1 // SPDX-License-Identifier: GPL-2.0
5 #include "btree_key_cache.h"
6 #include "btree_update.h"
13 #include <linux/random.h>
18 * Keys in BTREE_ID_snapshot_trees identify a whole tree of snapshot nodes; they
19 * exist to provide a stable identifier for the whole lifetime of a snapshot
23 void bch2_snapshot_tree_to_text(struct printbuf *out, struct bch_fs *c,
26 struct bkey_s_c_snapshot_tree t = bkey_s_c_to_snapshot_tree(k);
28 prt_printf(out, "subvol %u root snapshot %u",
29 le32_to_cpu(t.v->master_subvol),
30 le32_to_cpu(t.v->root_snapshot));
33 int bch2_snapshot_tree_invalid(struct bch_fs *c, struct bkey_s_c k,
34 enum bkey_invalid_flags flags,
39 bkey_fsck_err_on(bkey_gt(k.k->p, POS(0, U32_MAX)) ||
40 bkey_lt(k.k->p, POS(0, 1)), c, err,
41 snapshot_tree_pos_bad,
47 int bch2_snapshot_tree_lookup(struct btree_trans *trans, u32 id,
48 struct bch_snapshot_tree *s)
50 int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_snapshot_trees, POS(0, id),
51 BTREE_ITER_WITH_UPDATES, snapshot_tree, s);
53 if (bch2_err_matches(ret, ENOENT))
54 ret = -BCH_ERR_ENOENT_snapshot_tree;
58 struct bkey_i_snapshot_tree *
59 __bch2_snapshot_tree_create(struct btree_trans *trans)
61 struct btree_iter iter;
62 int ret = bch2_bkey_get_empty_slot(trans, &iter,
63 BTREE_ID_snapshot_trees, POS(0, U32_MAX));
64 struct bkey_i_snapshot_tree *s_t;
66 if (ret == -BCH_ERR_ENOSPC_btree_slot)
67 ret = -BCH_ERR_ENOSPC_snapshot_tree;
71 s_t = bch2_bkey_alloc(trans, &iter, 0, snapshot_tree);
72 ret = PTR_ERR_OR_ZERO(s_t);
73 bch2_trans_iter_exit(trans, &iter);
74 return ret ? ERR_PTR(ret) : s_t;
77 static int bch2_snapshot_tree_create(struct btree_trans *trans,
78 u32 root_id, u32 subvol_id, u32 *tree_id)
80 struct bkey_i_snapshot_tree *n_tree =
81 __bch2_snapshot_tree_create(trans);
84 return PTR_ERR(n_tree);
86 n_tree->v.master_subvol = cpu_to_le32(subvol_id);
87 n_tree->v.root_snapshot = cpu_to_le32(root_id);
88 *tree_id = n_tree->k.p.offset;
94 static bool bch2_snapshot_is_ancestor_early(struct bch_fs *c, u32 id, u32 ancestor)
96 struct snapshot_table *t;
99 t = rcu_dereference(c->snapshots);
101 while (id && id < ancestor)
102 id = __snapshot_t(t, id)->parent;
105 return id == ancestor;
108 static inline u32 get_ancestor_below(struct snapshot_table *t, u32 id, u32 ancestor)
110 const struct snapshot_t *s = __snapshot_t(t, id);
112 if (s->skip[2] <= ancestor)
114 if (s->skip[1] <= ancestor)
116 if (s->skip[0] <= ancestor)
121 bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
123 struct snapshot_table *t;
126 EBUG_ON(c->recovery_pass_done <= BCH_RECOVERY_PASS_check_snapshots);
129 t = rcu_dereference(c->snapshots);
131 while (id && id < ancestor - IS_ANCESTOR_BITMAP)
132 id = get_ancestor_below(t, id, ancestor);
134 if (id && id < ancestor) {
135 ret = test_bit(ancestor - id - 1, __snapshot_t(t, id)->is_ancestor);
137 EBUG_ON(ret != bch2_snapshot_is_ancestor_early(c, id, ancestor));
139 ret = id == ancestor;
147 static noinline struct snapshot_t *__snapshot_t_mut(struct bch_fs *c, u32 id)
149 size_t idx = U32_MAX - id;
151 struct snapshot_table *new, *old;
153 new_size = max(16UL, roundup_pow_of_two(idx + 1));
155 new = kvzalloc(struct_size(new, s, new_size), GFP_KERNEL);
159 old = rcu_dereference_protected(c->snapshots, true);
162 rcu_dereference_protected(c->snapshots, true)->s,
163 sizeof(new->s[0]) * c->snapshot_table_size);
165 rcu_assign_pointer(c->snapshots, new);
166 c->snapshot_table_size = new_size;
167 kvfree_rcu_mightsleep(old);
169 return &rcu_dereference_protected(c->snapshots, true)->s[idx];
172 static inline struct snapshot_t *snapshot_t_mut(struct bch_fs *c, u32 id)
174 size_t idx = U32_MAX - id;
176 lockdep_assert_held(&c->snapshot_table_lock);
178 if (likely(idx < c->snapshot_table_size))
179 return &rcu_dereference_protected(c->snapshots, true)->s[idx];
181 return __snapshot_t_mut(c, id);
184 void bch2_snapshot_to_text(struct printbuf *out, struct bch_fs *c,
187 struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(k);
189 prt_printf(out, "is_subvol %llu deleted %llu parent %10u children %10u %10u subvol %u tree %u",
190 BCH_SNAPSHOT_SUBVOL(s.v),
191 BCH_SNAPSHOT_DELETED(s.v),
192 le32_to_cpu(s.v->parent),
193 le32_to_cpu(s.v->children[0]),
194 le32_to_cpu(s.v->children[1]),
195 le32_to_cpu(s.v->subvol),
196 le32_to_cpu(s.v->tree));
198 if (bkey_val_bytes(k.k) > offsetof(struct bch_snapshot, depth))
199 prt_printf(out, " depth %u skiplist %u %u %u",
200 le32_to_cpu(s.v->depth),
201 le32_to_cpu(s.v->skip[0]),
202 le32_to_cpu(s.v->skip[1]),
203 le32_to_cpu(s.v->skip[2]));
206 int bch2_snapshot_invalid(struct bch_fs *c, struct bkey_s_c k,
207 enum bkey_invalid_flags flags,
208 struct printbuf *err)
210 struct bkey_s_c_snapshot s;
214 bkey_fsck_err_on(bkey_gt(k.k->p, POS(0, U32_MAX)) ||
215 bkey_lt(k.k->p, POS(0, 1)), c, err,
219 s = bkey_s_c_to_snapshot(k);
221 id = le32_to_cpu(s.v->parent);
222 bkey_fsck_err_on(id && id <= k.k->p.offset, c, err,
224 "bad parent node (%u <= %llu)",
227 bkey_fsck_err_on(le32_to_cpu(s.v->children[0]) < le32_to_cpu(s.v->children[1]), c, err,
228 snapshot_children_not_normalized,
229 "children not normalized");
231 bkey_fsck_err_on(s.v->children[0] && s.v->children[0] == s.v->children[1], c, err,
232 snapshot_child_duplicate,
233 "duplicate child nodes");
235 for (i = 0; i < 2; i++) {
236 id = le32_to_cpu(s.v->children[i]);
238 bkey_fsck_err_on(id >= k.k->p.offset, c, err,
240 "bad child node (%u >= %llu)",
244 if (bkey_val_bytes(k.k) > offsetof(struct bch_snapshot, skip)) {
245 bkey_fsck_err_on(le32_to_cpu(s.v->skip[0]) > le32_to_cpu(s.v->skip[1]) ||
246 le32_to_cpu(s.v->skip[1]) > le32_to_cpu(s.v->skip[2]), c, err,
247 snapshot_skiplist_not_normalized,
248 "skiplist not normalized");
250 for (i = 0; i < ARRAY_SIZE(s.v->skip); i++) {
251 id = le32_to_cpu(s.v->skip[i]);
253 bkey_fsck_err_on(id && id < le32_to_cpu(s.v->parent), c, err,
254 snapshot_skiplist_bad,
255 "bad skiplist node %u", id);
262 static void __set_is_ancestor_bitmap(struct bch_fs *c, u32 id)
264 struct snapshot_t *t = snapshot_t_mut(c, id);
267 while ((parent = bch2_snapshot_parent_early(c, parent)) &&
268 parent - id - 1 < IS_ANCESTOR_BITMAP)
269 __set_bit(parent - id - 1, t->is_ancestor);
272 static void set_is_ancestor_bitmap(struct bch_fs *c, u32 id)
274 mutex_lock(&c->snapshot_table_lock);
275 __set_is_ancestor_bitmap(c, id);
276 mutex_unlock(&c->snapshot_table_lock);
279 static int __bch2_mark_snapshot(struct btree_trans *trans,
280 enum btree_id btree, unsigned level,
281 struct bkey_s_c old, struct bkey_s_c new,
284 struct bch_fs *c = trans->c;
285 struct snapshot_t *t;
286 u32 id = new.k->p.offset;
289 mutex_lock(&c->snapshot_table_lock);
291 t = snapshot_t_mut(c, id);
293 ret = -BCH_ERR_ENOMEM_mark_snapshot;
297 if (new.k->type == KEY_TYPE_snapshot) {
298 struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(new);
300 t->parent = le32_to_cpu(s.v->parent);
301 t->children[0] = le32_to_cpu(s.v->children[0]);
302 t->children[1] = le32_to_cpu(s.v->children[1]);
303 t->subvol = BCH_SNAPSHOT_SUBVOL(s.v) ? le32_to_cpu(s.v->subvol) : 0;
304 t->tree = le32_to_cpu(s.v->tree);
306 if (bkey_val_bytes(s.k) > offsetof(struct bch_snapshot, depth)) {
307 t->depth = le32_to_cpu(s.v->depth);
308 t->skip[0] = le32_to_cpu(s.v->skip[0]);
309 t->skip[1] = le32_to_cpu(s.v->skip[1]);
310 t->skip[2] = le32_to_cpu(s.v->skip[2]);
318 __set_is_ancestor_bitmap(c, id);
320 if (BCH_SNAPSHOT_DELETED(s.v)) {
321 set_bit(BCH_FS_need_delete_dead_snapshots, &c->flags);
322 if (c->curr_recovery_pass > BCH_RECOVERY_PASS_delete_dead_snapshots)
323 bch2_delete_dead_snapshots_async(c);
326 memset(t, 0, sizeof(*t));
329 mutex_unlock(&c->snapshot_table_lock);
333 int bch2_mark_snapshot(struct btree_trans *trans,
334 enum btree_id btree, unsigned level,
335 struct bkey_s_c old, struct bkey_s new,
338 return __bch2_mark_snapshot(trans, btree, level, old, new.s_c, flags);
341 int bch2_snapshot_lookup(struct btree_trans *trans, u32 id,
342 struct bch_snapshot *s)
344 return bch2_bkey_get_val_typed(trans, BTREE_ID_snapshots, POS(0, id),
345 BTREE_ITER_WITH_UPDATES, snapshot, s);
348 static int bch2_snapshot_live(struct btree_trans *trans, u32 id)
350 struct bch_snapshot v;
356 ret = bch2_snapshot_lookup(trans, id, &v);
357 if (bch2_err_matches(ret, ENOENT))
358 bch_err(trans->c, "snapshot node %u not found", id);
362 return !BCH_SNAPSHOT_DELETED(&v);
366 * If @k is a snapshot with just one live child, it's part of a linear chain,
367 * which we consider to be an equivalence class: and then after snapshot
368 * deletion cleanup, there should only be a single key at a given position in
369 * this equivalence class.
371 * This sets the equivalence class of @k to be the child's equivalence class, if
372 * it's part of such a linear chain: this correctly sets equivalence classes on
373 * startup if we run leaf to root (i.e. in natural key order).
375 static int bch2_snapshot_set_equiv(struct btree_trans *trans, struct bkey_s_c k)
377 struct bch_fs *c = trans->c;
378 unsigned i, nr_live = 0, live_idx = 0;
379 struct bkey_s_c_snapshot snap;
380 u32 id = k.k->p.offset, child[2];
382 if (k.k->type != KEY_TYPE_snapshot)
385 snap = bkey_s_c_to_snapshot(k);
387 child[0] = le32_to_cpu(snap.v->children[0]);
388 child[1] = le32_to_cpu(snap.v->children[1]);
390 for (i = 0; i < 2; i++) {
391 int ret = bch2_snapshot_live(trans, child[i]);
401 mutex_lock(&c->snapshot_table_lock);
403 snapshot_t_mut(c, id)->equiv = nr_live == 1
404 ? snapshot_t_mut(c, child[live_idx])->equiv
407 mutex_unlock(&c->snapshot_table_lock);
414 static u32 bch2_snapshot_child(struct bch_fs *c, u32 id, unsigned child)
416 return snapshot_t(c, id)->children[child];
419 static u32 bch2_snapshot_left_child(struct bch_fs *c, u32 id)
421 return bch2_snapshot_child(c, id, 0);
424 static u32 bch2_snapshot_right_child(struct bch_fs *c, u32 id)
426 return bch2_snapshot_child(c, id, 1);
429 static u32 bch2_snapshot_tree_next(struct bch_fs *c, u32 id)
433 n = bch2_snapshot_left_child(c, id);
437 while ((parent = bch2_snapshot_parent(c, id))) {
438 n = bch2_snapshot_right_child(c, parent);
447 static u32 bch2_snapshot_tree_oldest_subvol(struct bch_fs *c, u32 snapshot_root)
449 u32 id = snapshot_root;
453 s = snapshot_t(c, id)->subvol;
455 if (s && (!subvol || s < subvol))
458 id = bch2_snapshot_tree_next(c, id);
464 static int bch2_snapshot_tree_master_subvol(struct btree_trans *trans,
465 u32 snapshot_root, u32 *subvol_id)
467 struct bch_fs *c = trans->c;
468 struct btree_iter iter;
473 for_each_btree_key_norestart(trans, iter, BTREE_ID_subvolumes, POS_MIN,
475 if (k.k->type != KEY_TYPE_subvolume)
478 struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
479 if (!bch2_snapshot_is_ancestor(c, le32_to_cpu(s.v->snapshot), snapshot_root))
481 if (!BCH_SUBVOLUME_SNAP(s.v)) {
482 *subvol_id = s.k->p.offset;
488 bch2_trans_iter_exit(trans, &iter);
490 if (!ret && !found) {
491 struct bkey_i_subvolume *u;
493 *subvol_id = bch2_snapshot_tree_oldest_subvol(c, snapshot_root);
495 u = bch2_bkey_get_mut_typed(trans, &iter,
496 BTREE_ID_subvolumes, POS(0, *subvol_id),
498 ret = PTR_ERR_OR_ZERO(u);
502 SET_BCH_SUBVOLUME_SNAP(&u->v, false);
508 static int check_snapshot_tree(struct btree_trans *trans,
509 struct btree_iter *iter,
512 struct bch_fs *c = trans->c;
513 struct bkey_s_c_snapshot_tree st;
514 struct bch_snapshot s;
515 struct bch_subvolume subvol;
516 struct printbuf buf = PRINTBUF;
520 if (k.k->type != KEY_TYPE_snapshot_tree)
523 st = bkey_s_c_to_snapshot_tree(k);
524 root_id = le32_to_cpu(st.v->root_snapshot);
526 ret = bch2_snapshot_lookup(trans, root_id, &s);
527 if (ret && !bch2_err_matches(ret, ENOENT))
530 if (fsck_err_on(ret ||
531 root_id != bch2_snapshot_root(c, root_id) ||
532 st.k->p.offset != le32_to_cpu(s.tree),
533 c, snapshot_tree_to_missing_snapshot,
534 "snapshot tree points to missing/incorrect snapshot:\n %s",
535 (bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf))) {
536 ret = bch2_btree_delete_at(trans, iter, 0);
540 ret = bch2_subvolume_get(trans, le32_to_cpu(st.v->master_subvol),
542 if (ret && !bch2_err_matches(ret, ENOENT))
546 c, snapshot_tree_to_missing_subvol,
547 "snapshot tree points to missing subvolume:\n %s",
548 (printbuf_reset(&buf),
549 bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf)) ||
550 fsck_err_on(!bch2_snapshot_is_ancestor_early(c,
551 le32_to_cpu(subvol.snapshot),
553 c, snapshot_tree_to_wrong_subvol,
554 "snapshot tree points to subvolume that does not point to snapshot in this tree:\n %s",
555 (printbuf_reset(&buf),
556 bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf)) ||
557 fsck_err_on(BCH_SUBVOLUME_SNAP(&subvol),
558 c, snapshot_tree_to_snapshot_subvol,
559 "snapshot tree points to snapshot subvolume:\n %s",
560 (printbuf_reset(&buf),
561 bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf))) {
562 struct bkey_i_snapshot_tree *u;
565 ret = bch2_snapshot_tree_master_subvol(trans, root_id, &subvol_id);
569 u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot_tree);
570 ret = PTR_ERR_OR_ZERO(u);
574 u->v.master_subvol = cpu_to_le32(subvol_id);
575 st = snapshot_tree_i_to_s_c(u);
584 * For each snapshot_tree, make sure it points to the root of a snapshot tree
585 * and that snapshot entry points back to it, or delete it.
587 * And, make sure it points to a subvolume within that snapshot tree, or correct
588 * it to point to the oldest subvolume within that snapshot tree.
590 int bch2_check_snapshot_trees(struct bch_fs *c)
592 int ret = bch2_trans_run(c,
593 for_each_btree_key_commit(trans, iter,
594 BTREE_ID_snapshot_trees, POS_MIN,
595 BTREE_ITER_PREFETCH, k,
596 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
597 check_snapshot_tree(trans, &iter, k)));
603 * Look up snapshot tree for @tree_id and find root,
604 * make sure @snap_id is a descendent:
606 static int snapshot_tree_ptr_good(struct btree_trans *trans,
607 u32 snap_id, u32 tree_id)
609 struct bch_snapshot_tree s_t;
610 int ret = bch2_snapshot_tree_lookup(trans, tree_id, &s_t);
612 if (bch2_err_matches(ret, ENOENT))
617 return bch2_snapshot_is_ancestor_early(trans->c, snap_id, le32_to_cpu(s_t.root_snapshot));
620 u32 bch2_snapshot_skiplist_get(struct bch_fs *c, u32 id)
622 const struct snapshot_t *s;
628 s = snapshot_t(c, id);
630 id = bch2_snapshot_nth_parent(c, id, get_random_u32_below(s->depth));
636 static int snapshot_skiplist_good(struct btree_trans *trans, u32 id, struct bch_snapshot s)
640 for (i = 0; i < 3; i++)
645 if (!bch2_snapshot_is_ancestor_early(trans->c, id, le32_to_cpu(s.skip[i])))
653 * snapshot_tree pointer was incorrect: look up root snapshot node, make sure
654 * its snapshot_tree pointer is correct (allocate new one if necessary), then
655 * update this node's pointer to root node's pointer:
657 static int snapshot_tree_ptr_repair(struct btree_trans *trans,
658 struct btree_iter *iter,
660 struct bch_snapshot *s)
662 struct bch_fs *c = trans->c;
663 struct btree_iter root_iter;
664 struct bch_snapshot_tree s_t;
665 struct bkey_s_c_snapshot root;
666 struct bkey_i_snapshot *u;
667 u32 root_id = bch2_snapshot_root(c, k.k->p.offset), tree_id;
670 root = bch2_bkey_get_iter_typed(trans, &root_iter,
671 BTREE_ID_snapshots, POS(0, root_id),
672 BTREE_ITER_WITH_UPDATES, snapshot);
673 ret = bkey_err(root);
677 tree_id = le32_to_cpu(root.v->tree);
679 ret = bch2_snapshot_tree_lookup(trans, tree_id, &s_t);
680 if (ret && !bch2_err_matches(ret, ENOENT))
683 if (ret || le32_to_cpu(s_t.root_snapshot) != root_id) {
684 u = bch2_bkey_make_mut_typed(trans, &root_iter, &root.s_c, 0, snapshot);
685 ret = PTR_ERR_OR_ZERO(u) ?:
686 bch2_snapshot_tree_create(trans, root_id,
687 bch2_snapshot_tree_oldest_subvol(c, root_id),
692 u->v.tree = cpu_to_le32(tree_id);
693 if (k.k->p.offset == root_id)
697 if (k.k->p.offset != root_id) {
698 u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
699 ret = PTR_ERR_OR_ZERO(u);
703 u->v.tree = cpu_to_le32(tree_id);
707 bch2_trans_iter_exit(trans, &root_iter);
711 static int check_snapshot(struct btree_trans *trans,
712 struct btree_iter *iter,
715 struct bch_fs *c = trans->c;
716 struct bch_snapshot s;
717 struct bch_subvolume subvol;
718 struct bch_snapshot v;
719 struct bkey_i_snapshot *u;
720 u32 parent_id = bch2_snapshot_parent_early(c, k.k->p.offset);
722 struct printbuf buf = PRINTBUF;
723 bool should_have_subvol;
727 if (k.k->type != KEY_TYPE_snapshot)
730 memset(&s, 0, sizeof(s));
731 memcpy(&s, k.v, min(sizeof(s), bkey_val_bytes(k.k)));
733 id = le32_to_cpu(s.parent);
735 ret = bch2_snapshot_lookup(trans, id, &v);
736 if (bch2_err_matches(ret, ENOENT))
737 bch_err(c, "snapshot with nonexistent parent:\n %s",
738 (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
742 if (le32_to_cpu(v.children[0]) != k.k->p.offset &&
743 le32_to_cpu(v.children[1]) != k.k->p.offset) {
744 bch_err(c, "snapshot parent %u missing pointer to child %llu",
751 for (i = 0; i < 2 && s.children[i]; i++) {
752 id = le32_to_cpu(s.children[i]);
754 ret = bch2_snapshot_lookup(trans, id, &v);
755 if (bch2_err_matches(ret, ENOENT))
756 bch_err(c, "snapshot node %llu has nonexistent child %u",
761 if (le32_to_cpu(v.parent) != k.k->p.offset) {
762 bch_err(c, "snapshot child %u has wrong parent (got %u should be %llu)",
763 id, le32_to_cpu(v.parent), k.k->p.offset);
769 should_have_subvol = BCH_SNAPSHOT_SUBVOL(&s) &&
770 !BCH_SNAPSHOT_DELETED(&s);
772 if (should_have_subvol) {
773 id = le32_to_cpu(s.subvol);
774 ret = bch2_subvolume_get(trans, id, 0, false, &subvol);
775 if (bch2_err_matches(ret, ENOENT))
776 bch_err(c, "snapshot points to nonexistent subvolume:\n %s",
777 (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
781 if (BCH_SNAPSHOT_SUBVOL(&s) != (le32_to_cpu(subvol.snapshot) == k.k->p.offset)) {
782 bch_err(c, "snapshot node %llu has wrong BCH_SNAPSHOT_SUBVOL",
788 if (fsck_err_on(s.subvol,
789 c, snapshot_should_not_have_subvol,
790 "snapshot should not point to subvol:\n %s",
791 (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
792 u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
793 ret = PTR_ERR_OR_ZERO(u);
802 ret = snapshot_tree_ptr_good(trans, k.k->p.offset, le32_to_cpu(s.tree));
806 if (fsck_err_on(!ret, c, snapshot_to_bad_snapshot_tree,
807 "snapshot points to missing/incorrect tree:\n %s",
808 (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
809 ret = snapshot_tree_ptr_repair(trans, iter, k, &s);
815 real_depth = bch2_snapshot_depth(c, parent_id);
817 if (fsck_err_on(le32_to_cpu(s.depth) != real_depth,
818 c, snapshot_bad_depth,
819 "snapshot with incorrect depth field, should be %u:\n %s",
820 real_depth, (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
821 u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
822 ret = PTR_ERR_OR_ZERO(u);
826 u->v.depth = cpu_to_le32(real_depth);
830 ret = snapshot_skiplist_good(trans, k.k->p.offset, s);
834 if (fsck_err_on(!ret, c, snapshot_bad_skiplist,
835 "snapshot with bad skiplist field:\n %s",
836 (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
837 u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
838 ret = PTR_ERR_OR_ZERO(u);
842 for (i = 0; i < ARRAY_SIZE(u->v.skip); i++)
843 u->v.skip[i] = cpu_to_le32(bch2_snapshot_skiplist_get(c, parent_id));
845 bubble_sort(u->v.skip, ARRAY_SIZE(u->v.skip), cmp_le32);
855 int bch2_check_snapshots(struct bch_fs *c)
858 * We iterate backwards as checking/fixing the depth field requires that
859 * the parent's depth already be correct:
861 int ret = bch2_trans_run(c,
862 for_each_btree_key_reverse_commit(trans, iter,
863 BTREE_ID_snapshots, POS_MAX,
864 BTREE_ITER_PREFETCH, k,
865 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
866 check_snapshot(trans, &iter, k)));
872 * Mark a snapshot as deleted, for future cleanup:
874 int bch2_snapshot_node_set_deleted(struct btree_trans *trans, u32 id)
876 struct btree_iter iter;
877 struct bkey_i_snapshot *s;
880 s = bch2_bkey_get_mut_typed(trans, &iter,
881 BTREE_ID_snapshots, POS(0, id),
883 ret = PTR_ERR_OR_ZERO(s);
885 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT),
886 trans->c, "missing snapshot %u", id);
890 /* already deleted? */
891 if (BCH_SNAPSHOT_DELETED(&s->v))
894 SET_BCH_SNAPSHOT_DELETED(&s->v, true);
895 SET_BCH_SNAPSHOT_SUBVOL(&s->v, false);
898 bch2_trans_iter_exit(trans, &iter);
902 static inline void normalize_snapshot_child_pointers(struct bch_snapshot *s)
904 if (le32_to_cpu(s->children[0]) < le32_to_cpu(s->children[1]))
905 swap(s->children[0], s->children[1]);
908 static int bch2_snapshot_node_delete(struct btree_trans *trans, u32 id)
910 struct bch_fs *c = trans->c;
911 struct btree_iter iter, p_iter = (struct btree_iter) { NULL };
912 struct btree_iter c_iter = (struct btree_iter) { NULL };
913 struct btree_iter tree_iter = (struct btree_iter) { NULL };
914 struct bkey_s_c_snapshot s;
915 u32 parent_id, child_id;
919 s = bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_snapshots, POS(0, id),
920 BTREE_ITER_INTENT, snapshot);
922 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
923 "missing snapshot %u", id);
928 BUG_ON(s.v->children[1]);
930 parent_id = le32_to_cpu(s.v->parent);
931 child_id = le32_to_cpu(s.v->children[0]);
934 struct bkey_i_snapshot *parent;
936 parent = bch2_bkey_get_mut_typed(trans, &p_iter,
937 BTREE_ID_snapshots, POS(0, parent_id),
939 ret = PTR_ERR_OR_ZERO(parent);
940 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
941 "missing snapshot %u", parent_id);
945 /* find entry in parent->children for node being deleted */
946 for (i = 0; i < 2; i++)
947 if (le32_to_cpu(parent->v.children[i]) == id)
950 if (bch2_fs_inconsistent_on(i == 2, c,
951 "snapshot %u missing child pointer to %u",
955 parent->v.children[i] = cpu_to_le32(child_id);
957 normalize_snapshot_child_pointers(&parent->v);
961 struct bkey_i_snapshot *child;
963 child = bch2_bkey_get_mut_typed(trans, &c_iter,
964 BTREE_ID_snapshots, POS(0, child_id),
966 ret = PTR_ERR_OR_ZERO(child);
967 bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
968 "missing snapshot %u", child_id);
972 child->v.parent = cpu_to_le32(parent_id);
974 if (!child->v.parent) {
975 child->v.skip[0] = 0;
976 child->v.skip[1] = 0;
977 child->v.skip[2] = 0;
983 * We're deleting the root of a snapshot tree: update the
984 * snapshot_tree entry to point to the new root, or delete it if
985 * this is the last snapshot ID in this tree:
987 struct bkey_i_snapshot_tree *s_t;
989 BUG_ON(s.v->children[1]);
991 s_t = bch2_bkey_get_mut_typed(trans, &tree_iter,
992 BTREE_ID_snapshot_trees, POS(0, le32_to_cpu(s.v->tree)),
994 ret = PTR_ERR_OR_ZERO(s_t);
998 if (s.v->children[0]) {
999 s_t->v.root_snapshot = s.v->children[0];
1001 s_t->k.type = KEY_TYPE_deleted;
1002 set_bkey_val_u64s(&s_t->k, 0);
1006 ret = bch2_btree_delete_at(trans, &iter, 0);
1008 bch2_trans_iter_exit(trans, &tree_iter);
1009 bch2_trans_iter_exit(trans, &p_iter);
1010 bch2_trans_iter_exit(trans, &c_iter);
1011 bch2_trans_iter_exit(trans, &iter);
1015 static int create_snapids(struct btree_trans *trans, u32 parent, u32 tree,
1017 u32 *snapshot_subvols,
1018 unsigned nr_snapids)
1020 struct bch_fs *c = trans->c;
1021 struct btree_iter iter;
1022 struct bkey_i_snapshot *n;
1025 u32 depth = bch2_snapshot_depth(c, parent);
1028 bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots,
1029 POS_MIN, BTREE_ITER_INTENT);
1030 k = bch2_btree_iter_peek(&iter);
1035 for (i = 0; i < nr_snapids; i++) {
1036 k = bch2_btree_iter_prev_slot(&iter);
1041 if (!k.k || !k.k->p.offset) {
1042 ret = -BCH_ERR_ENOSPC_snapshot_create;
1046 n = bch2_bkey_alloc(trans, &iter, 0, snapshot);
1047 ret = PTR_ERR_OR_ZERO(n);
1052 n->v.parent = cpu_to_le32(parent);
1053 n->v.subvol = cpu_to_le32(snapshot_subvols[i]);
1054 n->v.tree = cpu_to_le32(tree);
1055 n->v.depth = cpu_to_le32(depth);
1056 n->v.btime.lo = cpu_to_le64(bch2_current_time(c));
1059 for (j = 0; j < ARRAY_SIZE(n->v.skip); j++)
1060 n->v.skip[j] = cpu_to_le32(bch2_snapshot_skiplist_get(c, parent));
1062 bubble_sort(n->v.skip, ARRAY_SIZE(n->v.skip), cmp_le32);
1063 SET_BCH_SNAPSHOT_SUBVOL(&n->v, true);
1065 ret = __bch2_mark_snapshot(trans, BTREE_ID_snapshots, 0,
1066 bkey_s_c_null, bkey_i_to_s_c(&n->k_i), 0);
1070 new_snapids[i] = iter.pos.offset;
1072 mutex_lock(&c->snapshot_table_lock);
1073 snapshot_t_mut(c, new_snapids[i])->equiv = new_snapids[i];
1074 mutex_unlock(&c->snapshot_table_lock);
1077 bch2_trans_iter_exit(trans, &iter);
1082 * Create new snapshot IDs as children of an existing snapshot ID:
1084 static int bch2_snapshot_node_create_children(struct btree_trans *trans, u32 parent,
1086 u32 *snapshot_subvols,
1087 unsigned nr_snapids)
1089 struct btree_iter iter;
1090 struct bkey_i_snapshot *n_parent;
1093 n_parent = bch2_bkey_get_mut_typed(trans, &iter,
1094 BTREE_ID_snapshots, POS(0, parent),
1096 ret = PTR_ERR_OR_ZERO(n_parent);
1097 if (unlikely(ret)) {
1098 if (bch2_err_matches(ret, ENOENT))
1099 bch_err(trans->c, "snapshot %u not found", parent);
1103 if (n_parent->v.children[0] || n_parent->v.children[1]) {
1104 bch_err(trans->c, "Trying to add child snapshot nodes to parent that already has children");
1109 ret = create_snapids(trans, parent, le32_to_cpu(n_parent->v.tree),
1110 new_snapids, snapshot_subvols, nr_snapids);
1114 n_parent->v.children[0] = cpu_to_le32(new_snapids[0]);
1115 n_parent->v.children[1] = cpu_to_le32(new_snapids[1]);
1116 n_parent->v.subvol = 0;
1117 SET_BCH_SNAPSHOT_SUBVOL(&n_parent->v, false);
1119 bch2_trans_iter_exit(trans, &iter);
1124 * Create a snapshot node that is the root of a new tree:
1126 static int bch2_snapshot_node_create_tree(struct btree_trans *trans,
1128 u32 *snapshot_subvols,
1129 unsigned nr_snapids)
1131 struct bkey_i_snapshot_tree *n_tree;
1134 n_tree = __bch2_snapshot_tree_create(trans);
1135 ret = PTR_ERR_OR_ZERO(n_tree) ?:
1136 create_snapids(trans, 0, n_tree->k.p.offset,
1137 new_snapids, snapshot_subvols, nr_snapids);
1141 n_tree->v.master_subvol = cpu_to_le32(snapshot_subvols[0]);
1142 n_tree->v.root_snapshot = cpu_to_le32(new_snapids[0]);
1146 int bch2_snapshot_node_create(struct btree_trans *trans, u32 parent,
1148 u32 *snapshot_subvols,
1149 unsigned nr_snapids)
1151 BUG_ON((parent == 0) != (nr_snapids == 1));
1152 BUG_ON((parent != 0) != (nr_snapids == 2));
1155 ? bch2_snapshot_node_create_children(trans, parent,
1156 new_snapids, snapshot_subvols, nr_snapids)
1157 : bch2_snapshot_node_create_tree(trans,
1158 new_snapids, snapshot_subvols, nr_snapids);
1163 * If we have an unlinked inode in an internal snapshot node, and the inode
1164 * really has been deleted in all child snapshots, how does this get cleaned up?
1166 * first there is the problem of how keys that have been overwritten in all
1167 * child snapshots get deleted (unimplemented?), but inodes may perhaps be
1170 * also: unlinked inode in internal snapshot appears to not be getting deleted
1171 * correctly if inode doesn't exist in leaf snapshots
1175 * for a key in an interior snapshot node that needs work to be done that
1176 * requires it to be mutated: iterate over all descendent leaf nodes and copy
1177 * that key to snapshot leaf nodes, where we can mutate it
1180 static int snapshot_delete_key(struct btree_trans *trans,
1181 struct btree_iter *iter,
1183 snapshot_id_list *deleted,
1184 snapshot_id_list *equiv_seen,
1185 struct bpos *last_pos)
1187 struct bch_fs *c = trans->c;
1188 u32 equiv = bch2_snapshot_equiv(c, k.k->p.snapshot);
1190 if (!bkey_eq(k.k->p, *last_pos))
1194 if (snapshot_list_has_id(deleted, k.k->p.snapshot) ||
1195 snapshot_list_has_id(equiv_seen, equiv)) {
1196 return bch2_btree_delete_at(trans, iter,
1197 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
1199 return snapshot_list_add(c, equiv_seen, equiv);
1203 static int move_key_to_correct_snapshot(struct btree_trans *trans,
1204 struct btree_iter *iter,
1207 struct bch_fs *c = trans->c;
1208 u32 equiv = bch2_snapshot_equiv(c, k.k->p.snapshot);
1211 * When we have a linear chain of snapshot nodes, we consider
1212 * those to form an equivalence class: we're going to collapse
1213 * them all down to a single node, and keep the leaf-most node -
1214 * which has the same id as the equivalence class id.
1216 * If there are multiple keys in different snapshots at the same
1217 * position, we're only going to keep the one in the newest
1218 * snapshot - the rest have been overwritten and are redundant,
1219 * and for the key we're going to keep we need to move it to the
1220 * equivalance class ID if it's not there already.
1222 if (equiv != k.k->p.snapshot) {
1223 struct bkey_i *new = bch2_bkey_make_mut_noupdate(trans, k);
1224 struct btree_iter new_iter;
1227 ret = PTR_ERR_OR_ZERO(new);
1231 new->k.p.snapshot = equiv;
1233 bch2_trans_iter_init(trans, &new_iter, iter->btree_id, new->k.p,
1234 BTREE_ITER_ALL_SNAPSHOTS|
1238 ret = bch2_btree_iter_traverse(&new_iter) ?:
1239 bch2_trans_update(trans, &new_iter, new,
1240 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
1241 bch2_btree_delete_at(trans, iter,
1242 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
1243 bch2_trans_iter_exit(trans, &new_iter);
1251 static int bch2_snapshot_needs_delete(struct btree_trans *trans, struct bkey_s_c k)
1253 struct bkey_s_c_snapshot snap;
1257 if (k.k->type != KEY_TYPE_snapshot)
1260 snap = bkey_s_c_to_snapshot(k);
1261 if (BCH_SNAPSHOT_DELETED(snap.v) ||
1262 BCH_SNAPSHOT_SUBVOL(snap.v))
1265 children[0] = le32_to_cpu(snap.v->children[0]);
1266 children[1] = le32_to_cpu(snap.v->children[1]);
1268 ret = bch2_snapshot_live(trans, children[0]) ?:
1269 bch2_snapshot_live(trans, children[1]);
1276 * For a given snapshot, if it doesn't have a subvolume that points to it, and
1277 * it doesn't have child snapshot nodes - it's now redundant and we can mark it
1280 static int bch2_delete_redundant_snapshot(struct btree_trans *trans, struct bkey_s_c k)
1282 int ret = bch2_snapshot_needs_delete(trans, k);
1286 : bch2_snapshot_node_set_deleted(trans, k.k->p.offset);
1289 static inline u32 bch2_snapshot_nth_parent_skip(struct bch_fs *c, u32 id, u32 n,
1290 snapshot_id_list *skip)
1293 while (snapshot_list_has_id(skip, id))
1294 id = __bch2_snapshot_parent(c, id);
1298 id = __bch2_snapshot_parent(c, id);
1299 } while (snapshot_list_has_id(skip, id));
1306 static int bch2_fix_child_of_deleted_snapshot(struct btree_trans *trans,
1307 struct btree_iter *iter, struct bkey_s_c k,
1308 snapshot_id_list *deleted)
1310 struct bch_fs *c = trans->c;
1311 u32 nr_deleted_ancestors = 0;
1312 struct bkey_i_snapshot *s;
1315 if (k.k->type != KEY_TYPE_snapshot)
1318 if (snapshot_list_has_id(deleted, k.k->p.offset))
1321 s = bch2_bkey_make_mut_noupdate_typed(trans, k, snapshot);
1322 ret = PTR_ERR_OR_ZERO(s);
1326 darray_for_each(*deleted, i)
1327 nr_deleted_ancestors += bch2_snapshot_is_ancestor(c, s->k.p.offset, *i);
1329 if (!nr_deleted_ancestors)
1332 le32_add_cpu(&s->v.depth, -nr_deleted_ancestors);
1339 u32 depth = le32_to_cpu(s->v.depth);
1340 u32 parent = bch2_snapshot_parent(c, s->k.p.offset);
1342 for (unsigned j = 0; j < ARRAY_SIZE(s->v.skip); j++) {
1343 u32 id = le32_to_cpu(s->v.skip[j]);
1345 if (snapshot_list_has_id(deleted, id)) {
1346 id = bch2_snapshot_nth_parent_skip(c,
1349 ? get_random_u32_below(depth - 1)
1352 s->v.skip[j] = cpu_to_le32(id);
1356 bubble_sort(s->v.skip, ARRAY_SIZE(s->v.skip), cmp_le32);
1359 return bch2_trans_update(trans, iter, &s->k_i, 0);
1362 int bch2_delete_dead_snapshots(struct bch_fs *c)
1364 struct btree_trans *trans;
1365 snapshot_id_list deleted = { 0 };
1366 snapshot_id_list deleted_interior = { 0 };
1370 if (!test_and_clear_bit(BCH_FS_need_delete_dead_snapshots, &c->flags))
1373 if (!test_bit(BCH_FS_started, &c->flags)) {
1374 ret = bch2_fs_read_write_early(c);
1375 bch_err_msg(c, ret, "deleting dead snapshots: error going rw");
1380 trans = bch2_trans_get(c);
1383 * For every snapshot node: If we have no live children and it's not
1384 * pointed to by a subvolume, delete it:
1386 ret = for_each_btree_key_commit(trans, iter, BTREE_ID_snapshots,
1389 bch2_delete_redundant_snapshot(trans, k));
1390 bch_err_msg(c, ret, "deleting redundant snapshots");
1394 ret = for_each_btree_key(trans, iter, BTREE_ID_snapshots,
1396 bch2_snapshot_set_equiv(trans, k));
1397 bch_err_msg(c, ret, "in bch2_snapshots_set_equiv");
1401 ret = for_each_btree_key(trans, iter, BTREE_ID_snapshots,
1403 if (k.k->type != KEY_TYPE_snapshot)
1406 BCH_SNAPSHOT_DELETED(bkey_s_c_to_snapshot(k).v)
1407 ? snapshot_list_add(c, &deleted, k.k->p.offset)
1410 bch_err_msg(c, ret, "walking snapshots");
1414 for (id = 0; id < BTREE_ID_NR; id++) {
1415 struct bpos last_pos = POS_MIN;
1416 snapshot_id_list equiv_seen = { 0 };
1417 struct disk_reservation res = { 0 };
1419 if (!btree_type_has_snapshots(id))
1423 * deleted inodes btree is maintained by a trigger on the inodes
1424 * btree - no work for us to do here, and it's not safe to scan
1425 * it because we'll see out of date keys due to the btree write
1428 if (id == BTREE_ID_deleted_inodes)
1431 ret = for_each_btree_key_commit(trans, iter,
1433 BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
1434 &res, NULL, BCH_TRANS_COMMIT_no_enospc,
1435 snapshot_delete_key(trans, &iter, k, &deleted, &equiv_seen, &last_pos)) ?:
1436 for_each_btree_key_commit(trans, iter,
1438 BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
1439 &res, NULL, BCH_TRANS_COMMIT_no_enospc,
1440 move_key_to_correct_snapshot(trans, &iter, k));
1442 bch2_disk_reservation_put(c, &res);
1443 darray_exit(&equiv_seen);
1445 bch_err_msg(c, ret, "deleting keys from dying snapshots");
1450 bch2_trans_unlock(trans);
1451 down_write(&c->snapshot_create_lock);
1453 ret = for_each_btree_key(trans, iter, BTREE_ID_snapshots,
1455 u32 snapshot = k.k->p.offset;
1456 u32 equiv = bch2_snapshot_equiv(c, snapshot);
1459 ? snapshot_list_add(c, &deleted_interior, snapshot)
1463 bch_err_msg(c, ret, "walking snapshots");
1465 goto err_create_lock;
1468 * Fixing children of deleted snapshots can't be done completely
1469 * atomically, if we crash between here and when we delete the interior
1470 * nodes some depth fields will be off:
1472 ret = for_each_btree_key_commit(trans, iter, BTREE_ID_snapshots, POS_MIN,
1473 BTREE_ITER_INTENT, k,
1474 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
1475 bch2_fix_child_of_deleted_snapshot(trans, &iter, k, &deleted_interior));
1477 goto err_create_lock;
1479 darray_for_each(deleted, i) {
1480 ret = commit_do(trans, NULL, NULL, 0,
1481 bch2_snapshot_node_delete(trans, *i));
1482 bch_err_msg(c, ret, "deleting snapshot %u", *i);
1484 goto err_create_lock;
1487 darray_for_each(deleted_interior, i) {
1488 ret = commit_do(trans, NULL, NULL, 0,
1489 bch2_snapshot_node_delete(trans, *i));
1490 bch_err_msg(c, ret, "deleting snapshot %u", *i);
1492 goto err_create_lock;
1495 up_write(&c->snapshot_create_lock);
1497 darray_exit(&deleted_interior);
1498 darray_exit(&deleted);
1499 bch2_trans_put(trans);
1504 void bch2_delete_dead_snapshots_work(struct work_struct *work)
1506 struct bch_fs *c = container_of(work, struct bch_fs, snapshot_delete_work);
1508 bch2_delete_dead_snapshots(c);
1509 bch2_write_ref_put(c, BCH_WRITE_REF_delete_dead_snapshots);
1512 void bch2_delete_dead_snapshots_async(struct bch_fs *c)
1514 if (bch2_write_ref_tryget(c, BCH_WRITE_REF_delete_dead_snapshots) &&
1515 !queue_work(c->write_ref_wq, &c->snapshot_delete_work))
1516 bch2_write_ref_put(c, BCH_WRITE_REF_delete_dead_snapshots);
1519 int __bch2_key_has_snapshot_overwrites(struct btree_trans *trans,
1523 struct bch_fs *c = trans->c;
1524 struct btree_iter iter;
1528 bch2_trans_iter_init(trans, &iter, id, pos,
1529 BTREE_ITER_NOT_EXTENTS|
1530 BTREE_ITER_ALL_SNAPSHOTS);
1532 k = bch2_btree_iter_prev(&iter);
1540 if (!bkey_eq(pos, k.k->p))
1543 if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, pos.snapshot)) {
1548 bch2_trans_iter_exit(trans, &iter);
1553 static u32 bch2_snapshot_smallest_child(struct bch_fs *c, u32 id)
1555 const struct snapshot_t *s = snapshot_t(c, id);
1557 return s->children[1] ?: s->children[0];
1560 static u32 bch2_snapshot_smallest_descendent(struct bch_fs *c, u32 id)
1564 while ((child = bch2_snapshot_smallest_child(c, id)))
1569 static int bch2_propagate_key_to_snapshot_leaf(struct btree_trans *trans,
1570 enum btree_id btree,
1571 struct bkey_s_c interior_k,
1572 u32 leaf_id, struct bpos *new_min_pos)
1574 struct btree_iter iter;
1575 struct bpos pos = interior_k.k->p;
1580 pos.snapshot = leaf_id;
1582 bch2_trans_iter_init(trans, &iter, btree, pos, BTREE_ITER_INTENT);
1583 k = bch2_btree_iter_peek_slot(&iter);
1588 /* key already overwritten in this snapshot? */
1589 if (k.k->p.snapshot != interior_k.k->p.snapshot)
1592 if (bpos_eq(*new_min_pos, POS_MIN)) {
1593 *new_min_pos = k.k->p;
1594 new_min_pos->snapshot = leaf_id;
1597 new = bch2_bkey_make_mut_noupdate(trans, interior_k);
1598 ret = PTR_ERR_OR_ZERO(new);
1602 new->k.p.snapshot = leaf_id;
1603 ret = bch2_trans_update(trans, &iter, new, 0);
1605 bch2_trans_iter_exit(trans, &iter);
1609 int bch2_propagate_key_to_snapshot_leaves(struct btree_trans *trans,
1610 enum btree_id btree,
1612 struct bpos *new_min_pos)
1614 struct bch_fs *c = trans->c;
1616 u32 restart_count = trans->restart_count;
1619 bch2_bkey_buf_init(&sk);
1620 bch2_bkey_buf_reassemble(&sk, c, k);
1621 k = bkey_i_to_s_c(sk.k);
1623 *new_min_pos = POS_MIN;
1625 for (u32 id = bch2_snapshot_smallest_descendent(c, k.k->p.snapshot);
1626 id < k.k->p.snapshot;
1628 if (!bch2_snapshot_is_ancestor(c, id, k.k->p.snapshot) ||
1629 !bch2_snapshot_is_leaf(c, id))
1632 ret = btree_trans_too_many_iters(trans) ?:
1633 bch2_propagate_key_to_snapshot_leaf(trans, btree, k, id, new_min_pos) ?:
1634 bch2_trans_commit(trans, NULL, NULL, 0);
1635 if (ret && bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
1636 bch2_trans_begin(trans);
1644 bch2_bkey_buf_exit(&sk, c);
1646 return ret ?: trans_was_restarted(trans, restart_count);
1649 static int bch2_check_snapshot_needs_deletion(struct btree_trans *trans, struct bkey_s_c k)
1651 struct bch_fs *c = trans->c;
1652 struct bkey_s_c_snapshot snap;
1655 if (k.k->type != KEY_TYPE_snapshot)
1658 snap = bkey_s_c_to_snapshot(k);
1659 if (BCH_SNAPSHOT_DELETED(snap.v) ||
1660 bch2_snapshot_equiv(c, k.k->p.offset) != k.k->p.offset ||
1661 (ret = bch2_snapshot_needs_delete(trans, k)) > 0) {
1662 set_bit(BCH_FS_need_delete_dead_snapshots, &c->flags);
1669 int bch2_snapshots_read(struct bch_fs *c)
1671 int ret = bch2_trans_run(c,
1672 for_each_btree_key(trans, iter, BTREE_ID_snapshots,
1674 __bch2_mark_snapshot(trans, BTREE_ID_snapshots, 0, bkey_s_c_null, k, 0) ?:
1675 bch2_snapshot_set_equiv(trans, k) ?:
1676 bch2_check_snapshot_needs_deletion(trans, k)) ?:
1677 for_each_btree_key(trans, iter, BTREE_ID_snapshots,
1679 (set_is_ancestor_bitmap(c, k.k->p.offset), 0)));
1684 void bch2_fs_snapshots_exit(struct bch_fs *c)
1686 kvfree(rcu_dereference_protected(c->snapshots, true));