From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120527010428.972090489@linuxfoundation.org> Date: Sun, 27 May 2012 10:05:00 +0900 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Shaohua Li , Holger Kiehl , Hugh Dickins , Konrad Rzeszutek Wilk , William Dauchy Subject: [ 37/94] swap: dont do discard if no discard option added In-Reply-To: <20120527010332.GA11170@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shaohua Li commit 052b1987faca3606109d88d96bce124851f7c4c2 upstream. When swapon() was not passed the SWAP_FLAG_DISCARD option, sys_swapon() will still perform a discard operation. This can cause problems if discard is slow or buggy. Reverse the order of the check so that a discard operation is performed only if the sys_swapon() caller is attempting to enable discard. Signed-off-by: Shaohua Li Reported-by: Holger Kiehl Tested-by: Holger Kiehl Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Konrad Rzeszutek Wilk Cc: William Dauchy Signed-off-by: Greg Kroah-Hartman --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2103,7 +2103,7 @@ SYSCALL_DEFINE2(swapon, const char __use p->flags |= SWP_SOLIDSTATE; p->cluster_next = 1 + (random32() % p->highest_bit); } - if (discard_swap(p) == 0 && (swap_flags & SWAP_FLAG_DISCARD)) + if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0) p->flags |= SWP_DISCARDABLE; }