diff options
Diffstat (limited to 'pkg/sentry/fs/inode_overlay.go')
| -rw-r--r-- | pkg/sentry/fs/inode_overlay.go | 63 |
1 files changed, 45 insertions, 18 deletions
diff --git a/pkg/sentry/fs/inode_overlay.go b/pkg/sentry/fs/inode_overlay.go index 5a388dad1..537c8d257 100644 --- a/pkg/sentry/fs/inode_overlay.go +++ b/pkg/sentry/fs/inode_overlay.go @@ -19,19 +19,19 @@ import ( "strings" "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/log" - "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport" "gvisor.dev/gvisor/pkg/syserror" ) -func overlayHasWhiteout(parent *Inode, name string) bool { - s, err := parent.Getxattr(XattrOverlayWhiteout(name)) +func overlayHasWhiteout(ctx context.Context, parent *Inode, name string) bool { + s, err := parent.GetXattr(ctx, XattrOverlayWhiteout(name), 1) return err == nil && s == "y" } -func overlayCreateWhiteout(parent *Inode, name string) error { - return parent.InodeOperations.Setxattr(parent, XattrOverlayWhiteout(name), "y") +func overlayCreateWhiteout(ctx context.Context, parent *Inode, name string) error { + return parent.InodeOperations.SetXattr(ctx, parent, XattrOverlayWhiteout(name), "y", 0 /* flags */) } func overlayWriteOut(ctx context.Context, o *overlayEntry) error { @@ -89,7 +89,7 @@ func overlayLookup(ctx context.Context, parent *overlayEntry, inode *Inode, name } // Are we done? - if overlayHasWhiteout(parent.upper, name) { + if overlayHasWhiteout(ctx, parent.upper, name) { if upperInode == nil { parent.copyMu.RUnlock() if negativeUpperChild { @@ -231,7 +231,8 @@ func overlayCreate(ctx context.Context, o *overlayEntry, parent *Dirent, name st upperFile.Dirent.Inode.IncRef() entry, err := newOverlayEntry(ctx, upperFile.Dirent.Inode, nil, false) if err != nil { - cleanupUpper(ctx, o.upper, name) + werr := fmt.Errorf("newOverlayEntry failed: %v", err) + cleanupUpper(ctx, o.upper, name, werr) return nil, err } @@ -345,7 +346,7 @@ func overlayRemove(ctx context.Context, o *overlayEntry, parent *Dirent, child * } } if child.Inode.overlay.lowerExists { - if err := overlayCreateWhiteout(o.upper, child.name); err != nil { + if err := overlayCreateWhiteout(ctx, o.upper, child.name); err != nil { return err } } @@ -426,7 +427,7 @@ func overlayRename(ctx context.Context, o *overlayEntry, oldParent *Dirent, rena return err } if renamed.Inode.overlay.lowerExists { - if err := overlayCreateWhiteout(oldParent.Inode.overlay.upper, oldName); err != nil { + if err := overlayCreateWhiteout(ctx, oldParent.Inode.overlay.upper, oldName); err != nil { return err } } @@ -436,7 +437,7 @@ func overlayRename(ctx context.Context, o *overlayEntry, oldParent *Dirent, rena } func overlayBind(ctx context.Context, o *overlayEntry, parent *Dirent, name string, data transport.BoundEndpoint, perm FilePermissions) (*Dirent, error) { - if err := copyUp(ctx, parent); err != nil { + if err := copyUpLockedForRename(ctx, parent); err != nil { return nil, err } @@ -462,7 +463,9 @@ func overlayBind(ctx context.Context, o *overlayEntry, parent *Dirent, name stri inode.DecRef() return nil, err } - return NewDirent(ctx, newOverlayInode(ctx, entry, inode.MountSource), name), nil + // Use the parent's MountSource, since that corresponds to the overlay, + // and not the upper filesystem. + return NewDirent(ctx, newOverlayInode(ctx, entry, parent.Inode.MountSource), name), nil } func overlayBoundEndpoint(o *overlayEntry, path string) transport.BoundEndpoint { @@ -526,7 +529,7 @@ func overlayUnstableAttr(ctx context.Context, o *overlayEntry) (UnstableAttr, er return attr, err } -func overlayGetxattr(o *overlayEntry, name string) (string, error) { +func overlayGetXattr(ctx context.Context, o *overlayEntry, name string, size uint64) (string, error) { // Hot path. This is how the overlay checks for whiteout files. // Avoid defers. var ( @@ -542,26 +545,38 @@ func overlayGetxattr(o *overlayEntry, name string) (string, error) { o.copyMu.RLock() if o.upper != nil { - s, err = o.upper.Getxattr(name) + s, err = o.upper.GetXattr(ctx, name, size) } else { - s, err = o.lower.Getxattr(name) + s, err = o.lower.GetXattr(ctx, name, size) } o.copyMu.RUnlock() return s, err } -func overlayListxattr(o *overlayEntry) (map[string]struct{}, error) { +func overlaySetxattr(ctx context.Context, o *overlayEntry, d *Dirent, name, value string, flags uint32) error { + // Don't allow changes to overlay xattrs through a setxattr syscall. + if strings.HasPrefix(XattrOverlayPrefix, name) { + return syserror.EPERM + } + + if err := copyUp(ctx, d); err != nil { + return err + } + return o.upper.SetXattr(ctx, d, name, value, flags) +} + +func overlayListXattr(ctx context.Context, o *overlayEntry, size uint64) (map[string]struct{}, error) { o.copyMu.RLock() defer o.copyMu.RUnlock() var names map[string]struct{} var err error if o.upper != nil { - names, err = o.upper.Listxattr() + names, err = o.upper.ListXattr(ctx, size) } else { - names, err = o.lower.Listxattr() + names, err = o.lower.ListXattr(ctx, size) } for name := range names { - // Same as overlayGetxattr, we shouldn't forward along + // Same as overlayGetXattr, we shouldn't forward along // overlay attributes. if strings.HasPrefix(XattrOverlayPrefix, name) { delete(names, name) @@ -570,6 +585,18 @@ func overlayListxattr(o *overlayEntry) (map[string]struct{}, error) { return names, err } +func overlayRemoveXattr(ctx context.Context, o *overlayEntry, d *Dirent, name string) error { + // Don't allow changes to overlay xattrs through a removexattr syscall. + if strings.HasPrefix(XattrOverlayPrefix, name) { + return syserror.EPERM + } + + if err := copyUp(ctx, d); err != nil { + return err + } + return o.upper.RemoveXattr(ctx, d, name) +} + func overlayCheck(ctx context.Context, o *overlayEntry, p PermMask) error { o.copyMu.RLock() // Hot path. Avoid defers. |