Eliminate reserveSpace flag

src/libstore/gc.cc

@@ -608,6 +608,9 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
 
     state.shouldDelete = options.action == GCOptions::gcDeleteDead || options.action == GCOptions::gcDeleteSpecific;
 
+    if (state.shouldDelete && pathExists(reservedPath))
+        deletePath(reservedPath);
+
     /* Acquire the global GC root.  This prevents
        a) New roots from being added.
        b) Processes from creating new temporary root files. */

src/libstore/local-store.cc

@@ -216,8 +216,9 @@ void checkStoreNotSymlink()
 }
 
 
-LocalStore::LocalStore(bool reserveSpace)
-    : didSetSubstituterEnv(false)
+LocalStore::LocalStore()
+    : reservedPath(settings.nixDBPath + "/reserved")
+    , didSetSubstituterEnv(false)
 {
     schemaPath = settings.nixDBPath + "/schema";
 
@@ -276,25 +277,20 @@ LocalStore::LocalStore(bool reserveSpace)
        needed, we reserve some dummy space that we can free just
        before doing a garbage collection. */
     try {
-        Path reservedPath = settings.nixDBPath + "/reserved";
-        if (reserveSpace) {
-            struct stat st;
-            if (stat(reservedPath.c_str(), &st) == -1 ||
-                st.st_size != settings.reservedSize)
-            {
-                AutoCloseFD fd = open(reservedPath.c_str(), O_WRONLY | O_CREAT, 0600);
-                int res = -1;
+        struct stat st;
+        if (stat(reservedPath.c_str(), &st) == -1 ||
+            st.st_size != settings.reservedSize)
+        {
+            AutoCloseFD fd = open(reservedPath.c_str(), O_WRONLY | O_CREAT, 0600);
+            int res = -1;
 #if HAVE_POSIX_FALLOCATE
-                res = posix_fallocate(fd, 0, settings.reservedSize);
+            res = posix_fallocate(fd, 0, settings.reservedSize);
 #endif
-                if (res == -1) {
-                    writeFull(fd, string(settings.reservedSize, 'X'));
-                    ftruncate(fd, settings.reservedSize);
-                }
+            if (res == -1) {
+                writeFull(fd, string(settings.reservedSize, 'X'));
+                ftruncate(fd, settings.reservedSize);
             }
         }
-        else
-            deletePath(reservedPath);
     } catch (SysError & e) { /* don't care about errors */
     }
 

src/libstore/local-store.hh

@@ -88,11 +88,13 @@ private:
 
     Path linksDir;
 
+    Path reservedPath;
+
 public:
 
     /* Initialise the local store, upgrading the schema if
        necessary. */
-    LocalStore(bool reserveSpace = true);
+    LocalStore();
 
     ~LocalStore();
 

src/libstore/remote-store.cc

@@ -49,7 +49,7 @@ RemoteStore::RemoteStore(size_t maxConnections)
 }
 
 
-ref<RemoteStore::Connection> RemoteStore::openConnection(bool reserveSpace)
+ref<RemoteStore::Connection> RemoteStore::openConnection()
 {
     auto conn = make_ref<Connection>();
 
@@ -106,7 +106,7 @@ ref<RemoteStore::Connection> RemoteStore::openConnection(bool reserveSpace)
         }
 
         if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 11)
-            conn->to << reserveSpace;
+            conn->to << false;
 
         conn->processStderr();
     }

src/libstore/remote-store.hh

@@ -106,7 +106,7 @@ private:
 
     ref<Pool<Connection>> connections;
 
-    ref<Connection> openConnection(bool reserveSpace = true);
+    ref<Connection> openConnection();
 
     void setOptions(ref<Connection> conn);
 };

src/libstore/store-api.cc

@@ -320,7 +320,7 @@ void Store::exportPaths(const Paths & paths,
 namespace nix {
 
 
-ref<Store> openStoreAt(const std::string & uri, bool reserveSpace)
+ref<Store> openStoreAt(const std::string & uri)
 {
     if (std::string(uri, 0, 7) == "file://") {
         auto store = make_ref<LocalBinaryCacheStore>(std::shared_ptr<Store>(0),
@@ -345,13 +345,13 @@ ref<Store> openStoreAt(const std::string & uri, bool reserveSpace)
 
     return mode == mDaemon
         ? (ref<Store>) make_ref<RemoteStore>()
-        : (ref<Store>) make_ref<LocalStore>(reserveSpace);
+        : (ref<Store>) make_ref<LocalStore>();
 }
 
 
-ref<Store> openStore(bool reserveSpace)
+ref<Store> openStore()
 {
-    return openStoreAt(getEnv("NIX_REMOTE"), reserveSpace);
+    return openStoreAt(getEnv("NIX_REMOTE"));
 }
 
 

src/libstore/store-api.hh

@@ -432,16 +432,12 @@ void removeTempRoots();
 
    If ‘uri’ is empty, it defaults to ‘direct’ or ‘daemon’ depending on
    whether the user has write access to the local Nix store/database.
-
-   The Boolean ‘reserveSpace’ denotes whether some disk space should
-   be reserved to enable future garbage collector runs. It should be
-   set to true *unless* you're going to collect garbage.
-*/
-ref<Store> openStoreAt(const std::string & uri, bool reserveSpace = true);
+   set to true *unless* you're going to collect garbage. */
+ref<Store> openStoreAt(const std::string & uri);
 
 
 /* Open the store indicated by the ‘NIX_REMOTE’ environment variable. */
-ref<Store> openStore(bool reserveSpace = true);
+ref<Store> openStore();
 
 
 /* Display a set of paths in human-readable form (i.e., between quotes

src/nix-collect-garbage/nix-collect-garbage.cc

@@ -82,7 +82,7 @@ int main(int argc, char * * argv)
 
         // Run the actual garbage collector.
         if (!dryRun) {
-            auto store = openStore(false);
+            auto store = openStore();
             options.action = GCOptions::gcDeleteDead;
             GCResults results;
             PrintFreed freed(true, results);

src/nix-daemon/nix-daemon.cc

@@ -562,9 +562,8 @@ static void processConnection(bool trusted)
     if (GET_PROTOCOL_MINOR(clientVersion) >= 14 && readInt(from))
         setAffinityTo(readInt(from));
 
-    bool reserveSpace = true;
     if (GET_PROTOCOL_MINOR(clientVersion) >= 11)
-        reserveSpace = readInt(from) != 0;
+        readInt(from); // obsolete reserveSpace
 
     /* Send startup error messages to the client. */
     startWork();
@@ -582,7 +581,7 @@ static void processConnection(bool trusted)
 #endif
 
         /* Open the store. */
-        auto store = make_ref<LocalStore>(reserveSpace);
+        auto store = make_ref<LocalStore>();
 
         stopWork();
         to.flush();

src/nix-store/nix-store.cc

@@ -1131,7 +1131,7 @@ int main(int argc, char * * argv)
         if (!op) throw UsageError("no operation specified");
 
         if (op != opDump && op != opRestore) /* !!! hack */
-            store = openStore(op != opGC);
+            store = openStore();
 
         op(opFlags, opArgs);
     });