append_challenged_posix_file_impl: allow destructing file with no que…

…ued work

There is no problem destructing the file if nothing is queued on it.
posix_file_impl::~posix_file_impl will auto close its file descriptor.

Refs scylladb/scylladb#7285

Test: unit(dev), file_io(debug)
Signed-off-by: Benny Halevy <[email protected]>
Message-Id: <[email protected]>

src/core/file.cc

@@ -498,7 +498,10 @@ append_challenged_posix_file_impl::append_challenged_posix_file_impl(int fd, ope
 append_challenged_posix_file_impl::~append_challenged_posix_file_impl() {
     // If the file has not been closed we risk having running tasks
     // that will try to access freed memory.
-    assert(_closing_state == state::closed);
+    //
+    // It is safe to destory it if nothing is queued.
+    // Note that posix_file_impl::~posix_file_impl auto-closes the file descriptor.
+    assert(_q.empty() && _logical_size == _committed_size);
 }
 
 bool

tests/unit/file_io_test.cc

@@ -676,3 +676,38 @@ SEASTAR_TEST_CASE(test_nowait_flag_correctness) {
         }
     });
 }
+
+SEASTAR_TEST_CASE(test_destruct_just_constructed_append_challenged_file) {
+    return tmp_dir::do_with_thread([] (tmp_dir& t) {
+        sstring filename = (t.get_path() / "testfile.tmp").native();
+        auto oflags = open_flags::rw | open_flags::create;
+        auto f = open_file_dma(filename, oflags).get0();
+    });
+}
+
+SEASTAR_TEST_CASE(test_destruct_append_challenged_file_after_write) {
+    return tmp_dir::do_with_thread([] (tmp_dir& t) {
+        sstring filename = (t.get_path() / "testfile.tmp").native();
+        auto buf = allocate_aligned_buffer<unsigned char>(4096, 4096);
+        std::fill(buf.get(), buf.get() + 4096, 0);
+
+        auto f = open_file_dma(filename, open_flags::rw | open_flags::create).get0();
+        f.dma_write(0, buf.get(), 4096).get();
+    });
+}
+
+SEASTAR_TEST_CASE(test_destruct_append_challenged_file_after_read) {
+    return tmp_dir::do_with_thread([] (tmp_dir& t) {
+        sstring filename = (t.get_path() / "testfile.tmp").native();
+        auto buf = allocate_aligned_buffer<unsigned char>(4096, 4096);
+        std::fill(buf.get(), buf.get() + 4096, 0);
+
+        auto f = open_file_dma(filename, open_flags::rw | open_flags::create).get0();
+        f.dma_write(0, buf.get(), 4096).get();
+        f.flush().get0();
+        f.close().get();
+
+        f = open_file_dma(filename, open_flags::rw).get0();
+        f.dma_read(0, buf.get(), 4096).get();
+    });
+}