Enum ItemPayload 

pub enum ItemPayload {
    InodeItem(InodeItem),
    InodeRef(Vec<InodeRef>),
    InodeExtref(Vec<InodeExtref>),
    DirItem(Vec<DirItem>),
    DirLogItem {
        end: u64,
    },
    OrphanItem,
    RootItem(RootItem),
    RootRef(RootRef),
    FileExtentItem(FileExtentItem),
    ExtentCsum {
        data: Vec<u8>,
    },
    ExtentItem(ExtentItem),
    TreeBlockRef,
    SharedBlockRef,
    ExtentDataRef(ExtentDataRef),
    SharedDataRef(SharedDataRef),
    ExtentOwnerRef {
        root: u64,
    },
    BlockGroupItem(BlockGroupItem),
    FreeSpaceInfo(FreeSpaceInfo),
    FreeSpaceExtent,
    FreeSpaceBitmap,
    ChunkItem(ChunkItem),
    DeviceItem(DeviceItem),
    DeviceExtent(DeviceExtent),
    QgroupStatus(QgroupStatus),
    QgroupInfo(QgroupInfo),
    QgroupLimit(QgroupLimit),
    QgroupRelation,
    DeviceStats(DeviceStats),
    BalanceItem {
        flags: u64,
    },
    DeviceReplace(DeviceReplaceItem),
    UuidItem(UuidItem),
    StringItem(Vec<u8>),
    RaidStripe(RaidStripeItem),
    Unknown(Vec<u8>),
}

Parsed item payload: the typed result of parsing a leaf item’s raw data based on its key type.

Returned by parse_item_payload. Each variant wraps the corresponding item struct. Unknown holds the raw bytes for unrecognized key types.

Variants

InodeItem(InodeItem)

Inode metadata (POSIX attributes, timestamps, flags).

InodeRef(Vec<InodeRef>)

One or more hard-link references packed in a single item.

InodeExtref(Vec<InodeExtref>)

One or more extended inode references.

DirItem(Vec<DirItem>)

One or more directory entries (also used for DIR_INDEX and XATTR_ITEM).

DirLogItem

Directory log item with the logged range end offset.

Fields

end: u64

End of the logged directory range.

OrphanItem

Orphan marker (no data payload).

RootItem(RootItem)

Tree root descriptor (subvolume, snapshot, or internal tree).

RootRef(RootRef)

Root forward or back reference (ROOT_REF / ROOT_BACKREF).

FileExtentItem(FileExtentItem)

File extent descriptor.

ExtentCsum

Raw extent checksum data.

Fields

data: Vec<u8>

Raw checksum bytes (array of per-sector checksums).

ExtentItem(ExtentItem)

Extent allocation record (EXTENT_ITEM or METADATA_ITEM).

TreeBlockRef

Standalone tree block backref (no data payload; the key offset is the root).

SharedBlockRef

Standalone shared block backref (no data payload; the key offset is the parent bytenr).

ExtentDataRef(ExtentDataRef)

Standalone data extent backref.

SharedDataRef(SharedDataRef)

Standalone shared data extent backref.

ExtentOwnerRef

Simple ownership reference for an extent.

Fields

root: u64

Tree objectid that owns this extent.

BlockGroupItem(BlockGroupItem)

Block group descriptor.

FreeSpaceInfo(FreeSpaceInfo)

Free space info for a block group.

FreeSpaceExtent

Free space extent (no data payload; key encodes start and length).

FreeSpaceBitmap

Free space bitmap (data payload is the bitmap).

ChunkItem(ChunkItem)

Chunk item mapping logical to physical addresses.

DeviceItem(DeviceItem)

Device item describing a single device.

DeviceExtent(DeviceExtent)

Physical extent mapping on a device.

QgroupStatus(QgroupStatus)

Quota group status.

QgroupInfo(QgroupInfo)

Quota group accounting info.

QgroupLimit(QgroupLimit)

Quota group limits.

QgroupRelation

Quota group relation (no data payload; parent/child encoded in key).

DeviceStats(DeviceStats)

Per-device I/O error statistics.

BalanceItem

Balance status item.

Fields

flags: u64

Balance flags from the first 8 bytes of the item data.

DeviceReplace(DeviceReplaceItem)

Device replace status.

UuidItem(UuidItem)

UUID tree entry mapping a UUID to subvolume objectids.

StringItem(Vec<u8>)

String item (typically the superblock label).

RaidStripe(RaidStripeItem)

RAID stripe extent mapping.

Unknown(Vec<u8>)

Unrecognized item type; raw data preserved.