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path: root/pkg/sentry/fsimpl/memfs/filesystem.go
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Diffstat (limited to 'pkg/sentry/fsimpl/memfs/filesystem.go')
-rw-r--r--pkg/sentry/fsimpl/memfs/filesystem.go129
1 files changed, 111 insertions, 18 deletions
diff --git a/pkg/sentry/fsimpl/memfs/filesystem.go b/pkg/sentry/fsimpl/memfs/filesystem.go
index f79e2d9c8..af4389459 100644
--- a/pkg/sentry/fsimpl/memfs/filesystem.go
+++ b/pkg/sentry/fsimpl/memfs/filesystem.go
@@ -19,6 +19,7 @@ import (
"sync/atomic"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fspath"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
@@ -159,7 +160,7 @@ func (fs *filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, op
return nil, err
}
}
- inode.incRef() // vfsd.IncRef(&fs.vfsfs)
+ inode.incRef()
return vfsd, nil
}
@@ -233,7 +234,7 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
if err != nil {
return err
}
- _, err = checkCreateLocked(rp, parentVFSD, parentInode)
+ pc, err := checkCreateLocked(rp, parentVFSD, parentInode)
if err != nil {
return err
}
@@ -241,17 +242,49 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
return err
}
defer rp.Mount().EndWrite()
- // TODO: actually implement mknod
- return syserror.EPERM
+
+ switch opts.Mode.FileType() {
+ case 0:
+ // "Zero file type is equivalent to type S_IFREG." - mknod(2)
+ fallthrough
+ case linux.ModeRegular:
+ // TODO(b/138862511): Implement.
+ return syserror.EINVAL
+
+ case linux.ModeNamedPipe:
+ child := fs.newDentry(fs.newNamedPipe(rp.Credentials(), opts.Mode))
+ parentVFSD.InsertChild(&child.vfsd, pc)
+ parentInode.impl.(*directory).childList.PushBack(child)
+ return nil
+
+ case linux.ModeSocket:
+ // TODO(b/138862511): Implement.
+ return syserror.EINVAL
+
+ case linux.ModeCharacterDevice:
+ fallthrough
+ case linux.ModeBlockDevice:
+ // TODO(b/72101894): We don't support creating block or character
+ // devices at the moment.
+ //
+ // When we start supporting block and character devices, we'll
+ // need to check for CAP_MKNOD here.
+ return syserror.EPERM
+
+ default:
+ // "EINVAL - mode requested creation of something other than a
+ // regular file, device special file, FIFO or socket." - mknod(2)
+ return syserror.EINVAL
+ }
}
// OpenAt implements vfs.FilesystemImpl.OpenAt.
func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
// Filter out flags that are not supported by memfs. O_DIRECTORY and
// O_NOFOLLOW have no effect here (they're handled by VFS by setting
- // appropriate bits in rp), but are returned by
- // FileDescriptionImpl.StatusFlags().
- opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_TRUNC | linux.O_DIRECTORY | linux.O_NOFOLLOW
+ // appropriate bits in rp), but are visible in FD status flags. O_NONBLOCK
+ // is supported only by pipes.
+ opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_TRUNC | linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_NONBLOCK
if opts.Flags&linux.O_CREAT == 0 {
fs.mu.RLock()
@@ -260,7 +293,7 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf
if err != nil {
return nil, err
}
- return inode.open(rp, vfsd, opts.Flags, false)
+ return inode.open(ctx, rp, vfsd, opts.Flags, false)
}
mustCreate := opts.Flags&linux.O_EXCL != 0
@@ -275,7 +308,7 @@ func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf
if mustCreate {
return nil, syserror.EEXIST
}
- return inode.open(rp, vfsd, opts.Flags, false)
+ return inode.open(ctx, rp, vfsd, opts.Flags, false)
}
afterTrailingSymlink:
// Walk to the parent directory of the last path component.
@@ -320,7 +353,7 @@ afterTrailingSymlink:
child := fs.newDentry(childInode)
vfsd.InsertChild(&child.vfsd, pc)
inode.impl.(*directory).childList.PushBack(child)
- return childInode.open(rp, &child.vfsd, opts.Flags, true)
+ return childInode.open(ctx, rp, &child.vfsd, opts.Flags, true)
}
// Open existing file or follow symlink.
if mustCreate {
@@ -336,29 +369,31 @@ afterTrailingSymlink:
// symlink target.
goto afterTrailingSymlink
}
- return childInode.open(rp, childVFSD, opts.Flags, false)
+ return childInode.open(ctx, rp, childVFSD, opts.Flags, false)
}
-func (i *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32, afterCreate bool) (*vfs.FileDescription, error) {
+func (i *inode) open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32, afterCreate bool) (*vfs.FileDescription, error) {
ats := vfs.AccessTypesForOpenFlags(flags)
if !afterCreate {
if err := i.checkPermissions(rp.Credentials(), ats, i.isDir()); err != nil {
return nil, err
}
}
+ mnt := rp.Mount()
switch impl := i.impl.(type) {
case *regularFile:
var fd regularFileFD
- fd.flags = flags
fd.readable = vfs.MayReadFileWithOpenFlags(flags)
fd.writable = vfs.MayWriteFileWithOpenFlags(flags)
if fd.writable {
- if err := rp.Mount().CheckBeginWrite(); err != nil {
+ if err := mnt.CheckBeginWrite(); err != nil {
return nil, err
}
- // Mount.EndWrite() is called by regularFileFD.Release().
+ // mnt.EndWrite() is called by regularFileFD.Release().
}
- fd.vfsfd.Init(&fd, rp.Mount(), vfsd)
+ mnt.IncRef()
+ vfsd.IncRef()
+ fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
if flags&linux.O_TRUNC != 0 {
impl.mu.Lock()
impl.data = impl.data[:0]
@@ -372,12 +407,15 @@ func (i *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32, afte
return nil, syserror.EISDIR
}
var fd directoryFD
- fd.vfsfd.Init(&fd, rp.Mount(), vfsd)
- fd.flags = flags
+ mnt.IncRef()
+ vfsd.IncRef()
+ fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
return &fd.vfsfd, nil
case *symlink:
// Can't open symlinks without O_PATH (which is unimplemented).
return nil, syserror.ELOOP
+ case *namedPipe:
+ return newNamedPipeFD(ctx, impl, rp, vfsd, flags)
default:
panic(fmt.Sprintf("unknown inode type: %T", i.impl))
}
@@ -542,3 +580,58 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
inode.decLinksLocked()
return nil
}
+
+// ListxattrAt implements vfs.FilesystemImpl.ListxattrAt.
+func (fs *filesystem) ListxattrAt(ctx context.Context, rp *vfs.ResolvingPath) ([]string, error) {
+ fs.mu.RLock()
+ defer fs.mu.RUnlock()
+ _, _, err := walkExistingLocked(rp)
+ if err != nil {
+ return nil, err
+ }
+ // TODO(b/127675828): support extended attributes
+ return nil, syserror.ENOTSUP
+}
+
+// GetxattrAt implements vfs.FilesystemImpl.GetxattrAt.
+func (fs *filesystem) GetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) (string, error) {
+ fs.mu.RLock()
+ defer fs.mu.RUnlock()
+ _, _, err := walkExistingLocked(rp)
+ if err != nil {
+ return "", err
+ }
+ // TODO(b/127675828): support extended attributes
+ return "", syserror.ENOTSUP
+}
+
+// SetxattrAt implements vfs.FilesystemImpl.SetxattrAt.
+func (fs *filesystem) SetxattrAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.SetxattrOptions) error {
+ fs.mu.RLock()
+ defer fs.mu.RUnlock()
+ _, _, err := walkExistingLocked(rp)
+ if err != nil {
+ return err
+ }
+ // TODO(b/127675828): support extended attributes
+ return syserror.ENOTSUP
+}
+
+// RemovexattrAt implements vfs.FilesystemImpl.RemovexattrAt.
+func (fs *filesystem) RemovexattrAt(ctx context.Context, rp *vfs.ResolvingPath, name string) error {
+ fs.mu.RLock()
+ defer fs.mu.RUnlock()
+ _, _, err := walkExistingLocked(rp)
+ if err != nil {
+ return err
+ }
+ // TODO(b/127675828): support extended attributes
+ return syserror.ENOTSUP
+}
+
+// PrependPath implements vfs.FilesystemImpl.PrependPath.
+func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDentry, b *fspath.Builder) error {
+ fs.mu.RLock()
+ defer fs.mu.RUnlock()
+ return vfs.GenericPrependPath(vfsroot, vd, b)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-31 14:31:28 +0000