ext: filesystem boilerplate code.

PiperOrigin-RevId: 259865366

1 files changed, 0 insertions, 61 deletions

diff --git a/pkg/sentry/fs/ext/ext.go b/pkg/sentry/fs/ext/ext.go
index 2604169de..10e235fb1 100644
--- a/pkg/sentry/fs/ext/ext.go
+++ b/pkg/sentry/fs/ext/ext.go
@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -36,48 +35,6 @@ type filesystemType struct{}
 // Compiles only if filesystemType implements vfs.FilesystemType.
 var _ vfs.FilesystemType = (*filesystemType)(nil)
 
-// filesystem implements vfs.FilesystemImpl.
-type filesystem struct {
-	// TODO(b/134676337): Remove when all methods have been implemented.
-	vfs.FilesystemImpl
-
-	vfsfs vfs.Filesystem
-
-	// mu serializes changes to the dentry tree and the usage of the read seeker.
-	mu sync.Mutex
-
-	// dev is the ReadSeeker for the underlying fs device. It is protected by mu.
-	//
-	// The ext filesystems aim to maximize locality, i.e. place all the data
-	// blocks of a file close together. On a spinning disk, locality reduces the
-	// amount of movement of the head hence speeding up IO operations. On an SSD
-	// there are no moving parts but locality increases the size of each transer
-	// request. Hence, having mutual exclusion on the read seeker while reading a
-	// file *should* help in achieving the intended performance gains.
-	//
-	// Note: This synchronization was not coupled with the ReadSeeker itself
-	// because we want to synchronize across read/seek operations for the
-	// performance gains mentioned above. Helps enforcing one-file-at-a-time IO.
-	dev io.ReadSeeker
-
-	// inodeCache maps absolute inode numbers to the corresponding Inode struct.
-	// Inodes should be removed from this once their reference count hits 0.
-	//
-	// Protected by mu because every addition and removal from this corresponds to
-	// a change in the dentry tree.
-	inodeCache map[uint32]*inode
-
-	// sb represents the filesystem superblock. Immutable after initialization.
-	sb disklayout.SuperBlock
-
-	// bgs represents all the block group descriptors for the filesystem.
-	// Immutable after initialization.
-	bgs []disklayout.BlockGroup
-}
-
-// Compiles only if filesystem implements vfs.FilesystemImpl.
-var _ vfs.FilesystemImpl = (*filesystem)(nil)
-
 // getDeviceFd returns the read seeker to the underlying device.
 // Currently there are two ways of mounting an ext(2/3/4) fs:
 //   1. Specify a mount with our internal special MountType in the OCI spec.
@@ -138,21 +95,3 @@ func (fstype filesystemType) NewFilesystem(ctx context.Context, creds *auth.Cred
 
 	return &fs.vfsfs, &newDentry(rootInode).vfsd, nil
 }
-
-// getOrCreateInode gets the inode corresponding to the inode number passed in.
-// It creates a new one with the given inode number if one does not exist.
-//
-// Preconditions: must be holding fs.mu.
-func (fs *filesystem) getOrCreateInode(inodeNum uint32) (*inode, error) {
-	if in, ok := fs.inodeCache[inodeNum]; ok {
-		return in, nil
-	}
-
-	in, err := newInode(fs.dev, fs.sb, fs.bgs, inodeNum)
-	if err != nil {
-		return nil, err
-	}
-
-	fs.inodeCache[inodeNum] = in
-	return in, nil
-}