Hi Metze Thanks for contacting Microsoft Support. We have created a case, 112101850229631, to track your inquiry and a support engineer will contact you to assist further.
Thanks Tarun Chopra. -----Original Message----- From: Stefan (metze) Metzmacher [mailto:me...@samba.org] Sent: Thursday, October 18, 2012 12:56 AM To: Interoperability Documentation Help; cifs-protocol@cifs.org; p...@tridgell.net Subject: Scope of a File.LeaseKey on the client Hi DocHelp, is it correct that the LeaseKey on a file is shared between different user contexts? >From 3.2.4.3 Application Requests Opening a File: [...] If the client implements the SMB 2.1 or SMB 3.0 dialect and Connection.SupportsFileLeasing is TRUE, the client MUST search the GlobalFileTable for an entry matching one of the following: - The application-supplied PathName if TreeConnect.IsDfsShare is TRUE. - The concatenation of Connection.ServerName, TreeConnect.ShareName, and the application-supplied PathName, joined with pathname separators (example: server\share\path), if TreeConnect.IsDfsShare is FALSE. If an entry is not found, a new File entry MUST be created and added to the GlobalFileTable and a File.LeaseKey, as specified in section 3.2.1.5, MUST be assigned to the entry. File.OpenTable MUST be initialized to an empty table and File.LeaseState MUST be initialized to SMB2_LEASE_NONE. [...] If the client accesses a file through multiple paths, such as using different server names or share names or parent directory names, it will create multiple File elements, and therefore multiple File.LeaseKeys for the same remote file. This loses the performance benefits of sharing cache state across all Opens of the same file, and may cause additional lease breaks to be generated, as actions by a client through one path will affect caching by that client through other paths. However, the impact is a matter of performance; cache correctness is preserved. [...] It seems that the LeaseKey is purely tight to the full path to the file from the client perspective. I guess on a terminal server where multiple users access the same path on the server, the LeaseKey is shared between them, is that correct? If this is true, then this implies that each user sees the same content in a file, which might not be true. E.g. in Samba we allow shares to expose different FSA level directories based on user account. The typical example is the "homes" share which exposes the unix home directory of the specific user. I fear that we have to disable such powerful features if we want to take advantage of leases, otherwise the client would treat \\sambaserver\homes\commonfile.doc of user1 and \\sambaserver\homes\commonfile.doc of user2 as the same file. I assume user1 and user2 should share the client_guid and lease_key, which means data corruption and/or security problems are very likely, if the server grants leases in this case. metze _______________________________________________ cifs-protocol mailing list cifs-protocol@cifs.org https://lists.samba.org/mailman/listinfo/cifs-protocol
