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Hi MS team,
I'm developing sync program with cloud filter API.
I encountered an issue with the access to the cloud file from any service application (from session 0):
When service app tries to open not yet hydrated file for reading it receives error: Access to the cloud file is denied
Error 0xC000CF18 STATUS_CLOUD_FILE_ACCESS_DENIED instead of trigger hydration of it.
Although service app can fetch new placeholders without any problem, can read their attributes, can open already hydrated files.
Also, I noticed that cloud app itself started as a service can fetch (hydrate) files in the sync root.
Is there any policy/setting can be applied to allow trigger the file hydration (CF_CALLBACK_TYPE_FETCH_DATA) for service apps?
For my implementation it is mandatory to have population/hydration by demand without restrictions for any process. (I have my own filtering in callbacks)
SDK in use 10.0.22000.0
Winver 21H2 19044.1706
Thanks,
How did you open the file, could you share a code sample? Does not contain any personal privacy.
Basically any service app can't access file data (error above) if file is not hydrated.
I made a simple checker service, it just tries to open file and return error:
HANDLE crt = CreateFile(path_to_file_in_sync_root, GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
GetLastError() return 395 (0x18B)
filemon shows this stack:
@Junjie Zhu - MSFT I'm getting this error with Cloud Mirror from windows-classic-samples as well.
I have also reproduced this issue, I will communicate with the engineer, if there is any news, I will update below.
Hi, MikhailMamedov,
How did you get this issue in Cloud Mirror, it seems that after I use admin rights, there is no issue.
Hi @Junjie Zhu - MSFT ,
This is how to get the error with CloudMirror sample:
sc.exe like sc.exe create TestService binpath= c:\path_to\test_service_reader.exe C:\service_out.txt Simple code (but this can be any 3rd party app running as service)
(215263-service-checker.txt)
Also you can see a difference if the file has been hydrated before.
I tried with a local service account and user in the admin group, no difference Im getting only this:
Access to the cloud file is denied same as above.
This is Windows 11 21H2 (22000.739)
Thanks for the detailed steps, I will reproduce this issue on my computer as soon as possible.
We successfully reproduced your issue, we will try to fix it internally first, if there is any progress we will update below.
In the local folder, do you have a file with the same name as the cloud file?
No I don't.
Originally, I have :
During the start of the cloud mirror, it populates placeholders in empty local sync root once.
Then user/s can open these files in any user session, opening would trigger hydration of the content.
File opened in service session can't be hydrated (error above) although service app can open and read already hydrated files (hydrated by user app in user session)
Not sure if it's a bug, if there is a file with the same name in the local folder, will the same issue occur?
Just tested: if I have a file in local folder (sync root) same as in cloud before registration occurred (like during launch of ~cloud mirror) then this file will be marked as "ready for sync" icon and service app can open and read the content of this file without errors.
I just discovered that service executable placed in %systemroot% (and its subdirs) can fetch data from the cloud without problem.
Any other executables in C:\Program Files etc are limited (error above)
This is a big problem for us and urgent. Please let me know if more details required,
also if we can take any other actions to speed up the investigation. Thanks,
Our team is trying to solve the problem you found, you can also submit your issue in GitHub issue, there will be the developers to give you feedback.
I'll update below if we make any progress.
I sent issue in github as well
https://github.com/microsoft/Windows-classic-samples/issues/245
Thanks,
Hi @Junjie Zhu - MSFT ,
is there any update we can expect on this one?
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Hi @Junjie Zhu - MSFT ,
We are also facing the same issue when the application running as service tries to open cloud file. If this issue is fixed in latest windows builds, do let us know.
Thanks
Ashok
Hi @Junjie Zhu - MSFT ,
We are also facing the same issue. The application running as a service tries to open cloud files and we see the same error code. Is this issue fixed in latest windows version? Please let us know if there is any update on this one.
Thanks
Ashok