From owner-svn-src-all@freebsd.org Thu Mar 1 02:05:48 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C6568F37D60; Thu, 1 Mar 2018 02:05:48 +0000 (UTC) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 35327721F7; Thu, 1 Mar 2018 02:05:47 +0000 (UTC) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: from pdx.rh.CN85.dnsmgr.net (localhost [127.0.0.1]) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3) with ESMTP id w2125f9K022878; Wed, 28 Feb 2018 18:05:41 -0800 (PST) (envelope-from freebsd@pdx.rh.CN85.dnsmgr.net) Received: (from freebsd@localhost) by pdx.rh.CN85.dnsmgr.net (8.13.3/8.13.3/Submit) id w2125fqx022877; Wed, 28 Feb 2018 18:05:41 -0800 (PST) (envelope-from freebsd) From: "Rodney W. Grimes" Message-Id: <201803010205.w2125fqx022877@pdx.rh.CN85.dnsmgr.net> Subject: Re: svn commit: r330135 - head/sys/ufs/ffs In-Reply-To: To: Warner Losh Date: Wed, 28 Feb 2018 18:05:41 -0800 (PST) CC: "Rodney W. Grimes" , Conrad Meyer , src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Reply-To: rgrimes@freebsd.org X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Mar 2018 02:05:49 -0000 > On Wed, Feb 28, 2018 at 5:59 PM, Rodney W. Grimes < > freebsd@pdx.rh.cn85.dnsmgr.net> wrote: > > > > Author: cem > > > Date: Thu Mar 1 00:29:52 2018 > > > New Revision: 330135 > > > URL: https://svnweb.freebsd.org/changeset/base/330135 > > > > > > Log: > > > ffs: softdep_disk_write_complete: Quiesce spurious Coverity warning > > > > > > Coverity cannot determine that handle_written_indirdep() does not > > access > > > uninitialized 'sbp' when flags argument is zero. > > > > > > So, simply move the initialization slightly sooner to silence the > > warning. > > > > > > No functional change. > > > > I am always concerned when we modify code just to silence a > > warning from a static analysis tool. There use to be a pretty > > hard and fast rule about this: Dont do it, at most document > > that the tool is lacking and giving false positives. > > > > It double raises an eye brow when the change is made to > > silence the tool and "no function change" should be occuring. > > > In this case, there's no harm, and I think it makes the code a little > easier to understand... If infact handle_written_indirdep() should not access sbp then it would be safe to pass it a void * and let the code blow up if it should derefernce it. Thus simply changing the call that was causing the problem and not moving any lines of code. > Warner > > > > > Reported by: Coverity > > > Sponsored by: Dell EMC Isilon > > > > > > Modified: > > > head/sys/ufs/ffs/ffs_softdep.c > > > > > > Modified: head/sys/ufs/ffs/ffs_softdep.c > > > ============================================================ > > ================== > > > --- head/sys/ufs/ffs/ffs_softdep.c Thu Mar 1 00:05:14 2018 > > (r330134) > > > +++ head/sys/ufs/ffs/ffs_softdep.c Thu Mar 1 00:29:52 2018 > > (r330135) > > > @@ -10984,6 +10984,8 @@ softdep_disk_write_complete(bp) > > > if (ump == NULL) > > > return; > > > > > > + sbp = NULL; > > > + > > > /* > > > * If an error occurred while doing the write, then the data > > > * has not hit the disk and the dependencies cannot be processed. > > > @@ -11026,7 +11028,6 @@ softdep_disk_write_complete(bp) > > > /* > > > * Ump SU lock must not be released anywhere in this code segment. > > > */ > > > - sbp = NULL; > > > owk = NULL; > > > while ((wk = LIST_FIRST(&bp->b_dep)) != NULL) { > > > WORKLIST_REMOVE(wk); > > > > > > > > > > -- > > Rod Grimes > > rgrimes@freebsd.org > > > > -- Rod Grimes rgrimes@freebsd.org