From owner-svn-src-head@freebsd.org Mon May 25 04:57:57 2020 Return-Path: Delivered-To: svn-src-head@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 F01B02F34CF; Mon, 25 May 2020 04:57:57 +0000 (UTC) (envelope-from mjg@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 "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49VlGF645Qz4JGx; Mon, 25 May 2020 04:57:57 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id CB782CB48; Mon, 25 May 2020 04:57:57 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 04P4vvov052021; Mon, 25 May 2020 04:57:57 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 04P4vvdC052020; Mon, 25 May 2020 04:57:57 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <202005250457.04P4vvdC052020@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Mon, 25 May 2020 04:57:57 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r361441 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 361441 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 May 2020 04:57:58 -0000 Author: mjg Date: Mon May 25 04:57:57 2020 New Revision: 361441 URL: https://svnweb.freebsd.org/changeset/base/361441 Log: vfs: use atomic_{store,load}_long to manage f_offset ... instead of depending on the compiler not to mess them up Modified: head/sys/kern/vfs_vnops.c Modified: head/sys/kern/vfs_vnops.c ============================================================================== --- head/sys/kern/vfs_vnops.c Mon May 25 04:56:41 2020 (r361440) +++ head/sys/kern/vfs_vnops.c Mon May 25 04:57:57 2020 (r361441) @@ -682,12 +682,8 @@ foffset_lock(struct file *fp, int flags) KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); - /* - * Caller only wants the current f_offset value. Assume that - * the long and shorter integer types reads are atomic. - */ if ((flags & FOF_NOLOCK) != 0) - return (fp->f_offset); + return (atomic_load_long(&fp->f_offset)); /* * According to McKusick the vn lock was protecting f_offset here. @@ -695,7 +691,7 @@ foffset_lock(struct file *fp, int flags) */ flagsp = &fp->f_vnread_flags; if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED)) - return (fp->f_offset); + return (atomic_load_long(&fp->f_offset)); sleepq_lock(&fp->f_vnread_flags); state = atomic_load_16(flagsp); @@ -718,7 +714,7 @@ foffset_lock(struct file *fp, int flags) sleepq_lock(&fp->f_vnread_flags); state = atomic_load_16(flagsp); } - res = fp->f_offset; + res = atomic_load_long(&fp->f_offset); sleepq_release(&fp->f_vnread_flags); return (res); } @@ -732,7 +728,7 @@ foffset_unlock(struct file *fp, off_t val, int flags) KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed")); if ((flags & FOF_NOUPDATE) == 0) - fp->f_offset = val; + atomic_store_long(&fp->f_offset, val); if ((flags & FOF_NEXTOFF) != 0) fp->f_nextoff = val;