diff options
Diffstat (limited to 'pkg/sentry/vfs')
| -rw-r--r-- | pkg/sentry/vfs/file_description.go | 3 | ||||
| -rw-r--r-- | pkg/sentry/vfs/file_description_impl_util.go | 6 |
2 files changed, 8 insertions, 1 deletions
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go index 2b29a3c3f..73bb36d3e 100644 --- a/pkg/sentry/vfs/file_description.go +++ b/pkg/sentry/vfs/file_description.go @@ -326,6 +326,9 @@ type FileDescriptionImpl interface { // Allocate grows the file to offset + length bytes. // Only mode == 0 is supported currently. // + // Allocate should return EISDIR on directories, ESPIPE on pipes, and ENODEV on + // other files where it is not supported. + // // Preconditions: The FileDescription was opened for writing. Allocate(ctx context.Context, mode, offset, length uint64) error diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go index 68b80a951..78da16bac 100644 --- a/pkg/sentry/vfs/file_description_impl_util.go +++ b/pkg/sentry/vfs/file_description_impl_util.go @@ -57,7 +57,11 @@ func (FileDescriptionDefaultImpl) StatFS(ctx context.Context) (linux.Statfs, err } // Allocate implements FileDescriptionImpl.Allocate analogously to -// fallocate called on regular file, directory or FIFO in Linux. +// fallocate called on an invalid type of file in Linux. +// +// Note that directories can rely on this implementation even though they +// should technically return EISDIR. Allocate should never be called for a +// directory, because it requires a writable fd. func (FileDescriptionDefaultImpl) Allocate(ctx context.Context, mode, offset, length uint64) error { return syserror.ENODEV } |