reorg to allow taking content lock

The lock will only persist during the perform stage, so the content must
be removed from the annex then, rather than in the cleanup stage.

(No lock is actually taken yet.)

Command/Drop.hs

@@ -52,17 +52,19 @@ startRemote file numcopies key remote = do
 	next $ performRemote key numcopies remote
 
 performLocal :: Key -> Maybe Int -> CommandPerform
-performLocal key numcopies = do
+performLocal key numcopies = lockExclusive key $ do
 	(remotes, trusteduuids) <- Remote.keyPossibilitiesTrusted key
 	untrusteduuids <- trustGet UnTrusted
 	let tocheck = Remote.remotesWithoutUUID remotes (trusteduuids++untrusteduuids)
 	success <- canDropKey key numcopies trusteduuids tocheck []
 	if success
-		then next $ cleanupLocal key
+		then do
+			whenM (inAnnex key) $ removeAnnex key
+			next $ cleanupLocal key
 		else stop
 
 performRemote :: Key -> Maybe Int -> Remote.Remote Annex -> CommandPerform
-performRemote key numcopies remote = do
+performRemote key numcopies remote = lockExclusive key $ do
 	-- Filter the remote it's being dropped from out of the lists of
 	-- places assumed to have the key, and places to check.
 	-- When the local repo has the key, that's one additional copy.
@@ -76,20 +78,20 @@ performRemote key numcopies remote = do
 		Remote.remotesWithoutUUID remotes (have++untrusteduuids)
 	success <- canDropKey key numcopies have tocheck [uuid]
 	if success
-		then next $ cleanupRemote key remote
+		then do
+			ok <- Remote.removeKey remote key
+			next $ cleanupRemote key remote ok
 		else stop
 	where
 		uuid = Remote.uuid remote
 
 cleanupLocal :: Key -> CommandCleanup
 cleanupLocal key = do
-	whenM (inAnnex key) $ removeAnnex key
 	logStatus key InfoMissing
 	return True
 
-cleanupRemote :: Key -> Remote.Remote Annex -> CommandCleanup
-cleanupRemote key remote = do
-	ok <- Remote.removeKey remote key
+cleanupRemote :: Key -> Remote.Remote Annex -> Bool -> CommandCleanup
+cleanupRemote key remote ok = do
 	-- better safe than sorry: assume the remote dropped the key
 	-- even if it seemed to fail; the failure could have occurred
 	-- after it really dropped it