From: Joel Rosdahl <joel@rosdahl.net>
Date: Mon, 12 Sep 2022 11:25:45 +0000 (+0200)
Subject: fix: Make sure that temporary files always have .tmp. in the name
X-Git-Tag: v4.7~56
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=60fe1672d9e36f4334d39d0c606dd07d401e1fa1;p=thirdparty%2Fccache.git

fix: Make sure that temporary files always have .tmp. in the name

PrimaryStorage::clean_dir relies on being able to classify temporary
files from the filename.
---

diff --git a/src/AtomicFile.cpp b/src/AtomicFile.cpp
index ec5fead6e..c9d82c3e2 100644
--- a/src/AtomicFile.cpp
+++ b/src/AtomicFile.cpp
@@ -27,7 +27,7 @@
 
 AtomicFile::AtomicFile(const std::string& path, Mode mode) : m_path(path)
 {
-  TemporaryFile tmp_file(path + ".tmp");
+  TemporaryFile tmp_file(path);
   m_stream = fdopen(tmp_file.fd.release(), mode == Mode::binary ? "w+b" : "w+");
   m_tmp_path = std::move(tmp_file.path);
 }
diff --git a/src/TemporaryFile.cpp b/src/TemporaryFile.cpp
index 0d7e80bfb..257481234 100644
--- a/src/TemporaryFile.cpp
+++ b/src/TemporaryFile.cpp
@@ -35,7 +35,7 @@
 
 TemporaryFile::TemporaryFile(std::string_view path_prefix,
                              std::string_view suffix)
-  : path(FMT("{}.XXXXXX{}", path_prefix, suffix))
+  : path(FMT("{}{}XXXXXX{}", path_prefix, tmp_file_infix, suffix))
 {
   Util::ensure_dir_exists(Util::dir_name(path));
 #ifdef _WIN32
@@ -59,3 +59,9 @@ TemporaryFile::TemporaryFile(std::string_view path_prefix,
   fchmod(*fd, 0666 & ~Util::get_umask());
 #endif
 }
+
+bool
+TemporaryFile::is_tmp_file(std::string_view path)
+{
+  return Util::base_name(path).find(tmp_file_infix) != std::string::npos;
+}
diff --git a/src/TemporaryFile.hpp b/src/TemporaryFile.hpp
index 29d8597e3..b773c0a4b 100644
--- a/src/TemporaryFile.hpp
+++ b/src/TemporaryFile.hpp
@@ -28,15 +28,19 @@
 class TemporaryFile
 {
 public:
+  static constexpr char tmp_file_infix[] = ".tmp.";
+
   // `path_prefix` is the base path. The resulting filename will be this path
-  //  plus a unique string plus `suffix`. If `path_prefix` refers to a
-  //  nonexistent directory the directory will be created if possible.`
-  TemporaryFile(std::string_view path_prefix, std::string_view suffix = {});
+  // plus a unique string plus `suffix`. If `path_prefix` refers to a
+  // nonexistent directory the directory will be created if possible.
+  TemporaryFile(std::string_view path_prefix, std::string_view suffix = ".tmp");
 
   TemporaryFile(TemporaryFile&& other) noexcept = default;
 
   TemporaryFile& operator=(TemporaryFile&& other) noexcept = default;
 
+  static bool is_tmp_file(std::string_view path);
+
   // The resulting open file descriptor in read/write mode. Unset on error.
   Fd fd;
 
diff --git a/src/Util.cpp b/src/Util.cpp
index 179bbc7f6..8b0b6e0ec 100644
--- a/src/Util.cpp
+++ b/src/Util.cpp
@@ -1315,7 +1315,8 @@ unlink_safe(const std::string& path, UnlinkLog unlink_log)
   // If path is on an NFS share, unlink isn't atomic, so we rename to a temp
   // file. We don't care if the temp file is trashed, so it's always safe to
   // unlink it first.
-  std::string tmp_name = path + ".ccache.rm.tmp";
+  const std::string tmp_name =
+    FMT("{}.ccache{}unlink", path, TemporaryFile::tmp_file_infix);
 
   bool success = true;
   try {
diff --git a/src/ccache.cpp b/src/ccache.cpp
index 0d1c4b027..4a10147e3 100644
--- a/src/ccache.cpp
+++ b/src/ccache.cpp
@@ -679,7 +679,7 @@ get_tmp_fd(Context& ctx,
 {
   if (capture_output) {
     TemporaryFile tmp_stdout(
-      FMT("{}/tmp.{}", ctx.config.temporary_dir(), description));
+      FMT("{}/{}", ctx.config.temporary_dir(), description));
     ctx.register_pending_tmp_file(tmp_stdout.path);
     return {std::move(tmp_stdout.fd), std::move(tmp_stdout.path)};
   } else {
@@ -1158,9 +1158,8 @@ get_result_key_from_cpp(Context& ctx, Args& args, Hash& hash)
 
     // preprocessed_path needs the proper cpp_extension for the compiler to do
     // its thing correctly.
-    TemporaryFile tmp_stdout(
-      FMT("{}/tmp.cpp_stdout", ctx.config.temporary_dir()),
-      FMT(".{}", ctx.config.cpp_extension()));
+    TemporaryFile tmp_stdout(FMT("{}/cpp_stdout", ctx.config.temporary_dir()),
+                             FMT(".{}", ctx.config.cpp_extension()));
     preprocessed_path = tmp_stdout.path;
     tmp_stdout.fd.close(); // We're only using the path.
     ctx.register_pending_tmp_file(preprocessed_path);
diff --git a/src/storage/primary/PrimaryStorage_cleanup.cpp b/src/storage/primary/PrimaryStorage_cleanup.cpp
index d3a0b1b93..6165c724d 100644
--- a/src/storage/primary/PrimaryStorage_cleanup.cpp
+++ b/src/storage/primary/PrimaryStorage_cleanup.cpp
@@ -23,6 +23,7 @@
 #include <Context.hpp>
 #include <File.hpp>
 #include <Logging.hpp>
+#include <TemporaryFile.hpp>
 #include <Util.hpp>
 #include <core/CacheEntry.hpp>
 #include <core/exceptions.hpp>
@@ -124,7 +125,7 @@ PrimaryStorage::clean_dir(const std::string& subdir,
 
     // Delete any tmp files older than 1 hour right away.
     if (file.lstat().mtime() + 3600 < current_time
-        && Util::base_name(file.path()).find(".tmp.") != std::string::npos) {
+        && TemporaryFile::is_tmp_file(file.path())) {
       Util::unlink_tmp(file.path());
       continue;
     }