1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "bcachefs.h"
4 #include "btree_key_cache.h"
5 #include "btree_update.h"
6 #include "enumerated_ref.h"
7 #include "errcode.h"
8 #include "error.h"
9 #include "fs.h"
10 #include "recovery_passes.h"
11 #include "snapshot.h"
12 #include "subvolume.h"
13
14 #include <linux/random.h>
15
16 static int bch2_subvolume_delete(struct btree_trans *, u32);
17
bch2_subvolume_missing(struct bch_fs * c,u32 subvolid)18 static int bch2_subvolume_missing(struct bch_fs *c, u32 subvolid)
19 {
20 struct printbuf buf = PRINTBUF;
21 bch2_log_msg_start(c, &buf);
22
23 prt_printf(&buf, "missing subvolume %u", subvolid);
24 bool print = bch2_count_fsck_err(c, subvol_missing, &buf);
25
26 int ret = bch2_run_explicit_recovery_pass(c, &buf,
27 BCH_RECOVERY_PASS_check_inodes, 0);
28 if (print)
29 bch2_print_str(c, KERN_ERR, buf.buf);
30 printbuf_exit(&buf);
31 return ret;
32 }
33
subvolume_children_pos(struct bkey_s_c k)34 static struct bpos subvolume_children_pos(struct bkey_s_c k)
35 {
36 if (k.k->type != KEY_TYPE_subvolume)
37 return POS_MIN;
38
39 struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
40 if (!s.v->fs_path_parent)
41 return POS_MIN;
42 return POS(le32_to_cpu(s.v->fs_path_parent), s.k->p.offset);
43 }
44
check_subvol(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c k)45 static int check_subvol(struct btree_trans *trans,
46 struct btree_iter *iter,
47 struct bkey_s_c k)
48 {
49 struct bch_fs *c = trans->c;
50 struct bkey_s_c_subvolume subvol;
51 struct btree_iter subvol_children_iter = {};
52 struct bch_snapshot snapshot;
53 struct printbuf buf = PRINTBUF;
54 unsigned snapid;
55 int ret = 0;
56
57 if (k.k->type != KEY_TYPE_subvolume)
58 return 0;
59
60 subvol = bkey_s_c_to_subvolume(k);
61 snapid = le32_to_cpu(subvol.v->snapshot);
62 ret = bch2_snapshot_lookup(trans, snapid, &snapshot);
63
64 if (bch2_err_matches(ret, ENOENT))
65 return bch2_run_print_explicit_recovery_pass(c,
66 BCH_RECOVERY_PASS_reconstruct_snapshots) ?: ret;
67 if (ret)
68 return ret;
69
70 if (BCH_SUBVOLUME_UNLINKED(subvol.v)) {
71 ret = bch2_subvolume_delete(trans, iter->pos.offset);
72 bch_err_msg(c, ret, "deleting subvolume %llu", iter->pos.offset);
73 return ret ?: -BCH_ERR_transaction_restart_nested;
74 }
75
76 if (fsck_err_on(subvol.k->p.offset == BCACHEFS_ROOT_SUBVOL &&
77 subvol.v->fs_path_parent,
78 trans, subvol_root_fs_path_parent_nonzero,
79 "root subvolume has nonzero fs_path_parent\n%s",
80 (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
81 struct bkey_i_subvolume *n =
82 bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume);
83 ret = PTR_ERR_OR_ZERO(n);
84 if (ret)
85 goto err;
86
87 n->v.fs_path_parent = 0;
88 }
89
90 if (subvol.v->fs_path_parent) {
91 struct bpos pos = subvolume_children_pos(k);
92
93 struct bkey_s_c subvol_children_k =
94 bch2_bkey_get_iter(trans, &subvol_children_iter,
95 BTREE_ID_subvolume_children, pos, 0);
96 ret = bkey_err(subvol_children_k);
97 if (ret)
98 goto err;
99
100 if (fsck_err_on(subvol_children_k.k->type != KEY_TYPE_set,
101 trans, subvol_children_not_set,
102 "subvolume not set in subvolume_children btree at %llu:%llu\n%s",
103 pos.inode, pos.offset,
104 (printbuf_reset(&buf),
105 bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
106 ret = bch2_btree_bit_mod(trans, BTREE_ID_subvolume_children, pos, true);
107 if (ret)
108 goto err;
109 }
110 }
111
112 struct bch_inode_unpacked inode;
113 ret = bch2_inode_find_by_inum_nowarn_trans(trans,
114 (subvol_inum) { k.k->p.offset, le64_to_cpu(subvol.v->inode) },
115 &inode);
116 if (!ret) {
117 if (fsck_err_on(inode.bi_subvol != subvol.k->p.offset,
118 trans, subvol_root_wrong_bi_subvol,
119 "subvol root %llu:%u has wrong bi_subvol field: got %u, should be %llu",
120 inode.bi_inum, inode.bi_snapshot,
121 inode.bi_subvol, subvol.k->p.offset)) {
122 inode.bi_subvol = subvol.k->p.offset;
123 inode.bi_snapshot = le32_to_cpu(subvol.v->snapshot);
124 ret = __bch2_fsck_write_inode(trans, &inode);
125 if (ret)
126 goto err;
127 }
128 } else if (bch2_err_matches(ret, ENOENT)) {
129 if (fsck_err(trans, subvol_to_missing_root,
130 "subvolume %llu points to missing subvolume root %llu:%u",
131 k.k->p.offset, le64_to_cpu(subvol.v->inode),
132 le32_to_cpu(subvol.v->snapshot))) {
133 /*
134 * Recreate - any contents that are still disconnected
135 * will then get reattached under lost+found
136 */
137 bch2_inode_init_early(c, &inode);
138 bch2_inode_init_late(c, &inode, bch2_current_time(c),
139 0, 0, S_IFDIR|0700, 0, NULL);
140 inode.bi_inum = le64_to_cpu(subvol.v->inode);
141 inode.bi_snapshot = le32_to_cpu(subvol.v->snapshot);
142 inode.bi_subvol = k.k->p.offset;
143 inode.bi_parent_subvol = le32_to_cpu(subvol.v->fs_path_parent);
144 ret = __bch2_fsck_write_inode(trans, &inode);
145 if (ret)
146 goto err;
147 }
148 } else {
149 goto err;
150 }
151
152 if (!BCH_SUBVOLUME_SNAP(subvol.v)) {
153 u32 snapshot_root = bch2_snapshot_root(c, le32_to_cpu(subvol.v->snapshot));
154 u32 snapshot_tree = bch2_snapshot_tree(c, snapshot_root);
155
156 struct bch_snapshot_tree st;
157 ret = bch2_snapshot_tree_lookup(trans, snapshot_tree, &st);
158
159 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
160 "%s: snapshot tree %u not found", __func__, snapshot_tree);
161
162 if (ret)
163 goto err;
164
165 if (fsck_err_on(le32_to_cpu(st.master_subvol) != subvol.k->p.offset,
166 trans, subvol_not_master_and_not_snapshot,
167 "subvolume %llu is not set as snapshot but is not master subvolume",
168 k.k->p.offset)) {
169 struct bkey_i_subvolume *s =
170 bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume);
171 ret = PTR_ERR_OR_ZERO(s);
172 if (ret)
173 goto err;
174
175 SET_BCH_SUBVOLUME_SNAP(&s->v, true);
176 }
177 }
178 err:
179 fsck_err:
180 bch2_trans_iter_exit(trans, &subvol_children_iter);
181 printbuf_exit(&buf);
182 return ret;
183 }
184
bch2_check_subvols(struct bch_fs * c)185 int bch2_check_subvols(struct bch_fs *c)
186 {
187 int ret = bch2_trans_run(c,
188 for_each_btree_key_commit(trans, iter,
189 BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k,
190 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
191 check_subvol(trans, &iter, k)));
192 bch_err_fn(c, ret);
193 return ret;
194 }
195
check_subvol_child(struct btree_trans * trans,struct btree_iter * child_iter,struct bkey_s_c child_k)196 static int check_subvol_child(struct btree_trans *trans,
197 struct btree_iter *child_iter,
198 struct bkey_s_c child_k)
199 {
200 struct bch_subvolume s;
201 int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, child_k.k->p.offset),
202 0, subvolume, &s);
203 if (ret && !bch2_err_matches(ret, ENOENT))
204 return ret;
205
206 if (fsck_err_on(ret ||
207 le32_to_cpu(s.fs_path_parent) != child_k.k->p.inode,
208 trans, subvol_children_bad,
209 "incorrect entry in subvolume_children btree %llu:%llu",
210 child_k.k->p.inode, child_k.k->p.offset)) {
211 ret = bch2_btree_delete_at(trans, child_iter, 0);
212 if (ret)
213 goto err;
214 }
215 err:
216 fsck_err:
217 return ret;
218 }
219
bch2_check_subvol_children(struct bch_fs * c)220 int bch2_check_subvol_children(struct bch_fs *c)
221 {
222 int ret = bch2_trans_run(c,
223 for_each_btree_key_commit(trans, iter,
224 BTREE_ID_subvolume_children, POS_MIN, BTREE_ITER_prefetch, k,
225 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
226 check_subvol_child(trans, &iter, k)));
227 bch_err_fn(c, ret);
228 return 0;
229 }
230
231 /* Subvolumes: */
232
bch2_subvolume_validate(struct bch_fs * c,struct bkey_s_c k,struct bkey_validate_context from)233 int bch2_subvolume_validate(struct bch_fs *c, struct bkey_s_c k,
234 struct bkey_validate_context from)
235 {
236 struct bkey_s_c_subvolume subvol = bkey_s_c_to_subvolume(k);
237 int ret = 0;
238
239 bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) ||
240 bkey_gt(k.k->p, SUBVOL_POS_MAX),
241 c, subvol_pos_bad,
242 "invalid pos");
243
244 bkey_fsck_err_on(!subvol.v->snapshot,
245 c, subvol_snapshot_bad,
246 "invalid snapshot");
247
248 bkey_fsck_err_on(!subvol.v->inode,
249 c, subvol_inode_bad,
250 "invalid inode");
251 fsck_err:
252 return ret;
253 }
254
bch2_subvolume_to_text(struct printbuf * out,struct bch_fs * c,struct bkey_s_c k)255 void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c,
256 struct bkey_s_c k)
257 {
258 struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
259
260 prt_printf(out, "root %llu snapshot id %u",
261 le64_to_cpu(s.v->inode),
262 le32_to_cpu(s.v->snapshot));
263
264 if (bkey_val_bytes(s.k) > offsetof(struct bch_subvolume, creation_parent)) {
265 prt_printf(out, " creation_parent %u", le32_to_cpu(s.v->creation_parent));
266 prt_printf(out, " fs_parent %u", le32_to_cpu(s.v->fs_path_parent));
267 }
268
269 if (BCH_SUBVOLUME_RO(s.v))
270 prt_printf(out, " ro");
271 if (BCH_SUBVOLUME_SNAP(s.v))
272 prt_printf(out, " snapshot");
273 if (BCH_SUBVOLUME_UNLINKED(s.v))
274 prt_printf(out, " unlinked");
275 }
276
subvolume_children_mod(struct btree_trans * trans,struct bpos pos,bool set)277 static int subvolume_children_mod(struct btree_trans *trans, struct bpos pos, bool set)
278 {
279 return !bpos_eq(pos, POS_MIN)
280 ? bch2_btree_bit_mod(trans, BTREE_ID_subvolume_children, pos, set)
281 : 0;
282 }
283
bch2_subvolume_trigger(struct btree_trans * trans,enum btree_id btree_id,unsigned level,struct bkey_s_c old,struct bkey_s new,enum btree_iter_update_trigger_flags flags)284 int bch2_subvolume_trigger(struct btree_trans *trans,
285 enum btree_id btree_id, unsigned level,
286 struct bkey_s_c old, struct bkey_s new,
287 enum btree_iter_update_trigger_flags flags)
288 {
289 if (flags & BTREE_TRIGGER_transactional) {
290 struct bpos children_pos_old = subvolume_children_pos(old);
291 struct bpos children_pos_new = subvolume_children_pos(new.s_c);
292
293 if (!bpos_eq(children_pos_old, children_pos_new)) {
294 int ret = subvolume_children_mod(trans, children_pos_old, false) ?:
295 subvolume_children_mod(trans, children_pos_new, true);
296 if (ret)
297 return ret;
298 }
299 }
300
301 return 0;
302 }
303
bch2_subvol_has_children(struct btree_trans * trans,u32 subvol)304 int bch2_subvol_has_children(struct btree_trans *trans, u32 subvol)
305 {
306 struct btree_iter iter;
307
308 bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolume_children, POS(subvol, 0), 0);
309 struct bkey_s_c k = bch2_btree_iter_peek(trans, &iter);
310 bch2_trans_iter_exit(trans, &iter);
311
312 return bkey_err(k) ?: k.k && k.k->p.inode == subvol
313 ? -BCH_ERR_ENOTEMPTY_subvol_not_empty
314 : 0;
315 }
316
317 static __always_inline int
bch2_subvolume_get_inlined(struct btree_trans * trans,unsigned subvol,bool inconsistent_if_not_found,struct bch_subvolume * s)318 bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol,
319 bool inconsistent_if_not_found,
320 struct bch_subvolume *s)
321 {
322 int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, subvol),
323 BTREE_ITER_cached|
324 BTREE_ITER_with_updates, subvolume, s);
325 if (bch2_err_matches(ret, ENOENT) && inconsistent_if_not_found)
326 ret = bch2_subvolume_missing(trans->c, subvol) ?: ret;
327 return ret;
328 }
329
bch2_subvolume_get(struct btree_trans * trans,unsigned subvol,bool inconsistent_if_not_found,struct bch_subvolume * s)330 int bch2_subvolume_get(struct btree_trans *trans, unsigned subvol,
331 bool inconsistent_if_not_found,
332 struct bch_subvolume *s)
333 {
334 return bch2_subvolume_get_inlined(trans, subvol, inconsistent_if_not_found, s);
335 }
336
bch2_subvol_is_ro_trans(struct btree_trans * trans,u32 subvol)337 int bch2_subvol_is_ro_trans(struct btree_trans *trans, u32 subvol)
338 {
339 struct bch_subvolume s;
340 int ret = bch2_subvolume_get_inlined(trans, subvol, true, &s);
341 if (ret)
342 return ret;
343
344 if (BCH_SUBVOLUME_RO(&s))
345 return -EROFS;
346 return 0;
347 }
348
bch2_subvol_is_ro(struct bch_fs * c,u32 subvol)349 int bch2_subvol_is_ro(struct bch_fs *c, u32 subvol)
350 {
351 return bch2_trans_do(c, bch2_subvol_is_ro_trans(trans, subvol));
352 }
353
bch2_snapshot_get_subvol(struct btree_trans * trans,u32 snapshot,struct bch_subvolume * subvol)354 int bch2_snapshot_get_subvol(struct btree_trans *trans, u32 snapshot,
355 struct bch_subvolume *subvol)
356 {
357 struct bch_snapshot snap;
358
359 return bch2_snapshot_lookup(trans, snapshot, &snap) ?:
360 bch2_subvolume_get(trans, le32_to_cpu(snap.subvol), true, subvol);
361 }
362
__bch2_subvolume_get_snapshot(struct btree_trans * trans,u32 subvolid,u32 * snapid,bool warn)363 int __bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid,
364 u32 *snapid, bool warn)
365 {
366 struct btree_iter iter;
367 struct bkey_s_c_subvolume subvol;
368 int ret;
369
370 subvol = bch2_bkey_get_iter_typed(trans, &iter,
371 BTREE_ID_subvolumes, POS(0, subvolid),
372 BTREE_ITER_cached|BTREE_ITER_with_updates,
373 subvolume);
374 ret = bkey_err(subvol);
375
376 if (bch2_err_matches(ret, ENOENT))
377 ret = bch2_subvolume_missing(trans->c, subvolid) ?: ret;
378
379 if (likely(!ret))
380 *snapid = le32_to_cpu(subvol.v->snapshot);
381 bch2_trans_iter_exit(trans, &iter);
382 return ret;
383 }
384
bch2_subvolume_get_snapshot(struct btree_trans * trans,u32 subvolid,u32 * snapid)385 int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid,
386 u32 *snapid)
387 {
388 return __bch2_subvolume_get_snapshot(trans, subvolid, snapid, true);
389 }
390
bch2_subvolume_reparent(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c k,u32 old_parent,u32 new_parent)391 static int bch2_subvolume_reparent(struct btree_trans *trans,
392 struct btree_iter *iter,
393 struct bkey_s_c k,
394 u32 old_parent, u32 new_parent)
395 {
396 struct bkey_i_subvolume *s;
397 int ret;
398
399 if (k.k->type != KEY_TYPE_subvolume)
400 return 0;
401
402 if (bkey_val_bytes(k.k) > offsetof(struct bch_subvolume, creation_parent) &&
403 le32_to_cpu(bkey_s_c_to_subvolume(k).v->creation_parent) != old_parent)
404 return 0;
405
406 s = bch2_bkey_make_mut_typed(trans, iter, &k, 0, subvolume);
407 ret = PTR_ERR_OR_ZERO(s);
408 if (ret)
409 return ret;
410
411 s->v.creation_parent = cpu_to_le32(new_parent);
412 return 0;
413 }
414
415 /*
416 * Separate from the snapshot tree in the snapshots btree, we record the tree
417 * structure of how snapshot subvolumes were created - the parent subvolume of
418 * each snapshot subvolume.
419 *
420 * When a subvolume is deleted, we scan for child subvolumes and reparant them,
421 * to avoid dangling references:
422 */
bch2_subvolumes_reparent(struct btree_trans * trans,u32 subvolid_to_delete)423 static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_delete)
424 {
425 struct bch_subvolume s;
426
427 return lockrestart_do(trans,
428 bch2_subvolume_get(trans, subvolid_to_delete, true, &s)) ?:
429 for_each_btree_key_commit(trans, iter,
430 BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k,
431 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
432 bch2_subvolume_reparent(trans, &iter, k,
433 subvolid_to_delete, le32_to_cpu(s.creation_parent)));
434 }
435
436 /*
437 * Delete subvolume, mark snapshot ID as deleted, queue up snapshot
438 * deletion/cleanup:
439 */
__bch2_subvolume_delete(struct btree_trans * trans,u32 subvolid)440 static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
441 {
442 struct btree_iter subvol_iter = {}, snapshot_iter = {}, snapshot_tree_iter = {};
443
444 struct bkey_s_c_subvolume subvol =
445 bch2_bkey_get_iter_typed(trans, &subvol_iter,
446 BTREE_ID_subvolumes, POS(0, subvolid),
447 BTREE_ITER_cached|BTREE_ITER_intent,
448 subvolume);
449 int ret = bkey_err(subvol);
450 if (bch2_err_matches(ret, ENOENT))
451 ret = bch2_subvolume_missing(trans->c, subvolid) ?: ret;
452 if (ret)
453 goto err;
454
455 u32 snapid = le32_to_cpu(subvol.v->snapshot);
456
457 struct bkey_s_c_snapshot snapshot =
458 bch2_bkey_get_iter_typed(trans, &snapshot_iter,
459 BTREE_ID_snapshots, POS(0, snapid),
460 0, snapshot);
461 ret = bkey_err(snapshot);
462 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
463 "missing snapshot %u", snapid);
464 if (ret)
465 goto err;
466
467 u32 treeid = le32_to_cpu(snapshot.v->tree);
468
469 struct bkey_s_c_snapshot_tree snapshot_tree =
470 bch2_bkey_get_iter_typed(trans, &snapshot_tree_iter,
471 BTREE_ID_snapshot_trees, POS(0, treeid),
472 0, snapshot_tree);
473 ret = bkey_err(snapshot_tree);
474 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
475 "missing snapshot tree %u", treeid);
476 if (ret)
477 goto err;
478
479 if (le32_to_cpu(snapshot_tree.v->master_subvol) == subvolid) {
480 struct bkey_i_snapshot_tree *snapshot_tree_mut =
481 bch2_bkey_make_mut_typed(trans, &snapshot_tree_iter,
482 &snapshot_tree.s_c,
483 0, snapshot_tree);
484 ret = PTR_ERR_OR_ZERO(snapshot_tree_mut);
485 if (ret)
486 goto err;
487
488 snapshot_tree_mut->v.master_subvol = 0;
489 }
490
491 ret = bch2_btree_delete_at(trans, &subvol_iter, 0) ?:
492 bch2_snapshot_node_set_deleted(trans, snapid);
493 err:
494 bch2_trans_iter_exit(trans, &snapshot_tree_iter);
495 bch2_trans_iter_exit(trans, &snapshot_iter);
496 bch2_trans_iter_exit(trans, &subvol_iter);
497 return ret;
498 }
499
bch2_subvolume_delete(struct btree_trans * trans,u32 subvolid)500 static int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
501 {
502 int ret = bch2_subvolumes_reparent(trans, subvolid) ?:
503 commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
504 __bch2_subvolume_delete(trans, subvolid));
505
506 bch2_recovery_pass_set_no_ratelimit(trans->c, BCH_RECOVERY_PASS_check_subvols);
507 return ret;
508 }
509
bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct * work)510 static void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work)
511 {
512 struct bch_fs *c = container_of(work, struct bch_fs,
513 snapshot_wait_for_pagecache_and_delete_work);
514 int ret = 0;
515
516 while (!ret) {
517 mutex_lock(&c->snapshots_unlinked_lock);
518 snapshot_id_list s = c->snapshots_unlinked;
519 darray_init(&c->snapshots_unlinked);
520 mutex_unlock(&c->snapshots_unlinked_lock);
521
522 if (!s.nr)
523 break;
524
525 bch2_evict_subvolume_inodes(c, &s);
526
527 darray_for_each(s, id) {
528 ret = bch2_trans_run(c, bch2_subvolume_delete(trans, *id));
529 bch_err_msg(c, ret, "deleting subvolume %u", *id);
530 if (ret)
531 break;
532 }
533
534 darray_exit(&s);
535 }
536
537 enumerated_ref_put(&c->writes, BCH_WRITE_REF_snapshot_delete_pagecache);
538 }
539
540 struct subvolume_unlink_hook {
541 struct btree_trans_commit_hook h;
542 u32 subvol;
543 };
544
bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans * trans,struct btree_trans_commit_hook * _h)545 static int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans,
546 struct btree_trans_commit_hook *_h)
547 {
548 struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h);
549 struct bch_fs *c = trans->c;
550 int ret = 0;
551
552 mutex_lock(&c->snapshots_unlinked_lock);
553 if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol))
554 ret = snapshot_list_add(c, &c->snapshots_unlinked, h->subvol);
555 mutex_unlock(&c->snapshots_unlinked_lock);
556
557 if (ret)
558 return ret;
559
560 if (!enumerated_ref_tryget(&c->writes, BCH_WRITE_REF_snapshot_delete_pagecache))
561 return -EROFS;
562
563 if (!queue_work(c->write_ref_wq, &c->snapshot_wait_for_pagecache_and_delete_work))
564 enumerated_ref_put(&c->writes, BCH_WRITE_REF_snapshot_delete_pagecache);
565 return 0;
566 }
567
bch2_subvolume_unlink(struct btree_trans * trans,u32 subvolid)568 int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
569 {
570 struct btree_iter iter;
571 struct bkey_i_subvolume *n;
572 struct subvolume_unlink_hook *h;
573 int ret = 0;
574
575 h = bch2_trans_kmalloc(trans, sizeof(*h));
576 ret = PTR_ERR_OR_ZERO(h);
577 if (ret)
578 return ret;
579
580 h->h.fn = bch2_subvolume_wait_for_pagecache_and_delete_hook;
581 h->subvol = subvolid;
582 bch2_trans_commit_hook(trans, &h->h);
583
584 n = bch2_bkey_get_mut_typed(trans, &iter,
585 BTREE_ID_subvolumes, POS(0, subvolid),
586 BTREE_ITER_cached, subvolume);
587 ret = PTR_ERR_OR_ZERO(n);
588 if (bch2_err_matches(ret, ENOENT))
589 ret = bch2_subvolume_missing(trans->c, subvolid) ?: ret;
590 if (unlikely(ret))
591 return ret;
592
593 SET_BCH_SUBVOLUME_UNLINKED(&n->v, true);
594 n->v.fs_path_parent = 0;
595 bch2_trans_iter_exit(trans, &iter);
596 return ret;
597 }
598
bch2_subvolume_create(struct btree_trans * trans,u64 inode,u32 parent_subvolid,u32 src_subvolid,u32 * new_subvolid,u32 * new_snapshotid,bool ro)599 int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
600 u32 parent_subvolid,
601 u32 src_subvolid,
602 u32 *new_subvolid,
603 u32 *new_snapshotid,
604 bool ro)
605 {
606 struct bch_fs *c = trans->c;
607 struct btree_iter dst_iter, src_iter = {};
608 struct bkey_i_subvolume *new_subvol = NULL;
609 struct bkey_i_subvolume *src_subvol = NULL;
610 u32 parent = 0, new_nodes[2], snapshot_subvols[2];
611 int ret = 0;
612
613 ret = bch2_bkey_get_empty_slot(trans, &dst_iter,
614 BTREE_ID_subvolumes, POS(0, U32_MAX));
615 if (ret == -BCH_ERR_ENOSPC_btree_slot)
616 ret = bch_err_throw(c, ENOSPC_subvolume_create);
617 if (ret)
618 return ret;
619
620 snapshot_subvols[0] = dst_iter.pos.offset;
621 snapshot_subvols[1] = src_subvolid;
622
623 if (src_subvolid) {
624 /* Creating a snapshot: */
625
626 src_subvol = bch2_bkey_get_mut_typed(trans, &src_iter,
627 BTREE_ID_subvolumes, POS(0, src_subvolid),
628 BTREE_ITER_cached, subvolume);
629 ret = PTR_ERR_OR_ZERO(src_subvol);
630 if (bch2_err_matches(ret, ENOENT))
631 ret = bch2_subvolume_missing(trans->c, src_subvolid) ?: ret;
632 if (unlikely(ret))
633 goto err;
634
635 parent = le32_to_cpu(src_subvol->v.snapshot);
636 }
637
638 ret = bch2_snapshot_node_create(trans, parent, new_nodes,
639 snapshot_subvols,
640 src_subvolid ? 2 : 1);
641 if (ret)
642 goto err;
643
644 if (src_subvolid) {
645 src_subvol->v.snapshot = cpu_to_le32(new_nodes[1]);
646 ret = bch2_trans_update(trans, &src_iter, &src_subvol->k_i, 0);
647 if (ret)
648 goto err;
649 }
650
651 new_subvol = bch2_bkey_alloc(trans, &dst_iter, 0, subvolume);
652 ret = PTR_ERR_OR_ZERO(new_subvol);
653 if (ret)
654 goto err;
655
656 new_subvol->v.flags = 0;
657 new_subvol->v.snapshot = cpu_to_le32(new_nodes[0]);
658 new_subvol->v.inode = cpu_to_le64(inode);
659 new_subvol->v.creation_parent = cpu_to_le32(src_subvolid);
660 new_subvol->v.fs_path_parent = cpu_to_le32(parent_subvolid);
661 new_subvol->v.otime.lo = cpu_to_le64(bch2_current_time(c));
662 new_subvol->v.otime.hi = 0;
663
664 SET_BCH_SUBVOLUME_RO(&new_subvol->v, ro);
665 SET_BCH_SUBVOLUME_SNAP(&new_subvol->v, src_subvolid != 0);
666
667 *new_subvolid = new_subvol->k.p.offset;
668 *new_snapshotid = new_nodes[0];
669 err:
670 bch2_trans_iter_exit(trans, &src_iter);
671 bch2_trans_iter_exit(trans, &dst_iter);
672 return ret;
673 }
674
bch2_initialize_subvolumes(struct bch_fs * c)675 int bch2_initialize_subvolumes(struct bch_fs *c)
676 {
677 struct bkey_i_snapshot_tree root_tree;
678 struct bkey_i_snapshot root_snapshot;
679 struct bkey_i_subvolume root_volume;
680 int ret;
681
682 bkey_snapshot_tree_init(&root_tree.k_i);
683 root_tree.k.p.offset = 1;
684 root_tree.v.master_subvol = cpu_to_le32(1);
685 root_tree.v.root_snapshot = cpu_to_le32(U32_MAX);
686
687 bkey_snapshot_init(&root_snapshot.k_i);
688 root_snapshot.k.p.offset = U32_MAX;
689 root_snapshot.v.flags = 0;
690 root_snapshot.v.parent = 0;
691 root_snapshot.v.subvol = cpu_to_le32(BCACHEFS_ROOT_SUBVOL);
692 root_snapshot.v.tree = cpu_to_le32(1);
693 SET_BCH_SNAPSHOT_SUBVOL(&root_snapshot.v, true);
694
695 bkey_subvolume_init(&root_volume.k_i);
696 root_volume.k.p.offset = BCACHEFS_ROOT_SUBVOL;
697 root_volume.v.flags = 0;
698 root_volume.v.snapshot = cpu_to_le32(U32_MAX);
699 root_volume.v.inode = cpu_to_le64(BCACHEFS_ROOT_INO);
700
701 ret = bch2_btree_insert(c, BTREE_ID_snapshot_trees, &root_tree.k_i, NULL, 0, 0) ?:
702 bch2_btree_insert(c, BTREE_ID_snapshots, &root_snapshot.k_i, NULL, 0, 0) ?:
703 bch2_btree_insert(c, BTREE_ID_subvolumes, &root_volume.k_i, NULL, 0, 0);
704 bch_err_fn(c, ret);
705 return ret;
706 }
707
__bch2_fs_upgrade_for_subvolumes(struct btree_trans * trans)708 static int __bch2_fs_upgrade_for_subvolumes(struct btree_trans *trans)
709 {
710 struct btree_iter iter;
711 struct bkey_s_c k;
712 struct bch_inode_unpacked inode;
713 int ret;
714
715 k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
716 SPOS(0, BCACHEFS_ROOT_INO, U32_MAX), 0);
717 ret = bkey_err(k);
718 if (ret)
719 return ret;
720
721 if (!bkey_is_inode(k.k)) {
722 struct bch_fs *c = trans->c;
723 bch_err(c, "root inode not found");
724 ret = bch_err_throw(c, ENOENT_inode);
725 goto err;
726 }
727
728 ret = bch2_inode_unpack(k, &inode);
729 BUG_ON(ret);
730
731 inode.bi_subvol = BCACHEFS_ROOT_SUBVOL;
732
733 ret = bch2_inode_write(trans, &iter, &inode);
734 err:
735 bch2_trans_iter_exit(trans, &iter);
736 return ret;
737 }
738
739 /* set bi_subvol on root inode */
bch2_fs_upgrade_for_subvolumes(struct bch_fs * c)740 int bch2_fs_upgrade_for_subvolumes(struct bch_fs *c)
741 {
742 int ret = bch2_trans_commit_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
743 __bch2_fs_upgrade_for_subvolumes(trans));
744 bch_err_fn(c, ret);
745 return ret;
746 }
747
bch2_fs_subvolumes_init_early(struct bch_fs * c)748 void bch2_fs_subvolumes_init_early(struct bch_fs *c)
749 {
750 INIT_WORK(&c->snapshot_wait_for_pagecache_and_delete_work,
751 bch2_subvolume_wait_for_pagecache_and_delete);
752 }
753