From patchwork Fri Jan 6 17:43:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 13091655 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60473C54E76 for ; Fri, 6 Jan 2023 17:43:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234552AbjAFRns (ORCPT ); Fri, 6 Jan 2023 12:43:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbjAFRnq (ORCPT ); Fri, 6 Jan 2023 12:43:46 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22BD276EDA for ; Fri, 6 Jan 2023 09:43:40 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 983B361EE2 for ; Fri, 6 Jan 2023 17:43:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB94BC433D2 for ; Fri, 6 Jan 2023 17:43:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673027019; bh=rKh4k3o7kKtkPHULv/T2Fjo2TWkap7PlYAPYEzx11gI=; h=Subject:From:To:Date:From; b=B03CjJVef+FMSZsjyfuWi+OcNUGf5jGcA+JP4+fdNM1yskDWNYXUqjUCr3oP77U46 Q5yukB9YvIj3O7G4QlJ1lRQQ5c5J14b5+Ud9dAz2bCGyBxYegpQ39Mrr0/YTBzYCk2 1ZTFuZm10DhEwwzBEqnSLVSb+fHujGCRXtSC2XLkbkEJfrTJFsqz4OCRdJ/26O4eAZ ULW0bKR6j3P23BLHnWRt5fSxzIMTPDyFgdw5xU5TJ8Je7M6b1/oBhs5mF+1O19cUqy h9WZO6QnxWQpHr59Ghh69nxHi691gUb6SdfwdlF/oxNqVejFnq3nkGPyUEb8fgieDN rNm/Nv4gOk+YQ== Subject: [PATCH v1] Revert "SUNRPC: Use RMW bitops in single-threaded hot paths" From: Chuck Lever To: linux-nfs@vger.kernel.org Date: Fri, 06 Jan 2023 12:43:37 -0500 Message-ID: <167302701777.4221.807573588471189662.stgit@klimt.1015granger.net> User-Agent: StGit/1.5.dev3+g9561319 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Chuck Lever The premise that "Once an svc thread is scheduled and executing an RPC, no other processes will touch svc_rqst::rq_flags" is false. svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd threads when determining which thread to wake up next. Found via KCSAN. Fixes: 28df0988815f ("SUNRPC: Use RMW bitops in single-threaded hot paths") Signed-off-by: Chuck Lever Reviewed-by: Jeff Layton --- fs/nfsd/nfs4proc.c | 7 +++---- fs/nfsd/nfs4xdr.c | 2 +- net/sunrpc/auth_gss/svcauth_gss.c | 4 ++-- net/sunrpc/svc.c | 6 +++--- net/sunrpc/svc_xprt.c | 2 +- net/sunrpc/svcsock.c | 8 ++++---- net/sunrpc/xprtrdma/svc_rdma_transport.c | 2 +- 7 files changed, 15 insertions(+), 16 deletions(-) diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index bd880d55f565..9b81d012666e 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -937,7 +937,7 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, * the client wants us to do more in this compound: */ if (!nfsd4_last_compound_op(rqstp)) - __clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); + clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); /* check stateid */ status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh, @@ -2607,12 +2607,11 @@ nfsd4_proc_compound(struct svc_rqst *rqstp) cstate->minorversion = args->minorversion; fh_init(current_fh, NFS4_FHSIZE); fh_init(save_fh, NFS4_FHSIZE); - /* * Don't use the deferral mechanism for NFSv4; compounds make it * too hard to avoid non-idempotency problems. */ - __clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); + clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); /* * According to RFC3010, this takes precedence over all other errors. @@ -2734,7 +2733,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp) out: cstate->status = status; /* Reset deferral mechanism for RPC deferrals */ - __set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); + set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); return rpc_success; } diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index ebb4d02a42ce..97edb32be77f 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2523,7 +2523,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp) argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE; if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack) - __clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags); + clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags); return true; } diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 148bb0a7fa5b..acb822b23af1 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -923,7 +923,7 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct g * rejecting the server-computed MIC in this somewhat rare case, * do not use splice with the GSS integrity service. */ - __clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); + clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); /* Did we already verify the signature on the original pass through? */ if (rqstp->rq_deferred) @@ -990,7 +990,7 @@ unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gs int pad, remaining_len, offset; u32 rseqno; - __clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); + clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags); priv_len = svc_getnl(&buf->head[0]); if (rqstp->rq_deferred) { diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 8f1b596db33f..b1da586c4476 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -1243,10 +1243,10 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv) goto err_short_len; /* Will be turned off by GSS integrity and privacy services */ - __set_bit(RQ_SPLICE_OK, &rqstp->rq_flags); + set_bit(RQ_SPLICE_OK, &rqstp->rq_flags); /* Will be turned off only when NFSv4 Sessions are used */ - __set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); - __clear_bit(RQ_DROPME, &rqstp->rq_flags); + set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags); + clear_bit(RQ_DROPME, &rqstp->rq_flags); svc_putu32(resv, rqstp->rq_xid); diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 2106003645a7..c2ce12538008 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -1238,7 +1238,7 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req) trace_svc_defer(rqstp); svc_xprt_get(rqstp->rq_xprt); dr->xprt = rqstp->rq_xprt; - __set_bit(RQ_DROPME, &rqstp->rq_flags); + set_bit(RQ_DROPME, &rqstp->rq_flags); dr->handle.revisit = svc_revisit; return &dr->handle; diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 2fc98fea59b4..e833103f4629 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -298,9 +298,9 @@ static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs) static void svc_sock_secure_port(struct svc_rqst *rqstp) { if (svc_port_is_privileged(svc_addr(rqstp))) - __set_bit(RQ_SECURE, &rqstp->rq_flags); + set_bit(RQ_SECURE, &rqstp->rq_flags); else - __clear_bit(RQ_SECURE, &rqstp->rq_flags); + clear_bit(RQ_SECURE, &rqstp->rq_flags); } /* @@ -1008,9 +1008,9 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp) rqstp->rq_xprt_ctxt = NULL; rqstp->rq_prot = IPPROTO_TCP; if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags)) - __set_bit(RQ_LOCAL, &rqstp->rq_flags); + set_bit(RQ_LOCAL, &rqstp->rq_flags); else - __clear_bit(RQ_LOCAL, &rqstp->rq_flags); + clear_bit(RQ_LOCAL, &rqstp->rq_flags); p = (__be32 *)rqstp->rq_arg.head[0].iov_base; calldir = p[1]; diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c index 199fa012f18a..94b20fb47135 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c @@ -602,7 +602,7 @@ static int svc_rdma_has_wspace(struct svc_xprt *xprt) static void svc_rdma_secure_port(struct svc_rqst *rqstp) { - __set_bit(RQ_SECURE, &rqstp->rq_flags); + set_bit(RQ_SECURE, &rqstp->rq_flags); } static void svc_rdma_kill_temp_xprt(struct svc_xprt *xprt)