github.com/nicocha30/gvisor-ligolo@v0.0.0-20230726075806-989fa2c0a413/pkg/sentry/fsimpl/gofer/fstree.go (about)

     1  package gofer
     2  
     3  import (
     4  	"github.com/nicocha30/gvisor-ligolo/pkg/fspath"
     5  	"github.com/nicocha30/gvisor-ligolo/pkg/sentry/vfs"
     6  )
     7  
     8  // IsAncestorDentry returns true if d is an ancestor of d2; that is, d is
     9  // either d2's parent or an ancestor of d2's parent.
    10  func genericIsAncestorDentry(d, d2 *dentry) bool {
    11  	for d2 != nil {
    12  		if d2.parent == d {
    13  			return true
    14  		}
    15  		if d2.parent == d2 {
    16  			return false
    17  		}
    18  		d2 = d2.parent
    19  	}
    20  	return false
    21  }
    22  
    23  // ParentOrSelf returns d.parent. If d.parent is nil, ParentOrSelf returns d.
    24  func genericParentOrSelf(d *dentry) *dentry {
    25  	if d.parent != nil {
    26  		return d.parent
    27  	}
    28  	return d
    29  }
    30  
    31  // PrependPath is a generic implementation of FilesystemImpl.PrependPath().
    32  func genericPrependPath(vfsroot vfs.VirtualDentry, mnt *vfs.Mount, d *dentry, b *fspath.Builder) error {
    33  	for {
    34  		if mnt == vfsroot.Mount() && &d.vfsd == vfsroot.Dentry() {
    35  			return vfs.PrependPathAtVFSRootError{}
    36  		}
    37  		if mnt != nil && &d.vfsd == mnt.Root() {
    38  			return nil
    39  		}
    40  		if d.parent == nil {
    41  			return vfs.PrependPathAtNonMountRootError{}
    42  		}
    43  		b.PrependComponent(d.name)
    44  		d = d.parent
    45  	}
    46  }
    47  
    48  // DebugPathname returns a pathname to d relative to its filesystem root.
    49  // DebugPathname does not correspond to any Linux function; it's used to
    50  // generate dentry pathnames for debugging.
    51  func genericDebugPathname(d *dentry) string {
    52  	var b fspath.Builder
    53  	_ = genericPrependPath(vfs.VirtualDentry{}, nil, d, &b)
    54  	return b.String()
    55  }