This change enhances the SMB backend in Rclone to automatically refresh
Kerberos credentials when the associated ccache file is updated.
Previously, credentials were only loaded once per path and cached
indefinitely, which caused issues when service tickets expired or the
cache was renewed on the server.
* Lower pacer minSleep to establish new connections faster
* Use Echo requests to check whether connections are working (required an upgrade of go-smb2)
* Only remount shares when needed
* Use context for connection establishment
* When returning a connection to the pool, only check the ones that encountered errors
* Close connections in parallel
Before this change the IP address of the server was used in the SMB
connect request (see CloudSoda/go-smb2#18).
The updated library now can pass the hostname instead.
The update requires a small change in the dial method call.
Fixes rclone#6672
Before this change smb drives sometimes showed a fraction of the
correct size using `rclone about`.
This fixes the problem by switching the upstream library from
github.com/hirochachacha/go-smb2 to github.com/cloudsoda/go-smb2 which
has a fix for the problem.
The new library passes the integration tests.
Fixes#6733
Before this change we were putting connections into the connection
pool which had a local context in.
This meant that when the operation had finished the context was
cancelled and the connection became unusable.
See: https://forum.rclone.org/t/failed-to-sync-context-canceled/34017/