From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751485AbWIWKNX (ORCPT ); Sat, 23 Sep 2006 06:13:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751465AbWIWKM4 (ORCPT ); Sat, 23 Sep 2006 06:12:56 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:18368 "EHLO ogre.sisk.pl") by vger.kernel.org with ESMTP id S1751470AbWIWKMj (ORCPT ); Sat, 23 Sep 2006 06:12:39 -0400 From: "Rafael J. Wysocki" To: Andrew Morton Subject: [PATCH -mm 5/6] mm: Print first block offset for swap areas Date: Sat, 23 Sep 2006 12:10:54 +0200 User-Agent: KMail/1.9.1 Cc: Dave Jones , Pavel Machek , LKML References: <200609231158.00147.rjw@sisk.pl> In-Reply-To: <200609231158.00147.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200609231210.54692.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In order to use a swap file with swsusp we need to know the offset at which its swap header is located. However, the swap header is always located in the first page block of the swap file and it's quite easy to make sys_swapon() print the offset of the swap file's (or swap partition's) first page block. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek --- --- mm/swapfile.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) Index: linux-2.6.18-rc7-mm1/mm/swapfile.c =================================================================== --- linux-2.6.18-rc7-mm1.orig/mm/swapfile.c +++ linux-2.6.18-rc7-mm1/mm/swapfile.c @@ -1047,7 +1047,8 @@ add_swap_extent(struct swap_info_struct * This is extremely effective. The average number of iterations in * map_swap_page() has been measured at about 0.3 per page. - akpm. */ -static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span) +static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span, + sector_t *start) { struct inode *inode; unsigned blocks_per_page; @@ -1060,6 +1061,7 @@ static int setup_swap_extents(struct swa int nr_extents = 0; int ret; + *start = 0; inode = sis->swap_file->f_mapping->host; if (S_ISBLK(inode->i_mode)) { ret = add_swap_extent(sis, 0, sis->max, 0); @@ -1114,6 +1116,8 @@ static int setup_swap_extents(struct swa lowest_block = first_block; if (first_block > highest_block) highest_block = first_block; + } else { + *start = first_block; } /* @@ -1407,7 +1411,7 @@ asmlinkage long sys_swapon(const char __ int swap_header_version; unsigned int nr_good_pages = 0; int nr_extents = 0; - sector_t span; + sector_t span, start; unsigned long maxpages = 1; int swapfilesize; unsigned short *swap_map; @@ -1608,7 +1612,7 @@ asmlinkage long sys_swapon(const char __ p->swap_map[0] = SWAP_MAP_BAD; p->max = maxpages; p->pages = nr_good_pages; - nr_extents = setup_swap_extents(p, &span); + nr_extents = setup_swap_extents(p, &span, &start); if (nr_extents < 0) { error = nr_extents; goto bad_swap; @@ -1628,9 +1632,10 @@ asmlinkage long sys_swapon(const char __ total_swap_pages += nr_good_pages; printk(KERN_INFO "Adding %uk swap on %s. " - "Priority:%d extents:%d across:%lluk\n", + "Priority:%d extents:%d across:%lluk offset:%llu\n", nr_good_pages<<(PAGE_SHIFT-10), name, p->prio, - nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10)); + nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10), + (unsigned long long)start); /* insert swap space into swap_list: */ prev = -1;