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4 .\" Copyright (c) 2017 Kyle Kneitinger
5 .\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
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35 .Nd library for creating, destroying and modifying ZFS boot environments
40 .Ft "libbe_handle_t *hdl" Ns
41 .Fn libbe_init "const char *be_root"
44 .Fn libbe_close "libbe_handle_t *hdl"
47 .Fn be_active_name "libbe_handle_t *hdl"
50 .Fn be_active_path "libbe_handle_t *hdl"
53 .Fn be_nextboot_name "libbe_handle_t *hdl"
56 .Fn be_nextboot_path "libbe_handle_t *hdl"
59 .Fn be_root_path "libbe_handle_t *hdl"
62 .Fn be_snapshot "libbe_handle_t *hdl" "const char *be_name" "const char *snap_name" "bool recursive" "char *result"
65 .Fn be_is_auto_snapshot_name "libbe_handle_t *hdl" "const char *snap"
68 .Fn be_create "libbe_handle_t *hdl" "const char *be_name"
71 .Fn be_create_depth "libbe_handle_t *hdl" "const char *be_name" "const char *snap" "int depth"
74 .Fn be_create_from_existing "libbe_handle_t *hdl" "const char *be_name" "const char *be_origin"
77 .Fn be_create_from_existing_snap "libbe_handle_t *hdl" "const char *be_name" "const char *snap"
80 .Fn be_rename "libbe_handle_t *hdl" "const char *be_old" "const char *be_new"
83 .Fn be_activate "libbe_handle_t *hdl" "const char *be_name" "bool temporary"
86 .Fn be_deactivate "libbe_handle_t *hdl" "const char *be_name" "bool temporary"
89 .Fn be_destroy "libbe_handle_t *hdl" "const char *be_name" "int options"
92 .Fn be_nicenum "uint64_t num" "char *buf" "size_t bufsz"
94 .\" TODO: Write up of mount options
96 .\" BE_MNT_FORCE = 1 << 0,
97 .\" BE_MNT_DEEP = 1 << 1,
100 .Fn be_mount "libbe_handle_t *hdl" "const char *be_name" "const char *mntpoint" "int flags" "char *result"
103 .Fn be_mounted_at "libbe_handle_t *hdl" "const char *path" "nvlist_t *details"
106 .Fn be_unmount "libbe_handle_t *hdl" "const char *be_name" "int flags"
109 .Fn libbe_errno "libbe_handle_t *hdl"
112 .Fn libbe_error_description "libbe_handle_t *hdl"
115 .Fn libbe_print_on_error "libbe_handle_t *hdl" "bool doprint"
118 .Fn be_root_concat "libbe_handle_t *hdl" "const char *be_name" "char *result"
121 .Fn be_validate_name "libbe_handle_t *hdl" "const char *be_name"
124 .Fn be_validate_snap "libbe_handle_t *hdl" "const char *snap"
127 .Fn be_exists "libbe_handle_t *hdl" "const char *be_name"
130 .Fn be_export "libbe_handle_t *hdl" "const char *be_name" "int fd"
133 .Fn be_import "libbe_handle_t *hdl" "const char *be_name" "int fd"
136 .Fn be_prop_list_alloc "nvlist_t **prop_list"
139 .Fn be_get_bootenv_props "libbe_handle_t *hdl" "nvlist_t *be_list"
142 .Fn be_get_dataset_props "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *props"
145 .Fn be_get_dataset_snapshots "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *snap_list"
148 .Fn be_prop_list_free "nvlist_t *prop_list"
151 interfaces with libzfs to provide a set of functions for various operations
152 regarding ZFS boot environments including "deep" boot environments in which
153 a boot environments has child datasets.
155 A context structure is passed to each function, allowing for a small amount
156 of state to be retained, such as errors from previous operations.
158 may be configured to print the corresponding error message to
160 when an error is encountered with
161 .Fn libbe_print_on_error .
163 All functions returning an
165 return 0 on success, or a
167 errno otherwise as described in
172 function takes an optional BE root and initializes
175 .Vt "libbe_handle_t *"
179 If a BE root is supplied,
181 will only operate out of that pool and BE root.
182 An error may occur if:
184 .It /boot and / are not on the same filesystem and device,
185 .It libzfs fails to initialize,
186 .It The system has not been properly booted with a ZFS boot
189 fails to open the zpool the active boot environment resides on, or
191 fails to locate the boot environment that is currently mounted.
196 function frees all resources previously acquired in
198 invalidating the handle in the process.
202 function returns the name of the currently booted boot environment.
203 This boot environment may not belong to the same BE root as the root libbe
208 function returns the full path of the currently booted boot environment.
209 This boot environment may not belong to the same BE root as the root libbe
214 function returns the name of the boot environment that will be active on reboot.
218 function returns the full path of the boot environment that will be
223 function returns the boot environment root path.
227 function creates a snapshot of
234 may be used, indicating that
236 should derive the snapshot name from the current date and time.
241 will recursively snapshot the dataset.
246 then it will be populated with the final
247 .Dq Fa be_name Ns @ Ns Fa snap_name .
250 .Fn be_is_auto_snapshot_name
251 function is used to determine if the given snapshot name matches the format that
254 function will use by default if it is not given a snapshot name to use.
257 if the name matches the format, and
263 function creates a boot environment with the given name.
264 The new boot environment will be created from a recursive snapshot of the
265 currently booted boot environment.
269 function creates a boot environment with the given name from an existing
271 The depth parameter specifies the depth of recursion that will be cloned from
272 the existing snapshot.
273 A depth of '0' is no recursion and '-1' is unlimited (i.e., a recursive boot
277 .Fn be_create_from_existing
278 function creates a boot environment with the given name from the name of an
279 existing boot environment.
280 A recursive snapshot will be made of the origin boot environment, and the new
281 boot environment will be created from that.
284 .Fn be_create_from_existing_snap
285 function creates a recursive boot environment with the given name from an
290 function renames a boot environment without unmounting it, as if renamed with
293 argument were passed to
299 function makes a boot environment active on the next boot.
302 flag is set, then it will be active for the next boot only, as done by
307 function deactivates a boot environment.
310 flag is set, then it will cause removal of boot once configuration, set by
318 function will set zfs
325 function will recursively destroy the given boot environment.
326 It will not destroy a mounted boot environment unless the
331 .Dv BE_DESTROY_ORIGIN
336 function will destroy the origin snapshot to this boot environment as well.
342 in a traditional ZFS humanized format, similar to
343 .Xr humanize_number 3 .
344 This function effectively proxies
350 function will mount the given boot environment.
355 a mount point will be generated in
363 it should be large enough to accommodate
365 including the null terminator.
366 the final mount point will be copied into it.
377 function will check if there is a boot environment mounted at the given
383 it will be populated with a list of the mounted dataset's properties.
384 This list of properties matches the properties collected by
385 .Fn be_get_bootenv_props .
389 function will unmount the given boot environment.
405 .Fn libbe_error_description
406 function returns a string description of the currently set
411 .Fn libbe_print_on_error
412 function will change whether or not
414 prints the description of any encountered error to
421 function will concatenate the boot environment root and the given boot
422 environment name into
427 function will validate the given boot environment name for both length
428 restrictions as well as valid character restrictions.
429 This function does not set the internal library error state.
433 function will validate the given snapshot name.
434 The snapshot must have a valid name, exist, and have a mountpoint of
436 This function does not set the internal library error state.
440 function will check whether the given boot environment exists and has a
443 This function does not set the internal library error state, but will return
444 the appropriate error.
448 function will export the given boot environment to the file specified by
450 A snapshot will be created of the boot environment prior to export.
454 function will import the boot environment in the file specified by
460 .Fn be_prop_list_alloc
461 function allocates a property list suitable for passing to
462 .Fn be_get_bootenv_props ,
463 .Fn be_get_dataset_props ,
465 .Fn be_get_dataset_snapshots .
466 It should be freed later by
467 .Fa be_prop_list_free .
470 .Fn be_get_bootenv_props
471 function will populate
475 of boot environment names paired with an
478 The following properties are currently collected as appropriate:
479 .Bl -column "Returned name"
480 .It Sy Returned name Ta Sy Description
482 .It name Ta Boot environment name
483 .It mounted Ta Current mount point
484 .It mountpoint Ta Do mountpoint Dc property
485 .It origin Ta Do origin Dc property
486 .It creation Ta Do creation Dc property
487 .It active Ta Currently booted environment
488 .It used Ta Literal Do used Dc property
489 .It usedds Ta Literal Do usedds Dc property
490 .It usedsnap Ta Literal Do usedrefreserv Dc property
491 .It referenced Ta Literal Do referenced Dc property
492 .It nextboot Ta Active on next boot
501 returned values will always be present.
502 All other properties may be omitted if not available.
505 .Fn be_get_dataset_props
506 function will get properties of the specified dataset.
508 is populated directly with a list of the properties as returned by
509 .Fn be_get_bootenv_props .
512 .Fn be_get_dataset_snapshots
513 function will retrieve all snapshots of the given dataset.
515 will be populated with a list of
517 exactly as specified by
518 .Fn be_get_bootenv_props .
521 .Fn be_prop_list_free
522 function will free the property list.
524 Upon error, one of the following values will be returned:
525 .Bl -dash -offset indent -compact
573 and its corresponding command,
575 were written as a 2017 Google Summer of Code project with Allan Jude serving
577 Later work was done by
578 .An Kyle Evans Aq Mt kevans@FreeBSD.org .