Received-SPF: pass (google.com: domain of linux-nfs+bounces-2376-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Mon, 18 Mar 2024 16:12:17 -0400
From: Chuck Lever <chuck.lever@oracle.com>
To: Jan Kara <jack@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
        linux-nfs@vger.kernel.org, Jeff Layton <jlayton@kernel.org>
Subject: Re: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()
Message-ID: <ZfigId5Anil0U3cs@manet.1015granger.net>
References: <20240318163209.26493-1-jack@suse.cz>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240318163209.26493-1-jack@suse.cz>
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: 
	=?us-ascii?Q?9xJa4K7eFuuFZVuVbKyk7ujmyfcAc3iKYMyrENI8RdEP4a2JHLvqnH3kaHW5?=
 =?us-ascii?Q?e03K6/QWSTGX1Y+8AQXvrSw0RsPkoRHGQe+dtXDExnAzV+KvRoK7DXsnKJ3M?=
 =?us-ascii?Q?nAb7ee+nQPdY8mrqLVch2QU2z32PKo6ojo3P7Ol1Ujb0ROTzl9G8i8c4+Hsb?=
 =?us-ascii?Q?T1GEB+jLCENa/ly8NiKQGxBcEULyOkE+2qL3/R7sECBPy54voPVnNVbPemPA?=
 =?us-ascii?Q?JRkIvHr7zfRuXthQglAZEJHnzSpvWlMR45NbWDM5ndsQqqxG533JeUCtzsqW?=
 =?us-ascii?Q?r4Es9do+4UsNsnZo0VcdQAj6Egm9WXCZvXIrm2XalRk1Gl26W5H3kMyrq/Tm?=
 =?us-ascii?Q?stRC8scZgXKTBwFMtq98jDh3WjViSM0PAU2TZGofs423CS+IhIO8zc91yJc2?=
 =?us-ascii?Q?Y4L0MbW5qwEST3wXsF8VkT4LJmKihhGI5tW4W1J2MsKO2EvTvCRX4gnmuK7P?=
 =?us-ascii?Q?avpQttOke9J3xIHNWrU+aP3TD6fBocB/Ih3z0jrQ+1LUPuVOo5bsTkeGLTgP?=
 =?us-ascii?Q?AZ5pf3xu/IXFr+Cjny3nAu9cwca/HfhO0XddPaNWgt4PWp+j1TMElZB2Xqu5?=
 =?us-ascii?Q?e3kKLW9Y0Uks30TufV4iJUbzQajaH7wkjZcprOIvllfuYZLy+fthzdM9ko+J?=
 =?us-ascii?Q?Xs6UsJDMLTKkgmDuOg7XiCG4YAncs/lfR/oa2gsP5X/G7XkS1Ek0GSByV3UK?=
 =?us-ascii?Q?IasXk9xi2DoEU22MkR8hrTtWPkZME8/ZmBvEWlG7yS1FUtOq3aFxpcYgvtK/?=
 =?us-ascii?Q?51pCDGfC4XGrhxDVXtrzv+Sr3XyWa2PCc+gGb4Lekd1xMDAkTPEz6GHZlKm6?=
 =?us-ascii?Q?ktr7KEkNRqSNSXPET7R5ySDo0gHGg+awo4GXYOnSzM/a12HtuH8oxBk8KNnx?=
 =?us-ascii?Q?SkmmorGlKxEu6bnB9eohKDhnu6rQ2Qcf8fqfuSLAZM71D6s2qLCGb/rdJ7XQ?=
 =?us-ascii?Q?TRnePaxKOB5ll5aHec4/swNG1O4DN8aT72sg77IqkNZoPHiysCbgRGNNONOz?=
 =?us-ascii?Q?0E/GaH2vXMbHPOz0j0lx2v6glpMOpmTShFI3doHxJlx4d0+2HEgBhxaJVtDn?=
 =?us-ascii?Q?9Q6bNcZyySdCkZ8TJvRTbAJZH6FjskXEf8n+iWmeOm/lhIrcp/Wz6JRePTd4?=
 =?us-ascii?Q?MVPJ83dFlZrCjTyDrGj/xQE6MWv2iRWMYu38AZV5HcZrnhcd7pmnref1lDzj?=
 =?us-ascii?Q?+WiOuRaGXBwOkI6WHgRDfjbr+BNyYp4+WM/N9yRoKw4WuTaC+MepSAbW4lAL?=
 =?us-ascii?Q?ZTHXjsixE5RrHFqNMEL+nIS08W5kFpXejzkH0ljoAgp2dMBCB+N31hqaVobX?=
 =?us-ascii?Q?MXdfTgQAsrB2cg0vcRRz5WNnK/IhHLVSWC6H8NSKl+OvRgCrhctQRNKwUs0Z?=
 =?us-ascii?Q?BElwzPXVEac64ZlkkamDegwh6Yn9BRHCO+IDSpTP1s1zVIelseUmp5HsuJEN?=
 =?us-ascii?Q?er0oDZLNpabKulow6zsp+ExaryN96K5c0Kzp4ivCvSDEsgGXYeicRk6oYhfF?=
 =?us-ascii?Q?l7UXAC+Xu+6TXYXPi8h15frnb8x7H1mAZTtIng1h6hYKDTXr0+2Flih7EeNW?=
 =?us-ascii?Q?quytqvszspe9jGeGHJeO4T4Aiej3LWKOAg/ZsFP4xYefH0v8p7yaMZNUkHSI?=
 =?us-ascii?Q?yw=3D=3D?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 
	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
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: f33dff2f-c889-4e14-c65d-08dc4787b79b
X-MS-Exchange-CrossTenant-AuthSource: BN0PR10MB5128.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Mar 2024 20:12:20.8909
 (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: s6R7rjGhsoG8d6a1qT20tqIUYJ+i94G46exSyYqffI9QYiwECkgI8X5n1rUAMh1oYKqT39uRPD/ibp6vT9Mr3A==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR10MB7310
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.272,Aquarius:18.0.1011,Hydra:6.0.619,FMLib:17.11.176.26
 definitions=2024-03-18_12,2024-03-18_03,2023-05-22_02
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 mlxscore=0 adultscore=0
 spamscore=0 bulkscore=0 mlxlogscore=999 malwarescore=0 phishscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2403140000
 definitions=main-2403180153
X-Proofpoint-GUID: imHFKDkcj_uyNiDcZ1mRZoOvpRZBPA9-
X-Proofpoint-ORIG-GUID: imHFKDkcj_uyNiDcZ1mRZoOvpRZBPA9-

On Mon, Mar 18, 2024 at 05:32:09PM +0100, Jan Kara wrote:
> Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
> having no common ancestor") added an error bail out path. However this
> path does not drop the remount protection that has been acquired. Fix
> the cleanup path to properly drop the remount protection.
> 
> Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
> Signed-off-by: Jan Kara <jack@suse.cz>

Al, Jan, let me know if you'd like me to take this through the
nfsd tree for v6.9-rc. If not:

Acked-by: Chuck Lever <chuck.lever@oracle.com>


> ---
>  fs/nfsd/vfs.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> index 6a9464262fae..2e41eb4c3cec 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
>  	trap = lock_rename(tdentry, fdentry);
>  	if (IS_ERR(trap)) {
>  		err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
> -		goto out;
> +		goto out_want_write;
>  	}
>  	err = fh_fill_pre_attrs(ffhp);
>  	if (err != nfs_ok)
> @@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
>  	}
>  out_unlock:
>  	unlock_rename(tdentry, fdentry);
> +out_want_write:
>  	fh_drop_write(ffhp);
>  
>  	/*
> -- 
> 2.35.3
> 

-- 
Chuck Lever