Updating fingerprint file is not atomci about unabto

[mkm85]

What version is this behavior observed on?

On current master we do an fclose before the rename, we believe that should be enough to make the file written to the disk.
https://github.com/nabto/unabto/blob/master/src/modules/fingerprint_acl/fp_acl_file.c line 139 - 162

[dpkds]

From fclose man:
Note that fclose() flushes only the user-space buffers provided by the C library. To ensure that the data is physically stored on disk the kernel buffers must be flushed too, for example, with sync(2) or fsync(2).

In my case I'm running on a ubifs where it could take very long for the data to reach the physical storage. However it could happen on any file system not mounted specifically with sync.

It's observed with version:
unabto_tunnel -V
Version: 3.0.15
... but the save functionality has not changed since.

[mkm85]

we will add fsync

[mkm85]

fsync added to master