bcachefs: Better bch2_trans_copy_iter()

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

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 4baa4ab3aa4b35f776a46be9b1b62a9f55a2291e..5280e77f548f33498d317519be8d28efb2b226b0 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1606,7 +1606,6 @@ static inline void bch2_btree_iter_init(struct btree_trans *trans,
        for (i = 0; i < ARRAY_SIZE(iter->l); i++)
                iter->l[i].b            = NULL;
        iter->l[iter->level].b          = BTREE_ITER_NOT_END;
-       iter->next                      = iter;
 
        prefetch(c->btree_roots[btree_id].b);
 }
@@ -1638,11 +1637,11 @@ static void bch2_btree_iter_link(struct btree_iter *iter, struct btree_iter *new
        iter->next = new;
 }
 
-void bch2_btree_iter_copy(struct btree_iter *dst, struct btree_iter *src)
+static void __bch2_btree_iter_copy(struct btree_iter *dst,
+                                  struct btree_iter *src)
 {
        unsigned i;
 
-       __bch2_btree_iter_unlock(dst);
        memcpy(dst, src, offsetof(struct btree_iter, next));
 
        for (i = 0; i < BTREE_MAX_DEPTH; i++)
@@ -1651,6 +1650,12 @@ void bch2_btree_iter_copy(struct btree_iter *dst, struct btree_iter *src)
                                           __btree_lock_want(dst, i));
 }
 
+void bch2_btree_iter_copy(struct btree_iter *dst, struct btree_iter *src)
+{
+       __bch2_btree_iter_unlock(dst);
+       __bch2_btree_iter_copy(dst, src);
+}
+
 /* new transactional stuff: */
 
 static void btree_trans_verify(struct btree_trans *trans)
@@ -1789,6 +1794,35 @@ void bch2_trans_preload_iters(struct btree_trans *trans)
        btree_trans_realloc_iters(trans, BTREE_ITER_MAX);
 }
 
+static int btree_trans_iter_alloc(struct btree_trans *trans)
+{
+       struct btree_iter *iter;
+       unsigned idx = ffz(trans->iters_linked);
+
+       if (idx < trans->nr_iters)
+               goto got_slot;
+
+       if (trans->nr_iters == trans->size) {
+               int ret = btree_trans_realloc_iters(trans, trans->size * 2);
+               if (ret)
+                       return ret;
+       }
+
+       idx = trans->nr_iters++;
+       BUG_ON(trans->nr_iters > trans->size);
+got_slot:
+       iter = &trans->iters[idx];
+       iter->next = iter;
+
+       BUG_ON(trans->iters_linked & (1ULL << idx));
+
+       if (trans->iters_linked)
+               bch2_btree_iter_link(&trans->iters[__ffs(trans->iters_linked)],
+                                    &trans->iters[idx]);
+       trans->iters_linked |= 1ULL << idx;
+       return idx;
+}
+
 static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
                                                 unsigned btree_id, struct bpos pos,
                                                 unsigned flags, u64 iter_id)
@@ -1799,6 +1833,9 @@ static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
        BUG_ON(trans->nr_iters > BTREE_ITER_MAX);
 
        for (idx = 0; idx < trans->nr_iters; idx++) {
+               if (!(trans->iters_linked & (1ULL << idx)))
+                       continue;
+
                iter = &trans->iters[idx];
                if (iter_id
                    ? iter->id == iter_id
@@ -1809,22 +1846,10 @@ static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
        idx = -1;
 found:
        if (idx < 0) {
-               idx = ffz(trans->iters_linked);
-               if (idx < trans->nr_iters)
-                       goto got_slot;
+               idx = btree_trans_iter_alloc(trans);
+               if (idx < 0)
+                       return ERR_PTR(idx);
 
-               BUG_ON(trans->nr_iters > trans->size);
-
-               if (trans->nr_iters == trans->size) {
-                       int ret = btree_trans_realloc_iters(trans,
-                                                       trans->size * 2);
-                       if (ret)
-                               return ERR_PTR(ret);
-               }
-
-               idx = trans->nr_iters++;
-               BUG_ON(trans->nr_iters > trans->size);
-got_slot:
                iter = &trans->iters[idx];
                iter->id = iter_id;
 
@@ -1841,13 +1866,6 @@ got_slot:
        trans->iters_live       |= 1ULL << idx;
        trans->iters_touched    |= 1ULL << idx;
 
-       if (trans->iters_linked &&
-           !(trans->iters_linked & (1 << idx)))
-               bch2_btree_iter_link(&trans->iters[__ffs(trans->iters_linked)],
-                                    iter);
-
-       trans->iters_linked |= 1ULL << idx;
-
        btree_trans_verify(trans);
 
        BUG_ON(iter->btree_id != btree_id);
@@ -1894,20 +1912,22 @@ struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *trans,
        return iter;
 }
 
-struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *trans,
-                                         struct btree_iter *src,
-                                         u64 iter_id)
+struct btree_iter *bch2_trans_copy_iter(struct btree_trans *trans,
+                                       struct btree_iter *src)
 {
-       struct btree_iter *iter =
-               __btree_trans_get_iter(trans, src->btree_id,
-                                      POS_MIN, src->flags, iter_id);
+       int idx;
 
-       if (!IS_ERR(iter)) {
-               trans->iters_unlink_on_restart |=
-                       1ULL << btree_trans_iter_idx(trans, iter);
-               bch2_btree_iter_copy(iter, src);
-       }
-       return iter;
+       idx = btree_trans_iter_alloc(trans);
+       if (idx < 0)
+               return ERR_PTR(idx);
+
+       trans->iters_live               |= 1ULL << idx;
+       trans->iters_touched            |= 1ULL << idx;
+       trans->iters_unlink_on_restart  |= 1ULL << idx;
+
+       __bch2_btree_iter_copy(&trans->iters[idx], src);
+
+       return &trans->iters[idx];
 }
 
 void *bch2_trans_kmalloc(struct btree_trans *trans,

diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 285490697a96da31fb3571e02c6e3f9982d51343..4be472e4531039deaebd34bfe7ecb349e403c58c 100644 (file)
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -268,8 +268,8 @@ void bch2_trans_unlink_iters(struct btree_trans *, u64);
 
 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
                                         struct bpos, unsigned, u64);
-struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
-                                         struct btree_iter *, u64);
+struct btree_iter *bch2_trans_copy_iter(struct btree_trans *,
+                                       struct btree_iter *);
 
 static __always_inline u64 __btree_iter_id(void)
 {
@@ -290,13 +290,6 @@ bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
                                     __btree_iter_id());
 }
 
-static __always_inline struct btree_iter *
-bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
-{
-
-       return __bch2_trans_copy_iter(trans, src, __btree_iter_id());
-}
-
 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
                                enum btree_id, struct bpos,
                                unsigned, unsigned, unsigned);