be.c (485172f537e195e3d5ca9467192f73c1893ab537) be.c (8f5c6c31ae7b2fe787fbe11909e33fd151c6d524)
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions

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28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/mount.h>
34#include <sys/stat.h>
35#include <sys/ucred.h>
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions

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28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/mount.h>
34#include <sys/stat.h>
35#include <sys/ucred.h>
36
36#include <sys/queue.h>
37#include <sys/zfs_context.h>
38#include <sys/mntent.h>
39
40#include <ctype.h>
41#include <libgen.h>
42#include <libzfs_core.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <time.h>
46#include <unistd.h>
47
48#include "be.h"
49#include "be_impl.h"
50
37#include <sys/zfs_context.h>
38#include <sys/mntent.h>
39
40#include <ctype.h>
41#include <libgen.h>
42#include <libzfs_core.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <time.h>
46#include <unistd.h>
47
48#include "be.h"
49#include "be_impl.h"
50
51struct promote_entry {
52 char name[BE_MAXPATHLEN];
53 SLIST_ENTRY(promote_entry) link;
54};
55
51struct be_destroy_data {
56struct be_destroy_data {
52 libbe_handle_t *lbh;
53 char *snapname;
57 libbe_handle_t *lbh;
58 char target_name[BE_MAXPATHLEN];
59 char *snapname;
60 SLIST_HEAD(, promote_entry) promotelist;
54};
55
56#if SOON
57static int be_create_child_noent(libbe_handle_t *lbh, const char *active,
58 const char *child_path);
59static int be_create_child_cloned(libbe_handle_t *lbh, const char *active);
60#endif
61

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189 */
190void
191be_nicenum(uint64_t num, char *buf, size_t buflen)
192{
193
194 zfs_nicenum(num, buf, buflen);
195}
196
61};
62
63#if SOON
64static int be_create_child_noent(libbe_handle_t *lbh, const char *active,
65 const char *child_path);
66static int be_create_child_cloned(libbe_handle_t *lbh, const char *active);
67#endif
68

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196 */
197void
198be_nicenum(uint64_t num, char *buf, size_t buflen)
199{
200
201 zfs_nicenum(num, buf, buflen);
202}
203
204static bool
205be_should_promote_clones(zfs_handle_t *zfs_hdl, struct be_destroy_data *bdd)
206{
207 char *atpos;
208
209 if (zfs_get_type(zfs_hdl) != ZFS_TYPE_SNAPSHOT)
210 return (false);
211
212 /*
213 * If we're deleting a snapshot, we need to make sure we only promote
214 * clones that are derived from one of the snapshots we're deleting,
215 * rather than that of a snapshot we're not touching. This keeps stuff
216 * in a consistent state, making sure that we don't error out unless
217 * we really need to.
218 */
219 if (bdd->snapname == NULL)
220 return (true);
221
222 atpos = strchr(zfs_get_name(zfs_hdl), '@');
223 return (strcmp(atpos + 1, bdd->snapname) == 0);
224}
225
226/*
227 * This is executed from be_promote_dependent_clones via zfs_iter_dependents,
228 * It checks if the dependent type is a snapshot then attempts to find any
229 * clones associated with it. Any clones not related to the destroy target are
230 * added to the promote list.
231 */
197static int
232static int
233be_dependent_clone_cb(zfs_handle_t *zfs_hdl, void *data)
234{
235 int err;
236 bool found;
237 char *name;
238 struct nvlist *nvl;
239 struct nvpair *nvp;
240 struct be_destroy_data *bdd;
241 struct promote_entry *entry, *newentry;
242
243 nvp = NULL;
244 err = 0;
245 bdd = (struct be_destroy_data *)data;
246
247 if (be_should_promote_clones(zfs_hdl, bdd) &&
248 (nvl = zfs_get_clones_nvl(zfs_hdl)) != NULL) {
249 while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) {
250 name = nvpair_name(nvp);
251
252 /*
253 * Skip if the clone is equal to, or a child of, the
254 * destroy target.
255 */
256 if (strncmp(name, bdd->target_name,
257 strlen(bdd->target_name)) == 0 ||
258 strstr(name, bdd->target_name) == name) {
259 continue;
260 }
261
262 found = false;
263 SLIST_FOREACH(entry, &bdd->promotelist, link) {
264 if (strcmp(entry->name, name) == 0) {
265 found = true;
266 break;
267 }
268 }
269
270 if (found)
271 continue;
272
273 newentry = malloc(sizeof(struct promote_entry));
274 if (newentry == NULL) {
275 err = ENOMEM;
276 break;
277 }
278
279#define BE_COPY_NAME(entry, src) \
280 strlcpy((entry)->name, (src), sizeof((entry)->name))
281 if (BE_COPY_NAME(newentry, name) >=
282 sizeof(newentry->name)) {
283 /* Shouldn't happen. */
284 free(newentry);
285 err = ENAMETOOLONG;
286 break;
287 }
288#undef BE_COPY_NAME
289
290 /*
291 * We're building up a SLIST here to make sure both that
292 * we get the order right and so that we don't
293 * inadvertently observe the wrong state by promoting
294 * datasets while we're still walking the tree. The
295 * latter can lead to situations where we promote a BE
296 * then effectively demote it again.
297 */
298 SLIST_INSERT_HEAD(&bdd->promotelist, newentry, link);
299 }
300 nvlist_free(nvl);
301 }
302 zfs_close(zfs_hdl);
303 return (err);
304}
305
306/*
307 * This is called before a destroy, so that any datasets(environments) that are
308 * dependent on this one get promoted before destroying the target.
309 */
310static int
311be_promote_dependent_clones(zfs_handle_t *zfs_hdl, struct be_destroy_data *bdd)
312{
313 int err;
314 zfs_handle_t *clone;
315 struct promote_entry *entry;
316
317 snprintf(bdd->target_name, BE_MAXPATHLEN, "%s/", zfs_get_name(zfs_hdl));
318 err = zfs_iter_dependents(zfs_hdl, true, be_dependent_clone_cb, bdd);
319
320 /*
321 * Drain the list and walk away from it if we're only deleting a
322 * snapshot.
323 */
324 if (bdd->snapname != NULL && !SLIST_EMPTY(&bdd->promotelist))
325 err = BE_ERR_HASCLONES;
326 while (!SLIST_EMPTY(&bdd->promotelist)) {
327 entry = SLIST_FIRST(&bdd->promotelist);
328 SLIST_REMOVE_HEAD(&bdd->promotelist, link);
329
330#define ZFS_GRAB_CLONE() \
331 zfs_open(bdd->lbh->lzh, entry->name, ZFS_TYPE_FILESYSTEM)
332 /*
333 * Just skip this part on error, we still want to clean up the
334 * promotion list after the first error. We'll then preserve it
335 * all the way back.
336 */
337 if (err == 0 && (clone = ZFS_GRAB_CLONE()) != NULL) {
338 err = zfs_promote(clone);
339 if (err != 0)
340 err = BE_ERR_DESTROYMNT;
341 zfs_close(clone);
342 }
343#undef ZFS_GRAB_CLONE
344 free(entry);
345 }
346
347 return (err);
348}
349
350static int
198be_destroy_cb(zfs_handle_t *zfs_hdl, void *data)
199{
200 char path[BE_MAXPATHLEN];
201 struct be_destroy_data *bdd;
202 zfs_handle_t *snap;
203 int err;
204
205 bdd = (struct be_destroy_data *)data;

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234
235#define BE_DESTROY_WANTORIGIN (BE_DESTROY_ORIGIN | BE_DESTROY_AUTOORIGIN)
236/*
237 * Destroy the boot environment or snapshot specified by the name
238 * parameter. Options are or'd together with the possible values:
239 * BE_DESTROY_FORCE : forces operation on mounted datasets
240 * BE_DESTROY_ORIGIN: destroy the origin snapshot as well
241 */
351be_destroy_cb(zfs_handle_t *zfs_hdl, void *data)
352{
353 char path[BE_MAXPATHLEN];
354 struct be_destroy_data *bdd;
355 zfs_handle_t *snap;
356 int err;
357
358 bdd = (struct be_destroy_data *)data;

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387
388#define BE_DESTROY_WANTORIGIN (BE_DESTROY_ORIGIN | BE_DESTROY_AUTOORIGIN)
389/*
390 * Destroy the boot environment or snapshot specified by the name
391 * parameter. Options are or'd together with the possible values:
392 * BE_DESTROY_FORCE : forces operation on mounted datasets
393 * BE_DESTROY_ORIGIN: destroy the origin snapshot as well
394 */
242int
243be_destroy(libbe_handle_t *lbh, const char *name, int options)
395static int
396be_destroy_internal(libbe_handle_t *lbh, const char *name, int options,
397 bool odestroyer)
244{
245 struct be_destroy_data bdd;
246 char origin[BE_MAXPATHLEN], path[BE_MAXPATHLEN];
247 zfs_handle_t *fs;
248 char *snapdelim;
249 int err, force, mounted;
250 size_t rootlen;
251
252 bdd.lbh = lbh;
253 bdd.snapname = NULL;
398{
399 struct be_destroy_data bdd;
400 char origin[BE_MAXPATHLEN], path[BE_MAXPATHLEN];
401 zfs_handle_t *fs;
402 char *snapdelim;
403 int err, force, mounted;
404 size_t rootlen;
405
406 bdd.lbh = lbh;
407 bdd.snapname = NULL;
408 SLIST_INIT(&bdd.promotelist);
254 force = options & BE_DESTROY_FORCE;
255 *origin = '\0';
256
257 be_root_concat(lbh, name, path);
258
259 if ((snapdelim = strchr(path, '@')) == NULL) {
260 if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_FILESYSTEM))
261 return (set_error(lbh, BE_ERR_NOENT));
262
263 if (strcmp(path, lbh->rootfs) == 0 ||
264 strcmp(path, lbh->bootfs) == 0)
265 return (set_error(lbh, BE_ERR_DESTROYACT));
266
267 fs = zfs_open(lbh->lzh, path, ZFS_TYPE_FILESYSTEM);
268 if (fs == NULL)
269 return (set_error(lbh, BE_ERR_ZFSOPEN));
270
409 force = options & BE_DESTROY_FORCE;
410 *origin = '\0';
411
412 be_root_concat(lbh, name, path);
413
414 if ((snapdelim = strchr(path, '@')) == NULL) {
415 if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_FILESYSTEM))
416 return (set_error(lbh, BE_ERR_NOENT));
417
418 if (strcmp(path, lbh->rootfs) == 0 ||
419 strcmp(path, lbh->bootfs) == 0)
420 return (set_error(lbh, BE_ERR_DESTROYACT));
421
422 fs = zfs_open(lbh->lzh, path, ZFS_TYPE_FILESYSTEM);
423 if (fs == NULL)
424 return (set_error(lbh, BE_ERR_ZFSOPEN));
425
271 if ((options & BE_DESTROY_WANTORIGIN) != 0 &&
272 zfs_prop_get(fs, ZFS_PROP_ORIGIN, origin, sizeof(origin),
273 NULL, NULL, 0, 1) != 0 &&
274 (options & BE_DESTROY_ORIGIN) != 0)
275 return (set_error(lbh, BE_ERR_NOORIGIN));
276
277 /*
278 * If the caller wants auto-origin destruction and the origin
279 * name matches one of our automatically created snapshot names
280 * (i.e. strftime("%F-%T") with a serial at the end), then
281 * we'll set the DESTROY_ORIGIN flag and nuke it
282 * be_is_auto_snapshot_name is exported from libbe(3) so that
283 * the caller can determine if it needs to warn about the origin
284 * not being destroyed or not.
285 */
286 if ((options & BE_DESTROY_AUTOORIGIN) != 0 && *origin != '\0' &&
287 be_is_auto_snapshot_name(lbh, origin))
288 options |= BE_DESTROY_ORIGIN;
289
290 /* Don't destroy a mounted dataset unless force is specified */
291 if ((mounted = zfs_is_mounted(fs, NULL)) != 0) {
292 if (force) {
293 zfs_unmount(fs, NULL, 0);
294 } else {
295 free(bdd.snapname);
296 return (set_error(lbh, BE_ERR_DESTROYMNT));
297 }
298 }
299 } else {
426 /* Don't destroy a mounted dataset unless force is specified */
427 if ((mounted = zfs_is_mounted(fs, NULL)) != 0) {
428 if (force) {
429 zfs_unmount(fs, NULL, 0);
430 } else {
431 free(bdd.snapname);
432 return (set_error(lbh, BE_ERR_DESTROYMNT));
433 }
434 }
435 } else {
436 /*
437 * If we're initially destroying a snapshot, origin options do
438 * not make sense. If we're destroying the origin snapshot of
439 * a BE, we want to maintain the options in case we need to
440 * fake success after failing to promote.
441 */
442 if (!odestroyer)
443 options &= ~BE_DESTROY_WANTORIGIN;
300 if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_SNAPSHOT))
301 return (set_error(lbh, BE_ERR_NOENT));
302
303 bdd.snapname = strdup(snapdelim + 1);
304 if (bdd.snapname == NULL)
305 return (set_error(lbh, BE_ERR_NOMEM));
306 *snapdelim = '\0';
307 fs = zfs_open(lbh->lzh, path, ZFS_TYPE_DATASET);
308 if (fs == NULL) {
309 free(bdd.snapname);
310 return (set_error(lbh, BE_ERR_ZFSOPEN));
311 }
312 }
313
444 if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_SNAPSHOT))
445 return (set_error(lbh, BE_ERR_NOENT));
446
447 bdd.snapname = strdup(snapdelim + 1);
448 if (bdd.snapname == NULL)
449 return (set_error(lbh, BE_ERR_NOMEM));
450 *snapdelim = '\0';
451 fs = zfs_open(lbh->lzh, path, ZFS_TYPE_DATASET);
452 if (fs == NULL) {
453 free(bdd.snapname);
454 return (set_error(lbh, BE_ERR_ZFSOPEN));
455 }
456 }
457
458 /*
459 * Whether we're destroying a BE or a single snapshot, we need to walk
460 * the tree of what we're going to destroy and promote everything in our
461 * path so that we can make it happen.
462 */
463 if ((err = be_promote_dependent_clones(fs, &bdd)) != 0) {
464 free(bdd.snapname);
465
466 /*
467 * If we're just destroying the origin of some other dataset
468 * we were invoked to destroy, then we just ignore
469 * BE_ERR_HASCLONES and return success unless the caller wanted
470 * to force the issue.
471 */
472 if (odestroyer && err == BE_ERR_HASCLONES &&
473 (options & BE_DESTROY_AUTOORIGIN) != 0)
474 return (0);
475 return (set_error(lbh, err));
476 }
477
478 /*
479 * This was deferred until after we promote all of the derivatives so
480 * that we grab the new origin after everything's settled down.
481 */
482 if ((options & BE_DESTROY_WANTORIGIN) != 0 &&
483 zfs_prop_get(fs, ZFS_PROP_ORIGIN, origin, sizeof(origin),
484 NULL, NULL, 0, 1) != 0 &&
485 (options & BE_DESTROY_ORIGIN) != 0)
486 return (set_error(lbh, BE_ERR_NOORIGIN));
487
488 /*
489 * If the caller wants auto-origin destruction and the origin
490 * name matches one of our automatically created snapshot names
491 * (i.e. strftime("%F-%T") with a serial at the end), then
492 * we'll set the DESTROY_ORIGIN flag and nuke it
493 * be_is_auto_snapshot_name is exported from libbe(3) so that
494 * the caller can determine if it needs to warn about the origin
495 * not being destroyed or not.
496 */
497 if ((options & BE_DESTROY_AUTOORIGIN) != 0 && *origin != '\0' &&
498 be_is_auto_snapshot_name(lbh, origin))
499 options |= BE_DESTROY_ORIGIN;
500
314 err = be_destroy_cb(fs, &bdd);
315 zfs_close(fs);
316 free(bdd.snapname);
317 if (err != 0) {
318 /* Children are still present or the mount is referenced */
319 if (err == EBUSY)
320 return (set_error(lbh, BE_ERR_DESTROYMNT));
321 return (set_error(lbh, BE_ERR_UNKNOWN));

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332 /*
333 * We'll be chopping off the BE root and running this back through
334 * be_destroy, so that we properly handle the origin snapshot whether
335 * it be that of a deep BE or not.
336 */
337 if (strncmp(origin, lbh->root, rootlen) != 0 || origin[rootlen] != '/')
338 return (0);
339
501 err = be_destroy_cb(fs, &bdd);
502 zfs_close(fs);
503 free(bdd.snapname);
504 if (err != 0) {
505 /* Children are still present or the mount is referenced */
506 if (err == EBUSY)
507 return (set_error(lbh, BE_ERR_DESTROYMNT));
508 return (set_error(lbh, BE_ERR_UNKNOWN));

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519 /*
520 * We'll be chopping off the BE root and running this back through
521 * be_destroy, so that we properly handle the origin snapshot whether
522 * it be that of a deep BE or not.
523 */
524 if (strncmp(origin, lbh->root, rootlen) != 0 || origin[rootlen] != '/')
525 return (0);
526
340 return (be_destroy(lbh, origin + rootlen + 1,
341 options & ~BE_DESTROY_ORIGIN));
527 return (be_destroy_internal(lbh, origin + rootlen + 1,
528 options & ~BE_DESTROY_ORIGIN, true));
342}
343
529}
530
531int
532be_destroy(libbe_handle_t *lbh, const char *name, int options)
533{
534
535 /*
536 * The consumer must not set both BE_DESTROY_AUTOORIGIN and
537 * BE_DESTROY_ORIGIN. Internally, we'll set the latter from the former.
538 * The latter should imply that we must succeed at destroying the
539 * origin, or complain otherwise.
540 */
541 if ((options & BE_DESTROY_WANTORIGIN) == BE_DESTROY_WANTORIGIN)
542 return (set_error(lbh, BE_ERR_UNKNOWN));
543 return (be_destroy_internal(lbh, name, options, false));
544}
545
344static void
345be_setup_snapshot_name(libbe_handle_t *lbh, char *buf, size_t buflen)
346{
347 time_t rawtime;
348 int len, serial;
349
350 time(&rawtime);
351 len = strlen(buf);

--- 784 unchanged lines hidden --- 		546static void
547be_setup_snapshot_name(libbe_handle_t *lbh, char *buf, size_t buflen)
548{
549 time_t rawtime;
550 int len, serial;
551
552 time(&rawtime);
553 len = strlen(buf);

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