From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f174.google.com (mail-pd0-f174.google.com [209.85.192.174]) by kanga.kvack.org (Postfix) with ESMTP id 6C9CD6B0039 for ; Fri, 11 Oct 2013 05:54:42 -0400 (EDT) Received: by mail-pd0-f174.google.com with SMTP id y13so3975296pdi.33 for ; Fri, 11 Oct 2013 02:54:42 -0700 (PDT) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MUI005WY0UJ5P20@mailout2.w1.samsung.com> for linux-mm@kvack.org; Fri, 11 Oct 2013 10:54:38 +0100 (BST) From: Krzysztof Kozlowski Subject: [PATCH] swap: fix set_blocksize race during swapon/swapoff Date: Fri, 11 Oct 2013 11:54:22 +0200 Message-id: <1381485262-16792-1-git-send-email-k.kozlowski@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Weijie Yang , Bob Liu , Konrad Rzeszutek Wilk , Shaohua Li , Minchan Kim , Krzysztof Kozlowski Swapoff used old_block_size from swap_info which could be overwritten by concurrent swapon. Reported-by: Weijie Yang Signed-off-by: Krzysztof Kozlowski --- mm/swapfile.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 3963fc2..de7c904 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1824,6 +1824,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) struct filename *pathname; int i, type, prev; int err; + unsigned int old_block_size; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -1914,6 +1915,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) } swap_file = p->swap_file; + old_block_size = p->old_block_size; p->swap_file = NULL; p->max = 0; swap_map = p->swap_map; @@ -1938,7 +1940,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) inode = mapping->host; if (S_ISBLK(inode->i_mode)) { struct block_device *bdev = I_BDEV(inode); - set_blocksize(bdev, p->old_block_size); + set_blocksize(bdev, old_block_size); blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); } else { mutex_lock(&inode->i_mutex); -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org