Samba4 wearing out usn

[Matthieu Patou]

  Hello,

I witnessed a high speed wearout of usn in my production system after 
some investigation I noticed through an investigation on 
replPropertyMetaData that's it's operatingSystemVersion and 
operatingSystemServicePack that are quite often changed when obviously 
they shouldn't ....


I find this code in ./rpc_server/netlogon/dcerpc_netlogon.c :

                 /* Deletes old OS version values */
                 samdb_msg_add_delete(sam_ctx, mem_ctx, new_msg,
                         "operatingSystemServicePack");
                 samdb_msg_add_delete(sam_ctx, mem_ctx, new_msg,
                         "operatingSystemVersion");

                 if (dsdb_replace(sam_ctx, new_msg, 0) != LDB_SUCCESS) {
                         DEBUG(3,("Impossible to update samdb: %s\n",
                                 ldb_errstring(sam_ctx)));
                 }

                 talloc_free(new_msg);

                 new_msg = ldb_msg_new(mem_ctx);
                 NT_STATUS_HAVE_NO_MEMORY(new_msg);

                 new_msg->dn = workstation_dn;

                 /* Sets the OS name */
                 samdb_msg_set_string(sam_ctx, mem_ctx, new_msg,
                         "operatingSystem",
                         r->in.query->workstation_info->os_name.string);

                 /*
                  * Sets informations from "os_version". On a empty 
structure
                  * the values are cleared.
                  */
                 if (r->in.query->workstation_info->os_version.os != NULL) {
                         os_version = 
&r->in.query->workstation_info->os_version.os->os;

                         samdb_msg_set_string(sam_ctx, mem_ctx, new_msg,
                                              "operatingSystemServicePack",
                                              os_version->CSDVersion);

                         samdb_msg_set_string(sam_ctx, mem_ctx, new_msg,
                                 "operatingSystemVersion",
                                 talloc_asprintf(mem_ctx, "%d.%d (%d)",
                                         os_version->MajorVersion,
                                         os_version->MinorVersion,
                                         os_version->BuildNumber
                                 )
                         );
                 }

I'm pretty sure that the pb comes from the fact that the code has a 
simplistic logic and do remove/add instead of replace (or add the first 
time).

Mathias any reason for this to be done that way ?
Could we change this ?

Cheers.
Matthieu.

-- 
Matthieu Patou
Samba Team        http://samba.org