From patchwork Tue Sep 11 22:34:44 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Omar Sandoval X-Patchwork-Id: 10596441 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D65FF3E9D for ; Tue, 11 Sep 2018 22:35:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C524B29E17 for ; Tue, 11 Sep 2018 22:35:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B96A229E10; Tue, 11 Sep 2018 22:35:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4D58E29DDD for ; Tue, 11 Sep 2018 22:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727697AbeILDgl (ORCPT ); Tue, 11 Sep 2018 23:36:41 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:35519 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727047AbeILDgl (ORCPT ); Tue, 11 Sep 2018 23:36:41 -0400 Received: by mail-pg1-f196.google.com with SMTP id 7-v6so12975059pgf.2 for ; Tue, 11 Sep 2018 15:35:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osandov-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=T4zypnAVQJfVK6JjN6ITEGJDUN7vtLnMURc1S60reio=; b=rGJqKX4GqOEBzI51/hVK9a/V+lrJQvJwpsuMJsxJj4VrZzqJq6FsqW3SVnr0u7ss2w 2kUdQ4qiMib5tUyKrfqE6zUAtmLN9ls1ghLQ5VpV040OoH25kokfUHpa9CbqmH5cKCrh Pf1pNiVouOyhZ1EvQ0eT/Duxc+ctu4eAMYzYhMUtJrVpKN4o/EOyzyppyy+eZZ+ICmK9 vVhvsHBSTdF9YM1in9ZXnF1LRkVUUS/HCOWnuKQYaICbc/siXVczgAbe6OVS+8JAN7Yt XU/ZvwM6aLeg9+pxhTiv2qDbn4o/hncWNeJ2ahjuFI5Gx/dSW08Uf2qa+ngHEjcZUv26 vfMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=T4zypnAVQJfVK6JjN6ITEGJDUN7vtLnMURc1S60reio=; b=Cg/R2WG22e9VGkyLax/u/ZtaDUrsWJhRAl3WcTioxheBBMg75xYXIuKKtssJ/Lhpia 5lRNiQhqkD1pMX9PCp/x7943/bDHfFUwffQ0QNtmiw6F/5hg3Fcmqk/XLQZByjJXoxvi Pwj7RwGl0mSFTrRck2dkHH1qwH6+4U1wHcYQvzrl1xMMuTEToIjvpiP1+hIJ/IpNVnpu TUJ1nbmPNpQ+sZXP8fo4a7DXIriUYZuluDjysOakVNYc9EsntHg1lcJmN2m0e8b1UV4N //1LNcGro0YyIIsMT8foY77cbQ8jjGYlxmdHW79DJ9liOoFD9I97eJOwQrl/QhG5SbM5 5fJQ== X-Gm-Message-State: APzg51BMkO7d76weZWwU54b+36hdnGmIoKjKArkVUwFoMSTB6qSG2924 Jv7FFOi27IZyz+lqfBtt9XvNVlysj3M= X-Google-Smtp-Source: ANB0VdZAj+z283HOInNN1MV+JK6u0utwXRYvvGx8Aw8Q2aEzyrsjhmI3Tba1dIU8N5FBRzFOGzVoOA== X-Received: by 2002:a65:4043:: with SMTP id h3-v6mr30193789pgp.207.1536705313427; Tue, 11 Sep 2018 15:35:13 -0700 (PDT) Received: from vader.thefacebook.com ([2620:10d:c090:200::7:13b4]) by smtp.gmail.com with ESMTPSA id 186-v6sm18710176pgg.56.2018.09.11.15.35.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Sep 2018 15:35:12 -0700 (PDT) From: Omar Sandoval To: linux-btrfs@vger.kernel.org Cc: kernel-team@fb.com, linux-mm@kvack.org Subject: [PATCH v7 1/6] mm: split SWP_FILE into SWP_ACTIVATED and SWP_FS Date: Tue, 11 Sep 2018 15:34:44 -0700 Message-Id: <6d63d8668c4287a4f6d203d65696e96f80abdfc7.1536704650.git.osandov@fb.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Omar Sandoval The SWP_FILE flag serves two purposes: to make swap_{read,write}page() go through the filesystem, and to make swapoff() call ->swap_deactivate(). For Btrfs, we want the latter but not the former, so split this flag into two. This makes us always call ->swap_deactivate() if ->swap_activate() succeeded, not just if it didn't add any swap extents itself. This also resolves the issue of the very misleading name of SWP_FILE, which is only used for swap files over NFS. Reviewed-by: Nikolay Borisov Signed-off-by: Omar Sandoval Acked-by: Andrew Morton --- include/linux/swap.h | 13 +++++++------ mm/page_io.c | 6 +++--- mm/swapfile.c | 13 ++++++++----- 3 files changed, 18 insertions(+), 14 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 8e2c11e692ba..0fda0aa743f0 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -167,13 +167,14 @@ enum { SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ SWP_BLKDEV = (1 << 6), /* its a block device */ - SWP_FILE = (1 << 7), /* set after swap_activate success */ - SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */ - SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */ - SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */ - SWP_SYNCHRONOUS_IO = (1 << 11), /* synchronous IO is efficient */ + SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ + SWP_FS = (1 << 8), /* swap file goes through fs */ + SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ + SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ + SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ + SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ /* add others here before... */ - SWP_SCANNING = (1 << 12), /* refcount in scan_swap_map */ + SWP_SCANNING = (1 << 13), /* refcount in scan_swap_map */ }; #define SWAP_CLUSTER_MAX 32UL diff --git a/mm/page_io.c b/mm/page_io.c index aafd19ec1db4..e8653c368069 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -283,7 +283,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, struct swap_info_struct *sis = page_swap_info(page); VM_BUG_ON_PAGE(!PageSwapCache(page), page); - if (sis->flags & SWP_FILE) { + if (sis->flags & SWP_FS) { struct kiocb kiocb; struct file *swap_file = sis->swap_file; struct address_space *mapping = swap_file->f_mapping; @@ -365,7 +365,7 @@ int swap_readpage(struct page *page, bool synchronous) goto out; } - if (sis->flags & SWP_FILE) { + if (sis->flags & SWP_FS) { struct file *swap_file = sis->swap_file; struct address_space *mapping = swap_file->f_mapping; @@ -423,7 +423,7 @@ int swap_set_page_dirty(struct page *page) { struct swap_info_struct *sis = page_swap_info(page); - if (sis->flags & SWP_FILE) { + if (sis->flags & SWP_FS) { struct address_space *mapping = sis->swap_file->f_mapping; VM_BUG_ON_PAGE(!PageSwapCache(page), page); diff --git a/mm/swapfile.c b/mm/swapfile.c index d954b71c4f9c..d3f95833d12e 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -989,7 +989,7 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size) goto nextsi; } if (size == SWAPFILE_CLUSTER) { - if (!(si->flags & SWP_FILE)) + if (!(si->flags & SWP_FS)) n_ret = swap_alloc_cluster(si, swp_entries); } else n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE, @@ -2310,12 +2310,13 @@ static void destroy_swap_extents(struct swap_info_struct *sis) kfree(se); } - if (sis->flags & SWP_FILE) { + if (sis->flags & SWP_ACTIVATED) { struct file *swap_file = sis->swap_file; struct address_space *mapping = swap_file->f_mapping; - sis->flags &= ~SWP_FILE; - mapping->a_ops->swap_deactivate(swap_file); + sis->flags &= ~SWP_ACTIVATED; + if (mapping->a_ops->swap_deactivate) + mapping->a_ops->swap_deactivate(swap_file); } } @@ -2411,8 +2412,10 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span) if (mapping->a_ops->swap_activate) { ret = mapping->a_ops->swap_activate(sis, swap_file, span); + if (ret >= 0) + sis->flags |= SWP_ACTIVATED; if (!ret) { - sis->flags |= SWP_FILE; + sis->flags |= SWP_FS; ret = add_swap_extent(sis, 0, sis->max, 0); *span = sis->pages; }