On Thu, Aug 31, 2023 at 01:24:29PM +0200, Bernd Schubert wrote: > While adding shared direct IO write locks to fuse Miklos noticed > that file_remove_privs() needs an exclusive lock. I then > noticed that btrfs actually has the same issue as I had in my patch, > it was calling into that function with a shared lock. > This series adds a new exported function file_needs_remove_privs(), > which used by the follow up btrfs patch and will be used by the > DIO code path in fuse as well. If that function returns any mask > the shared lock needs to be dropped and replaced by the exclusive > variant. > > Note: Compilation tested only. The fix makes sense, there should be no noticeable performance impact, basically the same check is done in the newly exported helper for the IS_NOSEC bit. I can give it a test locally for the default case, I'm not sure if we have specific tests for the security layers in fstests. Regarding merge, I can take the two patches via btrfs tree or can wait until the export is present in Linus' tree in case FUSE needs it independently.
