diff --git a/app/src/main/java/io/legado/app/help/coroutine/OrderCoroutine.kt b/app/src/main/java/io/legado/app/help/coroutine/OrderCoroutine.kt
index 3b0989588..315da7c34 100644
--- a/app/src/main/java/io/legado/app/help/coroutine/OrderCoroutine.kt
+++ b/app/src/main/java/io/legado/app/help/coroutine/OrderCoroutine.kt
@@ -2,30 +2,24 @@ package io.legado.app.help.coroutine
 
 import kotlinx.coroutines.*
 import kotlinx.coroutines.Dispatchers.IO
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
 import java.util.concurrent.ConcurrentHashMap
-import java.util.concurrent.ConcurrentLinkedQueue
 import java.util.concurrent.PriorityBlockingQueue
+import java.util.concurrent.atomic.AtomicInteger
 
 class OrderCoroutine<T>(val threadCount: Int) {
-    private val taskList = ConcurrentLinkedQueue<suspend CoroutineScope.() -> T>()
+    private val taskList = ArrayList<suspend CoroutineScope.() -> T>()
     private val taskResultMap = ConcurrentHashMap<Int, T>()
     private val finishTaskIndex = PriorityBlockingQueue<Int>()
-    private val mutex = Mutex()
 
     private suspend fun start() = coroutineScope {
-        var taskIndex = 0
+        val taskIndex = AtomicInteger(0)
+        val tasks = taskList.toList()
         for (i in 1..threadCount) {
             launch {
                 while (true) {
                     ensureActive()
-                    val task: suspend CoroutineScope.() -> T
-                    val curIndex: Int
-                    mutex.withLock {
-                        task = taskList.poll() ?: return@launch
-                        curIndex = taskIndex++
-                    }
+                    val curIndex = taskIndex.getAndIncrement()
+                    val task = tasks.getOrNull(curIndex) ?: return@launch
                     taskResultMap[curIndex] = task.invoke(this)
                     finishTaskIndex.add(curIndex)
                 }
diff --git a/app/src/main/java/io/legado/app/ui/book/group/GroupEditDialog.kt b/app/src/main/java/io/legado/app/ui/book/group/GroupEditDialog.kt
index 068116e60..c50b73bfc 100644
--- a/app/src/main/java/io/legado/app/ui/book/group/GroupEditDialog.kt
+++ b/app/src/main/java/io/legado/app/ui/book/group/GroupEditDialog.kt
@@ -29,7 +29,11 @@ class GroupEditDialog() : BaseDialogFragment(R.layout.dialog_book_group_edit) {
     val selectImage = registerForActivityResult(SelectImageContract()) {
         readUri(it?.uri) { fileDoc, inputStream ->
             var file = requireContext().externalFiles
-            file = FileUtils.createFileIfNotExist(file, "covers", fileDoc.name)
+            val suffix = fileDoc.name.substringAfterLast(".")
+            val fileName = it.uri!!.inputStream(requireContext())!!.use {
+                MD5Utils.md5Encode(it) + ".$suffix"
+            }
+            file = FileUtils.createFileIfNotExist(file, "covers", fileName)
             FileOutputStream(file).use { outputStream ->
                 inputStream.copyTo(outputStream)
             }
diff --git a/app/src/main/java/io/legado/app/ui/book/info/edit/BookInfoEditActivity.kt b/app/src/main/java/io/legado/app/ui/book/info/edit/BookInfoEditActivity.kt
index ad31c4bcc..c48954998 100644
--- a/app/src/main/java/io/legado/app/ui/book/info/edit/BookInfoEditActivity.kt
+++ b/app/src/main/java/io/legado/app/ui/book/info/edit/BookInfoEditActivity.kt
@@ -118,7 +118,11 @@ class BookInfoEditActivity :
         readUri(uri) { fileDoc, inputStream ->
             inputStream.use {
                 var file = this.externalFiles
-                file = FileUtils.createFileIfNotExist(file, "covers", fileDoc.name)
+                val suffix = fileDoc.name.substringAfterLast(".")
+                val fileName = uri.inputStream(this)!!.use {
+                    MD5Utils.md5Encode(it) + ".$suffix"
+                }
+                file = FileUtils.createFileIfNotExist(file, "covers", fileName)
                 FileOutputStream(file).use { outputStream ->
                     inputStream.copyTo(outputStream)
                 }
diff --git a/app/src/main/java/io/legado/app/ui/config/CoverConfigFragment.kt b/app/src/main/java/io/legado/app/ui/config/CoverConfigFragment.kt
index 6931ed155..1866b5edb 100644
--- a/app/src/main/java/io/legado/app/ui/config/CoverConfigFragment.kt
+++ b/app/src/main/java/io/legado/app/ui/config/CoverConfigFragment.kt
@@ -140,7 +140,11 @@ class CoverConfigFragment : PreferenceFragment(),
     private fun setCoverFromUri(preferenceKey: String, uri: Uri) {
         readUri(uri) { fileDoc, inputStream ->
             var file = requireContext().externalFiles
-            file = FileUtils.createFileIfNotExist(file, "covers", fileDoc.name)
+            val suffix = fileDoc.name.substringAfterLast(".")
+            val fileName = uri.inputStream(requireContext())!!.use {
+                MD5Utils.md5Encode(it) + ".$suffix"
+            }
+            file = FileUtils.createFileIfNotExist(file, "covers", fileName)
             FileOutputStream(file).use {
                 inputStream.copyTo(it)
             }
diff --git a/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt b/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt
index 5863fa600..a38f71d5c 100644
--- a/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt
+++ b/app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt
@@ -304,7 +304,11 @@ class ThemeConfigFragment : PreferenceFragment(),
     private fun setBgFromUri(uri: Uri, preferenceKey: String, success: () -> Unit) {
         readUri(uri) { fileDoc, inputStream ->
             var file = requireContext().externalFiles
-            file = FileUtils.createFileIfNotExist(file, preferenceKey, fileDoc.name)
+            val suffix = fileDoc.name.substringAfterLast(".")
+            val fileName = uri.inputStream(requireContext())!!.use {
+                MD5Utils.md5Encode(it) + ".$suffix"
+            }
+            file = FileUtils.createFileIfNotExist(file, preferenceKey, fileName)
             FileOutputStream(file).use {
                 inputStream.copyTo(it)
             }
diff --git a/app/src/main/java/io/legado/app/ui/config/WelcomeConfigFragment.kt b/app/src/main/java/io/legado/app/ui/config/WelcomeConfigFragment.kt
index 33b1b1689..680890c9b 100644
--- a/app/src/main/java/io/legado/app/ui/config/WelcomeConfigFragment.kt
+++ b/app/src/main/java/io/legado/app/ui/config/WelcomeConfigFragment.kt
@@ -120,7 +120,11 @@ class WelcomeConfigFragment : PreferenceFragment(),
     private fun setCoverFromUri(preferenceKey: String, uri: Uri) {
         readUri(uri) { fileDoc, inputStream ->
             var file = requireContext().externalFiles
-            file = FileUtils.createFileIfNotExist(file, "covers", fileDoc.name)
+            val suffix = fileDoc.name.substringAfterLast(".")
+            val fileName = uri.inputStream(requireContext())!!.use {
+                MD5Utils.md5Encode(it) + ".$suffix"
+            }
+            file = FileUtils.createFileIfNotExist(file, "covers", fileName)
             FileOutputStream(file).use {
                 inputStream.copyTo(it)
             }
diff --git a/app/src/main/java/io/legado/app/utils/UriExtensions.kt b/app/src/main/java/io/legado/app/utils/UriExtensions.kt
index db2d62f79..aea7beff2 100644
--- a/app/src/main/java/io/legado/app/utils/UriExtensions.kt
+++ b/app/src/main/java/io/legado/app/utils/UriExtensions.kt
@@ -53,6 +53,9 @@ fun AppCompatActivity.readUri(
     } catch (e: Exception) {
         e.printOnDebug()
         toastOnUi(e.localizedMessage ?: "read uri error")
+        if (e is SecurityException) {
+            throw e
+        }
     }
 }