On 2024-03-08 17:21, Corinna Vinschen wrote:
On Mar 8 14:56, Corinna Vinschen via Cygwin wrote:
On Mar 8 08:15, Jeffrey Altman via Cygwin wrote:
On 3/8/2024 7:52 AM, Thomas Wolff via Cygwin wrote:
Am 08.03.2024 um 11:37 schrieb Corinna Vinschen via Cygwin:
FILE_OPEN_NO_RECALL (0x00400000)
[...]
This sounds like we could simply add this flag to all NtOpenFile
used for path conversion or stat-like calls, without having to care
for any file attributes specificially.
Does that make sense?
Sounds good, without even studying the other details...
I speculate some more handling would still be needed to avoid executable
detection via magic tags.
Agreed. FILE_OPEN_NO_RECALL has been defined for at least a decade but was
not documented by Microsoft relatively recently.
Thanks for the feedback, guys.
Another suggestion would be to try opening the file with
FILE_READ_ATTRIBUTES instead of GENERIC_READ if the file data is not
required. See
https://github.com/microsoft/BuildXL/commit/4fb8e7ce07d243ccd95de0d66da551538a794493
Cygwin uses the minimum of required permissions in NtCreateFile/
NtOpenFile calls anyway.
I'm just running a test cygwin DLL locally with a lot of added
FILE_OPEN_NO_RECALL bits and a couple of added attribute checks for
being offline to allow skipping some code.
I think I'll push this change in a bit so we get a test release out
so people using OneDrive can test.
I pushed this change as well as a followup change to make sure we don't
inadvertently recall an offline file. I also added handling for the
Pinned and Unpinned attributes to chattr(1) and lsattr(1).
The full set of changes can be tested by installing the Cygwin test
release 3.6.0-0.77.g06aa5a751682.
Please give it a try. If you encounter a situation which still results
in recalling an offline file in a situation which doesn't qualify for
it, please report. We will have to analyze that situation further
then.
Thanks,
Corinna
Thanks for doing this work so quickly. I'm not subscribed to this
mailing list so I didn't see previous messages.
I will try to check this in Cygwin this weekend but should tell you that
I'm not cygwin user and now found a report of another user claiming this
only happens in MSys and not in Cygwin.
https://github.com/msys2/MSYS2-packages/issues/3049
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