Module subvolume 

Subvolume and snapshot management: creating, deleting, and querying subvolumes

Subvolumes are independently snapshotable subtrees within a btrfs filesystem. Snapshots are subvolumes created as copy-on-write clones of an existing subvolume. This module covers the full lifecycle: creating and deleting subvolumes and snapshots, reading subvolume metadata and flags, listing all subvolumes in a filesystem, and getting or setting the default subvolume that is mounted when no subvolume is explicitly requested.

Structs

SubvolumeFlags

Flags on a btrfs subvolume (the flags field of the root item / BTRFS_IOC_SUBVOL_{GET,SET}FLAGS).

SubvolumeInfo

Subvolume metadata returned by BTRFS_IOC_GET_SUBVOL_INFO.

SubvolumeListItem

A single subvolume entry returned by subvolume_list.

Constants

FS_TREE_OBJECTID

The top-level subvolume (FS tree); objectid 5, always present.

Functions

snapshot_create

Create a snapshot of the subvolume referred to by source_fd, placing it as name inside the directory referred to by parent_fd.

subvolume_create

Create a new subvolume named name inside the directory referred to by parent_fd.

subvolume_default_get

Query the ID of the default subvolume of the filesystem referred to by fd.

subvolume_default_set

Set the default subvolume of the filesystem referred to by fd to subvolid.

subvolume_delete

Delete the subvolume or snapshot named name from the directory referred to by parent_fd.

subvolume_flags_get

Read the flags of the subvolume that fd belongs to.

subvolume_flags_set

Set the flags of the subvolume that fd belongs to.

subvolume_info

Query detailed information about the subvolume that fd belongs to.

subvolume_list

List all user subvolumes and snapshots in the filesystem referred to by fd by walking the root tree.