diff options
Diffstat (limited to 'libbcachefs/snapshot.c')
| -rw-r--r-- | libbcachefs/snapshot.c | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/libbcachefs/snapshot.c b/libbcachefs/snapshot.c index ac6ba04d..4e074136 100644 --- a/libbcachefs/snapshot.c +++ b/libbcachefs/snapshot.c @@ -91,23 +91,29 @@ static int bch2_snapshot_tree_create(struct btree_trans *trans, /* Snapshot nodes: */ -static bool bch2_snapshot_is_ancestor_early(struct bch_fs *c, u32 id, u32 ancestor) +static bool __bch2_snapshot_is_ancestor_early(struct snapshot_table *t, u32 id, u32 ancestor) { - struct snapshot_table *t; + while (id && id < ancestor) { + const struct snapshot_t *s = __snapshot_t(t, id); + id = s ? s->parent : 0; + } + return id == ancestor; +} +static bool bch2_snapshot_is_ancestor_early(struct bch_fs *c, u32 id, u32 ancestor) +{ rcu_read_lock(); - t = rcu_dereference(c->snapshots); - - while (id && id < ancestor) - id = __snapshot_t(t, id)->parent; + bool ret = __bch2_snapshot_is_ancestor_early(rcu_dereference(c->snapshots), id, ancestor); rcu_read_unlock(); - return id == ancestor; + return ret; } static inline u32 get_ancestor_below(struct snapshot_table *t, u32 id, u32 ancestor) { const struct snapshot_t *s = __snapshot_t(t, id); + if (!s) + return 0; if (s->skip[2] <= ancestor) return s->skip[2]; @@ -120,13 +126,15 @@ static inline u32 get_ancestor_below(struct snapshot_table *t, u32 id, u32 ances bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor) { - struct snapshot_table *t; bool ret; - EBUG_ON(c->recovery_pass_done <= BCH_RECOVERY_PASS_check_snapshots); - rcu_read_lock(); - t = rcu_dereference(c->snapshots); + struct snapshot_table *t = rcu_dereference(c->snapshots); + + if (unlikely(c->recovery_pass_done <= BCH_RECOVERY_PASS_check_snapshots)) { + ret = __bch2_snapshot_is_ancestor_early(t, id, ancestor); + goto out; + } while (id && id < ancestor - IS_ANCESTOR_BITMAP) id = get_ancestor_below(t, id, ancestor); @@ -134,11 +142,11 @@ bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor) if (id && id < ancestor) { ret = test_bit(ancestor - id - 1, __snapshot_t(t, id)->is_ancestor); - EBUG_ON(ret != bch2_snapshot_is_ancestor_early(c, id, ancestor)); + EBUG_ON(ret != __bch2_snapshot_is_ancestor_early(t, id, ancestor)); } else { ret = id == ancestor; } - +out: rcu_read_unlock(); return ret; @@ -147,36 +155,39 @@ bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor) static noinline struct snapshot_t *__snapshot_t_mut(struct bch_fs *c, u32 id) { size_t idx = U32_MAX - id; - size_t new_size; struct snapshot_table *new, *old; - new_size = max(16UL, roundup_pow_of_two(idx + 1)); + size_t new_bytes = kmalloc_size_roundup(struct_size(new, s, idx + 1)); + size_t new_size = (new_bytes - sizeof(*new)) / sizeof(new->s[0]); - new = kvzalloc(struct_size(new, s, new_size), GFP_KERNEL); + new = kvzalloc(new_bytes, GFP_KERNEL); if (!new) return NULL; + new->nr = new_size; + old = rcu_dereference_protected(c->snapshots, true); if (old) - memcpy(new->s, - rcu_dereference_protected(c->snapshots, true)->s, - sizeof(new->s[0]) * c->snapshot_table_size); + memcpy(new->s, old->s, sizeof(old->s[0]) * old->nr); rcu_assign_pointer(c->snapshots, new); - c->snapshot_table_size = new_size; - kvfree_rcu_mightsleep(old); + kvfree_rcu(old, rcu); - return &rcu_dereference_protected(c->snapshots, true)->s[idx]; + return &rcu_dereference_protected(c->snapshots, + lockdep_is_held(&c->snapshot_table_lock))->s[idx]; } static inline struct snapshot_t *snapshot_t_mut(struct bch_fs *c, u32 id) { size_t idx = U32_MAX - id; + struct snapshot_table *table = + rcu_dereference_protected(c->snapshots, + lockdep_is_held(&c->snapshot_table_lock)); lockdep_assert_held(&c->snapshot_table_lock); - if (likely(idx < c->snapshot_table_size)) - return &rcu_dereference_protected(c->snapshots, true)->s[idx]; + if (likely(table && idx < table->nr)) + return &table->s[idx]; return __snapshot_t_mut(c, id); } @@ -547,7 +558,7 @@ static int check_snapshot_tree(struct btree_trans *trans, "snapshot tree points to missing subvolume:\n %s", (printbuf_reset(&buf), bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf)) || - fsck_err_on(!bch2_snapshot_is_ancestor_early(c, + fsck_err_on(!bch2_snapshot_is_ancestor(c, le32_to_cpu(subvol.snapshot), root_id), c, snapshot_tree_to_wrong_subvol, |