]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - c_src/libbcachefs/btree_journal_iter.c
move Rust sources to top level, C sources into c_src
[bcachefs-tools-debian] / c_src / libbcachefs / btree_journal_iter.c
diff --git a/c_src/libbcachefs/btree_journal_iter.c b/c_src/libbcachefs/btree_journal_iter.c
new file mode 100644 (file)
index 0000000..719a94a
--- /dev/null
@@ -0,0 +1,556 @@
+// 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));
+}
+
+/* Returns first non-overwritten key >= search key: */
+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 (*idx &&
+              __journal_key_cmp(btree_id, level, end_pos, idx_to_key(keys, *idx - 1)) <= 0) {
+               --(*idx);
+               iters++;
+               if (iters == 10) {
+                       *idx = 0;
+                       goto search;
+               }
+       }
+
+       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 (k->overwritten) {
+                       (*idx)++;
+                       continue;
+               }
+
+               if (__journal_key_cmp(btree_id, level, pos, k) <= 0)
+                       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 &&
+                      !journal_key_cmp(src, src + 1))
+                       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;
+}