Merge release-20210419.0-12-gc2955339d (automated)

4 files changed, 51 insertions, 76 deletions

diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index 176bcc242..f612a71b2 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -524,7 +524,7 @@ func (fd *FileDescription) Stat(ctx context.Context, opts StatOptions) (linux.St
 			Start: fd.vd,
 		})
 		stat, err := fd.vd.mount.fs.impl.StatAt(ctx, rp, opts)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return stat, err
 	}
 	return fd.impl.Stat(ctx, opts)
@@ -539,7 +539,7 @@ func (fd *FileDescription) SetStat(ctx context.Context, opts SetStatOptions) err
 			Start: fd.vd,
 		})
 		err := fd.vd.mount.fs.impl.SetStatAt(ctx, rp, opts)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return err
 	}
 	return fd.impl.SetStat(ctx, opts)
@@ -555,7 +555,7 @@ func (fd *FileDescription) StatFS(ctx context.Context) (linux.Statfs, error) {
 			Start: fd.vd,
 		})
 		statfs, err := fd.vd.mount.fs.impl.StatFSAt(ctx, rp)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return statfs, err
 	}
 	return fd.impl.StatFS(ctx)
@@ -701,7 +701,7 @@ func (fd *FileDescription) ListXattr(ctx context.Context, size uint64) ([]string
 			Start: fd.vd,
 		})
 		names, err := fd.vd.mount.fs.impl.ListXattrAt(ctx, rp, size)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return names, err
 	}
 	names, err := fd.impl.ListXattr(ctx, size)
@@ -730,7 +730,7 @@ func (fd *FileDescription) GetXattr(ctx context.Context, opts *GetXattrOptions)
 			Start: fd.vd,
 		})
 		val, err := fd.vd.mount.fs.impl.GetXattrAt(ctx, rp, *opts)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return val, err
 	}
 	return fd.impl.GetXattr(ctx, *opts)
@@ -746,7 +746,7 @@ func (fd *FileDescription) SetXattr(ctx context.Context, opts *SetXattrOptions)
 			Start: fd.vd,
 		})
 		err := fd.vd.mount.fs.impl.SetXattrAt(ctx, rp, *opts)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return err
 	}
 	return fd.impl.SetXattr(ctx, *opts)
@@ -762,7 +762,7 @@ func (fd *FileDescription) RemoveXattr(ctx context.Context, name string) error {
 			Start: fd.vd,
 		})
 		err := fd.vd.mount.fs.impl.RemoveXattrAt(ctx, rp, name)
-		rp.Release(ctx)
+		vfsObj.putResolvingPath(ctx, rp)
 		return err
 	}
 	return fd.impl.RemoveXattr(ctx, name)
diff --git a/pkg/sentry/vfs/opath.go b/pkg/sentry/vfs/opath.go
index 47848c76b..39fbac987 100644
--- a/pkg/sentry/vfs/opath.go
+++ b/pkg/sentry/vfs/opath.go
@@ -121,7 +121,7 @@ func (fd *opathFD) Stat(ctx context.Context, opts StatOptions) (linux.Statx, err
 		Start: fd.vfsfd.vd,
 	})
 	stat, err := fd.vfsfd.vd.mount.fs.impl.StatAt(ctx, rp, opts)
-	rp.Release(ctx)
+	vfsObj.putResolvingPath(ctx, rp)
 	return stat, err
 }
 
@@ -134,6 +134,6 @@ func (fd *opathFD) StatFS(ctx context.Context) (linux.Statfs, error) {
 		Start: fd.vfsfd.vd,
 	})
 	statfs, err := fd.vfsfd.vd.mount.fs.impl.StatFSAt(ctx, rp)
-	rp.Release(ctx)
+	vfsObj.putResolvingPath(ctx, rp)
 	return statfs, err
 }
diff --git a/pkg/sentry/vfs/resolving_path.go b/pkg/sentry/vfs/resolving_path.go
index 634c8b097..e4fd55012 100644
--- a/pkg/sentry/vfs/resolving_path.go
+++ b/pkg/sentry/vfs/resolving_path.go
@@ -120,8 +120,6 @@ var resolvingPathPool = sync.Pool{
 	},
 }
 
-// getResolvingPath gets a new ResolvingPath from the pool. Caller must call
-// ResolvingPath.Release() when done.
 func (vfs *VirtualFilesystem) getResolvingPath(creds *auth.Credentials, pop *PathOperation) *ResolvingPath {
 	rp := resolvingPathPool.Get().(*ResolvingPath)
 	rp.vfs = vfs
@@ -144,30 +142,7 @@ func (vfs *VirtualFilesystem) getResolvingPath(creds *auth.Credentials, pop *Pat
 	return rp
 }
 
-// Copy creates another ResolvingPath with the same state as the original.
-// Copies are independent, using the copy does not change the original and
-// vice-versa.
-//
-// Caller must call Resease() when done.
-func (rp *ResolvingPath) Copy() *ResolvingPath {
-	copy := resolvingPathPool.Get().(*ResolvingPath)
-	*copy = *rp // All fields all shallow copiable.
-
-	// Take extra reference for the copy if the original had them.
-	if copy.flags&rpflagsHaveStartRef != 0 {
-		copy.start.IncRef()
-	}
-	if copy.flags&rpflagsHaveMountRef != 0 {
-		copy.mount.IncRef()
-	}
-	// Reset error state.
-	copy.nextStart = nil
-	copy.nextMount = nil
-	return copy
-}
-
-// Release decrements references if needed and returns the object to the pool.
-func (rp *ResolvingPath) Release(ctx context.Context) {
+func (vfs *VirtualFilesystem) putResolvingPath(ctx context.Context, rp *ResolvingPath) {
 	rp.root = VirtualDentry{}
 	rp.decRefStartAndMount(ctx)
 	rp.mount = nil
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 8b392232a..00f1847d8 100644
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -208,11 +208,11 @@ func (vfs *VirtualFilesystem) AccessAt(ctx context.Context, creds *auth.Credenti
 	for {
 		err := rp.mount.fs.impl.AccessAt(ctx, rp, creds, ats)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -230,11 +230,11 @@ func (vfs *VirtualFilesystem) GetDentryAt(ctx context.Context, creds *auth.Crede
 				dentry: d,
 			}
 			rp.mount.IncRef()
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return vd, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return VirtualDentry{}, err
 		}
 	}
@@ -252,7 +252,7 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
 			}
 			rp.mount.IncRef()
 			name := rp.Component()
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return parentVD, name, nil
 		}
 		if checkInvariants {
@@ -261,7 +261,7 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return VirtualDentry{}, "", err
 		}
 	}
@@ -292,7 +292,7 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
 	for {
 		err := rp.mount.fs.impl.LinkAt(ctx, rp, oldVD)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			oldVD.DecRef(ctx)
 			return nil
 		}
@@ -302,7 +302,7 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			oldVD.DecRef(ctx)
 			return err
 		}
@@ -331,7 +331,7 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
 	for {
 		err := rp.mount.fs.impl.MkdirAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if checkInvariants {
@@ -340,7 +340,7 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -366,7 +366,7 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
 	for {
 		err := rp.mount.fs.impl.MknodAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if checkInvariants {
@@ -375,7 +375,7 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -444,7 +444,7 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential
 	for {
 		fd, err := rp.mount.fs.impl.OpenAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 
 			if opts.FileExec {
 				if fd.Mount().Flags.NoExec {
@@ -468,7 +468,7 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential
 			return fd, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil, err
 		}
 	}
@@ -480,11 +480,11 @@ func (vfs *VirtualFilesystem) ReadlinkAt(ctx context.Context, creds *auth.Creden
 	for {
 		target, err := rp.mount.fs.impl.ReadlinkAt(ctx, rp)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return target, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return "", err
 		}
 	}
@@ -533,7 +533,7 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
 	for {
 		err := rp.mount.fs.impl.RenameAt(ctx, rp, oldParentVD, oldName, renameOpts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			oldParentVD.DecRef(ctx)
 			return nil
 		}
@@ -543,7 +543,7 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			oldParentVD.DecRef(ctx)
 			return err
 		}
@@ -569,7 +569,7 @@ func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentia
 	for {
 		err := rp.mount.fs.impl.RmdirAt(ctx, rp)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if checkInvariants {
@@ -578,7 +578,7 @@ func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentia
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -590,11 +590,11 @@ func (vfs *VirtualFilesystem) SetStatAt(ctx context.Context, creds *auth.Credent
 	for {
 		err := rp.mount.fs.impl.SetStatAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -606,11 +606,11 @@ func (vfs *VirtualFilesystem) StatAt(ctx context.Context, creds *auth.Credential
 	for {
 		stat, err := rp.mount.fs.impl.StatAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return stat, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return linux.Statx{}, err
 		}
 	}
@@ -623,11 +623,11 @@ func (vfs *VirtualFilesystem) StatFSAt(ctx context.Context, creds *auth.Credenti
 	for {
 		statfs, err := rp.mount.fs.impl.StatFSAt(ctx, rp)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return statfs, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return linux.Statfs{}, err
 		}
 	}
@@ -652,7 +652,7 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
 	for {
 		err := rp.mount.fs.impl.SymlinkAt(ctx, rp, target)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if checkInvariants {
@@ -661,7 +661,7 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -686,7 +686,7 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
 	for {
 		err := rp.mount.fs.impl.UnlinkAt(ctx, rp)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if checkInvariants {
@@ -695,7 +695,7 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -707,7 +707,7 @@ func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.C
 	for {
 		bep, err := rp.mount.fs.impl.BoundEndpointAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return bep, nil
 		}
 		if checkInvariants {
@@ -716,7 +716,7 @@ func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.C
 			}
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil, err
 		}
 	}
@@ -729,7 +729,7 @@ func (vfs *VirtualFilesystem) ListXattrAt(ctx context.Context, creds *auth.Crede
 	for {
 		names, err := rp.mount.fs.impl.ListXattrAt(ctx, rp, size)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return names, nil
 		}
 		if err == syserror.ENOTSUP {
@@ -737,11 +737,11 @@ func (vfs *VirtualFilesystem) ListXattrAt(ctx context.Context, creds *auth.Crede
 			// fs/xattr.c:vfs_listxattr() falls back to allowing the security
 			// subsystem to return security extended attributes, which by
 			// default don't exist.
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil, err
 		}
 	}
@@ -754,11 +754,11 @@ func (vfs *VirtualFilesystem) GetXattrAt(ctx context.Context, creds *auth.Creden
 	for {
 		val, err := rp.mount.fs.impl.GetXattrAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return val, nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return "", err
 		}
 	}
@@ -771,11 +771,11 @@ func (vfs *VirtualFilesystem) SetXattrAt(ctx context.Context, creds *auth.Creden
 	for {
 		err := rp.mount.fs.impl.SetXattrAt(ctx, rp, *opts)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}
@@ -787,11 +787,11 @@ func (vfs *VirtualFilesystem) RemoveXattrAt(ctx context.Context, creds *auth.Cre
 	for {
 		err := rp.mount.fs.impl.RemoveXattrAt(ctx, rp, name)
 		if err == nil {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return nil
 		}
 		if !rp.handleError(ctx, err) {
-			rp.Release(ctx)
+			vfs.putResolvingPath(ctx, rp)
 			return err
 		}
 	}