Add fh support for revise attr and fstat(2) test

According to Linux 4.4's FUSE behavior, the flags and fh attributes in
FUSE_GETATTR are only used in read, write, and lseek. fstat(2) doesn't
use them either. Add tests to ensure the requests sent from FUSE module
are consistent with Linux's.

Updates #3655

2 files changed, 108 insertions, 8 deletions

diff --git a/test/fuse/linux/BUILD b/test/fuse/linux/BUILD
index eb090cbfd..7a3e52fad 100644
--- a/test/fuse/linux/BUILD
+++ b/test/fuse/linux/BUILD
@@ -11,7 +11,9 @@ cc_binary(
     srcs = ["stat_test.cc"],
     deps = [
         gtest,
-        ":fuse_base",
+        ":fuse_fd_util",
+        "//test/util:cleanup",
+        "//test/util:fs_util",
         "//test/util:fuse_util",
         "//test/util:test_main",
         "//test/util:test_util",
diff --git a/test/fuse/linux/stat_test.cc b/test/fuse/linux/stat_test.cc
index 717fd1fac..6f032cac1 100644
--- a/test/fuse/linux/stat_test.cc
+++ b/test/fuse/linux/stat_test.cc
@@ -18,12 +18,15 @@
 #include <sys/stat.h>
 #include <sys/statfs.h>
 #include <sys/types.h>
+#include <sys/uio.h>
 #include <unistd.h>
 
 #include <vector>
 
 #include "gtest/gtest.h"
-#include "test/fuse/linux/fuse_base.h"
+#include "test/fuse/linux/fuse_fd_util.h"
+#include "test/util/cleanup.h"
+#include "test/util/fs_util.h"
 #include "test/util/fuse_util.h"
 #include "test/util/test_util.h"
 
@@ -32,19 +35,30 @@ namespace testing {
 
 namespace {
 
-class StatTest : public FuseTest {
+class StatTest : public FuseFdTest {
  public:
+  void SetUp() override {
+    FuseFdTest::SetUp();
+    test_file_path_ = JoinPath(mount_point_.path(), test_file_);
+  }
+
+ protected:
   bool StatsAreEqual(struct stat expected, struct stat actual) {
-    // device number will be dynamically allocated by kernel, we cannot know
-    // in advance
+    // Device number will be dynamically allocated by kernel, we cannot know in
+    // advance.
     actual.st_dev = expected.st_dev;
     return memcmp(&expected, &actual, sizeof(struct stat)) == 0;
   }
+
+  const std::string test_file_ = "testfile";
+  const mode_t expected_mode = S_IFREG | S_IRUSR | S_IWUSR;
+  const uint64_t fh = 23;
+
+  std::string test_file_path_;
 };
 
 TEST_F(StatTest, StatNormal) {
   // Set up fixture.
-  mode_t expected_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
   struct fuse_attr attr = DefaultFuseAttr(expected_mode, 1);
   struct fuse_out_header out_header = {
       .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
@@ -55,7 +69,7 @@ TEST_F(StatTest, StatNormal) {
   auto iov_out = FuseGenerateIovecs(out_header, out_payload);
   SetServerResponse(FUSE_GETATTR, iov_out);
 
-  // Do integration test.
+  // Make syscall.
   struct stat stat_buf;
   EXPECT_THAT(stat(mount_point_.path().c_str(), &stat_buf), SyscallSucceeds());
 
@@ -99,7 +113,7 @@ TEST_F(StatTest, StatNotFound) {
   auto iov_out = FuseGenerateIovecs(out_header);
   SetServerResponse(FUSE_GETATTR, iov_out);
 
-  // Do integration test.
+  // Make syscall.
   struct stat stat_buf;
   EXPECT_THAT(stat(mount_point_.path().c_str(), &stat_buf),
               SyscallFailsWithErrno(ENOENT));
@@ -115,6 +129,90 @@ TEST_F(StatTest, StatNotFound) {
   EXPECT_EQ(in_payload.fh, 0);
 }
 
+TEST_F(StatTest, FstatNormal) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDONLY, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_attr attr = DefaultFuseAttr(expected_mode, 2);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = attr,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_GETATTR, iov_out);
+
+  // Make syscall.
+  struct stat stat_buf;
+  EXPECT_THAT(fstat(fd.get(), &stat_buf), SyscallSucceeds());
+
+  // Check filesystem operation result.
+  struct stat expected_stat = {
+      .st_ino = attr.ino,
+      .st_nlink = attr.nlink,
+      .st_mode = expected_mode,
+      .st_uid = attr.uid,
+      .st_gid = attr.gid,
+      .st_rdev = attr.rdev,
+      .st_size = static_cast<off_t>(attr.size),
+      .st_blksize = attr.blksize,
+      .st_blocks = static_cast<blkcnt_t>(attr.blocks),
+      .st_atim = (struct timespec){.tv_sec = static_cast<int>(attr.atime),
+                                   .tv_nsec = attr.atimensec},
+      .st_mtim = (struct timespec){.tv_sec = static_cast<int>(attr.mtime),
+                                   .tv_nsec = attr.mtimensec},
+      .st_ctim = (struct timespec){.tv_sec = static_cast<int>(attr.ctime),
+                                   .tv_nsec = attr.ctimensec},
+  };
+  EXPECT_TRUE(StatsAreEqual(stat_buf, expected_stat));
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_getattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.opcode, FUSE_GETATTR);
+  EXPECT_EQ(in_payload.getattr_flags, 0);
+  EXPECT_EQ(in_payload.fh, 0);
+}
+
+TEST_F(StatTest, StatByFileHandle) {
+  // Set up fixture.
+  SetServerInodeLookup(test_file_, expected_mode, 0);
+  auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenPath(test_file_path_, O_RDONLY, fh));
+  auto close_fd = CloseFD(fd);
+
+  struct fuse_attr attr = DefaultFuseAttr(expected_mode, 2, 0);
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = attr,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload);
+  SetServerResponse(FUSE_GETATTR, iov_out);
+
+  // Make syscall.
+  std::vector<char> buf(1);
+  // Since this is an empty file, it won't issue FUSE_READ. But a FUSE_GETATTR
+  // will be issued before read completes.
+  EXPECT_THAT(read(fd.get(), buf.data(), buf.size()), SyscallSucceeds());
+
+  // Check FUSE request.
+  struct fuse_in_header in_header;
+  struct fuse_getattr_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+
+  GetServerActualRequest(iov_in);
+  EXPECT_EQ(in_header.opcode, FUSE_GETATTR);
+  EXPECT_EQ(in_payload.getattr_flags, FUSE_GETATTR_FH);
+  EXPECT_EQ(in_payload.fh, fh);
+}
+
 }  // namespace
 
 }  // namespace testing