Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752598Ab3HZOMr (ORCPT ); Mon, 26 Aug 2013 10:12:47 -0400 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:39660 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751391Ab3HZOMq (ORCPT ); Mon, 26 Aug 2013 10:12:46 -0400 From: "Aneesh Kumar K.V" To: Joonsoo Kim , Andrew Morton Cc: Rik van Riel , Mel Gorman , Michal Hocko , KAMEZAWA Hiroyuki , Hugh Dickins , Davidlohr Bueso , David Gibson , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Wanpeng Li , Naoya Horiguchi , Hillf Danton , Joonsoo Kim Subject: Re: [PATCH v2 18/20] mm, hugetlb: clean-up error handling in hugetlb_cow() In-Reply-To: <1376040398-11212-19-git-send-email-iamjoonsoo.kim@lge.com> References: <1376040398-11212-1-git-send-email-iamjoonsoo.kim@lge.com> <1376040398-11212-19-git-send-email-iamjoonsoo.kim@lge.com> User-Agent: Notmuch/0.15.2+167~g5306b2b (http://notmuchmail.org) Emacs/24.3.50.1 (x86_64-unknown-linux-gnu) Date: Mon, 26 Aug 2013 19:42:35 +0530 Message-ID: <87haecczho.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13082614-8256-0000-0000-000008F262F8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2418 Lines: 84 Joonsoo Kim writes: > Current code include 'Caller expects lock to be held' in every error path. > We can clean-up it as we do error handling in one place. > > Signed-off-by: Joonsoo Kim Reviewed-by: Aneesh Kumar K.V > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 7e9a651..8743e5c 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -2500,6 +2500,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, > int outside_reserve = 0; > long chg; > bool use_reserve = false; > + int ret = 0; > unsigned long mmun_start; /* For mmu_notifiers */ > unsigned long mmun_end; /* For mmu_notifiers */ > > @@ -2524,10 +2525,8 @@ retry_avoidcopy: > * anon_vma prepared. > */ > if (unlikely(anon_vma_prepare(vma))) { > - page_cache_release(old_page); > - /* Caller expects lock to be held */ > - spin_lock(&mm->page_table_lock); > - return VM_FAULT_OOM; > + ret = VM_FAULT_OOM; > + goto out_old_page; > } > > /* > @@ -2546,11 +2545,8 @@ retry_avoidcopy: > if (!outside_reserve) { > chg = vma_needs_reservation(h, vma, address); > if (chg == -ENOMEM) { > - page_cache_release(old_page); > - > - /* Caller expects lock to be held */ > - spin_lock(&mm->page_table_lock); > - return VM_FAULT_OOM; > + ret = VM_FAULT_OOM; > + goto out_old_page; > } > use_reserve = !chg; > } > @@ -2584,9 +2580,8 @@ retry_avoidcopy: > WARN_ON_ONCE(1); > } > > - /* Caller expects lock to be held */ > - spin_lock(&mm->page_table_lock); > - return VM_FAULT_SIGBUS; > + ret = VM_FAULT_SIGBUS; > + goto out_lock; > } > > copy_user_huge_page(new_page, old_page, address, vma, > @@ -2617,11 +2612,12 @@ retry_avoidcopy: > spin_unlock(&mm->page_table_lock); > mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); > page_cache_release(new_page); > +out_old_page: > page_cache_release(old_page); > - > +out_lock: > /* Caller expects lock to be held */ > spin_lock(&mm->page_table_lock); > - return 0; > + return ret; > } > > /* Return the pagecache page at a given address within a VMA */ > -- > 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/