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=-17.2 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,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 A9B0DC4361B for ; Mon, 14 Dec 2020 12:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 647AD2067C for ; Mon, 14 Dec 2020 12:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439370AbgLNMrN (ORCPT ); Mon, 14 Dec 2020 07:47:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:49036 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439416AbgLNMrC (ORCPT ); Mon, 14 Dec 2020 07:47:02 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1607949976; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=+yyU/g9Wjzocu5iv8QqEh8wrLCF68Jrw/Ug5BylQDoU=; b=rQs9relMMba1S3SDKP0uOxQrt2Q+mthTBsFogKUaDPHE/8brjUDc5ZnFLZG3xQtZaliU6g /U0eUZBwGbbyhRWpLXvVqwSFMOoajDtxbkbw6Wd/xC/h8u/j/64nBKSgihT0KFpHMKfySr XnB2N022yQs6I/uAH5brtcm7C6mHMUE= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 215BEAC90; Mon, 14 Dec 2020 12:46:16 +0000 (UTC) Subject: Re: [PATCH v2 16/18] btrfs: introduce btrfs_subpage for data inodes To: Qu Wenruo , linux-btrfs@vger.kernel.org References: <20201210063905.75727-1-wqu@suse.com> <20201210063905.75727-17-wqu@suse.com> From: Nikolay Borisov Autocrypt: addr=nborisov@suse.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201210063905.75727-17-wqu@suse.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 10.12.20 г. 8:39 ч., Qu Wenruo wrote: > To support subpage sector size, data also need extra info to make sure > which sectors in a page are uptodate/dirty/... > > This patch will make pages for data inodes to get btrfs_subpage > structure attached, and detached when the page is freed. > > This patch also slightly changes the timing when > set_page_extent_mapped() to make sure: > - We have page->mapping set > page->mapping->host is used to grab btrfs_fs_info, thus we can only > call this function after page is mapped to an inode. > > One call site attaches pages to inode manually, thus we have to modify > the timing of set_page_extent_mapped() a little. > > - As soon as possible, before other operations > Since memory allocation can fail, we have to do extra error handling. > Calling set_page_extent_mapped() as soon as possible can simply the > error handling for several call sites. > > The idea is pretty much the same as iomap_page, but with more bitmaps > for btrfs specific cases. > > Currently the plan is to switch iomap if iomap can provide sector > aligned write back (only write back dirty sectors, but not the full > page, data balance require this feature). > > So we will stick to btrfs specific bitmap for now. > > Signed-off-by: Qu Wenruo > --- > fs/btrfs/compression.c | 10 ++++++-- > fs/btrfs/extent_io.c | 47 +++++++++++++++++++++++++++++++++---- > fs/btrfs/extent_io.h | 3 ++- > fs/btrfs/file.c | 10 +++++--- > fs/btrfs/free-space-cache.c | 15 +++++++++--- > fs/btrfs/inode.c | 12 ++++++---- > fs/btrfs/ioctl.c | 5 +++- > fs/btrfs/reflink.c | 5 +++- > fs/btrfs/relocation.c | 12 ++++++++-- > 9 files changed, 98 insertions(+), 21 deletions(-) > > diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c > index 5ae3fa0386b7..6d203acfdeb3 100644 > --- a/fs/btrfs/compression.c > +++ b/fs/btrfs/compression.c > @@ -542,13 +542,19 @@ static noinline int add_ra_bio_pages(struct inode *inode, > goto next; > } > > - end = last_offset + PAGE_SIZE - 1; > /* > * at this point, we have a locked page in the page cache > * for these bytes in the file. But, we have to make > * sure they map to this compressed extent on disk. > */ > - set_page_extent_mapped(page); > + ret = set_page_extent_mapped(page); > + if (ret < 0) { > + unlock_page(page); > + put_page(page); > + break; > + } > + > + end = last_offset + PAGE_SIZE - 1; > lock_extent(tree, last_offset, end); > read_lock(&em_tree->lock); > em = lookup_extent_mapping(em_tree, last_offset, > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 64a19c1884fc..4e4ed9c453ae 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -3191,10 +3191,40 @@ static int attach_extent_buffer_page(struct extent_buffer *eb, > return 0; > } > > -void set_page_extent_mapped(struct page *page) > +int __must_check set_page_extent_mapped(struct page *page) > { > - if (!PagePrivate(page)) > + struct btrfs_fs_info *fs_info; > + > + ASSERT(page->mapping); > + > + if (PagePrivate(page)) > + return 0; > + > + fs_info = btrfs_sb(page->mapping->host->i_sb); > + if (fs_info->sectorsize == PAGE_SIZE) { > attach_page_private(page, (void *)EXTENT_PAGE_PRIVATE); > + return 0; > + } > + > + return btrfs_attach_subpage(fs_info, page); In all previous patches < PAGE_SIZE is the special case, in this function it's reversed. For the sake of consistency change that so btrfs_attch_subpage is executed inside the conditional. > +} > + > +void clear_page_extent_mapped(struct page *page) > +{ > + struct btrfs_fs_info *fs_info; > + > + ASSERT(page->mapping); > + > + if (!PagePrivate(page)) > + return; > + > + fs_info = btrfs_sb(page->mapping->host->i_sb); > + if (fs_info->sectorsize == PAGE_SIZE) { > + detach_page_private(page); > + return; > + } > + > + btrfs_detach_subpage(fs_info, page); DITTO > } > > static struct extent_map * > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index a29b50208eee..9b878616b489 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -1373,6 +1373,12 @@ static noinline int prepare_pages(struct inode *inode, struct page **pages, > goto fail; > } > > + err = set_page_extent_mapped(pages[i]); > + if (err < 0) { > + faili = i; > + goto fail; > + } > + > if (i == 0) > err = prepare_uptodate_page(inode, pages[i], pos, > force_uptodate); > @@ -1470,10 +1476,8 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, > * We'll call btrfs_dirty_pages() later on, and that will flip around > * delalloc bits and dirty the pages as required. > */ > - for (i = 0; i < num_pages; i++) { > - set_page_extent_mapped(pages[i]); > + for (i = 0; i < num_pages; i++) > WARN_ON(!PageLocked(pages[i])); > - } The comment above this needs to be removed/rewritten I guess? Essentially that set_page_extent_mapped is moved to prepare_pages. > > return ret; > } > @@ -8355,7 +8357,9 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) > wait_on_page_writeback(page); > > lock_extent_bits(io_tree, page_start, page_end, &cached_state); > - set_page_extent_mapped(page); > + ret = set_page_extent_mapped(page); > + if (ret < 0) > + goto out_unlock; You should use ret2, ret in this function is used for the retval of vmf_error(). > > /* > * we can't set the delalloc bits if there are pending ordered