bcachefs: Reduce stack usage in data_update_index_update()

Separate tracepoint message generation and other slowpath code into
non-inline functions, and use bch2_trans_log_str() instead of using a
printbuf for our journal message.

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

diff --git a/fs/bcachefs/data_update.c b/fs/bcachefs/data_update.c
index ef648a6..c34e5b8 100644 (file)
--- a/fs/bcachefs/data_update.c
+++ b/fs/bcachefs/data_update.c
@@ -100,9 +100,10 @@ static bool bkey_nocow_lock(struct bch_fs *c, struct moving_context *ctxt, struc
        return true;
 }
 
-static noinline void trace_io_move_finish2(struct data_update *u,
-                                              struct bkey_i *new,
-                                              struct bkey_i *insert)
+noinline_for_stack
+static void trace_io_move_finish2(struct data_update *u,
+                                 struct bkey_i *new,
+                                 struct bkey_i *insert)
 {
        struct bch_fs *c = u->op.c;
        struct printbuf buf = PRINTBUF;
@@ -124,6 +125,7 @@ static noinline void trace_io_move_finish2(struct data_update *u,
        printbuf_exit(&buf);
 }
 
+noinline_for_stack
 static void trace_io_move_fail2(struct data_update *m,
                         struct bkey_s_c new,
                         struct bkey_s_c wrote,
@@ -179,19 +181,84 @@ static void trace_io_move_fail2(struct data_update *m,
        printbuf_exit(&buf);
 }
 
+noinline_for_stack
+static void trace_data_update2(struct data_update *m,
+                              struct bkey_s_c old, struct bkey_s_c k,
+                              struct bkey_i *insert)
+{
+       struct bch_fs *c = m->op.c;
+       struct printbuf buf = PRINTBUF;
+
+       prt_str(&buf, "\nold: ");
+       bch2_bkey_val_to_text(&buf, c, old);
+       prt_str(&buf, "\nk:   ");
+       bch2_bkey_val_to_text(&buf, c, k);
+       prt_str(&buf, "\nnew: ");
+       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
+
+       trace_data_update(c, buf.buf);
+       printbuf_exit(&buf);
+}
+
+noinline_for_stack
+static void trace_io_move_created_rebalance2(struct data_update *m,
+                                            struct bkey_s_c old, struct bkey_s_c k,
+                                            struct bkey_i *insert)
+{
+       struct bch_fs *c = m->op.c;
+       struct printbuf buf = PRINTBUF;
+
+       bch2_data_update_opts_to_text(&buf, c, &m->op.opts, &m->data_opts);
+
+       prt_str(&buf, "\nold: ");
+       bch2_bkey_val_to_text(&buf, c, old);
+       prt_str(&buf, "\nk:   ");
+       bch2_bkey_val_to_text(&buf, c, k);
+       prt_str(&buf, "\nnew: ");
+       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
+
+       trace_io_move_created_rebalance(c, buf.buf);
+       printbuf_exit(&buf);
+
+       this_cpu_inc(c->counters[BCH_COUNTER_io_move_created_rebalance]);
+}
+
+noinline_for_stack
+static int data_update_invalid_bkey(struct data_update *m,
+                                   struct bkey_s_c old, struct bkey_s_c k,
+                                   struct bkey_i *insert)
+{
+       struct bch_fs *c = m->op.c;
+       struct printbuf buf = PRINTBUF;
+       bch2_log_msg_start(c, &buf);
+
+       prt_str(&buf, "about to insert invalid key in data update path");
+       prt_printf(&buf, "\nop.nonce: %u", m->op.nonce);
+       prt_str(&buf, "\nold: ");
+       bch2_bkey_val_to_text(&buf, c, old);
+       prt_str(&buf, "\nk:   ");
+       bch2_bkey_val_to_text(&buf, c, k);
+       prt_str(&buf, "\nnew: ");
+       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
+
+       bch2_fs_emergency_read_only2(c, &buf);
+
+       bch2_print_str(c, KERN_ERR, buf.buf);
+       printbuf_exit(&buf);
+
+       return -BCH_ERR_invalid_bkey;
+}
+
 static int __bch2_data_update_index_update(struct btree_trans *trans,
                                           struct bch_write_op *op)
 {
        struct bch_fs *c = op->c;
        struct btree_iter iter;
-       struct data_update *m =
-               container_of(op, struct data_update, op);
-       struct keylist *keys = &op->insert_keys;
-       struct printbuf journal_msg = PRINTBUF;
+       struct data_update *m = container_of(op, struct data_update, op);
        int ret = 0;
 
        bch2_trans_iter_init(trans, &iter, m->btree_id,
-                            bkey_start_pos(&bch2_keylist_front(keys)->k),
+                            bkey_start_pos(&bch2_keylist_front(&op->insert_keys)->k),
                             BTREE_ITER_slots|BTREE_ITER_intent);
 
        while (1) {
@@ -216,11 +283,11 @@ static int __bch2_data_update_index_update(struct btree_trans *trans,
                if (ret)
                        goto err;
 
-               new = bkey_i_to_extent(bch2_keylist_front(keys));
+               new = bkey_i_to_extent(bch2_keylist_front(&op->insert_keys));
 
                if (!bch2_extents_match(k, old)) {
                        trace_io_move_fail2(m, k, bkey_i_to_s_c(&new->k_i),
-                                               NULL, "no match:");
+                                           NULL, "no match:");
                        goto nowork;
                }
 
@@ -239,7 +306,7 @@ static int __bch2_data_update_index_update(struct btree_trans *trans,
                if (ret)
                        goto err;
 
-               bkey_copy(&new->k_i, bch2_keylist_front(keys));
+               bkey_copy(&new->k_i, bch2_keylist_front(&op->insert_keys));
                bch2_cut_front(iter.pos, &new->k_i);
 
                bch2_cut_front(iter.pos,        insert);
@@ -353,31 +420,11 @@ restart_drop_extra_replicas:
                                                        .flags  = BCH_VALIDATE_commit,
                                                 });
                if (unlikely(invalid)) {
-                       struct printbuf buf = PRINTBUF;
-                       bch2_log_msg_start(c, &buf);
-
-                       prt_str(&buf, "about to insert invalid key in data update path");
-                       prt_printf(&buf, "\nop.nonce: %u", m->op.nonce);
-                       prt_str(&buf, "\nold: ");
-                       bch2_bkey_val_to_text(&buf, c, old);
-                       prt_str(&buf, "\nk:   ");
-                       bch2_bkey_val_to_text(&buf, c, k);
-                       prt_str(&buf, "\nnew: ");
-                       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
-
-                       bch2_fs_emergency_read_only2(c, &buf);
-
-                       bch2_print_str(c, KERN_ERR, buf.buf);
-                       printbuf_exit(&buf);
-
-                       ret = -BCH_ERR_invalid_bkey;
+                       ret = data_update_invalid_bkey(m, old, k, insert);
                        goto out;
                }
 
-               printbuf_reset(&journal_msg);
-               prt_str(&journal_msg, bch2_data_update_type_strs[m->type]);
-
-               ret =   bch2_trans_log_msg(trans, &journal_msg) ?:
+               ret =   bch2_trans_log_str(trans, bch2_data_update_type_strs[m->type]) ?:
                        bch2_trans_log_bkey(trans, m->btree_id, 0, m->k.k) ?:
                        bch2_insert_snapshot_whiteouts(trans, m->btree_id,
                                                k.k->p, bkey_start_pos(&insert->k)) ?:
@@ -389,38 +436,12 @@ restart_drop_extra_replicas:
                if (ret)
                        goto err;
 
-               if (trace_data_update_enabled()) {
-                       struct printbuf buf = PRINTBUF;
-
-                       prt_str(&buf, "\nold: ");
-                       bch2_bkey_val_to_text(&buf, c, old);
-                       prt_str(&buf, "\nk:   ");
-                       bch2_bkey_val_to_text(&buf, c, k);
-                       prt_str(&buf, "\nnew: ");
-                       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
-
-                       trace_data_update(c, buf.buf);
-                       printbuf_exit(&buf);
-               }
+               if (trace_data_update_enabled())
+                       trace_data_update2(m, old, k, insert);
 
                if (bch2_bkey_sectors_need_rebalance(c, bkey_i_to_s_c(insert)) * k.k->size >
-                   bch2_bkey_sectors_need_rebalance(c, k) * insert->k.size) {
-                       struct printbuf buf = PRINTBUF;
-
-                       bch2_data_update_opts_to_text(&buf, c, &m->op.opts, &m->data_opts);
-
-                       prt_str(&buf, "\nold: ");
-                       bch2_bkey_val_to_text(&buf, c, old);
-                       prt_str(&buf, "\nk:   ");
-                       bch2_bkey_val_to_text(&buf, c, k);
-                       prt_str(&buf, "\nnew: ");
-                       bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
-
-                       trace_io_move_created_rebalance(c, buf.buf);
-                       printbuf_exit(&buf);
-
-                       this_cpu_inc(c->counters[BCH_COUNTER_io_move_created_rebalance]);
-               }
+                   bch2_bkey_sectors_need_rebalance(c, k) * insert->k.size)
+                       trace_io_move_created_rebalance2(m, old, k, insert);
 
                ret =   bch2_trans_commit(trans, &op->res,
                                NULL,
@@ -441,9 +462,9 @@ err:
                if (ret)
                        break;
 next:
-               while (bkey_ge(iter.pos, bch2_keylist_front(keys)->k.p)) {
-                       bch2_keylist_pop_front(keys);
-                       if (bch2_keylist_empty(keys))
+               while (bkey_ge(iter.pos, bch2_keylist_front(&op->insert_keys)->k.p)) {
+                       bch2_keylist_pop_front(&op->insert_keys);
+                       if (bch2_keylist_empty(&op->insert_keys))
                                goto out;
                }
                continue;
@@ -461,7 +482,6 @@ nowork:
                goto next;
        }
 out:
-       printbuf_exit(&journal_msg);
        bch2_trans_iter_exit(trans, &iter);
        BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
        return ret;