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-rw-r--r--pkg/abi/linux/linux_abi_autogen_unsafe.go12
-rw-r--r--pkg/sentry/fsimpl/gofer/filesystem.go17
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer.go11
3 files changed, 26 insertions, 14 deletions
diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index cd2b8718e..37df17dac 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -124,12 +124,12 @@ func (s *Statx) UnmarshalBytes(src []byte) {
// Packed implements marshal.Marshallable.Packed.
//go:nosplit
func (s *Statx) Packed() bool {
- return s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed()
+ return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed()
}
// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
func (s *Statx) MarshalUnsafe(dst []byte) {
- if s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() {
+ if s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
safecopy.CopyIn(dst, unsafe.Pointer(s))
} else {
s.MarshalBytes(dst)
@@ -138,7 +138,7 @@ func (s *Statx) MarshalUnsafe(dst []byte) {
// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
func (s *Statx) UnmarshalUnsafe(src []byte) {
- if s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() {
+ if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
safecopy.CopyOut(unsafe.Pointer(s), src)
} else {
s.UnmarshalBytes(src)
@@ -148,7 +148,7 @@ func (s *Statx) UnmarshalUnsafe(src []byte) {
// CopyOutN implements marshal.Marshallable.CopyOutN.
//go:nosplit
func (s *Statx) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
- if !s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() {
+ if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
// Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
s.MarshalBytes(buf) // escapes: fallback.
@@ -178,7 +178,7 @@ func (s *Statx) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {
// CopyIn implements marshal.Marshallable.CopyIn.
//go:nosplit
func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
- if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+ if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
// Type Statx doesn't have a packed layout in memory, fall back to UnmarshalBytes.
buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
length, err := task.CopyInBytes(addr, buf) // escapes: okay.
@@ -204,7 +204,7 @@ func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
// WriteTo implements io.WriterTo.WriteTo.
func (s *Statx) WriteTo(w io.Writer) (int64, error) {
- if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+ if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
// Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
buf := make([]byte, s.SizeBytes())
s.MarshalBytes(buf)
diff --git a/pkg/sentry/fsimpl/gofer/filesystem.go b/pkg/sentry/fsimpl/gofer/filesystem.go
index cd5f5049e..491495b16 100644
--- a/pkg/sentry/fsimpl/gofer/filesystem.go
+++ b/pkg/sentry/fsimpl/gofer/filesystem.go
@@ -150,11 +150,9 @@ afterSymlink:
return nil, err
}
if d != d.parent && !d.cachedMetadataAuthoritative() {
- _, attrMask, attr, err := d.parent.file.getAttr(ctx, dentryAttrMask())
- if err != nil {
+ if err := d.parent.updateFromGetattr(ctx); err != nil {
return nil, err
}
- d.parent.updateFromP9Attrs(attrMask, &attr)
}
rp.Advance()
return d.parent, nil
@@ -209,17 +207,28 @@ func (fs *filesystem) getChildLocked(ctx context.Context, vfsObj *vfs.VirtualFil
// Preconditions: As for getChildLocked. !parent.isSynthetic().
func (fs *filesystem) revalidateChildLocked(ctx context.Context, vfsObj *vfs.VirtualFilesystem, parent *dentry, name string, child *dentry, ds **[]*dentry) (*dentry, error) {
+ if child != nil {
+ // Need to lock child.metadataMu because we might be updating child
+ // metadata. We need to hold the lock *before* getting metadata from the
+ // server and release it after updating local metadata.
+ child.metadataMu.Lock()
+ }
qid, file, attrMask, attr, err := parent.file.walkGetAttrOne(ctx, name)
if err != nil && err != syserror.ENOENT {
+ if child != nil {
+ child.metadataMu.Unlock()
+ }
return nil, err
}
if child != nil {
if !file.isNil() && inoFromPath(qid.Path) == child.ino {
// The file at this path hasn't changed. Just update cached metadata.
file.close(ctx)
- child.updateFromP9Attrs(attrMask, &attr)
+ child.updateFromP9AttrsLocked(attrMask, &attr)
+ child.metadataMu.Unlock()
return child, nil
}
+ child.metadataMu.Unlock()
if file.isNil() && child.isSynthetic() {
// We have a synthetic file, and no remote file has arisen to
// replace it.
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index b74d489a0..ba7f650b3 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -785,8 +785,8 @@ func (d *dentry) cachedMetadataAuthoritative() bool {
// updateFromP9Attrs is called to update d's metadata after an update from the
// remote filesystem.
-func (d *dentry) updateFromP9Attrs(mask p9.AttrMask, attr *p9.Attr) {
- d.metadataMu.Lock()
+// Precondition: d.metadataMu must be locked.
+func (d *dentry) updateFromP9AttrsLocked(mask p9.AttrMask, attr *p9.Attr) {
if mask.Mode {
if got, want := uint32(attr.Mode.FileType()), d.fileType(); got != want {
d.metadataMu.Unlock()
@@ -822,7 +822,6 @@ func (d *dentry) updateFromP9Attrs(mask p9.AttrMask, attr *p9.Attr) {
if mask.Size {
d.updateFileSizeLocked(attr.Size)
}
- d.metadataMu.Unlock()
}
// Preconditions: !d.isSynthetic()
@@ -834,6 +833,10 @@ func (d *dentry) updateFromGetattr(ctx context.Context) error {
file p9file
handleMuRLocked bool
)
+ // d.metadataMu must be locked *before* we getAttr so that we do not end up
+ // updating stale attributes in d.updateFromP9AttrsLocked().
+ d.metadataMu.Lock()
+ defer d.metadataMu.Unlock()
d.handleMu.RLock()
if !d.handle.file.isNil() {
file = d.handle.file
@@ -849,7 +852,7 @@ func (d *dentry) updateFromGetattr(ctx context.Context) error {
if err != nil {
return err
}
- d.updateFromP9Attrs(attrMask, &attr)
+ d.updateFromP9AttrsLocked(attrMask, &attr)
return nil
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 10:08:50 +0000