Previously the cache was only updated once on startup, because the graph
code only check for filesystems on startup. However this breaks the API as it
was supposed and so unit tests.
Fixes#13142
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
The docker graph call driver.Exists() on initialisation for each filesystem in
the graph. This results will results in a lot `zfs get all` commands. To reduce
this, retrieve all descend filesystem at startup and cache it for later checks
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
instead of let zfs automaticly mount datasets, mount them on demand using mount(2).
This speed up this graph driver in 2 ways:
- less zfs processes needed to start a container
- /proc/mounts get smaller, so zfs userspace tools has less to read (which can
a significant amount of data as the number of layer grows)
This ways it can be also ensured that the correct mountpoint is always used.
Signed-off-by: Jörg Thalheim <joerg@higgsboson.tk>
