From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id B8FD4600762 for ; Tue, 8 Dec 2009 16:17:44 -0500 (EST) From: Andi Kleen References: <200912081016.198135742@firstfloor.org> In-Reply-To: <200912081016.198135742@firstfloor.org> Subject: [PATCH] [8/31] HWPOISON: abort on failed unmap Message-Id: <20091208211624.5884DB151F@basil.firstfloor.org> Date: Tue, 8 Dec 2009 22:16:24 +0100 (CET) Sender: owner-linux-mm@kvack.org To: fengguang.wu@intel.comfengguang.wu@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: From: Wu Fengguang Don't try to isolate a still mapped page. Otherwise we will hit the BUG_ON(page_mapped(page)) in __remove_from_page_cache(). Signed-off-by: Wu Fengguang Signed-off-by: Andi Kleen --- mm/memory-failure.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) Index: linux/mm/memory-failure.c =================================================================== --- linux.orig/mm/memory-failure.c +++ linux/mm/memory-failure.c @@ -657,7 +657,7 @@ static int page_action(struct page_state * Do all that is necessary to remove user space mappings. Unmap * the pages and send SIGBUS to the processes if the data was dirty. */ -static void hwpoison_user_mappings(struct page *p, unsigned long pfn, +static int hwpoison_user_mappings(struct page *p, unsigned long pfn, int trapno) { enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS; @@ -667,15 +667,18 @@ static void hwpoison_user_mappings(struc int i; int kill = 1; - if (PageReserved(p) || PageCompound(p) || PageSlab(p) || PageKsm(p)) - return; + if (PageReserved(p) || PageSlab(p)) + return SWAP_SUCCESS; /* * This check implies we don't kill processes if their pages * are in the swap cache early. Those are always late kills. */ if (!page_mapped(p)) - return; + return SWAP_SUCCESS; + + if (PageCompound(p) || PageKsm(p)) + return SWAP_FAIL; if (PageSwapCache(p)) { printk(KERN_ERR @@ -737,6 +740,8 @@ static void hwpoison_user_mappings(struc */ kill_procs_ao(&tokill, !!PageDirty(p), trapno, ret != SWAP_SUCCESS, pfn); + + return ret; } int __memory_failure(unsigned long pfn, int trapno, int flags) @@ -809,8 +814,13 @@ int __memory_failure(unsigned long pfn, /* * Now take care of user space mappings. + * Abort on fail: __remove_from_page_cache() assumes unmapped page. */ - hwpoison_user_mappings(p, pfn, trapno); + if (hwpoison_user_mappings(p, pfn, trapno) != SWAP_SUCCESS) { + printk(KERN_ERR "MCE %#lx: cannot unmap page, give up\n", pfn); + res = -EBUSY; + goto out; + } /* * Torn down by someone else? -- 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