From patchwork Fri Jun 30 01:52:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 13297501 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 960AFEB64DD for ; Fri, 30 Jun 2023 01:53:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231294AbjF3BxC (ORCPT ); Thu, 29 Jun 2023 21:53:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231176AbjF3BxA (ORCPT ); Thu, 29 Jun 2023 21:53:00 -0400 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 311391FE7 for ; Thu, 29 Jun 2023 18:52:59 -0700 (PDT) Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 35TNYYXc006152; Fri, 30 Jun 2023 01:52:57 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2023-03-30; bh=2La85BUQOxbap43h9JW0pIZ/IYr+a7OPmhQIJysPW9w=; b=EJVrgyLz6A1wIehVGrPGHtBbna0Ur4h+1p2JqCyoCeNf9izTOShtqk9eZI8a6IN9Q4QM bhdT2vGUwzD4YUVs00SXJFhTrPo6iMQuort+O0NPot+Y2ufQCBO7rTusDgQ/0tklCTlx WLxwHfWC0eLJ3DXyC6g/EoWmHsXNOoAm+pLDcziX0QCInqVRVAZy7SD7dx4j0gxi2X+w O9FFpMSf0DnaBi2sEIGlpn2VO8YZNRtWFYyV1zTUBuSIJk294Ll8Jxbzhu0g9QjZsvGl mJG5gCWKDZdzkd5VHoffovImGnayYHg7VLu1qnR+HvRIjhR9/8fnaM9O7pLFJtY+evut 2Q== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3rdq3172qr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Jun 2023 01:52:56 +0000 Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 35U0H1Tk020127; Fri, 30 Jun 2023 01:52:55 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3rdpxdyq0q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 30 Jun 2023 01:52:55 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 35U1qpex034790; Fri, 30 Jun 2023 01:52:54 GMT Received: from ca-common-hq.us.oracle.com (ca-common-hq.us.oracle.com [10.211.9.209]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3rdpxdypy9-5; Fri, 30 Jun 2023 01:52:54 +0000 From: Dai Ngo To: chuck.lever@oracle.com, jlayton@kernel.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v7 4/4] NFSD: Enable write delegation support for NFSv4.1+ client Date: Thu, 29 Jun 2023 18:52:40 -0700 Message-Id: <1688089960-24568-5-git-send-email-dai.ngo@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1688089960-24568-1-git-send-email-dai.ngo@oracle.com> References: <1688089960-24568-1-git-send-email-dai.ngo@oracle.com> X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-06-29_10,2023-06-27_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306300014 X-Proofpoint-ORIG-GUID: ZmAc_GH18ZPH3umHp3i5nQWkNDMPV6ra X-Proofpoint-GUID: ZmAc_GH18ZPH3umHp3i5nQWkNDMPV6ra Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org This patch grants write delegations for OPEN with NFS4_SHARE_ACCESS_WRITE if there is no conflict with other OPENs. Write delegation conflicts with another OPEN, REMOVE, RENAME and SETATTR are handled the same as read delegation using notify_change, try_break_deleg. The NFSv4.0 protocol does not enable a server to determine that a conflicting GETATTR originated from the client holding the delegation versus coming from some other client. With NFSv4.1 and later, the SEQUENCE operation that begins each COMPOUND contains a client ID, so delegation recall can be safely squelched in this case. With NFSv4.0, therefore, the server must recall or send a CB_GETATTR (per RFC 7530 Section 16.7.5) even when the GETATTR originates from the client holding that delegation. An NFSv4.0 client can trigger a pathological situation if it always sends a DELEGRETURN preceded by a conflicting GETATTR in the same COMPOUND. COMPOUND execution will always stop at the GETATTR and the DELEGRETURN will never get executed. The server eventually revokes the delegation, which can result in loss of open or lock state. Tracepoint added to track whether read or write delegation is granted. Signed-off-by: Dai Ngo --- fs/nfsd/nfs4state.c | 40 +++++++++++++++++++++++++++++----------- fs/nfsd/trace.h | 1 + 2 files changed, 30 insertions(+), 11 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 4c96cfe19531..15b5043eeca5 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1144,7 +1144,7 @@ static void block_delegations(struct knfsd_fh *fh) static struct nfs4_delegation * alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp, - struct nfs4_clnt_odstate *odstate) + struct nfs4_clnt_odstate *odstate, u32 dl_type) { struct nfs4_delegation *dp; long n; @@ -1170,7 +1170,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp, INIT_LIST_HEAD(&dp->dl_recall_lru); dp->dl_clnt_odstate = odstate; get_clnt_odstate(odstate); - dp->dl_type = NFS4_OPEN_DELEGATE_READ; + dp->dl_type = dl_type; dp->dl_retries = 1; dp->dl_recalled = false; nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client, @@ -5451,6 +5451,7 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, struct nfs4_delegation *dp; struct nfsd_file *nf; struct file_lock *fl; + u32 dl_type; /* * The fi_had_conflict and nfs_get_existing_delegation checks @@ -5460,7 +5461,13 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, if (fp->fi_had_conflict) return ERR_PTR(-EAGAIN); - nf = find_readable_file(fp); + if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) { + nf = find_writeable_file(fp); + dl_type = NFS4_OPEN_DELEGATE_WRITE; + } else { + nf = find_readable_file(fp); + dl_type = NFS4_OPEN_DELEGATE_READ; + } if (!nf) { /* * We probably could attempt another open and get a read @@ -5491,11 +5498,11 @@ nfs4_set_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, return ERR_PTR(status); status = -ENOMEM; - dp = alloc_init_deleg(clp, fp, odstate); + dp = alloc_init_deleg(clp, fp, odstate, dl_type); if (!dp) goto out_delegees; - fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ); + fl = nfs4_alloc_init_lease(dp, dl_type); if (!fl) goto out_clnt_odstate; @@ -5570,8 +5577,13 @@ static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status) /* * Attempt to hand out a delegation. * - * Note we don't support write delegations, and won't until the vfs has - * proper support for them. + * Note we don't support write delegations for NFSv4.0 client since the Linux + * client behavior is not compliant with RFC 7530 Section 16.7.5 with regard + * to handle the conflict GETATTR. It expects the server to look ahead in the + * compound (PUTFH, GETATTR, DELEGRETURN) to find a stateid in order to + * determine whether the client that sends the GETATTR is the same with the + * client that holds the write delegation. RFC 7530 spec does not call for + * the server to look ahead in order to service the conflict GETATTR op. */ static void nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, @@ -5590,8 +5602,6 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, case NFS4_OPEN_CLAIM_PREVIOUS: if (!cb_up) open->op_recall = 1; - if (open->op_delegate_type != NFS4_OPEN_DELEGATE_READ) - goto out_no_deleg; break; case NFS4_OPEN_CLAIM_NULL: parent = currentfh; @@ -5606,6 +5616,9 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, goto out_no_deleg; if (!cb_up || !(oo->oo_flags & NFS4_OO_CONFIRMED)) goto out_no_deleg; + if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE && + !clp->cl_minorversion) + goto out_no_deleg; break; default: goto out_no_deleg; @@ -5616,8 +5629,13 @@ nfs4_open_delegation(struct nfsd4_open *open, struct nfs4_ol_stateid *stp, memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid)); - trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid); - open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; + if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) { + open->op_delegate_type = NFS4_OPEN_DELEGATE_WRITE; + trace_nfsd_deleg_write(&dp->dl_stid.sc_stateid); + } else { + open->op_delegate_type = NFS4_OPEN_DELEGATE_READ; + trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid); + } nfs4_put_stid(&dp->dl_stid); return; out_no_deleg: diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index 72a906a053dc..56f28364cc6b 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -607,6 +607,7 @@ DEFINE_STATEID_EVENT(layout_recall_release); DEFINE_STATEID_EVENT(open); DEFINE_STATEID_EVENT(deleg_read); +DEFINE_STATEID_EVENT(deleg_write); DEFINE_STATEID_EVENT(deleg_return); DEFINE_STATEID_EVENT(deleg_recall);