From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC9F5C77B7F for ; Wed, 3 May 2023 15:48:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6670A6B0081; Wed, 3 May 2023 11:48:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6174A6B0082; Wed, 3 May 2023 11:48:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4E0896B0083; Wed, 3 May 2023 11:48:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by kanga.kvack.org (Postfix) with ESMTP id 27FD66B0081 for ; Wed, 3 May 2023 11:48:29 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=DysVl8ah3hMoGSeCuK3v7kqIkIueRi3AppErUPwlC/g=; b=FxIH2i9c1yFwyXmBMH5CkdRmJx MN9P9gnT8r99CEXpK38H3W5zpcq083Vxw+ifMaXhhKdOl9x4TyTa/AIhjqLgWWSRlI7Ed7/vI4Z+y ZEtPN/0tlpejHCF8l8vfSYk22GGoq5lY8RgxCPgYJo0vdeiYvJX+QZ1/rYdYpBu36KFRYp+JFhFhq T1Xqy2aPJdNkhDpF5t4X71Z67PSykSsnykIXkxe/TDZV/t+iNp/cOVDsb2RVWNReqayVpkPELO4P7 CUNCgdGPFbdIdofvPSoa1+ivxU8jzTGfAov9+5Wo957OSMqgFugK5v+NX+PTl00meOvdW/HCw3+bm FJoiOyQA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1puEiK-009gtE-Si; Wed, 03 May 2023 15:48:20 +0000 Date: Wed, 3 May 2023 16:48:20 +0100 From: Matthew Wilcox To: Christoph Hellwig Cc: akpm@linux-foundation.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, dhowells@redhat.com, marc.dionne@auristor.com, linux-afs@lists.infradead.org, syzbot+48011b86c8ea329af1b9@syzkaller.appspotmail.com Subject: Re: [PATCH 1/2] filemap: fix the conditional folio_put in filemap_fault Message-ID: References: <20230503154526.1223095-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230503154526.1223095-1-hch@lst.de> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 03, 2023 at 05:45:25PM +0200, Christoph Hellwig wrote: > @@ -3372,14 +3372,14 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) > > return VM_FAULT_SIGBUS; > > +out_retry_put_folio: > + folio_put(folio); > out_retry: > /* > * We dropped the mmap_lock, we need to return to the fault handler to > * re-find the vma and come back and find our hopefully still populated > * page. > */ > - if (folio) > - folio_put(folio); Why not simply: - if (folio) + if (!IS_ERR_OR_NULL(folio))