BTRFS: libblockdev Reference Manual for libblockdev 3.2.0.

BTRFS

BTRFS — plugin for operations with BTRFS devices

Functions

gboolean	bd_btrfs_init ()
void	bd_btrfs_close ()
GQuark	bd_btrfs_error_quark ()
void	bd_btrfs_device_info_free ()
BDBtrfsDeviceInfo *	bd_btrfs_device_info_copy ()
void	bd_btrfs_subvolume_info_free ()
BDBtrfsSubvolumeInfo *	bd_btrfs_subvolume_info_copy ()
void	bd_btrfs_filesystem_info_free ()
BDBtrfsFilesystemInfo *	bd_btrfs_filesystem_info_copy ()
gboolean	bd_btrfs_create_volume ()
gboolean	bd_btrfs_add_device ()
gboolean	bd_btrfs_remove_device ()
gboolean	bd_btrfs_create_subvolume ()
gboolean	bd_btrfs_delete_subvolume ()
guint64	bd_btrfs_get_default_subvolume_id ()
gboolean	bd_btrfs_set_default_subvolume ()
gboolean	bd_btrfs_create_snapshot ()
BDBtrfsDeviceInfo **	bd_btrfs_list_devices ()
BDBtrfsSubvolumeInfo **	bd_btrfs_list_subvolumes ()
BDBtrfsFilesystemInfo *	bd_btrfs_filesystem_info ()
gboolean	bd_btrfs_mkfs ()
gboolean	bd_btrfs_resize ()
gboolean	bd_btrfs_check ()
gboolean	bd_btrfs_repair ()
gboolean	bd_btrfs_change_label ()
gboolean	bd_btrfs_is_tech_avail ()

Types and Values

#define	BD_BTRFS_MAIN_VOLUME_ID
#define	BD_BTRFS_MIN_MEMBER_SIZE
#define	BD_BTRFS_ERROR
enum	BDBtrfsError
	BDBtrfsDeviceInfo
	BDBtrfsSubvolumeInfo
	BDBtrfsFilesystemInfo
enum	BDBtrfsTech
enum	BDBtrfsTechMode

Includes

#include <btrfs.h>

Description

A plugin for operations with btrfs devices.

Functions

bd_btrfs_init ()

gboolean
bd_btrfs_init (void);

Initializes the plugin. **This function is called automatically by the library's initialization functions.**

bd_btrfs_close ()

void
bd_btrfs_close (void);

Cleans up after the plugin. **This function is called automatically by the library's functions that unload it.**

bd_btrfs_error_quark ()

GQuark
bd_btrfs_error_quark (void);

[skip]

bd_btrfs_device_info_free ()

void
bd_btrfs_device_info_free (BDBtrfsDeviceInfo *info);

Frees info .

[skip]

Parameters

info

BDBtrfsDeviceInfo to free.

[nullable]

bd_btrfs_device_info_copy ()

BDBtrfsDeviceInfo *
bd_btrfs_device_info_copy (BDBtrfsDeviceInfo *info);

Creates a new copy of info .

[skip]

Parameters

info

BDBtrfsDeviceInfo to copy.

[nullable]

bd_btrfs_subvolume_info_free ()

void
bd_btrfs_subvolume_info_free (BDBtrfsSubvolumeInfo *info);

Frees info .

[skip]

Parameters

info

BDBtrfsSubvolumeInfo to free.

[nullable]

bd_btrfs_subvolume_info_copy ()

BDBtrfsSubvolumeInfo *
bd_btrfs_subvolume_info_copy (BDBtrfsSubvolumeInfo *info);

Creates a new copy of info .

[skip]

Parameters

info

BDBtrfsSubvolumeInfo to copy.

[nullable]

bd_btrfs_filesystem_info_free ()

void
bd_btrfs_filesystem_info_free (BDBtrfsFilesystemInfo *info);

Frees info .

[skip]

Parameters

info

BDBtrfsFilesystemInfo to free.

[nullable]

bd_btrfs_filesystem_info_copy ()

BDBtrfsFilesystemInfo *
bd_btrfs_filesystem_info_copy (BDBtrfsFilesystemInfo *info);

Creates a new copy of info .

[skip]

Parameters

info

BDBtrfsFilesystemInfo to copy.

[nullable]

bd_btrfs_create_volume ()

gboolean
bd_btrfs_create_volume (const gchar **devices,
                        const gchar *label,
                        const gchar *data_level,
                        const gchar *md_level,
                        const BDExtraArg **extra,
                        GError **error);

Parameters

devices	list of devices to create btrfs volume from.	[array zero-terminated=1]
label	label for the volume.	[nullable]
data_level	RAID level for the data or `NULL` to use the default.	[nullable]
md_level	RAID level for the metadata or `NULL` to use the default.	[nullable]
extra	extra options for the volume creation (right now passed to the 'mkfs.btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the new btrfs volume was created from devices or not

See mkfs.btrfs(8) for details about data_level , md_level and btrfs in general.

Tech category: BD_BTRFS_TECH_MULTI_DEV-BD_BTRFS_TECH_MODE_CREATE

bd_btrfs_add_device ()

gboolean
bd_btrfs_add_device (const gchar *mountpoint,
                     const gchar *device,
                     const BDExtraArg **extra,
                     GError **error);

Parameters

mountpoint	mountpoint of the btrfs volume to add new device to
device	a device to add to the btrfs volume
extra	extra options for the addition (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the device was successfully added to the mountpoint btrfs volume or not

Tech category: BD_BTRFS_TECH_MULTI_DEV-BD_BTRFS_TECH_MODE_MODIFY

bd_btrfs_remove_device ()

gboolean
bd_btrfs_remove_device (const gchar *mountpoint,
                        const gchar *device,
                        const BDExtraArg **extra,
                        GError **error);

Parameters

mountpoint	mountpoint of the btrfs volume to remove device from
device	a device to remove from the btrfs volume
extra	extra options for the removal (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the device was successfully removed from the mountpoint btrfs volume or not

Tech category: BD_BTRFS_TECH_MULTI_DEV-BD_BTRFS_TECH_MODE_MODIFY

bd_btrfs_create_subvolume ()

gboolean
bd_btrfs_create_subvolume (const gchar *mountpoint,
                           const gchar *name,
                           const BDExtraArg **extra,
                           GError **error);

Parameters

mountpoint	mountpoint of the btrfs volume to create subvolume under
name	name of the subvolume
extra	extra options for the subvolume creation (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the mountpoint /name subvolume was successfully created or not

Tech category: BD_BTRFS_TECH_SUBVOL-BD_BTRFS_TECH_MODE_CREATE

bd_btrfs_delete_subvolume ()

gboolean
bd_btrfs_delete_subvolume (const gchar *mountpoint,
                           const gchar *name,
                           const BDExtraArg **extra,
                           GError **error);

Parameters

mountpoint	mountpoint of the btrfs volume to delete subvolume from
name	name of the subvolume
extra	extra options for the subvolume deletion (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the mountpoint /name subvolume was successfully deleted or not

Tech category: BD_BTRFS_TECH_SUBVOL-BD_BTRFS_TECH_MODE_DELETE

bd_btrfs_get_default_subvolume_id ()

guint64
bd_btrfs_get_default_subvolume_id (const gchar *mountpoint,
                                   GError **error);

Parameters

mountpoint	mountpoint of the volume to get the default subvolume ID of
error	place to store error (if any).	[out][optional]

Returns

ID of the mountpoint volume's default subvolume. If 0, error may be set to indicate error

Tech category: BD_BTRFS_TECH_SUBVOL-BD_BTRFS_TECH_MODE_QUERY

bd_btrfs_set_default_subvolume ()

gboolean
bd_btrfs_set_default_subvolume (const gchar *mountpoint,
                                guint64 subvol_id,
                                const BDExtraArg **extra,
                                GError **error);

Parameters

mountpoint	mountpoint of the volume to set the default subvolume ID of
subvol_id	ID of the subvolume to be set as the default subvolume
extra	extra options for the setting (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the mountpoint volume's default subvolume was correctly set to subvol_id or not

Tech category: BD_BTRFS_TECH_SUBVOL-BD_BTRFS_TECH_MODE_MODIFY

bd_btrfs_create_snapshot ()

gboolean
bd_btrfs_create_snapshot (const gchar *source,
                          const gchar *dest,
                          gboolean ro,
                          const BDExtraArg **extra,
                          GError **error);

Parameters

source	path to source subvolume
dest	path to new snapshot volume
ro	whether the snapshot should be read-only
extra	extra options for the snapshot creation (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the dest snapshot of source was successfully created or not

Tech category: BD_BTRFS_TECH_SNAPSHOT-BD_BTRFS_TECH_MODE_CREATE

bd_btrfs_list_devices ()

BDBtrfsDeviceInfo **
bd_btrfs_list_devices (const gchar *device,
                       GError **error);

Parameters

device	a device that is part of the queried btrfs volume
error	place to store error (if any).	[out][optional]

Returns

information about the devices that are part of the btrfs volume containing device or NULL in case of error

Tech category: BD_BTRFS_TECH_MULTI_DEV-BD_BTRFS_TECH_MODE_QUERY.

[array zero-terminated=1]

bd_btrfs_list_subvolumes ()

BDBtrfsSubvolumeInfo **
bd_btrfs_list_subvolumes (const gchar *mountpoint,
                          gboolean snapshots_only,
                          GError **error);

Parameters

mountpoint	a mountpoint of the queried btrfs volume
snapshots_only	whether to list only snapshot subvolumes or not
error	place to store error (if any).	[out][optional]

Returns

information about the subvolumes that are part of the btrfs volume mounted at mountpoint or NULL in case of error

The subvolumes are sorted in a way that no child subvolume appears in the list before its parent (sub)volume.

Tech category: BD_BTRFS_TECH_SUBVOL-BD_BTRFS_TECH_MODE_QUERY.

[array zero-terminated=1]

bd_btrfs_filesystem_info ()

BDBtrfsFilesystemInfo *
bd_btrfs_filesystem_info (const gchar *device,
                          GError **error);

Parameters

device	a device that is part of the queried btrfs volume
error	place to store error (if any).	[out][optional]

Returns

information about the device 's volume's filesystem or NULL in case of error

Tech category: BD_BTRFS_TECH_FS-BD_BTRFS_TECH_MODE_QUERY

bd_btrfs_mkfs ()

gboolean
bd_btrfs_mkfs (const gchar **devices,
               const gchar *label,
               const gchar *data_level,
               const gchar *md_level,
               const BDExtraArg **extra,
               GError **error);

Parameters

devices	list of devices to create btrfs volume from.	[array zero-terminated=1]
label	label for the volume.	[nullable]
data_level	RAID level for the data or `NULL` to use the default.	[nullable]
md_level	RAID level for the metadata or `NULL` to use the default.	[nullable]
extra	extra options for the volume creation (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the new btrfs volume was created from devices or not

See mkfs.btrfs(8) for details about data_level , md_level and btrfs in general.

Tech category: BD_BTRFS_TECH_FS-BD_BTRFS_TECH_MODE_CREATE

bd_btrfs_resize ()

gboolean
bd_btrfs_resize (const gchar *mountpoint,
                 guint64 size,
                 const BDExtraArg **extra,
                 GError **error);

Parameters

mountpoint	a mountpoint of the to be resized btrfs filesystem
size	requested new size
extra	extra options for the volume resize (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the mountpoint filesystem was successfully resized to size or not

Tech category: BD_BTRFS_TECH_FS-BD_BTRFS_TECH_MODE_MODIFY

bd_btrfs_check ()

gboolean
bd_btrfs_check (const gchar *device,
                const BDExtraArg **extra,
                GError **error);

Parameters

device	a device that is part of the checked btrfs volume
extra	extra options for the check (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the filesystem was successfully checked or not

Tech category: BD_BTRFS_TECH_FS-BD_BTRFS_TECH_MODE_QUERY

bd_btrfs_repair ()

gboolean
bd_btrfs_repair (const gchar *device,
                 const BDExtraArg **extra,
                 GError **error);

Parameters

device	a device that is part of the to be repaired btrfs volume
extra	extra options for the repair (right now passed to the 'btrfs' utility).	[nullable][array zero-terminated=1]
error	place to store error (if any).	[out][optional]

Returns

whether the filesystem was successfully checked and repaired or not

Tech category: BD_BTRFS_TECH_FS-BD_BTRFS_TECH_MODE_MODIFY

bd_btrfs_change_label ()

gboolean
bd_btrfs_change_label (const gchar *mountpoint,
                       const gchar *label,
                       GError **error);

Parameters

mountpoint	a mountpoint of the btrfs filesystem to change label of
label	new label for the filesystem
error	place to store error (if any).	[out][optional]

Returns

whether the label of the mountpoint filesystem was successfully set to label or not

Tech category: BD_BTRFS_TECH_FS-BD_BTRFS_TECH_MODE_MODIFY

bd_btrfs_is_tech_avail ()

gboolean
bd_btrfs_is_tech_avail (BDBtrfsTech tech,
                        guint64 mode,
                        GError **error);

Parameters

tech	the queried tech
mode	a bit mask of queried modes of operation (BDBtrfsTechMode) for `tech`
error	place to store error (details about why the `tech` -`mode` combination is not available).	[out][optional]

Returns

whether the tech -mode combination is available -- supported by the plugin implementation and having all the runtime dependencies available

Types and Values

BD_BTRFS_MAIN_VOLUME_ID

#define             BD_BTRFS_MAIN_VOLUME_ID

BD_BTRFS_MIN_MEMBER_SIZE

#define             BD_BTRFS_MIN_MEMBER_SIZE

BD_BTRFS_ERROR

#define             BD_BTRFS_ERROR

enum BDBtrfsError

Members

BD_BTRFS_ERROR_TECH_UNAVAIL
BD_BTRFS_ERROR_DEVICE
BD_BTRFS_ERROR_PARSE

BDBtrfsDeviceInfo

typedef struct {
    guint64 id;
    gchar *path;
    guint64 size;
    guint64 used;
} BDBtrfsDeviceInfo;

Members

guint64 `id`;	ID of the device
gchar *`path`;	path of the device
guint64 `size`;	size of the device
guint64 `used`;	size of the used space

BDBtrfsSubvolumeInfo

typedef struct {
    guint64 id;
    guint64 parent_id;
    gchar *path;
} BDBtrfsSubvolumeInfo;

Members

guint64 `id`;	ID of the subvolume
guint64 `parent_id`;	ID of the parent (sub)volume
gchar *`path`;	path of the subvolume

BDBtrfsFilesystemInfo

typedef struct {
    gchar *label;
    gchar *uuid;
    guint64 num_devices;
    guint64 used;
} BDBtrfsFilesystemInfo;

Members

gchar *`label`;	label of the filesystem
gchar *`uuid`;	uuid of the filesystem
guint64 `num_devices`;	number of device in the filesystem
guint64 `used`;	size of the used space

enum BDBtrfsTech

Members

BD_BTRFS_TECH_FS
BD_BTRFS_TECH_MULTI_DEV
BD_BTRFS_TECH_SUBVOL
BD_BTRFS_TECH_SNAPSHOT

enum BDBtrfsTechMode

Members

BD_BTRFS_TECH_MODE_CREATE
BD_BTRFS_TECH_MODE_DELETE
BD_BTRFS_TECH_MODE_MODIFY
BD_BTRFS_TECH_MODE_QUERY