From owner-dev-commits-src-all@freebsd.org Fri Apr 2 18:25:13 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 6C68257DEFF; Fri, 2 Apr 2021 18:25:13 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FBpPj2Qlcz3jlZ; Fri, 2 Apr 2021 18:25:13 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 3DEAF24659; Fri, 2 Apr 2021 18:25:13 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 132IPDnt036012; Fri, 2 Apr 2021 18:25:13 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 132IPDlh036011; Fri, 2 Apr 2021 18:25:13 GMT (envelope-from git) Date: Fri, 2 Apr 2021 18:25:13 GMT Message-Id: <202104021825.132IPDlh036011@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Richard Scheffenegger Subject: git: cad4fd0365a5 - main - Make sbuf_drain safe for external use MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: rscheff X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: cad4fd0365a5e3235e715e072e6ee9dffaa7a3ab Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Apr 2021 18:25:13 -0000 The branch main has been updated by rscheff: URL: https://cgit.FreeBSD.org/src/commit/?id=cad4fd0365a5e3235e715e072e6ee9dffaa7a3ab commit cad4fd0365a5e3235e715e072e6ee9dffaa7a3ab Author: Richard Scheffenegger AuthorDate: 2021-04-02 18:11:45 +0000 Commit: Richard Scheffenegger CommitDate: 2021-04-02 18:12:11 +0000 Make sbuf_drain safe for external use While sbuf_drain was an internal function, two KASSERTS checked the sanity of it being called. However, an external caller may be ignorant if there is any data to drain, or if an error has already accumulated. Be nice and return immediately with the accumulated error. MFC after: 2 weeks Reviewed By: tuexen, #transport Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D29544 --- sys/kern/subr_sbuf.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/sys/kern/subr_sbuf.c b/sys/kern/subr_sbuf.c index 66822115dbcb..cdeaf690208f 100644 --- a/sys/kern/subr_sbuf.c +++ b/sys/kern/subr_sbuf.c @@ -388,8 +388,12 @@ sbuf_drain(struct sbuf *s) { int len; - KASSERT(s->s_len > 0, ("Shouldn't drain empty sbuf %p", s)); - KASSERT(s->s_error == 0, ("Called %s with error on %p", __func__, s)); + /* + * Immediately return when no work to do, + * or an error has already been accumulated. + */ + if ((s->s_len == 0) || (s->s_error != 0)) + return(s->s_error); if (SBUF_DODRAINTOEOR(s) && s->s_rec_off == 0) return (s->s_error = EDEADLK);