2 .\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 .\" Copyright (c) 2017 Kyle Kneitinger
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6 .\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
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36 .Nd library for creating, destroying and modifying ZFS boot environments
41 .Ft "libbe_handle_t *hdl" Ns
42 .Fn libbe_init "const char *be_root"
45 .Fn libbe_close "libbe_handle_t *hdl"
48 .Fn be_active_name "libbe_handle_t *hdl"
51 .Fn be_active_path "libbe_handle_t *hdl"
54 .Fn be_nextboot_name "libbe_handle_t *hdl"
57 .Fn be_nextboot_path "libbe_handle_t *hdl"
60 .Fn be_root_path "libbe_handle_t *hdl"
63 .Fn be_create "libbe_handle_t *hdl" "const char *be_name"
66 .Fn be_create_from_existing "libbe_handle_t *hdl" "const char *be_name" "const char *be_origin"
69 .Fn be_create_from_existing_snap "libbe_handle_t *hdl" "const char *be_name" "const char *snap"
72 .Fn be_rename "libbe_handle_t *hdl" "const char *be_old" "const char *be_new"
75 .Fn be_activate "libbe_handle_t *hdl" "const char *be_name" "bool temporary"
77 .Fn be_destroy "libbe_handle_t *hdl" "const char *be_name" "int options"
80 .Fn be_nicenum "uint64_t num" "char *buf" "size_t bufsz"
82 .\" TODO: Write up of mount options
84 .\" BE_MNT_FORCE = 1 << 0,
85 .\" BE_MNT_DEEP = 1 << 1,
88 .Fn be_mount "libbe_handle_t *hdl" "char *be_name" "char *mntpoint" "int flags" "char *result"
91 .Fn be_mounted_at "libbe_handle_t *hdl" "const char *path" "nvlist_t *details"
94 .Fn be_unmount "libbe_handle_t *hdl" "char *be_name" "int flags"
97 .Fn libbe_errno "libbe_handle_t *hdl"
100 .Fn libbe_error_description "libbe_handle_t *hdl"
103 .Fn libbe_print_on_error "libbe_handle_t *hdl" "bool doprint"
106 .Fn be_root_concat "libbe_handle_t *hdl" "const char *be_name" "char *result"
109 .Fn be_validate_name "libbe_handle_t *hdl" "const char *be_name"
112 .Fn be_validate_snap "libbe_handle_t *hdl" "const char *snap"
115 .Fn be_exists "libbe_handle_t *hdl" "char *be_name"
118 .Fn be_export "libbe_handle_t *hdl" "const char *be_name" "int fd"
121 .Fn be_import "libbe_handle_t *hdl" "const char *be_name" "int fd"
124 .Fn be_prop_list_alloc "nvlist_t **prop_list"
127 .Fn be_get_bootenv_props "libbe_handle_t *hdl" "nvlist_t *be_list"
130 .Fn be_get_dataset_props "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *props"
133 .Fn be_get_dataset_snapshots "libbe_handle_t *hdl" "const char *ds_name" "nvlist_t *snap_list"
136 .Fn be_prop_list_free "nvlist_t *prop_list"
139 interfaces with libzfs to provide a set of functions for various operations
140 regarding ZFS boot environments including "deep" boot environments in which
141 a boot environments has child datasets.
143 A context structure is passed to each function, allowing for a small amount
144 of state to be retained, such as errors from previous operations.
146 may be configured to print the corresponding error message to
148 when an error is encountered with
149 .Fn libbe_print_on_error .
151 All functions returning an
153 return 0 on success, or a
155 errno otherwise as described in
160 function takes an optional BE root and initializes
163 .Vt "libbe_handle_t *"
167 If a BE root is supplied,
169 will only operate out of that pool and BE root.
170 An error may occur if:
172 .It /boot and / are not on the same filesystem and device,
173 .It libzfs fails to initialize,
174 .It The system has not been properly booted with a ZFS boot
177 fails to open the zpool the active boot environment resides on, or
179 fails to locate the boot environment that is currently mounted.
184 function frees all resources previously acquired in
186 invalidating the handle in the process.
190 function returns the name of the currently booted boot environment.
191 This boot environment may not belong to the same BE root as the root libbe
196 function returns the full path of the currently booted boot environment.
197 This boot environment may not belong to the same BE root as the root libbe
202 function returns the name of the boot environment that will be active on reboot.
206 function returns the full path of the boot environment that will be
211 function returns the boot environment root path.
215 function creates a boot environment with the given name.
216 It will be created from a snapshot of the currently booted boot environment.
219 .Fn be_create_from_existing
220 function creates a boot environment with the given name from the name of an
221 existing boot environment.
222 A snapshot will be made of the base boot environment, and the new boot
223 environment will be created from that.
226 .Fn be_create_from_existing_snap
227 function creates a boot environment with the given name from an existing
232 function renames a boot environment without unmounting it, as if renamed with
235 argument were passed to
241 function makes a boot environment active on the next boot.
244 flag is set, then it will be active for the next boot only, as done by
246 Next boot functionality is currently only available when booting in x86 BIOS
251 function will recursively destroy the given boot environment.
252 It will not destroy a mounted boot environment unless the
261 in a traditional ZFS humanized format, similar to
262 .Xr humanize_number 3 .
263 This function effectively proxies
269 function will mount the given boot environment.
274 a mount point will be generated in
282 it should be large enough to accommodate
284 including the null terminator.
285 the final mount point will be copied into it.
296 function will check if there is a boot environment mounted at the given
302 it will be populated with a list of the mounted dataset's properties.
303 This list of properties matches the properties collected by
304 .Fn be_get_bootenv_props .
308 function will unmount the given boot environment.
324 .Fn libbe_error_description
325 function returns a string description of the currently set
330 .Fn libbe_print_on_error
331 function will change whether or not
333 prints the description of any encountered error to
340 function will concatenate the boot environment root and the given boot
341 environment name into
346 function will validate the given boot environment name for both length
347 restrictions as well as valid character restrictions.
348 This function does not set the internal library error state.
352 function will validate the given snapshot name.
353 The snapshot must have a valid name, exist, and have a mountpoint of
355 This function does not set the internal library error state.
359 function will check whether the given boot environment exists and has a
362 This function does not set the internal library error state, but will return
363 the appropriate error.
367 function will export the given boot environment to the file specified by
369 A snapshot will be created of the boot environment prior to export.
373 function will import the boot environment in the file specified by
379 .Fn be_prop_list_alloc
380 function allocates a property list suitable for passing to
381 .Fn be_get_bootenv_props ,
382 .Fn be_get_dataset_props ,
384 .Fn be_get_dataset_snapshots .
385 It should be freed later by
386 .Fa be_prop_list_free .
389 .Fn be_get_bootenv_props
390 function will populate
394 of boot environment names paired with an
397 The following properties are currently collected as appropriate:
398 .Bl -column "Returned name"
399 .It Sy Returned name Ta Sy Description
401 .It name Ta Boot environment name
402 .It mounted Ta Current mount point
403 .It mountpoint Ta Do mountpoint Dc property
404 .It origin Ta Do origin Dc property
405 .It creation Ta Do creation Dc property
406 .It active Ta Currently booted environment
407 .It used Ta Literal Do used Dc property
408 .It usedds Ta Literal Do usedds Dc property
409 .It usedsnap Ta Literal Do usedrefreserv Dc property
410 .It referenced Ta Literal Do referenced Dc property
411 .It nextboot Ta Active on next boot
420 returned values will always be present.
421 All other properties may be omitted if not available.
424 .Fn be_get_dataset_props
425 function will get properties of the specified dataset.
427 is populated directly with a list of the properties as returned by
428 .Fn be_get_bootenv_props .
431 .Fn be_get_dataset_snapshots
432 function will retrieve all snapshots of the given dataset.
434 will be populated with a list of
436 exactly as specified by
437 .Fn be_get_bootenv_props .
440 .Fn be_prop_list_free
441 function will free the property list.
443 Upon error, one of the following values will be returned.
444 .\" TODO: make each entry on its own line.
445 .Bd -ragged -offset indent
471 and its corresponding command,
473 were written as a 2017 Google Summer of Code project with Allan Jude serving
475 Later work was done by
476 .An Kyle Evans Aq Mt kevans@FreeBSD.org .