From patchwork Mon Sep 21 07:19:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11788455 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 15FBB1668 for ; Mon, 21 Sep 2020 07:20:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8A9E2067D for ; Mon, 21 Sep 2020 07:20:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="muTdr9Q0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726614AbgIUHUU (ORCPT ); Mon, 21 Sep 2020 03:20:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726533AbgIUHUQ (ORCPT ); Mon, 21 Sep 2020 03:20:16 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08A2DC0613D7; Mon, 21 Sep 2020 00:20:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=2ayaBUOXfktvOTjNfjilWVR81vP6mBqMDpKHyQ4yF8I=; b=muTdr9Q0kCcwvowRu+pixikTkn uEtunHlWR3/cO5sYwYPymYqroPkHU0rym28z4VZlm/kV1pDkDphJXGfWVXkO8Y06r4AsthRjqt8mG Gl/8BiFkKPlmxx2qMDJHL3fiIkm7EpJhYUWve6JERJGa4DWTAGUZpjKJh3hYRknB+rKQqKIhoRH3T j3Mu06iqpSGA5MvyZwvU8GPVna2ZJ29V6d/J+MF4i3TsvhBCj3f3NaqdsJlD2Rsw5eMttqsEiIR2b S/iJT0hXO9FTy3SjX0aEmBlcq4C5HiqeUlB7aQq5ERWuZkY9sLRCEXY3nvaBiu4p/0zcCp/qng9V1 hOD8k12Q==; Received: from p4fdb0c34.dip0.t-ipconnect.de ([79.219.12.52] helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKG7G-0003GN-Vf; Mon, 21 Sep 2020 07:20:03 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Josef Bacik , Minchan Kim , Stefan Haberland , Jan Hoeppner , Joseph Qi , "Rafael J. Wysocki" , Pavel Machek , Len Brown , Andrew Morton , linux-kernel@vger.kernel.org, nbd@other.debian.org, linux-ide@vger.kernel.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com, linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org Subject: [PATCH 12/14] mm: split swap_type_of Date: Mon, 21 Sep 2020 09:19:56 +0200 Message-Id: <20200921071958.307589-13-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921071958.307589-1-hch@lst.de> References: <20200921071958.307589-1-hch@lst.de> MIME-Version: 1.0 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 swap_type_of is used for two entirely different purposes: (1) check what swap type a given device/offset corresponds to (2) find the first available swap device that can be written to Mixing both in a single function creates an unreadable mess. Create two separate functions instead, and switch both to pass a dev_t instead of a struct block_device to further simplify the code. Signed-off-by: Christoph Hellwig --- include/linux/swap.h | 3 ++- kernel/power/swap.c | 17 ++++++++--------- kernel/power/user.c | 16 ++++------------ mm/swapfile.c | 39 +++++++++++++++++++++------------------ 4 files changed, 35 insertions(+), 40 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 661046994db4b9..4340a7b6e7a1dc 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -467,7 +467,8 @@ extern int swapcache_prepare(swp_entry_t); extern void swap_free(swp_entry_t); extern void swapcache_free_entries(swp_entry_t *entries, int n); extern int free_swap_and_cache(swp_entry_t); -extern int swap_type_of(dev_t, sector_t, struct block_device **); +int swap_type_of(dev_t device, sector_t offset); +int find_first_swap(dev_t *device); extern unsigned int count_swap_pages(int, int); extern sector_t map_swap_page(struct page *, struct block_device **); extern sector_t swapdev_block(int, pgoff_t); diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 01e2858b5fe367..9d3ffbfe08dbf6 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -335,12 +335,17 @@ static int swsusp_swap_check(void) { int res; - res = swap_type_of(swsusp_resume_device, swsusp_resume_block, - &hib_resume_bdev); + if (swsusp_resume_device) + res = swap_type_of(swsusp_resume_device, swsusp_resume_block); + else + res = find_first_swap(&swsusp_resume_device); if (res < 0) return res; - root_swap = res; + + hib_resume_bdev = bdget(swsusp_resume_device); + if (!hib_resume_bdev) + return -ENOMEM; res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL); if (res) return res; @@ -349,12 +354,6 @@ static int swsusp_swap_check(void) if (res < 0) blkdev_put(hib_resume_bdev, FMODE_WRITE); - /* - * Update the resume device to the one actually used, - * so the test_resume mode can use it in case it is - * invoked from hibernate() to test the snapshot. - */ - swsusp_resume_device = hib_resume_bdev->bd_dev; return res; } diff --git a/kernel/power/user.c b/kernel/power/user.c index b5815685b944fe..6510a8f7687f42 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -69,8 +69,7 @@ static int snapshot_open(struct inode *inode, struct file *filp) memset(&data->handle, 0, sizeof(struct snapshot_handle)); if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { /* Hibernating. The image device should be accessible. */ - data->swap = swsusp_resume_device ? - swap_type_of(swsusp_resume_device, 0, NULL) : -1; + data->swap = swap_type_of(swsusp_resume_device, 0); data->mode = O_RDONLY; data->free_bitmaps = false; error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls); @@ -210,7 +209,6 @@ struct compat_resume_swap_area { static int snapshot_set_swap_area(struct snapshot_data *data, void __user *argp) { - struct block_device *bdev; sector_t offset; dev_t swdev; @@ -237,16 +235,10 @@ static int snapshot_set_swap_area(struct snapshot_data *data, * User space encodes device types as two-byte values, * so we need to recode them */ - if (!swdev) { - data->swap = -1; - return -EINVAL; - } - data->swap = swap_type_of(swdev, offset, &bdev); + data->swap = swap_type_of(swdev, offset); if (data->swap < 0) - return -ENODEV; - - data->dev = bdev->bd_dev; - bdput(bdev); + return swdev ? -ENODEV : -EINVAL; + data->dev = swdev; return 0; } diff --git a/mm/swapfile.c b/mm/swapfile.c index 7438c4affc75fa..b90f8692074397 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1801,13 +1801,12 @@ int free_swap_and_cache(swp_entry_t entry) * * This is needed for the suspend to disk (aka swsusp). */ -int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p) +int swap_type_of(dev_t device, sector_t offset) { - struct block_device *bdev = NULL; int type; - if (device) - bdev = bdget(device); + if (!device) + return -1; spin_lock(&swap_lock); for (type = 0; type < nr_swapfiles; type++) { @@ -1816,30 +1815,34 @@ int swap_type_of(dev_t device, sector_t offset, struct block_device **bdev_p) if (!(sis->flags & SWP_WRITEOK)) continue; - if (!bdev) { - if (bdev_p) - *bdev_p = bdgrab(sis->bdev); - - spin_unlock(&swap_lock); - return type; - } - if (bdev == sis->bdev) { + if (device == sis->bdev->bd_dev) { struct swap_extent *se = first_se(sis); if (se->start_block == offset) { - if (bdev_p) - *bdev_p = bdgrab(sis->bdev); - spin_unlock(&swap_lock); - bdput(bdev); return type; } } } spin_unlock(&swap_lock); - if (bdev) - bdput(bdev); + return -ENODEV; +} +int find_first_swap(dev_t *device) +{ + int type; + + spin_lock(&swap_lock); + for (type = 0; type < nr_swapfiles; type++) { + struct swap_info_struct *sis = swap_info[type]; + + if (!(sis->flags & SWP_WRITEOK)) + continue; + *device = sis->bdev->bd_dev; + spin_unlock(&swap_lock); + return type; + } + spin_unlock(&swap_lock); return -ENODEV; }