diff options
| -rw-r--r-- | pkg/sentry/fsimpl/gofer/regular_file.go | 48 |
1 files changed, 24 insertions, 24 deletions
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go index eed05e369..340fea813 100644 --- a/pkg/sentry/fsimpl/gofer/regular_file.go +++ b/pkg/sentry/fsimpl/gofer/regular_file.go @@ -678,28 +678,28 @@ func (fd *regularFileFD) Sync(ctx context.Context) error { // ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. func (fd *regularFileFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { d := fd.dentry() - switch d.fs.opts.interop { - case InteropModeExclusive: - // Any mapping is fine. - case InteropModeWritethrough: - // Shared writable mappings require a host FD, since otherwise we can't - // synchronously flush memory-mapped writes to the remote file. - if opts.Private || !opts.MaxPerms.Write { - break - } - fallthrough - case InteropModeShared: - // All mappings require a host FD to be coherent with other filesystem - // users. - if d.fs.opts.forcePageCache { - // Whether or not we have a host FD, we're not allowed to use it. - return syserror.ENODEV - } - if atomic.LoadInt32(&d.mmapFD) < 0 { - return syserror.ENODEV + // Force sentry page caching at your own risk. + if !d.fs.opts.forcePageCache { + switch d.fs.opts.interop { + case InteropModeExclusive: + // Any mapping is fine. + case InteropModeWritethrough: + // Shared writable mappings require a host FD, since otherwise we + // can't synchronously flush memory-mapped writes to the remote + // file. + if opts.Private || !opts.MaxPerms.Write { + break + } + fallthrough + case InteropModeShared: + // All mappings require a host FD to be coherent with other + // filesystem users. + if atomic.LoadInt32(&d.mmapFD) < 0 { + return syserror.ENODEV + } + default: + panic(fmt.Sprintf("unknown InteropMode %v", d.fs.opts.interop)) } - default: - panic(fmt.Sprintf("unknown InteropMode %v", d.fs.opts.interop)) } // After this point, d may be used as a memmap.Mappable. d.pf.hostFileMapperInitOnce.Do(d.pf.hostFileMapper.Init) @@ -708,12 +708,12 @@ func (fd *regularFileFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpt } func (d *dentry) mayCachePages() bool { - if d.fs.opts.interop == InteropModeShared { - return false - } if d.fs.opts.forcePageCache { return true } + if d.fs.opts.interop == InteropModeShared { + return false + } return atomic.LoadInt32(&d.mmapFD) >= 0 } |