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-rw-r--r--fs/bcachefs/btree_journal_iter.c543
1 files changed, 543 insertions, 0 deletions
diff --git a/fs/bcachefs/btree_journal_iter.c b/fs/bcachefs/btree_journal_iter.c
new file mode 100644
index 0000000000..ec52f50d24
--- /dev/null
+++ b/fs/bcachefs/btree_journal_iter.c
@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "bset.h"
+#include "btree_journal_iter.h"
+#include "journal_io.h"
+
+#include <linux/sort.h>
+
+/*
+ * For managing keys we read from the journal: until journal replay works normal
+ * btree lookups need to be able to find and return keys from the journal where
+ * they overwrite what's in the btree, so we have a special iterator and
+ * operations for the regular btree iter code to use:
+ */
+
+static int __journal_key_cmp(enum btree_id l_btree_id,
+ unsigned l_level,
+ struct bpos l_pos,
+ const struct journal_key *r)
+{
+ return (cmp_int(l_btree_id, r->btree_id) ?:
+ cmp_int(l_level, r->level) ?:
+ bpos_cmp(l_pos, r->k->k.p));
+}
+
+static int journal_key_cmp(const struct journal_key *l, const struct journal_key *r)
+{
+ return __journal_key_cmp(l->btree_id, l->level, l->k->k.p, r);
+}
+
+static inline size_t idx_to_pos(struct journal_keys *keys, size_t idx)
+{
+ size_t gap_size = keys->size - keys->nr;
+
+ if (idx >= keys->gap)
+ idx += gap_size;
+ return idx;
+}
+
+static inline struct journal_key *idx_to_key(struct journal_keys *keys, size_t idx)
+{
+ return keys->d + idx_to_pos(keys, idx);
+}
+
+static size_t __bch2_journal_key_search(struct journal_keys *keys,
+ enum btree_id id, unsigned level,
+ struct bpos pos)
+{
+ size_t l = 0, r = keys->nr, m;
+
+ while (l < r) {
+ m = l + ((r - l) >> 1);
+ if (__journal_key_cmp(id, level, pos, idx_to_key(keys, m)) > 0)
+ l = m + 1;
+ else
+ r = m;
+ }
+
+ BUG_ON(l < keys->nr &&
+ __journal_key_cmp(id, level, pos, idx_to_key(keys, l)) > 0);
+
+ BUG_ON(l &&
+ __journal_key_cmp(id, level, pos, idx_to_key(keys, l - 1)) <= 0);
+
+ return l;
+}
+
+static size_t bch2_journal_key_search(struct journal_keys *keys,
+ enum btree_id id, unsigned level,
+ struct bpos pos)
+{
+ return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
+}
+
+struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
+ unsigned level, struct bpos pos,
+ struct bpos end_pos, size_t *idx)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ unsigned iters = 0;
+ struct journal_key *k;
+
+ BUG_ON(*idx > keys->nr);
+search:
+ if (!*idx)
+ *idx = __bch2_journal_key_search(keys, btree_id, level, pos);
+
+ while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
+ if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
+ return NULL;
+
+ if (__journal_key_cmp(btree_id, level, pos, k) <= 0 &&
+ !k->overwritten)
+ return k->k;
+
+ (*idx)++;
+ iters++;
+ if (iters == 10) {
+ *idx = 0;
+ goto search;
+ }
+ }
+
+ return NULL;
+}
+
+struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
+ unsigned level, struct bpos pos)
+{
+ size_t idx = 0;
+
+ return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
+}
+
+static void journal_iters_fix(struct bch_fs *c)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ /* The key we just inserted is immediately before the gap: */
+ size_t gap_end = keys->gap + (keys->size - keys->nr);
+ struct btree_and_journal_iter *iter;
+
+ /*
+ * If an iterator points one after the key we just inserted, decrement
+ * the iterator so it points at the key we just inserted - if the
+ * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
+ * handle that:
+ */
+ list_for_each_entry(iter, &c->journal_iters, journal.list)
+ if (iter->journal.idx == gap_end)
+ iter->journal.idx = keys->gap - 1;
+}
+
+static void journal_iters_move_gap(struct bch_fs *c, size_t old_gap, size_t new_gap)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ struct journal_iter *iter;
+ size_t gap_size = keys->size - keys->nr;
+
+ list_for_each_entry(iter, &c->journal_iters, list) {
+ if (iter->idx > old_gap)
+ iter->idx -= gap_size;
+ if (iter->idx >= new_gap)
+ iter->idx += gap_size;
+ }
+}
+
+int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
+ unsigned level, struct bkey_i *k)
+{
+ struct journal_key n = {
+ .btree_id = id,
+ .level = level,
+ .k = k,
+ .allocated = true,
+ /*
+ * Ensure these keys are done last by journal replay, to unblock
+ * journal reclaim:
+ */
+ .journal_seq = U32_MAX,
+ };
+ struct journal_keys *keys = &c->journal_keys;
+ size_t idx = bch2_journal_key_search(keys, id, level, k->k.p);
+
+ BUG_ON(test_bit(BCH_FS_RW, &c->flags));
+
+ if (idx < keys->size &&
+ journal_key_cmp(&n, &keys->d[idx]) == 0) {
+ if (keys->d[idx].allocated)
+ kfree(keys->d[idx].k);
+ keys->d[idx] = n;
+ return 0;
+ }
+
+ if (idx > keys->gap)
+ idx -= keys->size - keys->nr;
+
+ if (keys->nr == keys->size) {
+ struct journal_keys new_keys = {
+ .nr = keys->nr,
+ .size = max_t(size_t, keys->size, 8) * 2,
+ };
+
+ new_keys.d = kvmalloc_array(new_keys.size, sizeof(new_keys.d[0]), GFP_KERNEL);
+ if (!new_keys.d) {
+ bch_err(c, "%s: error allocating new key array (size %zu)",
+ __func__, new_keys.size);
+ return -BCH_ERR_ENOMEM_journal_key_insert;
+ }
+
+ /* Since @keys was full, there was no gap: */
+ memcpy(new_keys.d, keys->d, sizeof(keys->d[0]) * keys->nr);
+ kvfree(keys->d);
+ keys->d = new_keys.d;
+ keys->nr = new_keys.nr;
+ keys->size = new_keys.size;
+
+ /* And now the gap is at the end: */
+ keys->gap = keys->nr;
+ }
+
+ journal_iters_move_gap(c, keys->gap, idx);
+
+ move_gap(keys->d, keys->nr, keys->size, keys->gap, idx);
+ keys->gap = idx;
+
+ keys->nr++;
+ keys->d[keys->gap++] = n;
+
+ journal_iters_fix(c);
+
+ return 0;
+}
+
+/*
+ * Can only be used from the recovery thread while we're still RO - can't be
+ * used once we've got RW, as journal_keys is at that point used by multiple
+ * threads:
+ */
+int bch2_journal_key_insert(struct bch_fs *c, enum btree_id id,
+ unsigned level, struct bkey_i *k)
+{
+ struct bkey_i *n;
+ int ret;
+
+ n = kmalloc(bkey_bytes(&k->k), GFP_KERNEL);
+ if (!n)
+ return -BCH_ERR_ENOMEM_journal_key_insert;
+
+ bkey_copy(n, k);
+ ret = bch2_journal_key_insert_take(c, id, level, n);
+ if (ret)
+ kfree(n);
+ return ret;
+}
+
+int bch2_journal_key_delete(struct bch_fs *c, enum btree_id id,
+ unsigned level, struct bpos pos)
+{
+ struct bkey_i whiteout;
+
+ bkey_init(&whiteout.k);
+ whiteout.k.p = pos;
+
+ return bch2_journal_key_insert(c, id, level, &whiteout);
+}
+
+void bch2_journal_key_overwritten(struct bch_fs *c, enum btree_id btree,
+ unsigned level, struct bpos pos)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ size_t idx = bch2_journal_key_search(keys, btree, level, pos);
+
+ if (idx < keys->size &&
+ keys->d[idx].btree_id == btree &&
+ keys->d[idx].level == level &&
+ bpos_eq(keys->d[idx].k->k.p, pos))
+ keys->d[idx].overwritten = true;
+}
+
+static void bch2_journal_iter_advance(struct journal_iter *iter)
+{
+ if (iter->idx < iter->keys->size) {
+ iter->idx++;
+ if (iter->idx == iter->keys->gap)
+ iter->idx += iter->keys->size - iter->keys->nr;
+ }
+}
+
+static struct bkey_s_c bch2_journal_iter_peek(struct journal_iter *iter)
+{
+ struct journal_key *k = iter->keys->d + iter->idx;
+
+ while (k < iter->keys->d + iter->keys->size &&
+ k->btree_id == iter->btree_id &&
+ k->level == iter->level) {
+ if (!k->overwritten)
+ return bkey_i_to_s_c(k->k);
+
+ bch2_journal_iter_advance(iter);
+ k = iter->keys->d + iter->idx;
+ }
+
+ return bkey_s_c_null;
+}
+
+static void bch2_journal_iter_exit(struct journal_iter *iter)
+{
+ list_del(&iter->list);
+}
+
+static void bch2_journal_iter_init(struct bch_fs *c,
+ struct journal_iter *iter,
+ enum btree_id id, unsigned level,
+ struct bpos pos)
+{
+ iter->btree_id = id;
+ iter->level = level;
+ iter->keys = &c->journal_keys;
+ iter->idx = bch2_journal_key_search(&c->journal_keys, id, level, pos);
+}
+
+static struct bkey_s_c bch2_journal_iter_peek_btree(struct btree_and_journal_iter *iter)
+{
+ return bch2_btree_node_iter_peek_unpack(&iter->node_iter,
+ iter->b, &iter->unpacked);
+}
+
+static void bch2_journal_iter_advance_btree(struct btree_and_journal_iter *iter)
+{
+ bch2_btree_node_iter_advance(&iter->node_iter, iter->b);
+}
+
+void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *iter)
+{
+ if (bpos_eq(iter->pos, SPOS_MAX))
+ iter->at_end = true;
+ else
+ iter->pos = bpos_successor(iter->pos);
+}
+
+struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter)
+{
+ struct bkey_s_c btree_k, journal_k, ret;
+again:
+ if (iter->at_end)
+ return bkey_s_c_null;
+
+ while ((btree_k = bch2_journal_iter_peek_btree(iter)).k &&
+ bpos_lt(btree_k.k->p, iter->pos))
+ bch2_journal_iter_advance_btree(iter);
+
+ while ((journal_k = bch2_journal_iter_peek(&iter->journal)).k &&
+ bpos_lt(journal_k.k->p, iter->pos))
+ bch2_journal_iter_advance(&iter->journal);
+
+ ret = journal_k.k &&
+ (!btree_k.k || bpos_le(journal_k.k->p, btree_k.k->p))
+ ? journal_k
+ : btree_k;
+
+ if (ret.k && iter->b && bpos_gt(ret.k->p, iter->b->data->max_key))
+ ret = bkey_s_c_null;
+
+ if (ret.k) {
+ iter->pos = ret.k->p;
+ if (bkey_deleted(ret.k)) {
+ bch2_btree_and_journal_iter_advance(iter);
+ goto again;
+ }
+ } else {
+ iter->pos = SPOS_MAX;
+ iter->at_end = true;
+ }
+
+ return ret;
+}
+
+void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *iter)
+{
+ bch2_journal_iter_exit(&iter->journal);
+}
+
+void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
+ struct bch_fs *c,
+ struct btree *b,
+ struct btree_node_iter node_iter,
+ struct bpos pos)
+{
+ memset(iter, 0, sizeof(*iter));
+
+ iter->b = b;
+ iter->node_iter = node_iter;
+ bch2_journal_iter_init(c, &iter->journal, b->c.btree_id, b->c.level, pos);
+ INIT_LIST_HEAD(&iter->journal.list);
+ iter->pos = b->data->min_key;
+ iter->at_end = false;
+}
+
+/*
+ * this version is used by btree_gc before filesystem has gone RW and
+ * multithreaded, so uses the journal_iters list:
+ */
+void bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
+ struct bch_fs *c,
+ struct btree *b)
+{
+ struct btree_node_iter node_iter;
+
+ bch2_btree_node_iter_init_from_start(&node_iter, b);
+ __bch2_btree_and_journal_iter_init_node_iter(iter, c, b, node_iter, b->data->min_key);
+ list_add(&iter->journal.list, &c->journal_iters);
+}
+
+/* sort and dedup all keys in the journal: */
+
+void bch2_journal_entries_free(struct bch_fs *c)
+{
+ struct journal_replay **i;
+ struct genradix_iter iter;
+
+ genradix_for_each(&c->journal_entries, iter, i)
+ if (*i)
+ kvpfree(*i, offsetof(struct journal_replay, j) +
+ vstruct_bytes(&(*i)->j));
+ genradix_free(&c->journal_entries);
+}
+
+/*
+ * When keys compare equal, oldest compares first:
+ */
+static int journal_sort_key_cmp(const void *_l, const void *_r)
+{
+ const struct journal_key *l = _l;
+ const struct journal_key *r = _r;
+
+ return journal_key_cmp(l, r) ?:
+ cmp_int(l->journal_seq, r->journal_seq) ?:
+ cmp_int(l->journal_offset, r->journal_offset);
+}
+
+void bch2_journal_keys_put(struct bch_fs *c)
+{
+ struct journal_keys *keys = &c->journal_keys;
+ struct journal_key *i;
+
+ BUG_ON(atomic_read(&keys->ref) <= 0);
+
+ if (!atomic_dec_and_test(&keys->ref))
+ return;
+
+ move_gap(keys->d, keys->nr, keys->size, keys->gap, keys->nr);
+ keys->gap = keys->nr;
+
+ for (i = keys->d; i < keys->d + keys->nr; i++)
+ if (i->allocated)
+ kfree(i->k);
+
+ kvfree(keys->d);
+ keys->d = NULL;
+ keys->nr = keys->gap = keys->size = 0;
+
+ bch2_journal_entries_free(c);
+}
+
+static void __journal_keys_sort(struct journal_keys *keys)
+{
+ struct journal_key *src, *dst;
+
+ sort(keys->d, keys->nr, sizeof(keys->d[0]), journal_sort_key_cmp, NULL);
+
+ src = dst = keys->d;
+ while (src < keys->d + keys->nr) {
+ while (src + 1 < keys->d + keys->nr &&
+ src[0].btree_id == src[1].btree_id &&
+ src[0].level == src[1].level &&
+ bpos_eq(src[0].k->k.p, src[1].k->k.p))
+ src++;
+
+ *dst++ = *src++;
+ }
+
+ keys->nr = dst - keys->d;
+}
+
+int bch2_journal_keys_sort(struct bch_fs *c)
+{
+ struct genradix_iter iter;
+ struct journal_replay *i, **_i;
+ struct jset_entry *entry;
+ struct bkey_i *k;
+ struct journal_keys *keys = &c->journal_keys;
+ size_t nr_keys = 0, nr_read = 0;
+
+ genradix_for_each(&c->journal_entries, iter, _i) {
+ i = *_i;
+
+ if (!i || i->ignore)
+ continue;
+
+ for_each_jset_key(k, entry, &i->j)
+ nr_keys++;
+ }
+
+ if (!nr_keys)
+ return 0;
+
+ keys->size = roundup_pow_of_two(nr_keys);
+
+ keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
+ if (!keys->d) {
+ bch_err(c, "Failed to allocate buffer for sorted journal keys (%zu keys); trying slowpath",
+ nr_keys);
+
+ do {
+ keys->size >>= 1;
+ keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
+ } while (!keys->d && keys->size > nr_keys / 8);
+
+ if (!keys->d) {
+ bch_err(c, "Failed to allocate %zu size buffer for sorted journal keys; exiting",
+ keys->size);
+ return -BCH_ERR_ENOMEM_journal_keys_sort;
+ }
+ }
+
+ genradix_for_each(&c->journal_entries, iter, _i) {
+ i = *_i;
+
+ if (!i || i->ignore)
+ continue;
+
+ cond_resched();
+
+ for_each_jset_key(k, entry, &i->j) {
+ if (keys->nr == keys->size) {
+ __journal_keys_sort(keys);
+
+ if (keys->nr > keys->size * 7 / 8) {
+ bch_err(c, "Too many journal keys for slowpath; have %zu compacted, buf size %zu, processed %zu/%zu",
+ keys->nr, keys->size, nr_read, nr_keys);
+ return -BCH_ERR_ENOMEM_journal_keys_sort;
+ }
+ }
+
+ keys->d[keys->nr++] = (struct journal_key) {
+ .btree_id = entry->btree_id,
+ .level = entry->level,
+ .k = k,
+ .journal_seq = le64_to_cpu(i->j.seq),
+ .journal_offset = k->_data - i->j._data,
+ };
+
+ nr_read++;
+ }
+ }
+
+ __journal_keys_sort(keys);
+ keys->gap = keys->nr;
+
+ bch_verbose(c, "Journal keys: %zu read, %zu after sorting and compacting", nr_keys, keys->nr);
+ return 0;
+}