From 26adb3c4747288aba2475cb403d66d68481793dc Mon Sep 17 00:00:00 2001
From: Fabricio Voznika <fvoznika@google.com>
Date: Wed, 28 Apr 2021 17:00:47 -0700
Subject: Automated rollback of changelist 369686285
PiperOrigin-RevId: 371015541
---
pkg/sentry/vfs/file_description.go | 14 +++----
pkg/sentry/vfs/opath.go | 4 +-
pkg/sentry/vfs/resolving_path.go | 27 ++++++++++++-
pkg/sentry/vfs/vfs.go | 82 +++++++++++++++++++-------------------
4 files changed, 76 insertions(+), 51 deletions(-)
(limited to 'pkg/sentry/vfs')
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index f612a71b2..176bcc242 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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return err
}
return fd.impl.RemoveXattr(ctx, name)
diff --git a/pkg/sentry/vfs/opath.go b/pkg/sentry/vfs/opath.go
index 39fbac987..47848c76b 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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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)
- vfsObj.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return statfs, err
}
diff --git a/pkg/sentry/vfs/resolving_path.go b/pkg/sentry/vfs/resolving_path.go
index e4fd55012..634c8b097 100644
--- a/pkg/sentry/vfs/resolving_path.go
+++ b/pkg/sentry/vfs/resolving_path.go
@@ -120,6 +120,8 @@ 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
@@ -142,7 +144,30 @@ func (vfs *VirtualFilesystem) getResolvingPath(creds *auth.Credentials, pop *Pat
return rp
}
-func (vfs *VirtualFilesystem) putResolvingPath(ctx context.Context, rp *ResolvingPath) {
+// 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) {
rp.root = VirtualDentry{}
rp.decRefStartAndMount(ctx)
rp.mount = nil
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 00f1847d8..8b392232a 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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return err
}
}
@@ -230,11 +230,11 @@ func (vfs *VirtualFilesystem) GetDentryAt(ctx context.Context, creds *auth.Crede
dentry: d,
}
rp.mount.IncRef()
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return vd, nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return VirtualDentry{}, err
}
}
@@ -252,7 +252,7 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
}
rp.mount.IncRef()
name := rp.Component()
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return parentVD, name, nil
}
if checkInvariants {
@@ -261,7 +261,7 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
oldVD.DecRef(ctx)
return nil
}
@@ -302,7 +302,7 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if checkInvariants {
@@ -340,7 +340,7 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if checkInvariants {
@@ -375,7 +375,7 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return target, nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
oldParentVD.DecRef(ctx)
return nil
}
@@ -543,7 +543,7 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if checkInvariants {
@@ -578,7 +578,7 @@ func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentia
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return stat, nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return statfs, nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if checkInvariants {
@@ -661,7 +661,7 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if checkInvariants {
@@ -695,7 +695,7 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return bep, nil
}
if checkInvariants {
@@ -716,7 +716,7 @@ func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.C
}
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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.
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil, nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return val, nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
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 {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return nil
}
if !rp.handleError(ctx, err) {
- vfs.putResolvingPath(ctx, rp)
+ rp.Release(ctx)
return err
}
}
--
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