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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 4DF0BC07E95 for ; Fri, 16 Jul 2021 09:20:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3549F613D4 for ; Fri, 16 Jul 2021 09:20:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232559AbhGPJW4 (ORCPT ); Fri, 16 Jul 2021 05:22:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232690AbhGPJW4 (ORCPT ); Fri, 16 Jul 2021 05:22:56 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEF0AC06175F; Fri, 16 Jul 2021 02:20:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=9YTjbkFFuJ3p7Dou0+SBFN6U9uCNz73Kju0y+iDMBPg=; b=p2vq/OzL7M/kfm03Ldbvdi6tEO Oohe70lzt2AhQRCAn2d5n4d7Nd5F4eUbG+72h+yDCNG0HhHu9FzMd7otp1E93GkuCR+iTdjE0VpcL HkkpPC/O+KCEMhXT2097gnDSXQEe81jd3XU1AcWN0aG61/h7thcSQsrPwqxEmrBL2LJXMwv3Sy2J+ vA609QB9TOChAhfKiyTEOnR0yLPhqDBRRjwKjyi0Rmib9qeE1hg8010E0tlxZEjN9bxIvlXBMCHUb hc09KqVeCgRRmRYIYIgdGnMgwHKWEYpu2TQXjLrSDtTjQ4Zu3HdXrL7Siw1zHzJZXM3DmyoMDnND1 8No8MSLw==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m4Jzx-004LKp-2N; Fri, 16 Jul 2021 09:19:13 +0000 Date: Fri, 16 Jul 2021 10:19:09 +0100 From: Christoph Hellwig To: Gao Xiang Cc: linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, LKML , "Darrick J. Wong" , Christoph Hellwig , Chao Yu , Liu Bo , Joseph Qi , Liu Jiang , Andreas Gruenbacher Subject: Re: [PATCH 1/2] iomap: support tail packing inline read Message-ID: References: <20210716050724.225041-1-hsiangkao@linux.alibaba.com> <20210716050724.225041-2-hsiangkao@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210716050724.225041-2-hsiangkao@linux.alibaba.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org I'm pretty sure gfs2 supports direct writes to inline data, so we should not disable it. I also think we should share the code rather than duplicating it. Suggested version against the iomap-for-next branch attached, but this needs careful check from Andreas (please keep him on CC). --- >From 6067cd3462cea80cb2739602862296db41fc5638 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 16 Jul 2021 10:52:48 +0200 Subject: iomap: support tail packing inline read This tries to add tail packing inline read to iomap. Different from the previous approach, it only marks the block range uptodate in the page it covers. The write path remains untouched since EROFS cannot be used for testing. It'd be better to be implemented if upcoming real users care rather than leave untested dead code around. Signed-off-by: Gao Xiang --- fs/iomap/buffered-io.c | 56 ++++++++++++++++++++++++++++-------------- fs/iomap/direct-io.c | 6 +++-- 2 files changed, 41 insertions(+), 21 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 87ccb3438becd9..2efd4bc0328995 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -207,29 +207,28 @@ struct iomap_readpage_ctx { static void iomap_read_inline_data(struct inode *inode, struct page *page, - struct iomap *iomap) + struct iomap *iomap, loff_t pos, unsigned int size) { - size_t size = i_size_read(inode); + unsigned int block_aligned_size = round_up(size, i_blocksize(inode)); + unsigned int poff = offset_in_page(pos); void *addr; - if (PageUptodate(page)) - return; - - BUG_ON(page_has_private(page)); - BUG_ON(page->index); + /* make sure that inline_data doesn't cross page boundary */ BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data)); + BUG_ON(size != i_size_read(inode) - pos); addr = kmap_atomic(page); - memcpy(addr, iomap->inline_data, size); - memset(addr + size, 0, PAGE_SIZE - size); + memcpy(addr + poff, iomap->inline_data - iomap->offset + pos, size); + memset(addr + poff + size, 0, block_aligned_size - size); kunmap_atomic(addr); - SetPageUptodate(page); + + iomap_set_range_uptodate(page, poff, block_aligned_size); } static inline bool iomap_block_needs_zeroing(struct inode *inode, struct iomap *iomap, loff_t pos) { - return iomap->type != IOMAP_MAPPED || + return (iomap->type != IOMAP_MAPPED && iomap->type != IOMAP_INLINE) || (iomap->flags & IOMAP_F_NEW) || pos >= i_size_read(inode); } @@ -240,20 +239,18 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, { struct iomap_readpage_ctx *ctx = data; struct page *page = ctx->cur_page; - struct iomap_page *iop; + struct iomap_page *iop = NULL; bool same_page = false, is_contig = false; loff_t orig_pos = pos; unsigned poff, plen; sector_t sector; - if (iomap->type == IOMAP_INLINE) { - WARN_ON_ONCE(pos); - iomap_read_inline_data(inode, page, iomap); - return PAGE_SIZE; - } + if (iomap->type == IOMAP_INLINE && !pos) + WARN_ON_ONCE(to_iomap_page(page) != NULL); + else + iop = iomap_page_create(inode, page); /* zero post-eof blocks as the page may be mapped */ - iop = iomap_page_create(inode, page); iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen); if (plen == 0) goto done; @@ -264,6 +261,15 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, goto done; } + if (iomap->type == IOMAP_INLINE) { + iomap_read_inline_data(inode, page, iomap, pos, plen); + /* + * TODO: the old code used to return PAGE_SIZE here + * unconditionally. I think the actual i_size return should + * be fine for gfs2 as well, but please double check. + */ + goto done; + } ctx->cur_page_in_bio = true; if (iop) atomic_add(plen, &iop->read_bytes_pending); @@ -589,6 +595,18 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags, return 0; } +static int iomap_write_begin_inline(struct inode *inode, loff_t pos, + struct page *page, struct iomap *srcmap) +{ + /* needs more work for the tailpacking case, disable for now */ + if (WARN_ON_ONCE(pos != 0)) + return -EIO; + if (PageUptodate(page)) + return 0; + iomap_read_inline_data(inode, page, srcmap, pos, i_size_read(inode)); + return 0; +} + static int iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, struct page **pagep, struct iomap *iomap, struct iomap *srcmap) @@ -618,7 +636,7 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, } if (srcmap->type == IOMAP_INLINE) - iomap_read_inline_data(inode, page, srcmap); + status = iomap_write_begin_inline(inode, pos, page, srcmap); else if (iomap->flags & IOMAP_F_BUFFER_HEAD) status = __block_write_begin_int(page, pos, len, NULL, srcmap); else diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 9398b8c31323b3..a70a8632df226f 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -380,7 +380,8 @@ iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length, struct iov_iter *iter = dio->submit.iter; size_t copied; - BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data)); + /* inline data must be inside a single page */ + BUG_ON(length > PAGE_SIZE - offset_in_page(iomap->inline_data)); if (dio->flags & IOMAP_DIO_WRITE) { loff_t size = inode->i_size; @@ -394,7 +395,8 @@ iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length, mark_inode_dirty(inode); } } else { - copied = copy_to_iter(iomap->inline_data + pos, length, iter); + copied = copy_to_iter(iomap->inline_data + pos - iomap->offset, + length, iter); } dio->size += copied; return copied; -- 2.30.2