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Diffstat (limited to 'libbcachefs/snapshot.c')
-rw-r--r--libbcachefs/snapshot.c61
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,