Include context in kernfs.Inode.Stat method

To implement stat(2) in FUSE, we have to embed credentials and pid in request
header. The information should be extracted from the context passed to VFS
layer. Therefore `Stat()` signature in `kernfs.Inode` interface should include
context as first argument. Some other fs implementations need to be modified as
well, such as devpts, host, pipefs, and proc.

Fixes #3235

13 files changed, 25 insertions, 25 deletions

diff --git a/pkg/sentry/fsimpl/devpts/master.go b/pkg/sentry/fsimpl/devpts/master.go
index 69879498a..1081fff52 100644
--- a/pkg/sentry/fsimpl/devpts/master.go
+++ b/pkg/sentry/fsimpl/devpts/master.go
@@ -67,8 +67,8 @@ func (mi *masterInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vf
 }
 
 // Stat implements kernfs.Inode.Stat.
-func (mi *masterInode) Stat(vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
-	statx, err := mi.InodeAttrs.Stat(vfsfs, opts)
+func (mi *masterInode) Stat(ctx context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+	statx, err := mi.InodeAttrs.Stat(ctx, vfsfs, opts)
 	if err != nil {
 		return linux.Statx{}, err
 	}
@@ -186,7 +186,7 @@ func (mfd *masterFileDescription) SetStat(ctx context.Context, opts vfs.SetStatO
 // Stat implements vfs.FileDescriptionImpl.Stat.
 func (mfd *masterFileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	fs := mfd.vfsfd.VirtualDentry().Mount().Filesystem()
-	return mfd.inode.Stat(fs, opts)
+	return mfd.inode.Stat(ctx, fs, opts)
 }
 
 // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go
index cf1a0f0ac..2018b978a 100644
--- a/pkg/sentry/fsimpl/devpts/slave.go
+++ b/pkg/sentry/fsimpl/devpts/slave.go
@@ -73,8 +73,8 @@ func (si *slaveInode) Valid(context.Context) bool {
 }
 
 // Stat implements kernfs.Inode.Stat.
-func (si *slaveInode) Stat(vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
-	statx, err := si.InodeAttrs.Stat(vfsfs, opts)
+func (si *slaveInode) Stat(ctx context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+	statx, err := si.InodeAttrs.Stat(ctx, vfsfs, opts)
 	if err != nil {
 		return linux.Statx{}, err
 	}
@@ -183,7 +183,7 @@ func (sfd *slaveFileDescription) SetStat(ctx context.Context, opts vfs.SetStatOp
 // Stat implements vfs.FileDescriptionImpl.Stat.
 func (sfd *slaveFileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	fs := sfd.vfsfd.VirtualDentry().Mount().Filesystem()
-	return sfd.inode.Stat(fs, opts)
+	return sfd.inode.Stat(ctx, fs, opts)
 }
 
 // LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX.
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go
index 1cd2982cb..1a88cb657 100644
--- a/pkg/sentry/fsimpl/host/host.go
+++ b/pkg/sentry/fsimpl/host/host.go
@@ -259,7 +259,7 @@ func (i *inode) Mode() linux.FileMode {
 }
 
 // Stat implements kernfs.Inode.
-func (i *inode) Stat(vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+func (i *inode) Stat(ctx context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
 	if opts.Mask&linux.STATX__RESERVED != 0 {
 		return linux.Statx{}, syserror.EINVAL
 	}
@@ -534,8 +534,8 @@ func (f *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions)
 }
 
 // Stat implements vfs.FileDescriptionImpl.
-func (f *fileDescription) Stat(_ context.Context, opts vfs.StatOptions) (linux.Statx, error) {
-	return f.inode.Stat(f.vfsfd.Mount().Filesystem(), opts)
+func (f *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
+	return f.inode.Stat(ctx, f.vfsfd.Mount().Filesystem(), opts)
 }
 
 // Release implements vfs.FileDescriptionImpl.
diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
index 6886b0876..c6c4472e7 100644
--- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
+++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
@@ -127,7 +127,7 @@ func (fd *DynamicBytesFD) Release() {}
 // Stat implements vfs.FileDescriptionImpl.Stat.
 func (fd *DynamicBytesFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	fs := fd.vfsfd.VirtualDentry().Mount().Filesystem()
-	return fd.inode.Stat(fs, opts)
+	return fd.inode.Stat(ctx, fs, opts)
 }
 
 // SetStat implements vfs.FileDescriptionImpl.SetStat.
diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
index ca8b8c63b..3f0aea73a 100644
--- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
@@ -132,7 +132,7 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
 	opts := vfs.StatOptions{Mask: linux.STATX_INO}
 	// Handle ".".
 	if fd.off == 0 {
-		stat, err := fd.inode().Stat(fd.filesystem(), opts)
+		stat, err := fd.inode().Stat(ctx, fd.filesystem(), opts)
 		if err != nil {
 			return err
 		}
@@ -152,7 +152,7 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
 	if fd.off == 1 {
 		vfsd := fd.vfsfd.VirtualDentry().Dentry()
 		parentInode := genericParentOrSelf(vfsd.Impl().(*Dentry)).inode
-		stat, err := parentInode.Stat(fd.filesystem(), opts)
+		stat, err := parentInode.Stat(ctx, fd.filesystem(), opts)
 		if err != nil {
 			return err
 		}
@@ -176,7 +176,7 @@ func (fd *GenericDirectoryFD) IterDirents(ctx context.Context, cb vfs.IterDirent
 	childIdx := fd.off - 2
 	for it := fd.children.nthLocked(childIdx); it != nil; it = it.Next() {
 		inode := it.Dentry.Impl().(*Dentry).inode
-		stat, err := inode.Stat(fd.filesystem(), opts)
+		stat, err := inode.Stat(ctx, fd.filesystem(), opts)
 		if err != nil {
 			return err
 		}
@@ -226,7 +226,7 @@ func (fd *GenericDirectoryFD) Seek(ctx context.Context, offset int64, whence int
 func (fd *GenericDirectoryFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	fs := fd.filesystem()
 	inode := fd.inode()
-	return inode.Stat(fs, opts)
+	return inode.Stat(ctx, fs, opts)
 }
 
 // SetStat implements vfs.FileDescriptionImpl.SetStat.
diff --git a/pkg/sentry/fsimpl/kernfs/filesystem.go b/pkg/sentry/fsimpl/kernfs/filesystem.go
index 8939871c1..61a36cff9 100644
--- a/pkg/sentry/fsimpl/kernfs/filesystem.go
+++ b/pkg/sentry/fsimpl/kernfs/filesystem.go
@@ -684,7 +684,7 @@ func (fs *Filesystem) StatAt(ctx context.Context, rp *vfs.ResolvingPath, opts vf
 	if err != nil {
 		return linux.Statx{}, err
 	}
-	return inode.Stat(fs.VFSFilesystem(), opts)
+	return inode.Stat(ctx, fs.VFSFilesystem(), opts)
 }
 
 // StatFSAt implements vfs.FilesystemImpl.StatFSAt.
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index 4cb885d87..2ab3f1761 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -243,7 +243,7 @@ func (a *InodeAttrs) Mode() linux.FileMode {
 // Stat partially implements Inode.Stat. Note that this function doesn't provide
 // all the stat fields, and the embedder should consider extending the result
 // with filesystem-specific fields.
-func (a *InodeAttrs) Stat(*vfs.Filesystem, vfs.StatOptions) (linux.Statx, error) {
+func (a *InodeAttrs) Stat(context.Context, *vfs.Filesystem, vfs.StatOptions) (linux.Statx, error) {
 	var stat linux.Statx
 	stat.Mask = linux.STATX_TYPE | linux.STATX_MODE | linux.STATX_UID | linux.STATX_GID | linux.STATX_INO | linux.STATX_NLINK
 	stat.DevMajor = a.devMajor
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go
index 596de1edf..46f207664 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs.go
@@ -346,7 +346,7 @@ type inodeMetadata interface {
 
 	// Stat returns the metadata for this inode. This corresponds to
 	// vfs.FilesystemImpl.StatAt.
-	Stat(fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error)
+	Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error)
 
 	// SetStat updates the metadata for this inode. This corresponds to
 	// vfs.FilesystemImpl.SetStatAt. Implementations are responsible for checking
diff --git a/pkg/sentry/fsimpl/pipefs/pipefs.go b/pkg/sentry/fsimpl/pipefs/pipefs.go
index dd7eaf4a8..811f80a5f 100644
--- a/pkg/sentry/fsimpl/pipefs/pipefs.go
+++ b/pkg/sentry/fsimpl/pipefs/pipefs.go
@@ -115,7 +115,7 @@ func (i *inode) Mode() linux.FileMode {
 }
 
 // Stat implements kernfs.Inode.Stat.
-func (i *inode) Stat(vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+func (i *inode) Stat(_ context.Context, vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
 	ts := linux.NsecToStatxTimestamp(i.ctime.Nanoseconds())
 	return linux.Statx{
 		Mask:     linux.STATX_TYPE | linux.STATX_MODE | linux.STATX_NLINK | linux.STATX_UID | linux.STATX_GID | linux.STATX_ATIME | linux.STATX_MTIME | linux.STATX_CTIME | linux.STATX_INO | linux.STATX_SIZE | linux.STATX_BLOCKS,
diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go
index 36a89540c..dad4db1a7 100644
--- a/pkg/sentry/fsimpl/proc/subtasks.go
+++ b/pkg/sentry/fsimpl/proc/subtasks.go
@@ -165,8 +165,8 @@ func (i *subtasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *v
 }
 
 // Stat implements kernfs.Inode.
-func (i *subtasksInode) Stat(vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
-	stat, err := i.InodeAttrs.Stat(vsfs, opts)
+func (i *subtasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+	stat, err := i.InodeAttrs.Stat(ctx, vsfs, opts)
 	if err != nil {
 		return linux.Statx{}, err
 	}
diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go
index 8bb2b0ce1..a5c7aa470 100644
--- a/pkg/sentry/fsimpl/proc/task.go
+++ b/pkg/sentry/fsimpl/proc/task.go
@@ -156,8 +156,8 @@ func (fs *filesystem) newTaskOwnedDir(task *kernel.Task, ino uint64, perm linux.
 }
 
 // Stat implements kernfs.Inode.
-func (i *taskOwnedInode) Stat(fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
-	stat, err := i.Inode.Stat(fs, opts)
+func (i *taskOwnedInode) Stat(ctx context.Context, fs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+	stat, err := i.Inode.Stat(ctx, fs, opts)
 	if err != nil {
 		return linux.Statx{}, err
 	}
diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go
index 9af43b859..859b7d727 100644
--- a/pkg/sentry/fsimpl/proc/task_files.go
+++ b/pkg/sentry/fsimpl/proc/task_files.go
@@ -876,7 +876,7 @@ var _ vfs.FileDescriptionImpl = (*namespaceFD)(nil)
 // Stat implements FileDescriptionImpl.
 func (fd *namespaceFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	vfs := fd.vfsfd.VirtualDentry().Mount().Filesystem()
-	return fd.inode.Stat(vfs, opts)
+	return fd.inode.Stat(ctx, vfs, opts)
 }
 
 // SetStat implements FileDescriptionImpl.
diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go
index 2f214d0c2..6d2b90a8b 100644
--- a/pkg/sentry/fsimpl/proc/tasks.go
+++ b/pkg/sentry/fsimpl/proc/tasks.go
@@ -206,8 +206,8 @@ func (i *tasksInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.
 	return fd.VFSFileDescription(), nil
 }
 
-func (i *tasksInode) Stat(vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
-	stat, err := i.InodeAttrs.Stat(vsfs, opts)
+func (i *tasksInode) Stat(ctx context.Context, vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+	stat, err := i.InodeAttrs.Stat(ctx, vsfs, opts)
 	if err != nil {
 		return linux.Statx{}, err
 	}