diff --git a/clang-tools-extra/clangd/FS.cpp b/clang-tools-extra/clangd/FS.cpp
index bd3c6440c24b0f..5729b9341d9d4b 100644
--- a/clang-tools-extra/clangd/FS.cpp
+++ b/clang-tools-extra/clangd/FS.cpp
@@ -64,8 +64,8 @@ PreambleFileStatusCache::getProducingFS(
         : ProxyFileSystem(std::move(FS)), StatCache(StatCache) {}
 
     llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-    openFileForRead(const llvm::Twine &Path, bool IsText = true) override {
-      auto File = getUnderlyingFS().openFileForRead(Path, IsText);
+    openFileForRead(const llvm::Twine &Path) override {
+      auto File = getUnderlyingFS().openFileForRead(Path);
       if (!File || !*File)
         return File;
       // Eagerly stat opened file, as the followup `status` call on the file
diff --git a/clang-tools-extra/clangd/Preamble.cpp b/clang-tools-extra/clangd/Preamble.cpp
index 44c6acd3ed83aa..84e8fec342829c 100644
--- a/clang-tools-extra/clangd/Preamble.cpp
+++ b/clang-tools-extra/clangd/Preamble.cpp
@@ -479,9 +479,9 @@ class TimerFS : public llvm::vfs::ProxyFileSystem {
       : ProxyFileSystem(std::move(FS)) {}
 
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const llvm::Twine &Path, bool IsText = true) override {
+  openFileForRead(const llvm::Twine &Path) override {
     WallTimerRegion T(Timer);
-    auto FileOr = getUnderlyingFS().openFileForRead(Path, IsText);
+    auto FileOr = getUnderlyingFS().openFileForRead(Path);
     if (!FileOr)
       return FileOr;
     return std::make_unique<TimerFile>(Timer, std::move(FileOr.get()));
diff --git a/clang-tools-extra/clangd/support/ThreadsafeFS.cpp b/clang-tools-extra/clangd/support/ThreadsafeFS.cpp
index bc0b984e577cb8..7398e4258527ba 100644
--- a/clang-tools-extra/clangd/support/ThreadsafeFS.cpp
+++ b/clang-tools-extra/clangd/support/ThreadsafeFS.cpp
@@ -29,7 +29,7 @@ class VolatileFileSystem : public llvm::vfs::ProxyFileSystem {
       : ProxyFileSystem(std::move(FS)) {}
 
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const llvm::Twine &InPath, bool IsText = true) override {
+  openFileForRead(const llvm::Twine &InPath) override {
     llvm::SmallString<128> Path;
     InPath.toVector(Path);
 
diff --git a/clang-tools-extra/clangd/unittests/ClangdTests.cpp b/clang-tools-extra/clangd/unittests/ClangdTests.cpp
index e86385c2072b34..643b8e9f12d751 100644
--- a/clang-tools-extra/clangd/unittests/ClangdTests.cpp
+++ b/clang-tools-extra/clangd/unittests/ClangdTests.cpp
@@ -1010,7 +1010,7 @@ TEST(ClangdTests, PreambleVFSStatCache) {
             : ProxyFileSystem(std::move(FS)), CountStats(CountStats) {}
 
         llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-        openFileForRead(const Twine &Path, bool IsText = true) override {
+        openFileForRead(const Twine &Path) override {
           ++CountStats[llvm::sys::path::filename(Path.str())];
           return ProxyFileSystem::openFileForRead(Path);
         }
diff --git a/clang/include/clang/Basic/FileManager.h b/clang/include/clang/Basic/FileManager.h
index 67a69fb79ccefe..527bbef24793ee 100644
--- a/clang/include/clang/Basic/FileManager.h
+++ b/clang/include/clang/Basic/FileManager.h
@@ -286,21 +286,21 @@ class FileManager : public RefCountedBase<FileManager> {
   /// MemoryBuffer if successful, otherwise returning null.
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(FileEntryRef Entry, bool isVolatile = false,
-                   bool RequiresNullTerminator = true, bool IsText = true,
+                   bool RequiresNullTerminator = true,
                    std::optional<int64_t> MaybeLimit = std::nullopt);
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(StringRef Filename, bool isVolatile = false,
-                   bool RequiresNullTerminator = true, bool IsText = true,
+                   bool RequiresNullTerminator = true,
                    std::optional<int64_t> MaybeLimit = std::nullopt) const {
     return getBufferForFileImpl(Filename,
                                 /*FileSize=*/(MaybeLimit ? *MaybeLimit : -1),
-                                isVolatile, RequiresNullTerminator, IsText);
+                                isVolatile, RequiresNullTerminator);
   }
 
 private:
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFileImpl(StringRef Filename, int64_t FileSize, bool isVolatile,
-                       bool RequiresNullTerminator, bool IsText) const;
+                       bool RequiresNullTerminator) const;
 
   DirectoryEntry *&getRealDirEntry(const llvm::vfs::Status &Status);
 
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
index 635fdd0e00c433..d12814e7c9253e 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
@@ -346,7 +346,7 @@ class DependencyScanningWorkerFilesystem
 
   llvm::ErrorOr<llvm::vfs::Status> status(const Twine &Path) override;
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override;
+  openFileForRead(const Twine &Path) override;
 
   std::error_code getRealPath(const Twine &Path,
                               SmallVectorImpl<char> &Output) override;
diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 27075cefafdc2f..6097b85a03064b 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -530,7 +530,7 @@ void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) {
 
 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
 FileManager::getBufferForFile(FileEntryRef FE, bool isVolatile,
-                              bool RequiresNullTerminator, bool IsText,
+                              bool RequiresNullTerminator,
                               std::optional<int64_t> MaybeLimit) {
   const FileEntry *Entry = &FE.getFileEntry();
   // If the content is living on the file entry, return a reference to it.
@@ -558,21 +558,21 @@ FileManager::getBufferForFile(FileEntryRef FE, bool isVolatile,
 
   // Otherwise, open the file.
   return getBufferForFileImpl(Filename, FileSize, isVolatile,
-                              RequiresNullTerminator, IsText);
+                              RequiresNullTerminator);
 }
 
 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
 FileManager::getBufferForFileImpl(StringRef Filename, int64_t FileSize,
-                                  bool isVolatile, bool RequiresNullTerminator,
-                                  bool IsText) const {
+                                  bool isVolatile,
+                                  bool RequiresNullTerminator) const {
   if (FileSystemOpts.WorkingDir.empty())
     return FS->getBufferForFile(Filename, FileSize, RequiresNullTerminator,
-                                isVolatile, IsText);
+                                isVolatile);
 
   SmallString<128> FilePath(Filename);
   FixupRelativePath(FilePath);
   return FS->getBufferForFile(FilePath, FileSize, RequiresNullTerminator,
-                              isVolatile, IsText);
+                              isVolatile);
 }
 
 /// getStatValue - Get the 'stat' information for the specified path,
diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index fe3aff7a9af684..65a8a7253e054f 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -121,18 +121,8 @@ ContentCache::getBufferOrNone(DiagnosticsEngine &Diag, FileManager &FM,
   // Start with the assumption that the buffer is invalid to simplify early
   // return paths.
   IsBufferInvalid = true;
-  bool IsText = false;
-
-#ifdef __MVS__
-  // If the file is tagged with a text ccsid, it may require autoconversion.
-  llvm::ErrorOr<bool> IsFileText =
-      llvm::iszOSTextFile(ContentsEntry->getName().data());
-  if (IsFileText)
-    IsText = *IsFileText;
-#endif
-
-  auto BufferOrError = FM.getBufferForFile(
-      *ContentsEntry, IsFileVolatile, /*RequiresNullTerminator=*/true, IsText);
+
+  auto BufferOrError = FM.getBufferForFile(*ContentsEntry, IsFileVolatile);
 
   // If we were unable to open the file, then we are in an inconsistent
   // situation where the content cache referenced a file which no longer
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index ad0551ee117a97..7efcc81e194d95 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5317,8 +5317,7 @@ std::string ASTReader::getOriginalSourceFile(
     const PCHContainerReader &PCHContainerRdr, DiagnosticsEngine &Diags) {
   // Open the AST file.
   auto Buffer = FileMgr.getBufferForFile(ASTFileName, /*IsVolatile=*/false,
-                                         /*RequiresNullTerminator=*/false,
-                                         /*IsText=*/true);
+                                         /*RequiresNullTerminator=*/false);
   if (!Buffer) {
     Diags.Report(diag::err_fe_unable_to_read_pch_file)
         << ASTFileName << Buffer.getError().message();
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
index 7d6239a0732fe6..4d738e4bea41a6 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
@@ -353,13 +353,12 @@ DepScanFile::create(EntryRef Entry) {
 }
 
 llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-DependencyScanningWorkerFilesystem::openFileForRead(const Twine &Path,
-                                                    bool IsText) {
+DependencyScanningWorkerFilesystem::openFileForRead(const Twine &Path) {
   SmallString<256> OwnedFilename;
   StringRef Filename = Path.toStringRef(OwnedFilename);
 
   if (shouldBypass(Filename))
-    return getUnderlyingFS().openFileForRead(Path, IsText);
+    return getUnderlyingFS().openFileForRead(Path);
 
   llvm::ErrorOr<EntryRef> Result = getOrCreateFileSystemEntry(Filename);
   if (!Result)
diff --git a/clang/unittests/Driver/DistroTest.cpp b/clang/unittests/Driver/DistroTest.cpp
index 4c13b8bbb94089..43efc0dd8f51ec 100644
--- a/clang/unittests/Driver/DistroTest.cpp
+++ b/clang/unittests/Driver/DistroTest.cpp
@@ -352,9 +352,9 @@ TEST(DistroTest, DetectWindowsAndCrossCompile) {
     }
 
     llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-    openFileForRead(const llvm::Twine &Path, bool IsText = true) override {
+    openFileForRead(const llvm::Twine &Path) override {
       ++Count;
-      return llvm::vfs::ProxyFileSystem::openFileForRead(Path, IsText);
+      return llvm::vfs::ProxyFileSystem::openFileForRead(Path);
     }
 
     unsigned Count{};
diff --git a/clang/unittests/Driver/ToolChainTest.cpp b/clang/unittests/Driver/ToolChainTest.cpp
index 6c8b32dec879d1..a9b5f3c700315c 100644
--- a/clang/unittests/Driver/ToolChainTest.cpp
+++ b/clang/unittests/Driver/ToolChainTest.cpp
@@ -662,7 +662,7 @@ struct FileSystemWithError : public llvm::vfs::FileSystem {
     return std::make_error_code(std::errc::no_such_file_or_directory);
   }
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override {
+  openFileForRead(const Twine &Path) override {
     return std::make_error_code(std::errc::permission_denied);
   }
   llvm::vfs::directory_iterator dir_begin(const Twine &Dir,
diff --git a/clang/unittests/Frontend/PCHPreambleTest.cpp b/clang/unittests/Frontend/PCHPreambleTest.cpp
index 137dcf2377be47..2ce24c91ac0f13 100644
--- a/clang/unittests/Frontend/PCHPreambleTest.cpp
+++ b/clang/unittests/Frontend/PCHPreambleTest.cpp
@@ -36,10 +36,10 @@ class ReadCountingInMemoryFileSystem : public vfs::InMemoryFileSystem
   std::map<std::string, unsigned> ReadCounts;
 
 public:
-  ErrorOr<std::unique_ptr<vfs::File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override {
+  ErrorOr<std::unique_ptr<vfs::File>> openFileForRead(const Twine &Path) override
+  {
     ++ReadCounts[Canonicalize(Path)];
-    return InMemoryFileSystem::openFileForRead(Path, IsText);
+    return InMemoryFileSystem::openFileForRead(Path);
   }
 
   unsigned GetReadCount(const Twine &Path) const
diff --git a/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp b/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp
index 1012016ed03c7d..ec0e143be4a209 100644
--- a/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp
+++ b/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp
@@ -277,9 +277,9 @@ TEST(DependencyScanner, ScanDepsWithModuleLookup) {
     }
 
     llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-    openFileForRead(const Twine &Path, bool IsText = true) override {
+    openFileForRead(const Twine &Path) override {
       ReadFiles.push_back(Path.str());
-      return ProxyFileSystem::openFileForRead(Path, IsText);
+      return ProxyFileSystem::openFileForRead(Path);
     }
   };
 
diff --git a/lldb/unittests/Host/FileSystemTest.cpp b/lldb/unittests/Host/FileSystemTest.cpp
index 3c76f1d1bed21a..58887f6b2467e0 100644
--- a/lldb/unittests/Host/FileSystemTest.cpp
+++ b/lldb/unittests/Host/FileSystemTest.cpp
@@ -59,7 +59,7 @@ class DummyFileSystem : public vfs::FileSystem {
     return I->second;
   }
   ErrorOr<std::unique_ptr<vfs::File>>
-  openFileForRead(const Twine &Path, bool Text = true) override {
+  openFileForRead(const Twine &Path) override {
     auto S = status(Path);
     if (S)
       return std::unique_ptr<vfs::File>(new DummyFile{*S});
diff --git a/lldb/unittests/Utility/MockSymlinkFileSystem.h b/lldb/unittests/Utility/MockSymlinkFileSystem.h
index 32a86cd669fb14..7fa1f93bfa38a9 100644
--- a/lldb/unittests/Utility/MockSymlinkFileSystem.h
+++ b/lldb/unittests/Utility/MockSymlinkFileSystem.h
@@ -43,7 +43,7 @@ class MockSymlinkFileSystem : public llvm::vfs::FileSystem {
     return llvm::errc::operation_not_permitted;
   }
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const llvm::Twine &Path, bool IsText = true) override {
+  openFileForRead(const llvm::Twine &Path) override {
     return llvm::errc::operation_not_permitted;
   }
   llvm::vfs::directory_iterator dir_begin(const llvm::Twine &Dir,
diff --git a/llvm/include/llvm/Support/AutoConvert.h b/llvm/include/llvm/Support/AutoConvert.h
index 8ef6d3e8cf973e..6f45c4683f7775 100644
--- a/llvm/include/llvm/Support/AutoConvert.h
+++ b/llvm/include/llvm/Support/AutoConvert.h
@@ -52,12 +52,6 @@ std::error_code restorezOSStdHandleAutoConversion(int FD);
 /// \brief Set the tag information for a file descriptor.
 std::error_code setzOSFileTag(int FD, int CCSID, bool Text);
 
-// Get the the tag ccsid for a file name or a file descriptor.
-ErrorOr<__ccsid_t> getzOSFileTag(const char *FileName, const int FD = -1);
-
-// Query the file tag to determine if the file is a text file.
-ErrorOr<bool> iszOSTextFile(const char *Filename, const int FD = -1);
-
 } // namespace llvm
 #endif // __cplusplus
 
diff --git a/llvm/include/llvm/Support/VirtualFileSystem.h b/llvm/include/llvm/Support/VirtualFileSystem.h
index 2256fde2faa661..2531c075f262d7 100644
--- a/llvm/include/llvm/Support/VirtualFileSystem.h
+++ b/llvm/include/llvm/Support/VirtualFileSystem.h
@@ -273,14 +273,13 @@ class FileSystem : public llvm::ThreadSafeRefCountedBase<FileSystem>,
 
   /// Get a \p File object for the file at \p Path, if one exists.
   virtual llvm::ErrorOr<std::unique_ptr<File>>
-  openFileForRead(const Twine &Path, bool IsText = true) = 0;
+  openFileForRead(const Twine &Path) = 0;
 
   /// This is a convenience method that opens a file, gets its content and then
   /// closes the file.
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(const Twine &Name, int64_t FileSize = -1,
-                   bool RequiresNullTerminator = true, bool IsVolatile = false,
-                   bool IsText = true);
+                   bool RequiresNullTerminator = true, bool IsVolatile = false);
 
   /// Get a directory_iterator for \p Dir.
   /// \note The 'end' iterator is directory_iterator().
@@ -393,7 +392,7 @@ class OverlayFileSystem : public RTTIExtends<OverlayFileSystem, FileSystem> {
   llvm::ErrorOr<Status> status(const Twine &Path) override;
   bool exists(const Twine &Path) override;
   llvm::ErrorOr<std::unique_ptr<File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override;
+  openFileForRead(const Twine &Path) override;
   directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
   llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override;
   std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
@@ -447,8 +446,8 @@ class ProxyFileSystem : public RTTIExtends<ProxyFileSystem, FileSystem> {
   }
   bool exists(const Twine &Path) override { return FS->exists(Path); }
   llvm::ErrorOr<std::unique_ptr<File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override {
-    return FS->openFileForRead(Path, IsText);
+  openFileForRead(const Twine &Path) override {
+    return FS->openFileForRead(Path);
   }
   directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override {
     return FS->dir_begin(Dir, EC);
@@ -616,7 +615,7 @@ class InMemoryFileSystem : public RTTIExtends<InMemoryFileSystem, FileSystem> {
 
   llvm::ErrorOr<Status> status(const Twine &Path) override;
   llvm::ErrorOr<std::unique_ptr<File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override;
+  openFileForRead(const Twine &Path) override;
   directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
 
   llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override {
@@ -1052,8 +1051,7 @@ class RedirectingFileSystem
 
   ErrorOr<Status> status(const Twine &Path) override;
   bool exists(const Twine &Path) override;
-  ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path,
-                                                 bool IsText = true) override;
+  ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path) override;
 
   std::error_code getRealPath(const Twine &Path,
                               SmallVectorImpl<char> &Output) override;
@@ -1157,10 +1155,9 @@ class TracingFileSystem
     return ProxyFileSystem::status(Path);
   }
 
-  ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path,
-                                                 bool IsText = true) override {
+  ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path) override {
     ++NumOpenFileForReadCalls;
-    return ProxyFileSystem::openFileForRead(Path, IsText);
+    return ProxyFileSystem::openFileForRead(Path);
   }
 
   directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override {
diff --git a/llvm/lib/Support/AutoConvert.cpp b/llvm/lib/Support/AutoConvert.cpp
index 06130876c67f05..66570735f8fc88 100644
--- a/llvm/lib/Support/AutoConvert.cpp
+++ b/llvm/lib/Support/AutoConvert.cpp
@@ -116,30 +116,4 @@ std::error_code llvm::setzOSFileTag(int FD, int CCSID, bool Text) {
   return std::error_code();
 }
 
-ErrorOr<__ccsid_t> llvm::getzOSFileTag(const char *FileName, const int FD) {
-  // If we have a file descriptor, use it to find out file tagging. Otherwise we
-  // need to use stat() with the file path.
-  if (FD != -1) {
-    struct f_cnvrt Query = {
-        QUERYCVT, // cvtcmd
-        0,        // pccsid
-        0,        // fccsid
-    };
-    if (fcntl(FD, F_CONTROL_CVT, &Query) == -1)
-      return std::error_code(errno, std::generic_category());
-    return Query.fccsid;
-  }
-  struct stat Attr;
-  if (stat(FileName, &Attr) == -1)
-    return std::error_code(errno, std::generic_category());
-  return Attr.st_tag.ft_ccsid;
-}
-
-ErrorOr<bool> llvm::iszOSTextFile(const char *Filename, const int FD) {
-  ErrorOr<__ccsid_t> Ccsid = getzOSFileTag(Filename, FD);
-  if (std::error_code EC = Ccsid.getError())
-    return EC;
-  return *Ccsid != FT_BINARY;
-}
-
 #endif // __MVS__
diff --git a/llvm/lib/Support/FileCollector.cpp b/llvm/lib/Support/FileCollector.cpp
index fd4350da7f66a6..29436f85c2f23c 100644
--- a/llvm/lib/Support/FileCollector.cpp
+++ b/llvm/lib/Support/FileCollector.cpp
@@ -268,8 +268,8 @@ class FileCollectorFileSystem : public vfs::FileSystem {
   }
 
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const Twine &Path, bool IsText) override {
-    auto Result = FS->openFileForRead(Path, IsText);
+  openFileForRead(const Twine &Path) override {
+    auto Result = FS->openFileForRead(Path);
     if (Result && *Result)
       Collector->addFile(Path);
     return Result;
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index ceca65b46e486d..928c0b5a24ed65 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -117,9 +117,8 @@ FileSystem::~FileSystem() = default;
 
 ErrorOr<std::unique_ptr<MemoryBuffer>>
 FileSystem::getBufferForFile(const llvm::Twine &Name, int64_t FileSize,
-                             bool RequiresNullTerminator, bool IsVolatile,
-                             bool IsText) {
-  auto F = openFileForRead(Name, IsText);
+                             bool RequiresNullTerminator, bool IsVolatile) {
+  auto F = openFileForRead(Name);
   if (!F)
     return F.getError();
 
@@ -279,8 +278,7 @@ class RealFileSystem : public FileSystem {
   }
 
   ErrorOr<Status> status(const Twine &Path) override;
-  ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path,
-                                                 bool IsText = true) override;
+  ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path) override;
   directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
 
   llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override;
@@ -325,11 +323,10 @@ ErrorOr<Status> RealFileSystem::status(const Twine &Path) {
 }
 
 ErrorOr<std::unique_ptr<File>>
-RealFileSystem::openFileForRead(const Twine &Name, bool IsText) {
+RealFileSystem::openFileForRead(const Twine &Name) {
   SmallString<256> RealName, Storage;
   Expected<file_t> FDOrErr = sys::fs::openNativeFileForRead(
-      adjustPath(Name, Storage), IsText ? sys::fs::OF_Text : sys::fs::OF_None,
-      &RealName);
+      adjustPath(Name, Storage), sys::fs::OF_None, &RealName);
   if (!FDOrErr)
     return errorToErrorCode(FDOrErr.takeError());
   return std::unique_ptr<File>(
@@ -461,10 +458,10 @@ bool OverlayFileSystem::exists(const Twine &Path) {
 }
 
 ErrorOr<std::unique_ptr<File>>
-OverlayFileSystem::openFileForRead(const llvm::Twine &Path, bool IsText) {
+OverlayFileSystem::openFileForRead(const llvm::Twine &Path) {
   // FIXME: handle symlinks that cross file systems
   for (iterator I = overlays_begin(), E = overlays_end(); I != E; ++I) {
-    auto Result = (*I)->openFileForRead(Path, IsText);
+    auto Result = (*I)->openFileForRead(Path);
     if (Result || Result.getError() != llvm::errc::no_such_file_or_directory)
       return Result;
   }
@@ -1076,7 +1073,7 @@ llvm::ErrorOr<Status> InMemoryFileSystem::status(const Twine &Path) {
 }
 
 llvm::ErrorOr<std::unique_ptr<File>>
-InMemoryFileSystem::openFileForRead(const Twine &Path, bool IsText) {
+InMemoryFileSystem::openFileForRead(const Twine &Path) {
   auto Node = lookupNode(Path,/*FollowFinalSymlink=*/true);
   if (!Node)
     return Node.getError();
@@ -2540,7 +2537,7 @@ File::getWithPath(ErrorOr<std::unique_ptr<File>> Result, const Twine &P) {
 }
 
 ErrorOr<std::unique_ptr<File>>
-RedirectingFileSystem::openFileForRead(const Twine &OriginalPath, bool IsText) {
+RedirectingFileSystem::openFileForRead(const Twine &OriginalPath) {
   SmallString<256> Path;
   OriginalPath.toVector(Path);
 
diff --git a/llvm/unittests/Support/VirtualFileSystemTest.cpp b/llvm/unittests/Support/VirtualFileSystemTest.cpp
index 219aaefd43f65d..eb590e474c2ecc 100644
--- a/llvm/unittests/Support/VirtualFileSystemTest.cpp
+++ b/llvm/unittests/Support/VirtualFileSystemTest.cpp
@@ -67,7 +67,7 @@ class DummyFileSystem : public vfs::FileSystem {
     return I->second;
   }
   ErrorOr<std::unique_ptr<vfs::File>>
-  openFileForRead(const Twine &Path, bool IsText = true) override {
+  openFileForRead(const Twine &Path) override {
     auto S = status(Path);
     if (S)
       return std::unique_ptr<vfs::File>(new DummyFile{*S});
@@ -3389,9 +3389,9 @@ TEST(RedirectingFileSystemTest, ExternalPaths) {
     }
 
     llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-    openFileForRead(const Twine &Path, bool IsText = true) override {
+    openFileForRead(const Twine &Path) override {
       SeenPaths.push_back(Path.str());
-      return ProxyFileSystem::openFileForRead(Path, IsText);
+      return ProxyFileSystem::openFileForRead(Path);
     }
 
     std::error_code isLocal(const Twine &Path, bool &Result) override {