bcachefs: Kill snapshot_t->equiv

Now entirely dead code.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c
index 0d60251946f1363016d42a1bf84494ce2c845dfe..8e6d85504efbd9e54b9df0119f15fddfa5281f37 100644 (file)
--- a/fs/bcachefs/snapshot.c
+++ b/fs/bcachefs/snapshot.c
@@ -280,23 +280,6 @@ fsck_err:
        return ret;
 }
 
-static void __set_is_ancestor_bitmap(struct bch_fs *c, u32 id)
-{
-       struct snapshot_t *t = snapshot_t_mut(c, id);
-       u32 parent = id;
-
-       while ((parent = bch2_snapshot_parent_early(c, parent)) &&
-              parent - id - 1 < IS_ANCESTOR_BITMAP)
-               __set_bit(parent - id - 1, t->is_ancestor);
-}
-
-static void set_is_ancestor_bitmap(struct bch_fs *c, u32 id)
-{
-       mutex_lock(&c->snapshot_table_lock);
-       __set_is_ancestor_bitmap(c, id);
-       mutex_unlock(&c->snapshot_table_lock);
-}
-
 static int __bch2_mark_snapshot(struct btree_trans *trans,
                       enum btree_id btree, unsigned level,
                       struct bkey_s_c old, struct bkey_s_c new,
@@ -337,7 +320,11 @@ static int __bch2_mark_snapshot(struct btree_trans *trans,
                        t->skip[2]      = 0;
                }
 
-               __set_is_ancestor_bitmap(c, id);
+               u32 parent = id;
+
+               while ((parent = bch2_snapshot_parent_early(c, parent)) &&
+                      parent - id - 1 < IS_ANCESTOR_BITMAP)
+                       __set_bit(parent - id - 1, t->is_ancestor);
 
                if (BCH_SNAPSHOT_DELETED(s.v)) {
                        set_bit(BCH_FS_need_delete_dead_snapshots, &c->flags);
@@ -367,70 +354,6 @@ int bch2_snapshot_lookup(struct btree_trans *trans, u32 id,
                                       BTREE_ITER_with_updates, snapshot, s);
 }
 
-static int bch2_snapshot_live(struct btree_trans *trans, u32 id)
-{
-       struct bch_snapshot v;
-       int ret;
-
-       if (!id)
-               return 0;
-
-       ret = bch2_snapshot_lookup(trans, id, &v);
-       if (bch2_err_matches(ret, ENOENT))
-               bch_err(trans->c, "snapshot node %u not found", id);
-       if (ret)
-               return ret;
-
-       return !BCH_SNAPSHOT_DELETED(&v);
-}
-
-/*
- * If @k is a snapshot with just one live child, it's part of a linear chain,
- * which we consider to be an equivalence class: and then after snapshot
- * deletion cleanup, there should only be a single key at a given position in
- * this equivalence class.
- *
- * This sets the equivalence class of @k to be the child's equivalence class, if
- * it's part of such a linear chain: this correctly sets equivalence classes on
- * startup if we run leaf to root (i.e. in natural key order).
- */
-static int bch2_snapshot_set_equiv(struct btree_trans *trans, struct bkey_s_c k)
-{
-       struct bch_fs *c = trans->c;
-       unsigned i, nr_live = 0, live_idx = 0;
-       struct bkey_s_c_snapshot snap;
-       u32 id = k.k->p.offset, child[2];
-
-       if (k.k->type != KEY_TYPE_snapshot)
-               return 0;
-
-       snap = bkey_s_c_to_snapshot(k);
-
-       child[0] = le32_to_cpu(snap.v->children[0]);
-       child[1] = le32_to_cpu(snap.v->children[1]);
-
-       for (i = 0; i < 2; i++) {
-               int ret = bch2_snapshot_live(trans, child[i]);
-
-               if (ret < 0)
-                       return ret;
-
-               if (ret)
-                       live_idx = i;
-               nr_live += ret;
-       }
-
-       mutex_lock(&c->snapshot_table_lock);
-
-       snapshot_t_mut(c, id)->equiv = nr_live == 1
-               ? snapshot_t_mut(c, child[live_idx])->equiv
-               : id;
-
-       mutex_unlock(&c->snapshot_table_lock);
-
-       return 0;
-}
-
 /* fsck: */
 
 static u32 bch2_snapshot_child(struct bch_fs *c, u32 id, unsigned child)
@@ -964,8 +887,7 @@ static int check_snapshot_exists(struct btree_trans *trans, u32 id)
 
        return  bch2_btree_insert_trans(trans, BTREE_ID_snapshots, &snapshot->k_i, 0) ?:
                bch2_mark_snapshot(trans, BTREE_ID_snapshots, 0,
-                                  bkey_s_c_null, bkey_i_to_s(&snapshot->k_i), 0) ?:
-               bch2_snapshot_set_equiv(trans, bkey_i_to_s_c(&snapshot->k_i));
+                                  bkey_s_c_null, bkey_i_to_s(&snapshot->k_i), 0);
 }
 
 /* Figure out which snapshot nodes belong in the same tree: */
@@ -1309,10 +1231,6 @@ static int create_snapids(struct btree_trans *trans, u32 parent, u32 tree,
                        goto err;
 
                new_snapids[i]  = iter.pos.offset;
-
-               mutex_lock(&c->snapshot_table_lock);
-               snapshot_t_mut(c, new_snapids[i])->equiv = new_snapids[i];
-               mutex_unlock(&c->snapshot_table_lock);
        }
 err:
        bch2_trans_iter_exit(trans, &iter);
@@ -1774,15 +1692,15 @@ static int bch2_check_snapshot_needs_deletion(struct btree_trans *trans, struct
 
 int bch2_snapshots_read(struct bch_fs *c)
 {
+       /*
+        * Initializing the is_ancestor bitmaps requires ancestors to already be
+        * initialized - so mark in reverse:
+        */
        int ret = bch2_trans_run(c,
-               for_each_btree_key(trans, iter, BTREE_ID_snapshots,
-                                  POS_MIN, 0, k,
+               for_each_btree_key_reverse(trans, iter, BTREE_ID_snapshots,
+                                  POS_MAX, 0, k,
                        __bch2_mark_snapshot(trans, BTREE_ID_snapshots, 0, bkey_s_c_null, k, 0) ?:
-                       bch2_snapshot_set_equiv(trans, k) ?:
-                       bch2_check_snapshot_needs_deletion(trans, k)) ?:
-               for_each_btree_key(trans, iter, BTREE_ID_snapshots,
-                                  POS_MIN, 0, k,
-                          (set_is_ancestor_bitmap(c, k.k->p.offset), 0)));
+                       bch2_check_snapshot_needs_deletion(trans, k)));
        bch_err_fn(c, ret);
 
        /*

diff --git a/fs/bcachefs/snapshot.h b/fs/bcachefs/snapshot.h
index 3ff0ffa774f593303bdbedca63392f8d9df268be..00373cf32e7bcfe977b5df8932e808791e39a169 100644 (file)
--- a/fs/bcachefs/snapshot.h
+++ b/fs/bcachefs/snapshot.h
@@ -134,21 +134,6 @@ static inline bool bch2_snapshot_exists(struct bch_fs *c, u32 id)
        return ret;
 }
 
-static inline u32 __bch2_snapshot_equiv(struct bch_fs *c, u32 id)
-{
-       const struct snapshot_t *s = snapshot_t(c, id);
-       return s ? s->equiv : 0;
-}
-
-static inline u32 bch2_snapshot_equiv(struct bch_fs *c, u32 id)
-{
-       rcu_read_lock();
-       id = __bch2_snapshot_equiv(c, id);
-       rcu_read_unlock();
-
-       return id;
-}
-
 static inline int bch2_snapshot_is_internal_node(struct bch_fs *c, u32 id)
 {
        rcu_read_lock();

diff --git a/fs/bcachefs/subvolume_types.h b/fs/bcachefs/subvolume_types.h
index 8a7f7e87c381de71257fc7e9de776b30c20ea37f..1549d6daf7af5b78e4b7449a49ef292a2e529de1 100644 (file)
--- a/fs/bcachefs/subvolume_types.h
+++ b/fs/bcachefs/subvolume_types.h
@@ -16,7 +16,6 @@ struct snapshot_t {
        u32                     children[2];
        u32                     subvol; /* Nonzero only if a subvolume points to this node: */
        u32                     tree;
-       u32                     equiv;
        unsigned long           is_ancestor[BITS_TO_LONGS(IS_ANCESTOR_BITMAP)];
 };