fix local dropping to not require extra locking of copies, but only that the local copy be locked for removal

Command/Drop.hs

@@ -91,15 +91,11 @@ startRemote afile numcopies key remote = do
 	showStart' ("drop " ++ Remote.name remote) key afile
 	next $ performRemote key afile numcopies remote
 
--- Note that lockContentExclusive is called before checking if the key is
--- present on enough remotes to allow removal. This avoids a scenario where two
--- or more remotes are trying to remove a key at the same time, and each
--- sees the key is present on the other.
 performLocal :: Key -> AssociatedFile -> NumCopies -> [VerifiedCopy] -> CommandPerform
-performLocal key afile numcopies preverified = lockContentExclusive key $ \contentlock -> do
+performLocal key afile numcopies preverified = lockContentForRemoval key $ \contentlock -> do
 	u <- getUUID
 	(tocheck, verified) <- verifiableCopies key [u]
-	doDrop u key afile numcopies [] (preverified ++ verified) tocheck
+	doDrop u (Just contentlock) key afile numcopies [] (preverified ++ verified) tocheck
 		( \proof -> do
 			liftIO $ debugM "drop" $ unwords
 				[ "Dropping from here"
@@ -121,7 +117,7 @@ performRemote key afile numcopies remote = do
 	-- When the local repo has the key, that's one additional copy,
 	-- as long as the local repo is not untrusted.
 	(tocheck, verified) <- verifiableCopies key [uuid]
-	doDrop uuid key afile numcopies [uuid] verified tocheck
+	doDrop uuid Nothing key afile numcopies [uuid] verified tocheck
 		( \proof -> do 
 			liftIO $ debugM "drop" $ unwords
 				[ "Dropping from remote"
@@ -159,6 +155,7 @@ cleanupRemote key remote ok = do
  -}
 doDrop
 	:: UUID
+	-> Maybe ContentRemovalLock
 	-> Key
 	-> AssociatedFile
 	-> NumCopies
@@ -167,11 +164,12 @@ doDrop
 	-> [UnVerifiedCopy]
 	-> (Maybe SafeDropProof -> CommandPerform, CommandPerform)
 	-> CommandPerform
-doDrop dropfrom key afile numcopies skip preverified check (dropaction, nodropaction) = 
+doDrop dropfrom contentlock key afile numcopies skip preverified check (dropaction, nodropaction) = 
 	ifM (Annex.getState Annex.force)
 		( dropaction Nothing
 		, ifM (checkRequiredContent dropfrom key afile)
-			( verifyEnoughCopiesToDrop nolocmsg key numcopies
+			( verifyEnoughCopiesToDrop nolocmsg key 
+				contentlock numcopies
 				skip preverified check
 					(dropaction . Just)
 					(forcehint nodropaction)

Command/DropKey.hs

@@ -31,7 +31,7 @@ start key = stopUnless (inAnnex key) $ do
 	next $ perform key
 
 perform :: Key -> CommandPerform
-perform key = lockContentExclusive key $ \contentlock -> do
+perform key = lockContentForRemoval key $ \contentlock -> do
 	removeAnnex contentlock
 	next $ cleanup key
 

Command/Import.hs

@@ -139,5 +139,5 @@ verifyExisting key destfile (yes, no) = do
 	need <- getFileNumCopies destfile
 
 	(tocheck, preverified) <- verifiableCopies key []
-	verifyEnoughCopiesToDrop [] key need [] preverified tocheck
+	verifyEnoughCopiesToDrop [] key Nothing need [] preverified tocheck
 		(const yes) no

Command/Move.hs

@@ -123,7 +123,7 @@ toPerform dest move key afile fastcheck isthere =
 			finish
   where
 	finish
-		| move = lockContentExclusive key $ \contentlock -> do
+		| move = lockContentForRemoval key $ \contentlock -> do
 			removeAnnex contentlock
 			next $ Command.Drop.cleanupLocal key
 		| otherwise = next $ return True

Command/TestRemote.hs

@@ -120,7 +120,7 @@ test st r k =
 	, check "storeKey when already present" store
 	, present True
 	, check "retrieveKeyFile" $ do
-		lockContentExclusive k removeAnnex
+		lockContentForRemoval k removeAnnex
 		get
 	, check "fsck downloaded object" fsck
 	, check "retrieveKeyFile resume from 33%" $ do
@@ -130,20 +130,20 @@ test st r k =
 			sz <- hFileSize h
 			L.hGet h $ fromInteger $ sz `div` 3
 		liftIO $ L.writeFile tmp partial
-		lockContentExclusive k removeAnnex
+		lockContentForRemoval k removeAnnex
 		get
 	, check "fsck downloaded object" fsck
 	, check "retrieveKeyFile resume from 0" $ do
 		tmp <- prepTmp k
 		liftIO $ writeFile tmp ""
-		lockContentExclusive k removeAnnex
+		lockContentForRemoval k removeAnnex
 		get
 	, check "fsck downloaded object" fsck
 	, check "retrieveKeyFile resume from end" $ do
 		loc <- Annex.calcRepo (gitAnnexLocation k)
 		tmp <- prepTmp k
 		void $ liftIO $ copyFileExternal CopyAllMetaData loc tmp
-		lockContentExclusive k removeAnnex
+		lockContentForRemoval k removeAnnex
 		get
 	, check "fsck downloaded object" fsck
 	, check "removeKey when present" remove
@@ -189,7 +189,7 @@ testUnavailable st r k =
 cleanup :: [Remote] -> [Key] -> Bool -> CommandCleanup
 cleanup rs ks ok = do
 	forM_ rs $ \r -> forM_ ks (Remote.removeKey r)
-	forM_ ks $ \k -> lockContentExclusive k removeAnnex
+	forM_ ks $ \k -> lockContentForRemoval k removeAnnex
 	return ok
 
 chunkSizes :: Int -> Bool -> [Int]

Command/Uninit.hs

@@ -105,7 +105,7 @@ removeUnannexed = go []
 	go c [] = return c
 	go c (k:ks) = ifM (inAnnexCheck k $ liftIO . enoughlinks)
 		( do
-			lockContentExclusive k removeAnnex
+			lockContentForRemoval k removeAnnex
 			go c ks
 		, go (k:c) ks
 		)