From owner-dev-commits-src-branches@freebsd.org Mon Feb 1 12:46:39 2021 Return-Path: Delivered-To: dev-commits-src-branches@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 3E1CF4FF9EF; Mon, 1 Feb 2021 12:46:39 +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 4DTnkl14nWz3JsS; Mon, 1 Feb 2021 12:46:39 +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 438461B169; Mon, 1 Feb 2021 12:40:50 +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 111CeoH5097316; Mon, 1 Feb 2021 12:40:50 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 111Ceo2A097315; Mon, 1 Feb 2021 12:40:50 GMT (envelope-from git) Date: Mon, 1 Feb 2021 12:40:50 GMT Message-Id: <202102011240.111Ceo2A097315@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mateusz Guzik Subject: git: 247f652e622d - stable/13 - cache: make ->nc_flag accesses atomic-clean for lockless usage MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mjg X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 247f652e622d9aebda627ea34ba5af242dbb835e Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-branches@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commits to the stable branches of the FreeBSD src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Feb 2021 12:46:39 -0000 The branch stable/13 has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=247f652e622d9aebda627ea34ba5af242dbb835e commit 247f652e622d9aebda627ea34ba5af242dbb835e Author: Mateusz Guzik AuthorDate: 2021-01-25 20:58:59 +0000 Commit: Mateusz Guzik CommitDate: 2021-02-01 12:39:17 +0000 cache: make ->nc_flag accesses atomic-clean for lockless usage (cherry picked from commit 6ef8fede86f3feed7fb1e15b0e8a32ecfec33c6c) --- sys/kern/vfs_cache.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 9d5b18aa4132..ba3856ffe0b4 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -398,7 +398,7 @@ static inline struct negstate * NCP2NEGSTATE(struct namecache *ncp) { - MPASS(ncp->nc_flag & NCF_NEGATIVE); + MPASS(atomic_load_char(&ncp->nc_flag) & NCF_NEGATIVE); return (&ncp->nc_neg); } @@ -1994,7 +1994,7 @@ negative_success: } cache_out_ts(ncp, tsp, ticksp); - whiteout = (ncp->nc_flag & NCF_WHITE); + whiteout = (atomic_load_char(&ncp->nc_flag) & NCF_WHITE); neg_promote = cache_neg_hit_prep(ncp); if (!cache_ncp_canuse(ncp)) { cache_neg_hit_abort(ncp); @@ -2149,6 +2149,7 @@ cache_enter_lock(struct celockstate *cel, struct vnode *dvp, struct vnode *vp, { struct namecache *ncp; struct mtx *blps[2]; + u_char nc_flag; blps[0] = HASH2BUCKETLOCK(hash); for (;;) { @@ -2159,11 +2160,12 @@ cache_enter_lock(struct celockstate *cel, struct vnode *dvp, struct vnode *vp, ncp = vp->v_cache_dd; if (ncp == NULL) break; - if ((ncp->nc_flag & NCF_ISDOTDOT) == 0) + nc_flag = atomic_load_char(&ncp->nc_flag); + if ((nc_flag & NCF_ISDOTDOT) == 0) break; MPASS(ncp->nc_dvp == vp); blps[1] = NCP2BUCKETLOCK(ncp); - if (ncp->nc_flag & NCF_NEGATIVE) + if ((nc_flag & NCF_NEGATIVE) != 0) break; if (cache_lock_vnodes_cel_3(cel, ncp->nc_vp)) break; @@ -2190,6 +2192,7 @@ cache_enter_lock_dd(struct celockstate *cel, struct vnode *dvp, struct vnode *vp { struct namecache *ncp; struct mtx *blps[2]; + u_char nc_flag; blps[0] = HASH2BUCKETLOCK(hash); for (;;) { @@ -2198,11 +2201,12 @@ cache_enter_lock_dd(struct celockstate *cel, struct vnode *dvp, struct vnode *vp ncp = dvp->v_cache_dd; if (ncp == NULL) break; - if ((ncp->nc_flag & NCF_ISDOTDOT) == 0) + nc_flag = atomic_load_char(&ncp->nc_flag); + if ((nc_flag & NCF_ISDOTDOT) == 0) break; MPASS(ncp->nc_dvp == dvp); blps[1] = NCP2BUCKETLOCK(ncp); - if (ncp->nc_flag & NCF_NEGATIVE) + if ((nc_flag & NCF_NEGATIVE) != 0) break; if (cache_lock_vnodes_cel_3(cel, ncp->nc_vp)) break; @@ -2436,7 +2440,7 @@ cache_enter_time(struct vnode *dvp, struct vnode *vp, struct componentname *cnp, vp); } else { if (cnp->cn_flags & ISWHITEOUT) - ncp->nc_flag |= NCF_WHITE; + atomic_store_char(&ncp->nc_flag, ncp->nc_flag | NCF_WHITE); cache_neg_insert(ncp); SDT_PROBE2(vfs, namecache, enter_negative, done, dvp, ncp->nc_name);