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
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
163 .Vt "libbe_handle_t *"
167 An error may occur if:
169 .It /boot and / are not on the same filesystem and device,
170 .It libzfs fails to initialize,
171 .It The system has not been properly booted with a ZFS boot
174 fails to open the zpool the active boot environment resides on, or
176 fails to locate the boot environment that is currently mounted.
181 function frees all resources previously acquired in
183 invalidating the handle in the process.
187 function returns the name of the currently booted boot environment,
191 function returns the full path of the currently booted boot environment.
195 function returns the name of the boot environment that will be active on reboot.
199 function returns the full path of the boot environment that will be
204 function returns the boot environment root path.
208 function creates a boot environment with the given name.
209 It will be created from a snapshot of the currently booted boot environment.
212 .Fn be_create_from_existing
213 function creates a boot environment with the given name from the name of an
214 existing boot environment.
215 A snapshot will be made of the base boot environment, and the new boot
216 environment will be created from that.
219 .Fn be_create_from_existing_snap
220 function creates a boot environment with the given name from an existing
225 function renames a boot environment without unmounting it, as if renamed with
228 argument were passed to
234 function makes a boot environment active on the next boot.
237 flag is set, then it will be active for the next boot only, as done by
239 Next boot functionality is currently only available when booting in x86 BIOS
244 function will recursively destroy the given boot environment.
245 It will not destroy a mounted boot environment unless the
254 in a traditional ZFS humanized format, similar to
255 .Xr humanize_number 3 .
256 This function effectively proxies
262 function will mount the given boot environment.
267 a mount point will be generated in
275 it should be large enough to accommodate
277 including the null terminator.
278 the final mount point will be copied into it.
289 function will check if there is a boot environment mounted at the given
295 it will be populated with a list of the mounted dataset's properties.
296 This list of properties matches the properties collected by
297 .Fn be_get_bootenv_props .
301 function will unmount the given boot environment.
317 .Fn libbe_error_description
318 function returns a string description of the currently set
323 .Fn libbe_print_on_error
324 function will change whether or not
326 prints the description of any encountered error to
333 function will concatenate the boot environment root and the given boot
334 environment name into
339 function will validate the given boot environment name for both length
340 restrictions as well as valid character restrictions.
341 This function does not set the internal library error state.
345 function will validate the given snapshot name.
346 The snapshot must have a valid name, exist, and have a mountpoint of
348 This function does not set the internal library error state.
352 function will check whether the given boot environment exists and has a
358 function will export the given boot environment to the file specified by
360 A snapshot will be created of the boot environment prior to export.
364 function will import the boot environment in the file specified by
370 .Fn be_prop_list_alloc
371 function allocates a property list suitable for passing to
372 .Fn be_get_bootenv_props ,
373 .Fn be_get_dataset_props ,
375 .Fn be_get_dataset_snapshots .
376 It should be freed later by
377 .Fa be_prop_list_free .
380 .Fn be_get_bootenv_props
381 function will populate
385 of boot environment names paired with an
388 The following properties are currently collected as appropriate:
389 .Bl -column "Returned name"
390 .It Sy Returned name Ta Sy Description
392 .It name Ta Boot environment name
393 .It mounted Ta Current mount point
394 .It mountpoint Ta Do mountpoint Dc property
395 .It origin Ta Do origin Dc property
396 .It creation Ta Do creation Dc property
397 .It active Ta Currently booted environment
398 .It used Ta Literal Do used Dc property
399 .It usedds Ta Literal Do usedds Dc property
400 .It usedsnap Ta Literal Do usedrefreserv Dc property
401 .It referenced Ta Literal Do referenced Dc property
402 .It nextboot Ta Active on next boot
411 returned values will always be present.
412 All other properties may be omitted if not available.
415 .Fn be_get_dataset_props
416 function will get properties of the specified dataset.
418 is populated directly with a list of the properties as returned by
419 .Fn be_get_bootenv_props .
422 .Fn be_get_dataset_snapshots
423 function will retrieve all snapshots of the given dataset.
425 will be populated with a list of
427 exactly as specified by
428 .Fn be_get_bootenv_props .
431 .Fn be_prop_list_free
432 function will free the property list.
434 Upon error, one of the following values will be returned.
435 .\" TODO: make each entry on its own line.
436 .Bd -ragged -offset indent
462 and its corresponding command,
464 were written as a 2017 Google Summer of Code project with Allan Jude serving
466 Later work was done by
467 .An Kyle Evans Aq Mt kevans@FreeBSD.org .