bcachefs: trans->nr_paths

Start to plumb through dynamically growable btree_paths; this patch
replaces most BTREE_ITER_MAX references with trans->nr_paths.

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

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 3c45d9e195d09fb7b2b5bcf2f6ec5564da736cb4..12a357f357cd8a49e5a421e2897ec6c70a74ec9e 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1475,7 +1475,7 @@ static void bch2_trans_update_max_paths(struct btree_trans *trans)
 {
        struct btree_transaction_stats *s = btree_trans_stats(trans);
        struct printbuf buf = PRINTBUF;
-       size_t nr = bitmap_weight(trans->paths_allocated, BTREE_ITER_MAX);
+       size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths);
 
        if (!s)
                return;
@@ -1521,9 +1521,9 @@ static noinline void btree_path_overflow(struct btree_trans *trans)
 static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans,
                                                btree_path_idx_t pos)
 {
-       btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, BTREE_ITER_MAX);
+       btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths);
 
-       if (unlikely(idx == BTREE_ITER_MAX))
+       if (unlikely(idx == trans->nr_paths))
                btree_path_overflow(trans);
 
        /*
@@ -2527,7 +2527,7 @@ static void btree_trans_verify_sorted_refs(struct btree_trans *trans)
        struct btree_path *path;
        unsigned i;
 
-       BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, BTREE_ITER_MAX) - 1);
+       BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1);
 
        trans_for_each_path(trans, path, i) {
                BUG_ON(path->sorted_idx >= trans->nr_sorted);
@@ -2933,6 +2933,7 @@ got_trans:
        trans->journal_replay_not_finished =
                unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)) &&
                atomic_inc_not_zero(&c->journal_keys.ref);
+       trans->nr_paths         = ARRAY_SIZE(trans->_paths);
        trans->paths_allocated  = trans->_paths_allocated;
        trans->sorted           = trans->_sorted;
        trans->paths            = trans->_paths;

diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 0fab4952f9f771da78ad5ccb4f599929beadacf3..573c44d80cc37bb282eaff30567ccdf11f7b4334 100644 (file)
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -82,9 +82,25 @@ static inline unsigned long *trans_paths_allocated(struct btree_path *paths)
 static inline struct btree_path *
 __trans_next_path(struct btree_trans *trans, unsigned *idx)
 {
-       *idx = find_next_bit(trans->paths_allocated, BTREE_ITER_MAX, *idx);
+       unsigned long *w = trans->paths_allocated + *idx / BITS_PER_LONG;
+       /*
+        * Open coded find_next_bit(), because
+        *  - this is fast path, we can't afford the function call
+        *  - and we know that nr_paths is a multiple of BITS_PER_LONG,
+        */
+       while (*idx < trans->nr_paths) {
+               unsigned long v = *w >> (*idx & (BITS_PER_LONG - 1));
+               if (v) {
+                       *idx += __ffs(v);
+                       return trans->paths + *idx;
+               }
+
+               *idx += BITS_PER_LONG;
+               *idx &= ~(BITS_PER_LONG - 1);
+               w++;
+       }
 
-       return *idx < BTREE_ITER_MAX ? &trans->paths[*idx] : NULL;
+       return NULL;
 }
 
 /*
@@ -626,7 +642,7 @@ int __bch2_btree_trans_too_many_iters(struct btree_trans *);
 
 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 {
-       if (bitmap_weight(trans->paths_allocated, BTREE_ITER_MAX) > BTREE_ITER_MAX - 8)
+       if (bitmap_weight(trans->paths_allocated, trans->nr_paths) > BTREE_ITER_MAX - 8)
                return __bch2_btree_trans_too_many_iters(trans);
 
        return 0;

diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h
index 81f54a2c4e81443e2c504c7240a6b00dcff13a72..e4ebfc25df8e20be6beb4221fb8661ee2acd7fa9 100644 (file)
--- a/fs/bcachefs/btree_types.h
+++ b/fs/bcachefs/btree_types.h
@@ -390,6 +390,7 @@ struct btree_trans {
        unsigned                mem_bytes;
 
        btree_path_idx_t        nr_sorted;
+       btree_path_idx_t        nr_paths;
        btree_path_idx_t        nr_paths_max;
        u8                      fn_idx;
        u8                      nr_updates;

diff --git a/fs/bcachefs/btree_update.c b/fs/bcachefs/btree_update.c
index 140a44aeb3217e15debd998846cf744de13f55ba..83aa0fb8ba939412bc7c645eeeb15cb3cdae2962 100644 (file)
--- a/fs/bcachefs/btree_update.c
+++ b/fs/bcachefs/btree_update.c
@@ -386,7 +386,7 @@ bch2_trans_update_by_path(struct btree_trans *trans, btree_path_idx_t path_idx,
 
        struct btree_path *path = trans->paths + path_idx;
        EBUG_ON(!path->should_be_locked);
-       EBUG_ON(trans->nr_updates >= BTREE_ITER_MAX);
+       EBUG_ON(trans->nr_updates >= trans->nr_paths);
        EBUG_ON(!bpos_eq(k->k.p, path->pos));
 
        n = (struct btree_insert_entry) {