From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 5CBEF6B004D for ; Fri, 3 Apr 2009 04:22:25 -0400 (EDT) Date: Fri, 3 Apr 2009 16:22:30 +0800 From: Wu Fengguang Subject: [PATCH] vfs: fix find_lock_page_retry() return value parsing Message-ID: <20090403082230.GA6084@localhost> References: <604427e00812051140s67b2a89dm35806c3ee3b6ed7a@mail.gmail.com> <20090331150046.16539218.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090331150046.16539218.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Ying Han , linux-mm@kvack.org, linux-kernel@vger.kernel.org, mingo@elte.hu, mikew@google.com, rientjes@google.com, rohitseth@google.com, hugh@veritas.com, a.p.zijlstra@chello.nl, hpa@zytor.com, edwintorok@gmail.com, lee.schermerhorn@hp.com, npiggin@suse.de List-ID: find_lock_page_retry() won't touch the *ppage value when returning VM_FAULT_RETRY. This is fine except for the case if (VM_RandomReadHint()) goto no_cached_page; where the 'page' could be undefined after calling find_lock_page_retry(). Fix it by checking the VM_FAULT_RETRY case first. Cc: Ying Han Signed-off-by: Wu Fengguang --- mm/filemap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- mm.orig/mm/filemap.c +++ mm/mm/filemap.c @@ -759,7 +759,7 @@ EXPORT_SYMBOL(find_lock_page); * @retry: 1 indicate caller tolerate a retry. * * If retry flag is on, and page is already locked by someone else, return - * a hint of retry. + * a hint of retry and leave *ppage untouched. * * Return *ppage==NULL if page is not in pagecache. Otherwise return *ppage * points to the page in the pagecache with ret=VM_FAULT_RETRY indicate a @@ -1672,10 +1672,10 @@ no_cached_page: retry_ret = find_lock_page_retry(mapping, vmf->pgoff, vma, &page, retry_flag); + if (retry_ret == VM_FAULT_RETRY) + return retry_ret; if (!page) goto retry_find_nopage; - else if (retry_ret == VM_FAULT_RETRY) - return retry_ret; else goto retry_page_update; } -- 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