bcachefs: wb_flush_one_slowpath()

A bit of refactoring for better inlining in the main btree write buffer
flush path.

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

diff --git a/fs/bcachefs/btree_write_buffer.c b/fs/bcachefs/btree_write_buffer.c
index 6a19156804079d1a0538e2cba7e0f8a50ba0fdb8..9470d465718207e2a64c9c72c90c516dac5ecadd 100644 (file)
--- a/fs/bcachefs/btree_write_buffer.c
+++ b/fs/bcachefs/btree_write_buffer.c
@@ -33,17 +33,32 @@ static int btree_write_buffered_journal_cmp(const void *_l, const void *_r)
        return  cmp_int(l->journal_seq, r->journal_seq);
 }
 
-static int bch2_btree_write_buffer_flush_one(struct btree_trans *trans,
-                                            struct btree_iter *iter,
-                                            struct btree_write_buffered_key *wb,
-                                            unsigned commit_flags,
-                                            bool *write_locked,
-                                            size_t *fast)
+static noinline int wb_flush_one_slowpath(struct btree_trans *trans,
+                                         struct btree_iter *iter,
+                                         struct btree_write_buffered_key *wb)
+{
+       bch2_btree_node_unlock_write(trans, iter->path, iter->path->l[0].b);
+
+       trans->journal_res.seq = wb->journal_seq;
+
+       return bch2_trans_update(trans, iter, &wb->k,
+                                BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+               bch2_trans_commit(trans, NULL, NULL,
+                                 BCH_TRANS_COMMIT_no_enospc|
+                                 BCH_TRANS_COMMIT_no_check_rw|
+                                 BCH_TRANS_COMMIT_no_journal_res|
+                                 BCH_TRANS_COMMIT_journal_reclaim);
+}
+
+static inline int wb_flush_one(struct btree_trans *trans, struct btree_iter *iter,
+                              struct btree_write_buffered_key *wb,
+                              bool *write_locked, size_t *fast)
 {
        struct bch_fs *c = trans->c;
        struct btree_path *path;
        int ret;
 
+       EBUG_ON(!wb->journal_seq);
        ret = bch2_btree_iter_traverse(iter);
        if (ret)
                return ret;
@@ -66,26 +81,14 @@ static int bch2_btree_write_buffer_flush_one(struct btree_trans *trans,
                *write_locked = true;
        }
 
-       if (!bch2_btree_node_insert_fits(c, path->l[0].b, wb->k.k.u64s)) {
-               bch2_btree_node_unlock_write(trans, path, path->l[0].b);
+       if (unlikely(!bch2_btree_node_insert_fits(c, path->l[0].b, wb->k.k.u64s))) {
                *write_locked = false;
-               goto trans_commit;
+               return wb_flush_one_slowpath(trans, iter, wb);
        }
 
        bch2_btree_insert_key_leaf(trans, path, &wb->k, wb->journal_seq);
        (*fast)++;
        return 0;
-trans_commit:
-       trans->journal_res.seq = wb->journal_seq;
-
-       return  bch2_trans_update(trans, iter, &wb->k,
-                                 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
-               bch2_trans_commit(trans, NULL, NULL,
-                                 commit_flags|
-                                 BCH_TRANS_COMMIT_no_check_rw|
-                                 BCH_TRANS_COMMIT_no_enospc|
-                                 BCH_TRANS_COMMIT_no_journal_res|
-                                 BCH_TRANS_COMMIT_journal_reclaim);
 }
 
 static union btree_write_buffer_state btree_write_buffer_switch(struct btree_write_buffer *wb)
@@ -206,20 +209,18 @@ int bch2_btree_write_buffer_flush_locked(struct btree_trans *trans)
                iter.path->preserve = false;
 
                do {
-                       ret = bch2_btree_write_buffer_flush_one(trans, &iter, i, 0,
-                                                               &write_locked, &fast);
+                       ret = wb_flush_one(trans, &iter, i, &write_locked, &fast);
                        if (!write_locked)
                                bch2_trans_begin(trans);
                } while (bch2_err_matches(ret, BCH_ERR_transaction_restart));
 
-               if (ret == -BCH_ERR_journal_reclaim_would_deadlock) {
+               if (!ret) {
+                       i->journal_seq = 0;
+               } else if (ret == -BCH_ERR_journal_reclaim_would_deadlock) {
                        slowpath++;
-                       continue;
-               }
-               if (ret)
+                       ret = 0;
+               } else
                        break;
-
-               i->journal_seq = 0;
        }
 
        if (write_locked)