ext: Move to pkg/sentry/fsimpl.

fsimpl is the keeper of all filesystem implementations in VFS2.

PiperOrigin-RevId: 262617869

1 files changed, 0 insertions, 471 deletions

diff --git a/pkg/sentry/fs/ext/disklayout/superblock.go b/pkg/sentry/fs/ext/disklayout/superblock.go
deleted file mode 100644
index 8bb327006..000000000
--- a/pkg/sentry/fs/ext/disklayout/superblock.go
+++ /dev/null
@@ -1,471 +0,0 @@
-// Copyright 2019 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package disklayout
-
-const (
-	// SbOffset is the absolute offset at which the superblock is placed.
-	SbOffset = 1024
-)
-
-// SuperBlock should be implemented by structs representing the ext superblock.
-// The superblock holds a lot of information about the enclosing filesystem.
-// This interface aims to provide access methods to important information held
-// by the superblock. It does NOT expose all fields of the superblock, only the
-// ones necessary. This can be expanded when need be.
-//
-// Location and replication:
-//     - The superblock is located at offset 1024 in block group 0.
-//     - Redundant copies of the superblock and group descriptors are kept in
-//       all groups if SbSparse feature flag is NOT set. If it is set, the
-//       replicas only exist in groups whose group number is either 0 or a
-//       power of 3, 5, or 7.
-//     - There is also a sparse superblock feature v2 in which there are just
-//       two replicas saved in the block groups pointed by sb.s_backup_bgs.
-//
-// Replicas should eventually be updated if the superblock is updated.
-//
-// See https://www.kernel.org/doc/html/latest/filesystems/ext4/globals.html#super-block.
-type SuperBlock interface {
-	// InodesCount returns the total number of inodes in this filesystem.
-	InodesCount() uint32
-
-	// BlocksCount returns the total number of data blocks in this filesystem.
-	BlocksCount() uint64
-
-	// FreeBlocksCount returns the number of free blocks in this filesystem.
-	FreeBlocksCount() uint64
-
-	// FreeInodesCount returns the number of free inodes in this filesystem.
-	FreeInodesCount() uint32
-
-	// MountCount returns the number of mounts since the last fsck.
-	MountCount() uint16
-
-	// MaxMountCount returns the number of mounts allowed beyond which a fsck is
-	// needed.
-	MaxMountCount() uint16
-
-	// FirstDataBlock returns the absolute block number of the first data block,
-	// which contains the super block itself.
-	//
-	// If the filesystem has 1kb data blocks then this should return 1. For all
-	// other configurations, this typically returns 0.
-	FirstDataBlock() uint32
-
-	// BlockSize returns the size of one data block in this filesystem.
-	// This can be calculated by 2^(10 + sb.s_log_block_size). This ensures that
-	// the smallest block size is 1kb.
-	BlockSize() uint64
-
-	// BlocksPerGroup returns the number of data blocks in a block group.
-	BlocksPerGroup() uint32
-
-	// ClusterSize returns block cluster size (set during mkfs time by admin).
-	// This can be calculated by 2^(10 + sb.s_log_cluster_size). This ensures that
-	// the smallest cluster size is 1kb.
-	//
-	// sb.s_log_cluster_size must equal sb.s_log_block_size if bigalloc feature
-	// is NOT set and consequently BlockSize() = ClusterSize() in that case.
-	ClusterSize() uint64
-
-	// ClustersPerGroup returns:
-	//     - number of clusters per group        if bigalloc is enabled.
-	//     - BlocksPerGroup()                    otherwise.
-	ClustersPerGroup() uint32
-
-	// InodeSize returns the size of the inode disk record size in bytes. Use this
-	// to iterate over inode arrays on disk.
-	//
-	// In ext2 and ext3:
-	//     - Each inode had a disk record of 128 bytes.
-	//     - The inode struct size was fixed at 128 bytes.
-	//
-	// In ext4 its possible to allocate larger on-disk inodes:
-	//     - Inode disk record size = sb.s_inode_size (function return value).
-	//                              = 256 (default)
-	//     - Inode struct size = 128 + inode.i_extra_isize.
-	//                         = 128 + 32 = 160 (default)
-	InodeSize() uint16
-
-	// InodesPerGroup returns the number of inodes in a block group.
-	InodesPerGroup() uint32
-
-	// BgDescSize returns the size of the block group descriptor struct.
-	//
-	// In ext2, ext3, ext4 (without 64-bit feature), the block group descriptor
-	// is only 32 bytes long.
-	// In ext4 with 64-bit feature, the block group descriptor expands to AT LEAST
-	// 64 bytes. It might be bigger than that.
-	BgDescSize() uint16
-
-	// CompatibleFeatures returns the CompatFeatures struct which holds all the
-	// compatible features this fs supports.
-	CompatibleFeatures() CompatFeatures
-
-	// IncompatibleFeatures returns the CompatFeatures struct which holds all the
-	// incompatible features this fs supports.
-	IncompatibleFeatures() IncompatFeatures
-
-	// ReadOnlyCompatibleFeatures returns the CompatFeatures struct which holds all the
-	// readonly compatible features this fs supports.
-	ReadOnlyCompatibleFeatures() RoCompatFeatures
-
-	// Magic() returns the magic signature which must be 0xef53.
-	Magic() uint16
-
-	// Revision returns the superblock revision. Superblock struct fields from
-	// offset 0x54 till 0x150 should only be used if superblock has DynamicRev.
-	Revision() SbRevision
-}
-
-// SbRevision is the type for superblock revisions.
-type SbRevision uint32
-
-// Super block revisions.
-const (
-	// OldRev is the good old (original) format.
-	OldRev SbRevision = 0
-
-	// DynamicRev is v2 format w/ dynamic inode sizes.
-	DynamicRev SbRevision = 1
-)
-
-// Superblock compatible features.
-// This is not exhaustive, unused features are not listed.
-const (
-	// SbDirPrealloc indicates directory preallocation.
-	SbDirPrealloc = 0x1
-
-	// SbHasJournal indicates the presence of a journal. jbd2 should only work
-	// with this being set.
-	SbHasJournal = 0x4
-
-	// SbExtAttr indicates extended attributes support.
-	SbExtAttr = 0x8
-
-	// SbResizeInode indicates that the fs has reserved GDT blocks (right after
-	// group descriptors) for fs expansion.
-	SbResizeInode = 0x10
-
-	// SbDirIndex indicates that the fs has directory indices.
-	SbDirIndex = 0x20
-
-	// SbSparseV2 stands for Sparse superblock version 2.
-	SbSparseV2 = 0x200
-)
-
-// CompatFeatures represents a superblock's compatible feature set. If the
-// kernel does not understand any of these feature, it can still read/write
-// to this fs.
-type CompatFeatures struct {
-	DirPrealloc bool
-	HasJournal  bool
-	ExtAttr     bool
-	ResizeInode bool
-	DirIndex    bool
-	SparseV2    bool
-}
-
-// ToInt converts superblock compatible features back to its 32-bit rep.
-func (f CompatFeatures) ToInt() uint32 {
-	var res uint32
-
-	if f.DirPrealloc {
-		res |= SbDirPrealloc
-	}
-	if f.HasJournal {
-		res |= SbHasJournal
-	}
-	if f.ExtAttr {
-		res |= SbExtAttr
-	}
-	if f.ResizeInode {
-		res |= SbResizeInode
-	}
-	if f.DirIndex {
-		res |= SbDirIndex
-	}
-	if f.SparseV2 {
-		res |= SbSparseV2
-	}
-
-	return res
-}
-
-// CompatFeaturesFromInt converts the integer representation of superblock
-// compatible features to CompatFeatures struct.
-func CompatFeaturesFromInt(f uint32) CompatFeatures {
-	return CompatFeatures{
-		DirPrealloc: f&SbDirPrealloc > 0,
-		HasJournal:  f&SbHasJournal > 0,
-		ExtAttr:     f&SbExtAttr > 0,
-		ResizeInode: f&SbResizeInode > 0,
-		DirIndex:    f&SbDirIndex > 0,
-		SparseV2:    f&SbSparseV2 > 0,
-	}
-}
-
-// Superblock incompatible features.
-// This is not exhaustive, unused features are not listed.
-const (
-	// SbDirentFileType indicates that directory entries record the file type.
-	// We should use struct DirentNew for dirents then.
-	SbDirentFileType = 0x2
-
-	// SbRecovery indicates that the filesystem needs recovery.
-	SbRecovery = 0x4
-
-	// SbJournalDev indicates that the filesystem has a separate journal device.
-	SbJournalDev = 0x8
-
-	// SbMetaBG indicates that the filesystem is using Meta block groups. Moves
-	// the group descriptors from the congested first block group into the first
-	// group of each metablock group to increase the maximum block groups limit
-	// and hence support much larger filesystems.
-	//
-	// See https://www.kernel.org/doc/html/latest/filesystems/ext4/overview.html#meta-block-groups.
-	SbMetaBG = 0x10
-
-	// SbExtents indicates that the filesystem uses extents. Must be set in ext4
-	// filesystems.
-	SbExtents = 0x40
-
-	// SbIs64Bit indicates that this filesystem addresses blocks with 64-bits.
-	// Hence can support 2^64 data blocks.
-	SbIs64Bit = 0x80
-
-	// SbMMP indicates that this filesystem has multiple mount protection.
-	//
-	// See https://www.kernel.org/doc/html/latest/filesystems/ext4/globals.html#multiple-mount-protection.
-	SbMMP = 0x100
-
-	// SbFlexBg indicates that this filesystem has flexible block groups. Several
-	// block groups are tied into one logical block group so that all the metadata
-	// for the block groups (bitmaps and inode tables) are close together for
-	// faster loading. Consequently, large files will be continuous on disk.
-	// However, this does not affect the placement of redundant superblocks and
-	// group descriptors.
-	//
-	// See https://www.kernel.org/doc/html/latest/filesystems/ext4/overview.html#flexible-block-groups.
-	SbFlexBg = 0x200
-
-	// SbLargeDir shows that large directory enabled. Directory htree can be 3
-	// levels deep. Directory htrees are allowed to be 2 levels deep otherwise.
-	SbLargeDir = 0x4000
-
-	// SbInlineData allows inline data in inodes for really small files.
-	SbInlineData = 0x8000
-
-	// SbEncrypted indicates that this fs contains encrypted inodes.
-	SbEncrypted = 0x10000
-)
-
-// IncompatFeatures represents a superblock's incompatible feature set. If the
-// kernel does not understand any of these feature, it should refuse to mount.
-type IncompatFeatures struct {
-	DirentFileType bool
-	Recovery       bool
-	JournalDev     bool
-	MetaBG         bool
-	Extents        bool
-	Is64Bit        bool
-	MMP            bool
-	FlexBg         bool
-	LargeDir       bool
-	InlineData     bool
-	Encrypted      bool
-}
-
-// ToInt converts superblock incompatible features back to its 32-bit rep.
-func (f IncompatFeatures) ToInt() uint32 {
-	var res uint32
-
-	if f.DirentFileType {
-		res |= SbDirentFileType
-	}
-	if f.Recovery {
-		res |= SbRecovery
-	}
-	if f.JournalDev {
-		res |= SbJournalDev
-	}
-	if f.MetaBG {
-		res |= SbMetaBG
-	}
-	if f.Extents {
-		res |= SbExtents
-	}
-	if f.Is64Bit {
-		res |= SbIs64Bit
-	}
-	if f.MMP {
-		res |= SbMMP
-	}
-	if f.FlexBg {
-		res |= SbFlexBg
-	}
-	if f.LargeDir {
-		res |= SbLargeDir
-	}
-	if f.InlineData {
-		res |= SbInlineData
-	}
-	if f.Encrypted {
-		res |= SbEncrypted
-	}
-
-	return res
-}
-
-// IncompatFeaturesFromInt converts the integer representation of superblock
-// incompatible features to IncompatFeatures struct.
-func IncompatFeaturesFromInt(f uint32) IncompatFeatures {
-	return IncompatFeatures{
-		DirentFileType: f&SbDirentFileType > 0,
-		Recovery:       f&SbRecovery > 0,
-		JournalDev:     f&SbJournalDev > 0,
-		MetaBG:         f&SbMetaBG > 0,
-		Extents:        f&SbExtents > 0,
-		Is64Bit:        f&SbIs64Bit > 0,
-		MMP:            f&SbMMP > 0,
-		FlexBg:         f&SbFlexBg > 0,
-		LargeDir:       f&SbLargeDir > 0,
-		InlineData:     f&SbInlineData > 0,
-		Encrypted:      f&SbEncrypted > 0,
-	}
-}
-
-// Superblock readonly compatible features.
-// This is not exhaustive, unused features are not listed.
-const (
-	// SbSparse indicates sparse superblocks. Only groups with number either 0 or
-	// a power of 3, 5, or 7 will have redundant copies of the superblock and
-	// block descriptors.
-	SbSparse = 0x1
-
-	// SbLargeFile indicates that this fs has been used to store a file >= 2GiB.
-	SbLargeFile = 0x2
-
-	// SbHugeFile indicates that this fs contains files whose sizes are
-	// represented in units of logicals blocks, not 512-byte sectors.
-	SbHugeFile = 0x8
-
-	// SbGdtCsum indicates that group descriptors have checksums.
-	SbGdtCsum = 0x10
-
-	// SbDirNlink indicates that the new subdirectory limit is 64,999. Ext3 has a
-	// 32,000 subdirectory limit.
-	SbDirNlink = 0x20
-
-	// SbExtraIsize indicates that large inodes exist on this filesystem.
-	SbExtraIsize = 0x40
-
-	// SbHasSnapshot indicates the existence of a snapshot.
-	SbHasSnapshot = 0x80
-
-	// SbQuota enables usage tracking for all quota types.
-	SbQuota = 0x100
-
-	// SbBigalloc maps to the bigalloc feature. When set, the minimum allocation
-	// unit becomes a cluster rather than a data block. Then block bitmaps track
-	// clusters, not data blocks.
-	//
-	// See https://www.kernel.org/doc/html/latest/filesystems/ext4/overview.html#bigalloc.
-	SbBigalloc = 0x200
-
-	// SbMetadataCsum indicates that the fs supports metadata checksumming.
-	SbMetadataCsum = 0x400
-
-	// SbReadOnly marks this filesystem as readonly. Should refuse to mount in
-	// read/write mode.
-	SbReadOnly = 0x1000
-)
-
-// RoCompatFeatures represents a superblock's readonly compatible feature set.
-// If the kernel does not understand any of these feature, it can still mount
-// readonly. But if the user wants to mount read/write, the kernel should
-// refuse to mount.
-type RoCompatFeatures struct {
-	Sparse       bool
-	LargeFile    bool
-	HugeFile     bool
-	GdtCsum      bool
-	DirNlink     bool
-	ExtraIsize   bool
-	HasSnapshot  bool
-	Quota        bool
-	Bigalloc     bool
-	MetadataCsum bool
-	ReadOnly     bool
-}
-
-// ToInt converts superblock readonly compatible features to its 32-bit rep.
-func (f RoCompatFeatures) ToInt() uint32 {
-	var res uint32
-
-	if f.Sparse {
-		res |= SbSparse
-	}
-	if f.LargeFile {
-		res |= SbLargeFile
-	}
-	if f.HugeFile {
-		res |= SbHugeFile
-	}
-	if f.GdtCsum {
-		res |= SbGdtCsum
-	}
-	if f.DirNlink {
-		res |= SbDirNlink
-	}
-	if f.ExtraIsize {
-		res |= SbExtraIsize
-	}
-	if f.HasSnapshot {
-		res |= SbHasSnapshot
-	}
-	if f.Quota {
-		res |= SbQuota
-	}
-	if f.Bigalloc {
-		res |= SbBigalloc
-	}
-	if f.MetadataCsum {
-		res |= SbMetadataCsum
-	}
-	if f.ReadOnly {
-		res |= SbReadOnly
-	}
-
-	return res
-}
-
-// RoCompatFeaturesFromInt converts the integer representation of superblock
-// readonly compatible features to RoCompatFeatures struct.
-func RoCompatFeaturesFromInt(f uint32) RoCompatFeatures {
-	return RoCompatFeatures{
-		Sparse:       f&SbSparse > 0,
-		LargeFile:    f&SbLargeFile > 0,
-		HugeFile:     f&SbHugeFile > 0,
-		GdtCsum:      f&SbGdtCsum > 0,
-		DirNlink:     f&SbDirNlink > 0,
-		ExtraIsize:   f&SbExtraIsize > 0,
-		HasSnapshot:  f&SbHasSnapshot > 0,
-		Quota:        f&SbQuota > 0,
-		Bigalloc:     f&SbBigalloc > 0,
-		MetadataCsum: f&SbMetadataCsum > 0,
-		ReadOnly:     f&SbReadOnly > 0,
-	}
-}