Lets the kernel id-map a mount2 mount into a user namespace
(e.g. Kubernetes pods with hostUsers: false). Off by default;
requires Linux 6.12+ and implies default_permissions.
On Windows, passing "*" as mountPoint to the mount/mount RC command
auto-assigns a drive letter (e.g. "Z:"), but the resolved letter was
never propagated back to mountlib. This caused liveMounts to be keyed
on the literal "*", breaking tracking of multiple mounts and making
unmount unreliable.
Change MountFn to return the actual mount point as an additional
return value. Update MountPoint.Mount() to store the resolved value,
and mountRc() to use it as the liveMounts key. The mount/mount RC
response now returns the actual mountPoint so callers can discover
which drive letter was assigned.
This changes log statements from log to fs package, which is required for --use-json-log
to properly make log output in JSON format. The recently added custom linting rule,
handled by ruleguard via gocritic via golangci-lint, warns about these and suggests
the alternative. Fixing was therefore basically running "golangci-lint run --fix",
although some manual fixup of mainly imports are necessary following that.
Since version 3 of fuse libfuse no longer does anything when given the
nonempty option and it's default is to allow mounting over non empty
directories like normal mount does.
Some versions of libfuse give an error when using `--allow-non-empty`
which is annoying for the user.
We now do this check ourselves so we no longer need to pass the option
to libfuse.
Fixes#3562
Before this change, the device name was always the remote:path rclone
was configured with. However this can contain sensitive information
and it appears in the `mount` output, so `--devname` allows the user
to configure it.
See: https://forum.rclone.org/t/rclone-mount-blomp-problem/29151/11
