diff options
| -rw-r--r-- | pkg/sentry/fsimpl/tmpfs/tmpfs.go | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go index afd9f8533..8bc8818c0 100644 --- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go +++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go @@ -77,6 +77,11 @@ type FilesystemOpts struct { // RootSymlinkTarget is the target of the root symlink. Only valid if // RootFileType == S_IFLNK. RootSymlinkTarget string + + // FilesystemType allows setting a different FilesystemType for this + // tmpfs filesystem. This allows tmpfs to "impersonate" other + // filesystems, like ramdiskfs and cgroupfs. + FilesystemType vfs.FilesystemType } // GetFilesystem implements vfs.FilesystemType.GetFilesystem. @@ -91,15 +96,22 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt clock: clock, } - fs.vfsfs.Init(vfsObj, &fstype, &fs) - - typ := uint16(linux.S_IFDIR) + rootFileType := uint16(linux.S_IFDIR) + newFSType := vfs.FilesystemType(&fstype) tmpfsOpts, ok := opts.InternalData.(FilesystemOpts) - if ok && tmpfsOpts.RootFileType != 0 { - typ = tmpfsOpts.RootFileType + if ok { + if tmpfsOpts.RootFileType != 0 { + rootFileType = tmpfsOpts.RootFileType + } + if tmpfsOpts.FilesystemType != nil { + newFSType = tmpfsOpts.FilesystemType + } } + + fs.vfsfs.Init(vfsObj, newFSType, &fs) + var root *inode - switch typ { + switch rootFileType { case linux.S_IFREG: root = fs.newRegularFile(creds, 0777) case linux.S_IFLNK: @@ -107,7 +119,7 @@ func (fstype FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt case linux.S_IFDIR: root = fs.newDirectory(creds, 01777) default: - return nil, nil, fmt.Errorf("invalid tmpfs root file type: %#o", typ) + return nil, nil, fmt.Errorf("invalid tmpfs root file type: %#o", rootFileType) } return &fs.vfsfs, &fs.newDentry(root).vfsd, nil } |