From patchwork Fri Dec 15 21:47:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 13495031 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B8C8487A4 for ; Fri, 15 Dec 2023 21:49:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="cnQo9Vjp" 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 3BFK7soB020259; Fri, 15 Dec 2023 21:47:31 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-2023-11-20; bh=clqfrKp2EzJrU/yEImyYsR6EHCLrihWIHJ63NgZAmyA=; b=cnQo9VjpP8DCowT72xQkOfHrqHWRUpIpURJs6aSb6AqpI/HPgfnPgdoVGECWlnyge5bg xMsnfnEkgoHOrPK+lBwtLb06en55qa88rUCmuLE1xWB0kjQkSJMBb/BI2ad1WzH+JAoH q/A7CevST8L3Nc0FgNnbb9QxnjUosw7t7GjZC81WUa9RjSa5HKhcFmKbcAx2FMP/sCMy JXsj3g/1a3fTtrFMfgzSZOIbbfc9Z9Q+ctmiMV4VQcNKVyvXQ62mrek5lJpHwp25i6TC NFNKKngbnwug2l/t5Ob7eWUfN7pWDejUHCaWbgu66h5cBkf/GGC5WSuIPXCf6Qs82G0T nQ== Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.appoci.oracle.com [147.154.114.232]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3uveu2eb6f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 15 Dec 2023 21:47:30 +0000 Received: from pps.filterd (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 3BFKEb7w029929; Fri, 15 Dec 2023 21:47:30 GMT Received: from pps.reinject (localhost [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3uvepchqns-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 15 Dec 2023 21:47:30 +0000 Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3BFLlSH4022773; Fri, 15 Dec 2023 21:47:29 GMT Received: from ca-common-hq.us.oracle.com (ca-common-hq.us.oracle.com [10.211.9.209]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3uvepchqn0-3; Fri, 15 Dec 2023 21:47:29 +0000 From: Dai Ngo To: chuck.lever@oracle.com, jlayton@kernel.org Cc: linux-nfs@vger.kernel.org, linux-nfs@stwm.de Subject: [PATCH 2/3 v2] NFSD: restore delegation's sc_count if nfsd4_run_cb fails Date: Fri, 15 Dec 2023 13:47:16 -0800 Message-Id: <1702676837-31320-3-git-send-email-dai.ngo@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1702676837-31320-1-git-send-email-dai.ngo@oracle.com> References: <1702676837-31320-1-git-send-email-dai.ngo@oracle.com> X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-15_10,2023-12-14_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0 spamscore=0 suspectscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2312150152 X-Proofpoint-ORIG-GUID: 4a6MPWhX6dEuplH6-4Qjjk_hXgU4tAXG X-Proofpoint-GUID: 4a6MPWhX6dEuplH6-4Qjjk_hXgU4tAXG Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Under some load conditions the callback work request can not be queued and nfsd4_run_cb returns 0 to caller. When this happens, the sc_count of the delegation state was left with an extra reference count preventing the state to be freed later. We need to hold the flc_lock to prevent the lease to be removed which allows the delegation state to be released. We need to do this since we just do the refcount_dec if nfsd4_run_cb fails, instead of doing nfs4_put_stid to free the state if this is the last refcount. Fixes: 6c41d9a9bd02 ("NFSD: handle GETATTR conflict with write delegation") Signed-off-by: Dai Ngo --- fs/nfsd/nfs4state.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 40415929e2ae..175f3e9f5822 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2947,8 +2947,14 @@ void nfs4_cb_getattr(struct nfs4_cb_fattr *ncf) if (test_and_set_bit(CB_GETATTR_BUSY, &ncf->ncf_cb_flags)) return; + refcount_inc(&dp->dl_stid.sc_count); - nfsd4_run_cb(&ncf->ncf_getattr); + if (!nfsd4_run_cb(&ncf->ncf_getattr)) { + refcount_dec(&dp->dl_stid.sc_count); + clear_bit(CB_GETATTR_BUSY, &ncf->ncf_cb_flags); + wake_up_bit(&ncf->ncf_cb_flags, CB_GETATTR_BUSY); + WARN_ON_ONCE(1); + } } static struct nfs4_client *create_client(struct xdr_netobj name, @@ -4967,7 +4973,10 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp) * we know it's safe to take a reference. */ refcount_inc(&dp->dl_stid.sc_count); - WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall)); + if (!nfsd4_run_cb(&dp->dl_recall)) { + refcount_dec(&dp->dl_stid.sc_count); + WARN_ON_ONCE(1); + } } /* Called from break_lease() with flc_lock held. */ @@ -8543,12 +8552,12 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct inode *inode, return 0; } break_lease: - spin_unlock(&ctx->flc_lock); nfsd_stats_wdeleg_getattr_inc(); - dp = fl->fl_owner; ncf = &dp->dl_cb_fattr; nfs4_cb_getattr(&dp->dl_cb_fattr); + spin_unlock(&ctx->flc_lock); + wait_on_bit(&ncf->ncf_cb_flags, CB_GETATTR_BUSY, TASK_INTERRUPTIBLE); if (ncf->ncf_cb_status) { status = nfserrno(nfsd_open_break_lease(inode, NFSD_MAY_READ));