From 6c099d830091b3153e0dc39cf500dba441f45707 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Wed, 1 Jul 2020 22:03:14 -0700 Subject: Update preadv2/pwritev2 flag handling in vfs2. We do not support RWF_SYNC/RWF_DSYNC and probably shouldn't silently accept them, since the user may incorrectly believe that we are synchronizing I/O. Remove the pwritev2 test verifying that we support these flags. gvisor.dev/issue/2601 is the tracking bug for deciding which RWF_.* flags we need and supporting them. Updates #2923, #2601. PiperOrigin-RevId: 319351286 --- pkg/abi/linux/file.go | 5 +-- pkg/sentry/fsimpl/gofer/regular_file.go | 8 +++-- pkg/sentry/fsimpl/gofer/special_file.go | 8 +++-- pkg/sentry/fsimpl/host/host.go | 4 ++- pkg/sentry/fsimpl/tmpfs/regular_file.go | 14 +++++--- test/syscalls/BUILD | 1 + test/syscalls/linux/pwritev2.cc | 59 ++++++--------------------------- 7 files changed, 39 insertions(+), 60 deletions(-) diff --git a/pkg/abi/linux/file.go b/pkg/abi/linux/file.go index 055ac1d7c..e11ca2d62 100644 --- a/pkg/abi/linux/file.go +++ b/pkg/abi/linux/file.go @@ -191,8 +191,9 @@ var DirentType = abi.ValueSet{ // Values for preadv2/pwritev2. const ( - // Note: gVisor does not implement the RWF_HIPRI feature, but the flag is - // accepted as a valid flag argument for preadv2/pwritev2. + // NOTE(b/120162627): gVisor does not implement the RWF_HIPRI feature, but + // the flag is accepted as a valid flag argument for preadv2/pwritev2 and + // silently ignored. RWF_HIPRI = 0x00000001 RWF_DSYNC = 0x00000002 RWF_SYNC = 0x00000004 diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go index faba73af2..3d2d3530a 100644 --- a/pkg/sentry/fsimpl/gofer/regular_file.go +++ b/pkg/sentry/fsimpl/gofer/regular_file.go @@ -102,7 +102,9 @@ func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offs return 0, syserror.EINVAL } - // Check that flags are supported. Silently ignore RWF_HIPRI. + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. if opts.Flags&^linux.RWF_HIPRI != 0 { return 0, syserror.EOPNOTSUPP } @@ -155,7 +157,9 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off return 0, syserror.EINVAL } - // Check that flags are supported. Silently ignore RWF_HIPRI. + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select pwritev2 flags. if opts.Flags&^linux.RWF_HIPRI != 0 { return 0, syserror.EOPNOTSUPP } diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go index 2b381af05..3c4e7e2e4 100644 --- a/pkg/sentry/fsimpl/gofer/special_file.go +++ b/pkg/sentry/fsimpl/gofer/special_file.go @@ -130,7 +130,9 @@ func (fd *specialFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offs return 0, syserror.EINVAL } - // Check that flags are supported. Silently ignore RWF_HIPRI. + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. if opts.Flags&^linux.RWF_HIPRI != 0 { return 0, syserror.EOPNOTSUPP } @@ -176,7 +178,9 @@ func (fd *specialFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off return 0, syserror.EINVAL } - // Check that flags are supported. Silently ignore RWF_HIPRI. + // Check that flags are supported. + // + // TODO(gvisor.dev/issue/2601): Support select pwritev2 flags. if opts.Flags&^linux.RWF_HIPRI != 0 { return 0, syserror.EOPNOTSUPP } diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go index 007b3332e..1cd2982cb 100644 --- a/pkg/sentry/fsimpl/host/host.go +++ b/pkg/sentry/fsimpl/host/host.go @@ -588,8 +588,10 @@ func (f *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts } func readFromHostFD(ctx context.Context, hostFD int, dst usermem.IOSequence, offset int64, flags uint32) (int64, error) { + // Check that flags are supported. + // // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. - if flags != 0 { + if flags&^linux.RWF_HIPRI != 0 { return 0, syserror.EOPNOTSUPP } reader := hostfd.GetReadWriterAt(int32(hostFD), offset, flags) diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go index 6691add96..1cdb46e6f 100644 --- a/pkg/sentry/fsimpl/tmpfs/regular_file.go +++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go @@ -295,8 +295,11 @@ func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offs return 0, syserror.EINVAL } - // Check that flags are supported. Silently ignore RWF_HIPRI. - if opts.Flags&^linux.RWF_HIPRI != 0 { + // Check that flags are supported. RWF_DSYNC/RWF_SYNC can be ignored since + // all state is in-memory. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. + if opts.Flags&^(linux.RWF_HIPRI|linux.RWF_DSYNC|linux.RWF_SYNC) != 0 { return 0, syserror.EOPNOTSUPP } @@ -326,8 +329,11 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off return 0, syserror.EINVAL } - // Check that flags are supported. Silently ignore RWF_HIPRI. - if opts.Flags&^linux.RWF_HIPRI != 0 { + // Check that flags are supported. RWF_DSYNC/RWF_SYNC can be ignored since + // all state is in-memory. + // + // TODO(gvisor.dev/issue/2601): Support select preadv2 flags. + if opts.Flags&^(linux.RWF_HIPRI|linux.RWF_DSYNC|linux.RWF_SYNC) != 0 { return 0, syserror.EOPNOTSUPP } diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index 6fe397af9..7c4cd8192 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -531,6 +531,7 @@ syscall_test( syscall_test( add_overlay = True, test = "//test/syscalls/linux:pwritev2_test", + vfs2 = "True", ) syscall_test( diff --git a/test/syscalls/linux/pwritev2.cc b/test/syscalls/linux/pwritev2.cc index 3fe5a600f..63b686c62 100644 --- a/test/syscalls/linux/pwritev2.cc +++ b/test/syscalls/linux/pwritev2.cc @@ -69,7 +69,7 @@ ssize_t pwritev2(unsigned long fd, const struct iovec* iov, } // This test is the base case where we call pwritev (no offset, no flags). -TEST(Writev2Test, TestBaseCall) { +TEST(Writev2Test, BaseCall) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( @@ -97,7 +97,7 @@ TEST(Writev2Test, TestBaseCall) { } // This test is where we call pwritev2 with a positive offset and no flags. -TEST(Pwritev2Test, TestValidPositiveOffset) { +TEST(Pwritev2Test, ValidPositiveOffset) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); std::string prefix(kBufSize, '0'); @@ -129,7 +129,7 @@ TEST(Pwritev2Test, TestValidPositiveOffset) { // This test is the base case where we call writev by using -1 as the offset. // The write should use the file offset, so the test increments the file offset // prior to call pwritev2. -TEST(Pwritev2Test, TestNegativeOneOffset) { +TEST(Pwritev2Test, NegativeOneOffset) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const std::string prefix = "00"; @@ -164,7 +164,7 @@ TEST(Pwritev2Test, TestNegativeOneOffset) { // pwritev2 requires if the RWF_HIPRI flag is passed, the fd must be opened with // O_DIRECT. This test implements a correct call with the RWF_HIPRI flag. -TEST(Pwritev2Test, TestCallWithRWF_HIPRI) { +TEST(Pwritev2Test, CallWithRWF_HIPRI) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( @@ -189,47 +189,8 @@ TEST(Pwritev2Test, TestCallWithRWF_HIPRI) { EXPECT_EQ(buf, content); } -// This test checks that pwritev2 can be called with valid flags -TEST(Pwritev2Test, TestCallWithValidFlags) { - SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); - - const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( - GetAbsoluteTestTmpdir(), "", TempPath::kDefaultFileMode)); - const FileDescriptor fd = - ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDWR)); - - std::vector content(kBufSize, '0'); - struct iovec iov; - iov.iov_base = content.data(); - iov.iov_len = content.size(); - - EXPECT_THAT(pwritev2(fd.get(), &iov, /*iovcnt=*/1, - /*offset=*/0, /*flags=*/RWF_DSYNC), - SyscallSucceedsWithValue(kBufSize)); - - std::vector buf(content.size()); - EXPECT_THAT(read(fd.get(), buf.data(), buf.size()), - SyscallSucceedsWithValue(buf.size())); - - EXPECT_EQ(buf, content); - - SetContent(content); - - EXPECT_THAT(pwritev2(fd.get(), &iov, /*iovcnt=*/1, - /*offset=*/0, /*flags=*/0x4), - SyscallSucceedsWithValue(kBufSize)); - - ASSERT_THAT(lseek(fd.get(), 0, SEEK_CUR), - SyscallSucceedsWithValue(content.size())); - - EXPECT_THAT(pread(fd.get(), buf.data(), buf.size(), /*offset=*/0), - SyscallSucceedsWithValue(buf.size())); - - EXPECT_EQ(buf, content); -} - // This test calls pwritev2 with a bad file descriptor. -TEST(Writev2Test, TestBadFile) { +TEST(Writev2Test, BadFile) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); ASSERT_THAT(pwritev2(/*fd=*/-1, /*iov=*/nullptr, /*iovcnt=*/0, /*offset=*/0, /*flags=*/0), @@ -237,7 +198,7 @@ TEST(Writev2Test, TestBadFile) { } // This test calls pwrite2 with an invalid offset. -TEST(Pwritev2Test, TestInvalidOffset) { +TEST(Pwritev2Test, InvalidOffset) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( @@ -255,7 +216,7 @@ TEST(Pwritev2Test, TestInvalidOffset) { SyscallFailsWithErrno(EINVAL)); } -TEST(Pwritev2Test, TestUnseekableFileValid) { +TEST(Pwritev2Test, UnseekableFileValid) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); int pipe_fds[2]; @@ -285,7 +246,7 @@ TEST(Pwritev2Test, TestUnseekableFileValid) { // Calling pwritev2 with a non-negative offset calls pwritev. Calling pwritev // with an unseekable file is not allowed. A pipe is used for an unseekable // file. -TEST(Pwritev2Test, TestUnseekableFileInValid) { +TEST(Pwritev2Test, UnseekableFileInvalid) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); int pipe_fds[2]; @@ -304,7 +265,7 @@ TEST(Pwritev2Test, TestUnseekableFileInValid) { EXPECT_THAT(close(pipe_fds[1]), SyscallSucceeds()); } -TEST(Pwritev2Test, TestReadOnlyFile) { +TEST(Pwritev2Test, ReadOnlyFile) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( @@ -323,7 +284,7 @@ TEST(Pwritev2Test, TestReadOnlyFile) { } // This test calls pwritev2 with an invalid flag. -TEST(Pwritev2Test, TestInvalidFlag) { +TEST(Pwritev2Test, InvalidFlag) { SKIP_IF(pwritev2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( -- cgit v1.2.3