fs: Add context to NewFs #3257 #4685

This adds a context.Context parameter to NewFs and related calls.

This is necessary as part of reading config from the context -
backends need to be able to read the global config.

cmd/cmd.go

@@ -7,6 +7,7 @@ package cmd
 // would probably mean bringing all the flags in to here? Or define some flagsets in fs...
 
 import (
+	"context"
 	"fmt"
 	"log"
 	"math/rand"
@@ -88,7 +89,7 @@ func NewFsFile(remote string) (fs.Fs, string) {
 		err = fs.CountError(err)
 		log.Fatalf("Failed to create file system for %q: %v", remote, err)
 	}
-	f, err := cache.Get(remote)
+	f, err := cache.Get(context.Background(), remote)
 	switch err {
 	case fs.ErrorIsFile:
 		cache.Pin(f) // pin indefinitely since it was on the CLI
@@ -138,7 +139,7 @@ func NewFsSrc(args []string) fs.Fs {
 //
 // This must point to a directory
 func newFsDir(remote string) fs.Fs {
-	f, err := cache.Get(remote)
+	f, err := cache.Get(context.Background(), remote)
 	if err != nil {
 		err = fs.CountError(err)
 		log.Fatalf("Failed to create file system for %q: %v", remote, err)
@@ -192,7 +193,7 @@ func NewFsSrcDstFiles(args []string) (fsrc fs.Fs, srcFileName string, fdst fs.Fs
 			log.Fatalf("%q is a directory", args[1])
 		}
 	}
-	fdst, err := cache.Get(dstRemote)
+	fdst, err := cache.Get(context.Background(), dstRemote)
 	switch err {
 	case fs.ErrorIsFile:
 		_ = fs.CountError(err)
@@ -400,7 +401,7 @@ func initConfig() {
 	}
 
 	// Start the remote control server if configured
-	_, err = rcserver.Start(&rcflags.Opt)
+	_, err = rcserver.Start(context.Background(), &rcflags.Opt)
 	if err != nil {
 		log.Fatalf("Failed to start remote control: %v", err)
 	}