Implement FUSE_GETATTR

FUSE_GETATTR is called when a stat(2), fstat(2), or lstat(2) is issued
from VFS2 layer to a FUSE filesystem.

Fixes #3175

4 files changed, 197 insertions, 14 deletions

diff --git a/test/fuse/linux/BUILD b/test/fuse/linux/BUILD
index 49dc96c20..4871bb531 100644
--- a/test/fuse/linux/BUILD
+++ b/test/fuse/linux/BUILD
@@ -1,20 +1,31 @@
-load("//tools:defs.bzl", "cc_library", "gtest")
+load("//tools:defs.bzl", "cc_binary", "cc_library", "gtest")
 
 package(
     default_visibility = ["//:sandbox"],
     licenses = ["notice"],
 )
 
+cc_binary(
+    name = "stat_test",
+    testonly = 1,
+    srcs = ["stat_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
 cc_library(
     name = "fuse_base",
     testonly = 1,
-    srcs = [
-        "fuse_base.cc",
-        "fuse_base.h",
-    ],
+    srcs = ["fuse_base.cc"],
+    hdrs = ["fuse_base.h"],
     deps = [
         gtest,
         "//test/util:posix_error",
+        "//test/util:temp_path",
         "//test/util:test_util",
         "@com_google_absl//absl/strings:str_format",
     ],
diff --git a/test/fuse/linux/fuse_base.cc b/test/fuse/linux/fuse_base.cc
index ce69276c9..4a2c64998 100644
--- a/test/fuse/linux/fuse_base.cc
+++ b/test/fuse/linux/fuse_base.cc
@@ -12,23 +12,23 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "fuse_base.h"
+#include "test/fuse/linux/fuse_base.h"
 
 #include <fcntl.h>
 #include <linux/fuse.h>
-#include <stdio.h>
 #include <string.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <sys/uio.h>
 #include <unistd.h>
 
 #include <iostream>
 
-#include "gmock/gmock.h"
-#include "gtest/gtest.h"
 #include "absl/strings/str_format.h"
+#include "gtest/gtest.h"
 #include "test/util/posix_error.h"
+#include "test/util/temp_path.h"
 #include "test/util/test_util.h"
 
 namespace gvisor {
@@ -78,13 +78,14 @@ void FuseTest::MountFuse() {
   EXPECT_THAT(dev_fd_ = open("/dev/fuse", O_RDWR), SyscallSucceeds());
 
   std::string mount_opts = absl::StrFormat("fd=%d,%s", dev_fd_, kMountOpts);
-  EXPECT_THAT(mount("fuse", kMountPoint, "fuse", MS_NODEV | MS_NOSUID,
-                    mount_opts.c_str()),
+  mount_point_ = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
+  EXPECT_THAT(mount("fuse", mount_point_.path().c_str(), "fuse",
+                    MS_NODEV | MS_NOSUID, mount_opts.c_str()),
               SyscallSucceedsWithValue(0));
 }
 
 void FuseTest::UnmountFuse() {
-  EXPECT_THAT(umount(kMountPoint), SyscallSucceeds());
+  EXPECT_THAT(umount(mount_point_.path().c_str()), SyscallSucceeds());
   // TODO(gvisor.dev/issue/3330): ensure the process is terminated successfully.
 }
 
diff --git a/test/fuse/linux/fuse_base.h b/test/fuse/linux/fuse_base.h
index b008778de..3a2f255a9 100644
--- a/test/fuse/linux/fuse_base.h
+++ b/test/fuse/linux/fuse_base.h
@@ -20,14 +20,13 @@
 
 #include <vector>
 
-#include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "test/util/posix_error.h"
+#include "test/util/temp_path.h"
 
 namespace gvisor {
 namespace testing {
 
-constexpr char kMountPoint[] = "/mnt";
 constexpr char kMountOpts[] = "rootmode=755,user_id=0,group_id=0";
 
 class FuseTest : public ::testing::Test {
@@ -55,6 +54,9 @@ class FuseTest : public ::testing::Test {
   // complains if the FUSE server responds failure during tests.
   void WaitCompleted();
 
+ protected:
+  TempPath mount_point_;
+
  private:
   void MountFuse();
   void UnmountFuse();
diff --git a/test/fuse/linux/stat_test.cc b/test/fuse/linux/stat_test.cc
new file mode 100644
index 000000000..172e09867
--- /dev/null
+++ b/test/fuse/linux/stat_test.cc
@@ -0,0 +1,169 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class StatTest : public FuseTest {
+ public:
+  bool CompareRequest(void* expected_mem, size_t expected_len, void* real_mem,
+                      size_t real_len) override {
+    if (expected_len != real_len) return false;
+    struct fuse_in_header* real_header =
+        reinterpret_cast<fuse_in_header*>(real_mem);
+
+    if (real_header->opcode != FUSE_GETATTR) {
+      std::cerr << "expect header opcode " << FUSE_GETATTR << " but got "
+                << real_header->opcode << std::endl;
+      return false;
+    }
+    return true;
+  }
+
+  bool StatsAreEqual(struct stat expected, struct stat actual) {
+    // 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;
+  }
+};
+
+TEST_F(StatTest, StatNormal) {
+  struct iovec iov_in[2];
+  struct iovec iov_out[2];
+
+  struct fuse_in_header in_header = {
+      .len = sizeof(struct fuse_in_header) + sizeof(struct fuse_getattr_in),
+      .opcode = FUSE_GETATTR,
+      .unique = 4,
+      .nodeid = 1,
+      .uid = 0,
+      .gid = 0,
+      .pid = 4,
+      .padding = 0,
+  };
+  struct fuse_getattr_in in_payload = {0};
+  iov_in[0].iov_len = sizeof(in_header);
+  iov_in[0].iov_base = &in_header;
+  iov_in[1].iov_len = sizeof(in_payload);
+  iov_in[1].iov_base = &in_payload;
+
+  mode_t expected_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
+  struct timespec atime = {.tv_sec = 1595436289, .tv_nsec = 134150844};
+  struct timespec mtime = {.tv_sec = 1595436290, .tv_nsec = 134150845};
+  struct timespec ctime = {.tv_sec = 1595436291, .tv_nsec = 134150846};
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_attr_out),
+      .error = 0,
+      .unique = 4,
+  };
+  struct fuse_attr attr = {
+      .ino = 1,
+      .size = 512,
+      .blocks = 4,
+      .atime = static_cast<uint64_t>(atime.tv_sec),
+      .mtime = static_cast<uint64_t>(mtime.tv_sec),
+      .ctime = static_cast<uint64_t>(ctime.tv_sec),
+      .atimensec = static_cast<uint32_t>(atime.tv_nsec),
+      .mtimensec = static_cast<uint32_t>(mtime.tv_nsec),
+      .ctimensec = static_cast<uint32_t>(ctime.tv_nsec),
+      .mode = expected_mode,
+      .nlink = 2,
+      .uid = 1234,
+      .gid = 4321,
+      .rdev = 12,
+      .blksize = 4096,
+  };
+  struct fuse_attr_out out_payload = {
+      .attr = attr,
+  };
+  iov_out[0].iov_len = sizeof(out_header);
+  iov_out[0].iov_base = &out_header;
+  iov_out[1].iov_len = sizeof(out_payload);
+  iov_out[1].iov_base = &out_payload;
+
+  SetExpected(iov_in, 2, iov_out, 2);
+
+  struct stat stat_buf;
+  EXPECT_THAT(stat(mount_point_.path().c_str(), &stat_buf), SyscallSucceeds());
+
+  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 = atime,
+      .st_mtim = mtime,
+      .st_ctim = ctime,
+  };
+  EXPECT_TRUE(StatsAreEqual(stat_buf, expected_stat));
+  WaitCompleted();
+}
+
+TEST_F(StatTest, StatNotFound) {
+  struct iovec iov_in[2];
+  struct iovec iov_out[2];
+
+  struct fuse_in_header in_header = {
+      .len = sizeof(struct fuse_in_header) + sizeof(struct fuse_getattr_in),
+      .opcode = FUSE_GETATTR,
+      .unique = 4,
+  };
+  struct fuse_getattr_in in_payload = {0};
+  iov_in[0].iov_len = sizeof(in_header);
+  iov_in[0].iov_base = &in_header;
+  iov_in[1].iov_len = sizeof(in_payload);
+  iov_in[1].iov_base = &in_payload;
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header),
+      .error = -ENOENT,
+      .unique = 4,
+  };
+  iov_out[0].iov_len = sizeof(out_header);
+  iov_out[0].iov_base = &out_header;
+
+  SetExpected(iov_in, 2, iov_out, 1);
+
+  struct stat stat_buf;
+  EXPECT_THAT(stat(mount_point_.path().c_str(), &stat_buf),
+              SyscallFailsWithErrno(ENOENT));
+  WaitCompleted();
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor