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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?9CE6YXh7b0uaw3sHfe68s7rwIyVXfPw0v1MDosc33XIyQ3slFElF2Yp7SXZE?= =?us-ascii?Q?enDZlBa4WKqGEqVdNBIz0xSx+g3G1LWoDouAyATx+O5OacEnrEQoaw/SUsAr?= =?us-ascii?Q?5eGf25HRrVbDYIiryPAAOJdqniwRKDeaFNtW6peoF55jc45BDPRUcxSAM3lY?= =?us-ascii?Q?zlk93zlhSHeuPlZjDAhGuZCGj0kzvBNbxTWowbZ+URg6VA2O23eGiyl3BtEo?= =?us-ascii?Q?D/MbJnYO6F0fHstXAR3XVXWGFZIsQCoHXLLp9BY86GWJQQTakRw3LqVqb9//?= =?us-ascii?Q?LXvitaafgnNk9P6bklCsJId34nc8jfCfuduPIs5AiykrdEwOWITiKxC8ZWiJ?= =?us-ascii?Q?Z+P6KjGipgSRwhp6oWOBqXWasfi+fHt5j+wMVYGP9Ul2w0wy/CZ5oP2cNzdo?= =?us-ascii?Q?SKNqxmjZUODdRt7jqUUhey+iMGmbx4A/Trrs3LL8lhHP8G3EO+J0bXozYUZh?= =?us-ascii?Q?CssG7JWkZkGrI8ReKYraNtnmHwAmJLYrQ3ICqdDqHdOpxWYWCUzmjau3m6Mt?= =?us-ascii?Q?OSfn6ewshnknAJGbLvprvcwlrhb1COJ7AxOogG1tuUScSqkc3DjlTFYRLOKb?= =?us-ascii?Q?QPJfHH1V3U6XN3uX896i+McPRv3BS8iWPzjgWtzTh4ZN+i0hxkZ8yv5xSd4A?= =?us-ascii?Q?JJDcWI//O/0nEiAImdglKsyczkNdgc4t0Cd8Yp8wdkAECmcZP7gWUZsFUVpD?= =?us-ascii?Q?qTa1nwYYteHGEez+pSJSuZSd5uXec1c2+gNCTVbak9QLwJLiKL/5iaS/R+4V?= =?us-ascii?Q?bg4/QdmdmxWH75honNH9+wdRw/5HFPxD9pQqlXC4rAgN3nK2lETWZFgLmkG6?= =?us-ascii?Q?kXlPz5fQiSbEv/WxpyWPUn6osonVe4cr2x9fNGcISTYykf/A0QtMUqa8bD0e?= =?us-ascii?Q?IyQywFZzAzWUH8hA/lJPuR8ehAi47GKU1tKVJxs31hS/Muv9VOKwAsvMtlQy?= =?us-ascii?Q?5N2wue1RwAzMPA0z4mpzT2ozcDNsL09YzMElYH5l4IHGW736lo3flpCv1eHl?= =?us-ascii?Q?PxtRDbKWhJ3m0c7khwDj3i1lYIzrmLcXgnCngWjM/BCVmZunYy8TbtWvDhHP?= =?us-ascii?Q?jKKieHgdZh7VENo5IMG9HLdYwjvt+/KBK/fSI0lWKLW4woOk9zb2nGLwkec1?= =?us-ascii?Q?Wbm8iJOOMcIBeHki/Larw/T5ARnBeNz97sxgBJTHntqy6TpUoEyJccCzQdHp?= =?us-ascii?Q?bXb/eQv7LZ5uPlaqOkvIf39ZtHZEpOTX6hHFp/KN0RFf+RKlKvh61pYtFYXW?= =?us-ascii?Q?UhS1s0lLgMVWWad8a223OpUVnqe0rQPG1n8vlGcRzq+66YIpKPplYbu5dhLL?= =?us-ascii?Q?smFltuDr4P4R49jDS0nLp6evWSCrdlo3glN2BL2qVmDRvEp13DupCMZuUlbW?= =?us-ascii?Q?zozKBmbV/cVb3NkjrbPTpmdnFToaEMnEfbSd0MwayVNMkSnY7WUjdcgIc9+u?= =?us-ascii?Q?9wyvw17h2otcmm/ESFuRxhU9W2AeyZ+4/TZaS5nkWkZHQxNHsRV5691QH78n?= =?us-ascii?Q?xCF8AFmjKm2Oji7gTlUV34kt4C/ZbjI4AqU7me5wstOLaaSp8aF8WZ/baG8r?= =?us-ascii?Q?RjKrpvYfb9iKgQtxT+AxT4tSHO5EMNt3hSGfLGa8ME89XYKmLZBSS2qLNNF+?= =?us-ascii?Q?zA=3D=3D?= X-OriginatorOrg: hammerspace.com X-MS-Exchange-CrossTenant-Network-Message-Id: caf01209-187e-47a5-61bc-08de289a49fb X-MS-Exchange-CrossTenant-AuthSource: SN6PR13MB2365.namprd13.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Nov 2025 01:07:06.5774 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 0d4fed5c-3a70-46fe-9430-ece41741f59e X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: tEKESjuTrdHZvm/duCN+gb6AKkePyDQSuGlwG2zKEMXuIcqEPlPWgXmirv0RbDMpZLqj4tudCmJWNRltdYuIXRktHAKGikABbPJJ7J7tt1I= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR13MB7070 On 20 Nov 2025, at 17:26, NeilBrown wrote: > On Wed, 19 Nov 2025, Benjamin Coddington wrote: > >> Ah, it's true. I did not validate knfsd's behaviors, only its interface with >> VFS. IIUC knfsd gets around needing to pass O_EXCL by holding the directory >> inode lock over the create, and since it doesn't need to do lookup because >> it already has a filehandle, I think O_EXCL is moot. > > Holding the directory lock is sufficient for providing O_EXCL for local > filesystems which will be blocked from creating while that lock is held. > It is *not* sufficient for remote filesystems which are precisely those > which provide ->atomic_open. > > The fact that you are adding support for atomic_open means that O_EXCL > isn't moot. I mean to say: knfsd doesn't need to pass O_EXCL because its already taking care to produce an exclusive open via nfsv4 semantics. > I don't know what you mean by "since it doesn't need to do lookup because > it already has a filehandle". What filehandle does it already have? The client has sent along the filehandle of the parent directory, and knfsd has already done lookup_one() on the child name, and we pass along that negative dentry thet we looked up while holding the directory's inode lock. Ben