0cAAAA:8 a=IOCeXHPP9RvrO-5I4wsA:9 a=4EiQV0XcPOQVQSqq:21 a=hAGzneUFbVT3-FjE:21 a=CjuIK1q_8ugA:10 a=1CNFftbPRP8L7MoqJWF3:22 a=biEYGPWJfzWAr4FL6Ov7:22 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 Fri, May 15, 2020 at 06:16:34AM -0700, Matthew Wilcox wrote: > From: "Matthew Wilcox (Oracle)" > > Pass the struct page instead of the iomap_page so we can determine the > size of the page. Use offset_in_thp() instead of offset_in_page() and use > thp_size() instead of PAGE_SIZE. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > fs/iomap/buffered-io.c | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 4a79061073eb..423ffc9d4a97 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -83,15 +83,16 @@ iomap_page_release(struct page *page) > * Calculate the range inside the page that we actually need to read. > */ > static void > -iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop, > +iomap_adjust_read_range(struct inode *inode, struct page *page, > loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp) > { > + struct iomap_page *iop = to_iomap_page(page); > 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); > + unsigned poff = offset_in_thp(page, *pos); > + unsigned plen = min_t(loff_t, thp_size(page) - poff, length); > unsigned first = poff >> block_bits; > unsigned last = (poff + plen - 1) >> block_bits; > > @@ -129,7 +130,7 @@ 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_thp(page, isize - 1) >> block_bits; > > if (first <= end && last > end) > plen -= (last - end) * block_size; > @@ -256,7 +257,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, > } > > /* zero post-eof blocks as the page may be mapped */ > - iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); > + iomap_adjust_read_range(inode, page, &pos, length, &poff, &plen); > if (plen == 0) > goto done; > > @@ -571,7 +572,6 @@ static int > __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > struct page *page, struct iomap *srcmap) > { > - struct iomap_page *iop = iomap_page_create(inode, page); > loff_t block_size = i_blocksize(inode); > loff_t block_start = pos & ~(block_size - 1); > loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1); > @@ -580,9 +580,10 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, > > if (PageUptodate(page)) > return 0; > + iomap_page_create(inode, page); What problem does this fix? i.e. if we can get here with an uninitialised page, why isn't this a separate bug fix. I don't see anything in this patch that actually changes behaviour, and there's nothing in the commit description to tell me why this is here, so... ??? Cheers, Dave. -- Dave Chinner david@fromorbit.com