Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Chuck Lever III <chuck.lever@oracle.com>
To:     Bruce Fields <bfields@redhat.com>
CC:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH 1/5] nfsd: ensure new clients break delegations
Thread-Topic: [PATCH 1/5] nfsd: ensure new clients break delegations
Thread-Index: AQHXMupj8yPyCxQuREas8WmnEN293Kq3gs8A
Date:   Fri, 16 Apr 2021 19:11:36 +0000
Message-ID: <742D63C9-53E9-45B2-9604-C8DBB42EC810@oracle.com>
References: <1618596018-9899-1-git-send-email-bfields@redhat.com>
In-Reply-To: <1618596018-9899-1-git-send-email-bfields@redhat.com>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="us-ascii"
Content-ID: <B723AE35CDE97148991327E11898AE25@namprd10.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: efd3f806-5836-42e0-b6c2-08d9010b7505
X-MS-Exchange-CrossTenant-originalarrivaltime: 16 Apr 2021 19:11:36.7599
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: t/iYoWDCMLPnXc9nRlXql4e4XFiSLjnvrdiDHzzbJYBUxPmmkd2YDOLL1+Ztl4UebUaznnU+sWz4dM0qSyjsWg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR10MB2760
X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9956 signatures=668683
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 suspectscore=0
 mlxscore=0 malwarescore=0 adultscore=0 bulkscore=0 spamscore=0
 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2104060000 definitions=main-2104160134
X-Proofpoint-ORIG-GUID: 4EaWxO_pG5gQPciVA6lkN1VToaUAgGXv
X-Proofpoint-GUID: 4EaWxO_pG5gQPciVA6lkN1VToaUAgGXv
X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9956 signatures=668683
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0
 phishscore=0 suspectscore=0 mlxlogscore=999 priorityscore=1501
 clxscore=1015 lowpriorityscore=0 spamscore=0 impostorscore=0 bulkscore=0
 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2104060000 definitions=main-2104160134
Precedence: bulk
List-ID: <linux-nfs.vger.kernel.org>
X-Mailing-List: linux-nfs@vger.kernel.org


> On Apr 16, 2021, at 2:00 PM, J. Bruce Fields <bfields@redhat.com> wrote:
>=20
> From: "J. Bruce Fields" <bfields@redhat.com>
>=20
> If nfsd already has an open file that it plans to use for IO from
> another,

from another... client?


> it may not need to do another vfs open, but it still may need
> to break any delegations in case the existing opens are for another
> client.
>=20
> Symptoms are that we may incorrectly fail to break a delegation on a
> write open from a different client, when the delegation-holding client
> already has a write open.
>=20
> Fixes: 28df3d1539de ("nfsd: clients don't need to break their own delegat=
ions")
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> ---
> fs/nfsd/nfs4state.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
>=20
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 97447a64bad0..886e50ed07c2 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4869,6 +4869,11 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *r=
qstp, struct nfs4_file *fp,
> 	if (nf)
> 		nfsd_file_put(nf);
>=20
> +	status =3D nfserrno(nfsd_open_break_lease(cur_fh->fh_dentry->d_inode,
> +								access));
> +	if (status)
> +		goto out_put_access;
> +
> 	status =3D nfsd4_truncate(rqstp, cur_fh, open);
> 	if (status)
> 		goto out_put_access;
> @@ -6849,11 +6854,20 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_c=
ompound_state *cstate,
> static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, =
struct file_lock *lock)
> {
> 	struct nfsd_file *nf;
> -	__be32 err =3D nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
> -	if (!err) {
> -		err =3D nfserrno(vfs_test_lock(nf->nf_file, lock));
> -		nfsd_file_put(nf);
> -	}
> +	__be32 err;
> +
> +	err =3D nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
> +	if (err)
> +		return err;
> +	fh_lock(fhp); /* to block new leases till after test_lock: */
> +	err =3D nfserrno(nfsd_open_break_lease(fhp->fh_dentry->d_inode,
> +							NFSD_MAY_READ));
> +	if (err)
> +		goto out;
> +	err =3D nfserrno(vfs_test_lock(nf->nf_file, lock));
> +out:
> +	fh_unlock(fhp);
> +	nfsd_file_put(nf);
> 	return err;
> }
>=20
> --=20
> 2.30.2
>=20

--
Chuck Lever