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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_is_auto_snapshot_name "libbe_handle_t *hdl" "const char *snap"
65 .Fn be_create "libbe_handle_t *hdl" "const char *be_name"
68 .Fn be_create_depth "libbe_handle_t *hdl" "const char *be_name" "const char *snap" "int depth"
71 .Fn be_create_from_existing "libbe_handle_t *hdl" "const char *be_name" "const char *be_origin"
74 .Fn be_create_from_existing_snap "libbe_handle_t *hdl" "const char *be_name" "const char *snap"
77 .Fn be_rename "libbe_handle_t *hdl" "const char *be_old" "const char *be_new"
80 .Fn be_activate "libbe_handle_t *hdl" "const char *be_name" "bool temporary"
83 .Fn be_deactivate "libbe_handle_t *hdl" "const char *be_name" "bool temporary"
86 .Fn be_destroy "libbe_handle_t *hdl" "const char *be_name" "int options"
89 .Fn be_nicenum "uint64_t num" "char *buf" "size_t bufsz"
91 .\" TODO: Write up of mount options
93 .\" BE_MNT_FORCE = 1 << 0,
94 .\" BE_MNT_DEEP = 1 << 1,
97 .Fn be_mount "libbe_handle_t *hdl" "char *be_name" "char *mntpoint" "int flags" "char *result"
100 .Fn be_mounted_at "libbe_handle_t *hdl" "const char *path" "nvlist_t *details"
103 .Fn be_unmount "libbe_handle_t *hdl" "char *be_name" "int flags"
106 .Fn libbe_errno "libbe_handle_t *hdl"
109 .Fn libbe_error_description "libbe_handle_t *hdl"
112 .Fn libbe_print_on_error "libbe_handle_t *hdl" "bool doprint"
115 .Fn be_root_concat "libbe_handle_t *hdl" "const char *be_name" "char *result"
118 .Fn be_validate_name "libbe_handle_t *hdl" "const char *be_name"
121 .Fn be_validate_snap "libbe_handle_t *hdl" "const char *snap"
124 .Fn be_exists "libbe_handle_t *hdl" "char *be_name"
127 .Fn be_export "libbe_handle_t *hdl" "const char *be_name" "int fd"
130 .Fn be_import "libbe_handle_t *hdl" "const char *be_name" "int fd"
133 .Fn be_prop_list_alloc "nvlist_t **prop_list"
136 .Fn be_get_bootenv_props "libbe_handle_t *hdl" "nvlist_t *be_list"
139 .Fn be_get_dataset_props "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *props"
142 .Fn be_get_dataset_snapshots "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *snap_list"
145 .Fn be_prop_list_free "nvlist_t *prop_list"
148 interfaces with libzfs to provide a set of functions for various operations
149 regarding ZFS boot environments including "deep" boot environments in which
150 a boot environments has child datasets.
152 A context structure is passed to each function, allowing for a small amount
153 of state to be retained, such as errors from previous operations.
155 may be configured to print the corresponding error message to
157 when an error is encountered with
158 .Fn libbe_print_on_error .
160 All functions returning an
162 return 0 on success, or a
164 errno otherwise as described in
169 function takes an optional BE root and initializes
172 .Vt "libbe_handle_t *"
176 If a BE root is supplied,
178 will only operate out of that pool and BE root.
179 An error may occur if:
181 .It /boot and / are not on the same filesystem and device,
182 .It libzfs fails to initialize,
183 .It The system has not been properly booted with a ZFS boot
186 fails to open the zpool the active boot environment resides on, or
188 fails to locate the boot environment that is currently mounted.
193 function frees all resources previously acquired in
195 invalidating the handle in the process.
199 function returns the name of the currently booted boot environment.
200 This boot environment may not belong to the same BE root as the root libbe
205 function returns the full path of the currently booted boot environment.
206 This boot environment may not belong to the same BE root as the root libbe
211 function returns the name of the boot environment that will be active on reboot.
215 function returns the full path of the boot environment that will be
220 function returns the boot environment root path.
223 .Fn be_is_auto_snapshot_name
224 function is used to determine if the given snapshot name matches the format that
227 function will use by default if it is not given a snapshot name to use.
230 if the name matches the format, and
236 function creates a boot environment with the given name.
237 The new boot environment will be created from a recursive snapshot of the
238 currently booted boot environment.
242 function creates a boot environment with the given name from an existing
244 The depth parameter specifies the depth of recursion that will be cloned from
245 the existing snapshot.
246 A depth of '0' is no recursion and '-1' is unlimited (i.e., a recursive boot
250 .Fn be_create_from_existing
251 function creates a boot environment with the given name from the name of an
252 existing boot environment.
253 A recursive snapshot will be made of the origin boot environment, and the new
254 boot environment will be created from that.
257 .Fn be_create_from_existing_snap
258 function creates a recursive boot environment with the given name from an
263 function renames a boot environment without unmounting it, as if renamed with
266 argument were passed to
272 function makes a boot environment active on the next boot.
275 flag is set, then it will be active for the next boot only, as done by
280 function deactivates a boot environment.
283 flag is set, then it will cause removal of boot once configuration, set by
291 function will set zfs
298 function will recursively destroy the given boot environment.
299 It will not destroy a mounted boot environment unless the
304 .Dv BE_DESTROY_ORIGIN
309 function will destroy the origin snapshot to this boot environment as well.
315 in a traditional ZFS humanized format, similar to
316 .Xr humanize_number 3 .
317 This function effectively proxies
323 function will mount the given boot environment.
328 a mount point will be generated in
336 it should be large enough to accommodate
338 including the null terminator.
339 the final mount point will be copied into it.
350 function will check if there is a boot environment mounted at the given
356 it will be populated with a list of the mounted dataset's properties.
357 This list of properties matches the properties collected by
358 .Fn be_get_bootenv_props .
362 function will unmount the given boot environment.
378 .Fn libbe_error_description
379 function returns a string description of the currently set
384 .Fn libbe_print_on_error
385 function will change whether or not
387 prints the description of any encountered error to
394 function will concatenate the boot environment root and the given boot
395 environment name into
400 function will validate the given boot environment name for both length
401 restrictions as well as valid character restrictions.
402 This function does not set the internal library error state.
406 function will validate the given snapshot name.
407 The snapshot must have a valid name, exist, and have a mountpoint of
409 This function does not set the internal library error state.
413 function will check whether the given boot environment exists and has a
416 This function does not set the internal library error state, but will return
417 the appropriate error.
421 function will export the given boot environment to the file specified by
423 A snapshot will be created of the boot environment prior to export.
427 function will import the boot environment in the file specified by
433 .Fn be_prop_list_alloc
434 function allocates a property list suitable for passing to
435 .Fn be_get_bootenv_props ,
436 .Fn be_get_dataset_props ,
438 .Fn be_get_dataset_snapshots .
439 It should be freed later by
440 .Fa be_prop_list_free .
443 .Fn be_get_bootenv_props
444 function will populate
448 of boot environment names paired with an
451 The following properties are currently collected as appropriate:
452 .Bl -column "Returned name"
453 .It Sy Returned name Ta Sy Description
455 .It name Ta Boot environment name
456 .It mounted Ta Current mount point
457 .It mountpoint Ta Do mountpoint Dc property
458 .It origin Ta Do origin Dc property
459 .It creation Ta Do creation Dc property
460 .It active Ta Currently booted environment
461 .It used Ta Literal Do used Dc property
462 .It usedds Ta Literal Do usedds Dc property
463 .It usedsnap Ta Literal Do usedrefreserv Dc property
464 .It referenced Ta Literal Do referenced Dc property
465 .It nextboot Ta Active on next boot
474 returned values will always be present.
475 All other properties may be omitted if not available.
478 .Fn be_get_dataset_props
479 function will get properties of the specified dataset.
481 is populated directly with a list of the properties as returned by
482 .Fn be_get_bootenv_props .
485 .Fn be_get_dataset_snapshots
486 function will retrieve all snapshots of the given dataset.
488 will be populated with a list of
490 exactly as specified by
491 .Fn be_get_bootenv_props .
494 .Fn be_prop_list_free
495 function will free the property list.
497 Upon error, one of the following values will be returned:
498 .Bl -dash -offset indent -compact
546 and its corresponding command,
548 were written as a 2017 Google Summer of Code project with Allan Jude serving
550 Later work was done by
551 .An Kyle Evans Aq Mt kevans@FreeBSD.org .