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/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 ++++++++++---- 4 files changed, 25 insertions(+), 9 deletions(-) (limited to 'pkg/sentry/fsimpl') 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 } -- cgit v1.2.3