From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id DBB086B0047 for ; Fri, 3 Apr 2009 04:35:41 -0400 (EDT) Date: Fri, 3 Apr 2009 16:35:59 +0800 From: Wu Fengguang Subject: [PATCH v2] vfs: fix find_lock_page_retry() return value parsing Message-ID: <20090403083559.GB6084@localhost> References: <604427e00812051140s67b2a89dm35806c3ee3b6ed7a@mail.gmail.com> <20090331150046.16539218.akpm@linux-foundation.org> <20090403082230.GA6084@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090403082230.GA6084@localhost> 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. Also do this for the other two find_lock_page_retry() invocations for the sake of consistency. Cc: Ying Han Signed-off-by: Wu Fengguang --- mm/filemap.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 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 @@ -1575,10 +1575,10 @@ retry_find_nopage: vmf->pgoff, 1); retry_ret = find_lock_page_retry(mapping, vmf->pgoff, vma, &page, retry_flag); - if (!page) - goto no_cached_page; if (retry_ret == VM_FAULT_RETRY) return retry_ret; + if (!page) + goto no_cached_page; } if (PageReadahead(page)) { page_cache_async_readahead(mapping, ra, file, page, @@ -1617,10 +1617,10 @@ retry_find_nopage: } retry_ret = find_lock_page_retry(mapping, vmf->pgoff, vma, &page, retry_flag); - if (!page) - goto no_cached_page; if (retry_ret == VM_FAULT_RETRY) return retry_ret; + if (!page) + goto no_cached_page; } if (!did_readaround) @@ -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