fix: support retry when io write incompletely (#818)

include/dsn/utility/fail_point.h

@@ -22,8 +22,8 @@
 
 #include <dsn/utility/string_view.h>
 
-/// The only entry to define a fail point.
-/// When a fail point is defined, it's referenced via the name.
+/// The only entry to define a fail point with `return` function: lambda function must be
+/// return non-void type. When a fail point is defined, it's referenced via the name.
 #define FAIL_POINT_INJECT_F(name, lambda)                                                          \
     do {                                                                                           \
         if (dsn_likely(!::dsn::fail::_S_FAIL_POINT_ENABLED))                                       \
@@ -35,6 +35,19 @@
         }                                                                                          \
     } while (0)
 
+/// The only entry to define a fail point with `void` function: lambda  function must be
+/// return void type. When a fail point is defined, it's referenced via the name.
+#define FAIL_POINT_INJECT_VOID_F(name, lambda)                                                     \
+    do {                                                                                           \
+        if (dsn_likely(!::dsn::fail::_S_FAIL_POINT_ENABLED))                                       \
+            break;                                                                                 \
+        auto __Func = lambda;                                                                      \
+        auto __Res = ::dsn::fail::eval(name);                                                      \
+        if (__Res == nullptr) {                                                                    \
+            __Func();                                                                              \
+        }                                                                                          \
+    } while (0)
+
 namespace dsn {
 namespace fail {
 

src/aio/native_linux_aio_provider.cpp

@@ -27,6 +27,9 @@
 #include "native_linux_aio_provider.h"
 
 #include <dsn/tool-api/async_calls.h>
+#include <dsn/c/api_utilities.h>
+#include <dsn/dist/fmt_logging.h>
+#include <dsn/utility/fail_point.h>
 
 namespace dsn {
 
@@ -66,15 +69,43 @@ error_code native_linux_aio_provider::flush(dsn_handle_t fh)
 error_code native_linux_aio_provider::write(const aio_context &aio_ctx,
                                             /*out*/ uint32_t *processed_bytes)
 {
-    ssize_t ret = pwrite(static_cast<int>((ssize_t)aio_ctx.file),
-                         aio_ctx.buffer,
-                         aio_ctx.buffer_size,
-                         aio_ctx.file_offset);
-    if (ret < 0) {
-        return ERR_FILE_OPERATION_FAILED;
-    }
-    *processed_bytes = static_cast<uint32_t>(ret);
-    return ERR_OK;
+    dsn::error_code resp = ERR_OK;
+    uint32_t buffer_offset = 0;
+    do {
+        // ret is the written data size
+        uint32_t ret = pwrite(static_cast<int>((ssize_t)aio_ctx.file),
+                              (char *)aio_ctx.buffer + buffer_offset,
+                              aio_ctx.buffer_size - buffer_offset,
+                              aio_ctx.file_offset + buffer_offset);
+        if (dsn_unlikely(ret < 0)) {
+            if (errno == EINTR) {
+                dwarn_f("write failed with errno={} and will retry it.", strerror(errno));
+                continue;
+            }
+            resp = ERR_FILE_OPERATION_FAILED;
+            derror_f("write failed with errno={}, return {}.", strerror(errno), resp);
+            return resp;
+        }
+
+        // mock the `ret` to reproduce the `write incomplete` case in the first write
+        FAIL_POINT_INJECT_VOID_F("aio_pwrite_incomplete", [&]() -> void {
+            if (dsn_unlikely(buffer_offset == 0)) {
+                --ret;
+            }
+        });
+
+        buffer_offset += ret;
+        if (dsn_unlikely(buffer_offset != aio_ctx.buffer_size)) {
+            dwarn_f("write incomplete, request_size={}, total_write_size={}, this_write_size={}, "
+                    "and will retry it.",
+                    aio_ctx.buffer_size,
+                    buffer_offset,
+                    ret);
+        }
+    } while (dsn_unlikely(buffer_offset < aio_ctx.buffer_size));
+
+    *processed_bytes = buffer_offset;
+    return resp;
 }
 
 error_code native_linux_aio_provider::read(const aio_context &aio_ctx,

src/aio/test/aio.cpp

@@ -27,6 +27,7 @@
 #include <dsn/tool-api/async_calls.h>
 #include <dsn/utility/filesystem.h>
 #include <dsn/utility/smart_pointers.h>
+#include <dsn/utility/fail_point.h>
 
 #include <gtest/gtest.h>
 
@@ -37,6 +38,8 @@ DEFINE_TASK_CODE_AIO(LPC_AIO_TEST, TASK_PRIORITY_COMMON, THREAD_POOL_TEST_SERVER
 
 TEST(core, aio)
 {
+    fail::setup();
+    fail::cfg("aio_pwrite_incomplete", "off()");
     const char *buffer = "hello, world";
     int len = (int)strlen(buffer);
 
@@ -122,6 +125,7 @@ TEST(core, aio)
     }
 
     err = file::close(fp);
+    fail::teardown();
     EXPECT_TRUE(err == ERR_OK);
 
     utils::filesystem::remove_path("tmp");
@@ -143,6 +147,9 @@ TEST(core, aio_share)
 
 TEST(core, operation_failed)
 {
+    fail::setup();
+    fail::cfg("aio_pwrite_incomplete", "off()");
+
     auto fp = file::open("tmp_test_file", O_WRONLY, 0600);
     EXPECT_TRUE(fp == nullptr);
 
@@ -171,16 +178,19 @@ TEST(core, operation_failed)
     t = ::dsn::file::read(fp2, buffer, 512, 0, LPC_AIO_TEST, nullptr, io_callback, 0);
     t->wait();
     EXPECT_TRUE(*err == ERR_OK && *count == strlen(str));
+    EXPECT_TRUE(strncmp(buffer, str, 10) == 0);
 
     t = ::dsn::file::read(fp2, buffer, 5, 0, LPC_AIO_TEST, nullptr, io_callback, 0);
     t->wait();
     EXPECT_TRUE(*err == ERR_OK && *count == 5);
+    EXPECT_TRUE(strncmp(buffer, str, 5) == 0);
 
     t = ::dsn::file::read(fp2, buffer, 512, 100, LPC_AIO_TEST, nullptr, io_callback, 0);
     t->wait();
     ddebug("error code: %s", err->to_string());
     file::close(fp);
     file::close(fp2);
+    fail::teardown();
 
     EXPECT_TRUE(utils::filesystem::remove_path("tmp_test_file"));
 }