diff --git a/src/Worker/Worker.py b/src/Worker/Worker.py
index 5b97099a..4cdb83cb 100644
--- a/src/Worker/Worker.py
+++ b/src/Worker/Worker.py
@@ -1,9 +1,23 @@
 import time
 
 import gevent
+import gevent.lock
 
 from Debug import Debug
 from Config import config
+from Content.ContentManager import VerifyError
+
+
+class WorkerDownloadError(Exception):
+    pass
+
+
+class WorkerIOError(Exception):
+    pass
+
+
+class WorkerStop(Exception):
+    pass
 
 
 class Worker(object):
@@ -24,134 +38,181 @@ class Worker(object):
     def __repr__(self):
         return "<%s>" % self.__str__()
 
-    # Downloader thread
+    def waitForTask(self, task, timeout):  # Wait for other workers to finish the task
+        for sleep_i in range(1, timeout * 10):
+            time.sleep(0.1)
+            if task["done"] or task["workers_num"] == 0:
+                if config.verbose:
+                    self.manager.log.debug("%s: %s, picked task free after %ss sleep. (done: %s)" % (
+                        self.key, task["inner_path"], 0.1 * sleep_i, task["done"]
+                    ))
+                break
+
+            if sleep_i % 10 == 0:
+                workers = self.manager.findWorkers(task)
+                if not workers or not workers[0].peer.connection:
+                    break
+                worker_idle = time.time() - workers[0].peer.connection.last_recv_time
+                if worker_idle > 1:
+                    if config.verbose:
+                        self.manager.log.debug("%s: %s, worker %s seems idle, picked up task after %ss sleep. (done: %s)" % (
+                            self.key, task["inner_path"], workers[0].key, 0.1 * sleep_i, task["done"]
+                        ))
+                    break
+        return True
+
+    def pickTask(self):  # Find and select a new task for the worker
+        task = self.manager.getTask(self.peer)
+        if not task:  # No more task
+            time.sleep(0.1)  # Wait a bit for new tasks
+            task = self.manager.getTask(self.peer)
+            if not task:  # Still no task, stop it
+                stats = "downloaded files: %s, failed: %s" % (self.num_downloaded, self.num_failed)
+                self.manager.log.debug("%s: No task found, stopping (%s)" % (self.key, stats))
+                return False
+
+        if not task["time_started"]:
+            task["time_started"] = time.time()  # Task started now
+
+        if task["workers_num"] > 0:  # Wait a bit if someone already working on it
+            if task["peers"]:  # It's an update
+                timeout = 3
+            else:
+                timeout = 1
+
+            if task["size"] > 100 * 1024 * 1024:
+                timeout = timeout * 2
+
+            if config.verbose:
+                self.manager.log.debug("%s: Someone already working on %s (pri: %s), sleeping %s sec..." % (
+                    self.key, task["inner_path"], task["priority"], timeout
+                ))
+
+            self.waitForTask(task, timeout)
+        return task
+
+    def downloadTask(self, task):
+        try:
+            buff = self.peer.getFile(task["site"].address, task["inner_path"], task["size"])
+        except Exception as err:
+            self.manager.log.debug("%s: getFile error: %s" % (self.key, err))
+            raise WorkerDownloadError(str(err))
+
+        if not buff:
+            raise WorkerDownloadError("No response")
+
+        return buff
+
+    def getTaskLock(self, task):
+        if task["lock"] is None:
+            task["lock"] = gevent.lock.Semaphore()
+        return task["lock"]
+
+    def writeTask(self, task, buff):
+        buff.seek(0)
+        try:
+            task["site"].storage.write(task["inner_path"], buff)
+        except Exception as err:
+            if type(err) == Debug.Notify:
+                self.manager.log.debug("%s: Write aborted: %s (%s)" % (self.key, task["inner_path"], err))
+            else:
+                self.manager.log.error("%s: Error writing: %s (%s)" % (self.key, task["inner_path"], err))
+            raise WorkerIOError(str(err))
+
+    def onTaskVerifyFail(self, task, error_message):
+        self.num_failed += 1
+        if self.manager.started_task_num < 50 or config.verbose:
+            self.manager.log.debug(
+                "%s: Verify failed: %s, error: %s, failed peers: %s, workers: %s" %
+                (self.key, task["inner_path"], error_message, len(task["failed"]), task["workers_num"])
+            )
+        task["failed"].append(self.peer)
+        self.peer.hash_failed += 1
+        if self.peer.hash_failed >= max(len(self.manager.tasks), 3) or self.peer.connection_error > 10:
+            # Broken peer: More fails than tasks number but atleast 3
+            raise WorkerStop(
+                "Too many errors (hash failed: %s, connection error: %s)" %
+                (self.peer.hash_failed, self.peer.connection_error)
+            )
+
+    def handleTask(self, task):
+        download_err = write_err = False
+
+        write_lock = None
+        try:
+            buff = self.downloadTask(task)
+
+            if task["done"] is True:  # Task done, try to find new one
+                return None
+
+            if self.running is False:  # Worker no longer needed or got killed
+                self.manager.log.debug("%s: No longer needed, returning: %s" % (self.key, task["inner_path"]))
+                raise WorkerStop("Running got disabled")
+
+            write_lock = self.getTaskLock(task)
+            write_lock.acquire()
+            if task["site"].content_manager.verifyFile(task["inner_path"], buff) is None:
+                is_same = True
+            else:
+                is_same = False
+            is_valid = True
+        except (WorkerDownloadError, VerifyError) as err:
+            download_err = err
+            is_valid = False
+            is_same = False
+
+        if is_valid and not is_same:
+            if self.manager.started_task_num < 50 or config.verbose:
+                self.manager.log.debug("%s: Verify correct: %s" % (self.key, task["inner_path"]))
+            try:
+                self.writeTask(task, buff)
+            except WorkerIOError as err:
+                write_err = err
+
+        if not task["done"]:
+            if write_err:
+                self.manager.failTask(task)
+                self.num_failed += 1
+                self.manager.log.error("%s: Error writing %s: %s" % (self.key, task["inner_path"], write_err))
+            elif is_valid:
+                self.manager.doneTask(task)
+                self.num_downloaded += 1
+
+        if write_lock is not None and write_lock.locked():
+            write_lock.release()
+
+        if not is_valid:
+            self.onTaskVerifyFail(task, download_err)
+            time.sleep(1)
+            return False
+
+        return True
+
     def downloader(self):
         self.peer.hash_failed = 0  # Reset hash error counter
         while self.running:
             # Try to pickup free file download task
-            task = self.manager.getTask(self.peer)
-            if not task:  # No more task
-                time.sleep(0.1)  # Wait a bit for new tasks
-                task = self.manager.getTask(self.peer)
-                if not task:  # Still no task, stop it
-                    stats = "downloaded files: %s, failed: %s" % (self.num_downloaded, self.num_failed)
-                    self.manager.log.debug("%s: No task found, stopping (%s)" % (self.key, stats))
-                    break
-            if not task["time_started"]:
-                task["time_started"] = time.time()  # Task started now
+            task = self.pickTask()
 
-            if task["workers_num"] > 0:  # Wait a bit if someone already working on it
-                if task["peers"]:  # It's an update
-                    timeout = 3
-                else:
-                    timeout = 1
-
-                if task["size"] > 100 * 1024 * 1024:
-                    timeout = timeout * 2
-
-                if config.verbose:
-                    self.manager.log.debug("%s: Someone already working on %s (pri: %s), sleeping %s sec..." % (
-                        self.key, task["inner_path"], task["priority"], timeout
-                    ))
-
-                for sleep_i in range(1, timeout * 10):
-                    time.sleep(0.1)
-                    if task["done"] or task["workers_num"] == 0:
-                        if config.verbose:
-                            self.manager.log.debug("%s: %s, picked task free after %ss sleep. (done: %s)" % (
-                                self.key, task["inner_path"], 0.1 * sleep_i, task["done"]
-                            ))
-                        break
-
-                    if sleep_i % 10 == 0:
-                        workers = self.manager.findWorkers(task)
-                        if not workers or not workers[0].peer.connection:
-                            break
-                        worker_idle = time.time() - workers[0].peer.connection.last_recv_time
-                        if worker_idle > 1:
-                            if config.verbose:
-                                self.manager.log.debug("%s: %s, worker %s seems idle, picked up task after %ss sleep. (done: %s)" % (
-                                    self.key, task["inner_path"], workers[0].key, 0.1 * sleep_i, task["done"]
-                                ))
-                            break
+            if not task:
+                break
 
             if task["done"]:
                 continue
 
             self.task = task
-            site = task["site"]
+
             self.manager.addTaskWorker(task, self)
 
-            error_message = "Unknown error"
             try:
-                buff = self.peer.getFile(site.address, task["inner_path"], task["size"])
-            except Exception as err:
-                self.manager.log.debug("%s: getFile error: %s" % (self.key, err))
-                error_message = str(err)
-                buff = None
-            if self.running is False:  # Worker no longer needed or got killed
-                self.manager.log.debug("%s: No longer needed, returning: %s" % (self.key, task["inner_path"]))
+                success = self.handleTask(task)
+            except WorkerStop as err:
+                self.manager.log.debug("%s: Worker stopped: %s" % (self.key, err))
+                self.manager.removeTaskWorker(task, self)
                 break
-            if task["done"] is True:  # Task done, try to find new one
-                continue
-            if buff:  # Download ok
-                try:
-                    correct = site.content_manager.verifyFile(task["inner_path"], buff)
-                except Exception as err:
-                    error_message = str(err)
-                    correct = False
-            else:  # Download error
-                error_message = "Download failed"
-                correct = False
-            if correct is True or correct is None:  # Verify ok or same file
-                if self.manager.started_task_num < 50 or config.verbose:
-                    self.manager.log.debug("%s: Verify correct: %s" % (self.key, task["inner_path"]))
-                write_error = None
-                task_finished = False
-                if correct is True and task["locked"] is False:  # Save if changed and task not done yet
-                    task["locked"] = True
-                    buff.seek(0)
-                    try:
-                        site.storage.write(task["inner_path"], buff)
-                        write_error = False
-                    except Exception as err:
-                        if type(err) == Debug.Notify:
-                            self.manager.log.debug("%s: Write aborted: %s (%s)" % (self.key, task["inner_path"], err))
-                        else:
-                            self.manager.log.error("%s: Error writing: %s (%s)" % (self.key, task["inner_path"], err))
-                        write_error = err
-                    task_finished = True
 
-                if correct is None and task["locked"] is False:  # Mark as done if same file
-                    task["locked"] = True
-                    task_finished = True
+            self.manager.removeTaskWorker(task, self)
 
-                if task_finished and not task["done"]:
-                    if write_error:
-                        self.manager.failTask(task)
-                        self.num_failed += 1
-                    else:
-                        self.manager.doneTask(task)
-                        self.num_downloaded += 1
-
-                self.manager.removeTaskWorker(task, self)
-            else:  # Verify failed
-                self.num_failed += 1
-                self.manager.removeTaskWorker(task, self)
-                if self.manager.started_task_num < 50 or config.verbose:
-                    self.manager.log.debug(
-                        "%s: Verify failed: %s, error: %s, failed peers: %s, workers: %s" %
-                        (self.key, task["inner_path"], error_message, len(task["failed"]), task["workers_num"])
-                    )
-                task["failed"].append(self.peer)
-                self.peer.hash_failed += 1
-                if self.peer.hash_failed >= max(len(self.manager.tasks), 3) or self.peer.connection_error > 10:
-                    # Broken peer: More fails than tasks number but atleast 3
-                    break
-                if task["inner_path"] not in site.bad_files:
-                    # Don't need this file anymore
-                    break
-                time.sleep(1)
         self.peer.onWorkerDone()
         self.running = False
         self.manager.removeWorker(self)
@@ -175,4 +236,4 @@ class Worker(object):
         if self.thread:
             self.thread.kill(exception=Debug.Notify("Worker stopped"))
         del self.thread
-        self.manager.removeWorker(self)
\ No newline at end of file
+        self.manager.removeWorker(self)
diff --git a/src/Worker/WorkerManager.py b/src/Worker/WorkerManager.py
index bce3a3dd..252d34ca 100644
--- a/src/Worker/WorkerManager.py
+++ b/src/Worker/WorkerManager.py
@@ -21,7 +21,7 @@ class WorkerManager(object):
         self.tasks = WorkerTaskManager()
         self.next_task_id = 1
         # {"id": 1, "evt": evt, "workers_num": 0, "site": self.site, "inner_path": inner_path, "done": False, "optional_hash_id": None,
-        # "time_started": None, "time_added": time.time(), "peers": peers, "priority": 0, "failed": peer_ids, "locked": False}
+        # "time_started": None, "time_added": time.time(), "peers": peers, "priority": 0, "failed": peer_ids, "lock": None or gevent.lock.RLock}
         self.started_task_num = 0  # Last added task num
         self.asked_peers = []
         self.running = True
@@ -500,7 +500,7 @@ class WorkerManager(object):
 
             task = {
                 "id": self.next_task_id, "evt": evt, "workers_num": 0, "site": self.site, "inner_path": inner_path, "done": False,
-                "optional_hash_id": optional_hash_id, "time_added": time.time(), "time_started": None, "locked": False,
+                "optional_hash_id": optional_hash_id, "time_added": time.time(), "time_started": None, "lock": None,
                 "time_action": None, "peers": peers, "priority": priority, "failed": [], "size": size
             }
 
@@ -575,4 +575,4 @@ class WorkerManager(object):
             self.site.onFileFail(task["inner_path"])
             task["evt"].set(False)
             if not self.tasks:
-                self.started_task_num = 0
\ No newline at end of file
+                self.started_task_num = 0