We've been seeing some livelock-ish behavior in the index update part of
the main write path, and while we've got low level btree path
tracepoints, we've been lacking high level btree iterator tracepoints.
Signed-off-by: Kent Overstreet <kent.overstr...@linux.dev>
---
fs/bcachefs/btree_iter.c | 67 +++++++++++++++++++++++++++++++++++++---
fs/bcachefs/trace.h | 20 ++++++++++++
2 files changed, 82 insertions(+), 5 deletions(-)
diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index b78403376c07..b586ecf2fdfa 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -2326,6 +2326,20 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct
btree_trans *trans, struct
}
bch2_btree_iter_verify(trans, iter);
+
+ if (trace___btree_iter_peek_enabled()) {
+ CLASS(printbuf, buf)();
+
+ int ret = bkey_err(k);
+ if (ret)
+ prt_str(&buf, bch2_err_str(ret));
+ else if (k.k)
+ bch2_bkey_val_to_text(&buf, trans->c, k);
+ else
+ prt_str(&buf, "(null)");
+ trace___btree_iter_peek(trans->c, buf.buf);
+ }
+
return k;
}
@@ -2484,6 +2498,19 @@ struct bkey_s_c bch2_btree_iter_peek_max(struct
btree_trans *trans, struct btree
bch2_btree_iter_verify_entry_exit(iter);
+ if (trace_btree_iter_peek_max_enabled()) {
+ CLASS(printbuf, buf)();
+
+ int ret = bkey_err(k);
+ if (ret)
+ prt_str(&buf, bch2_err_str(ret));
+ else if (k.k)
+ bch2_bkey_val_to_text(&buf, trans->c, k);
+ else
+ prt_str(&buf, "(null)");
+ trace_btree_iter_peek_max(trans->c, buf.buf);
+ }
+
return k;
end:
bch2_btree_iter_set_pos(trans, iter, end);
@@ -2724,6 +2751,19 @@ struct bkey_s_c bch2_btree_iter_peek_prev_min(struct
btree_trans *trans, struct
bch2_btree_iter_verify_entry_exit(iter);
bch2_btree_iter_verify(trans, iter);
+
+ if (trace_btree_iter_peek_prev_min_enabled()) {
+ CLASS(printbuf, buf)();
+
+ int ret = bkey_err(k);
+ if (ret)
+ prt_str(&buf, bch2_err_str(ret));
+ else if (k.k)
+ bch2_bkey_val_to_text(&buf, trans->c, k);
+ else
+ prt_str(&buf, "(null)");
+ trace_btree_iter_peek_prev_min(trans->c, buf.buf);
+ }
return k;
end:
bch2_btree_iter_set_pos(trans, iter, end);
@@ -2767,8 +2807,10 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct
btree_trans *trans, struct btre
/* extents can't span inode numbers: */
if ((iter->flags & BTREE_ITER_is_extents) &&
unlikely(iter->pos.offset == KEY_OFFSET_MAX)) {
- if (iter->pos.inode == KEY_INODE_MAX)
- return bkey_s_c_null;
+ if (iter->pos.inode == KEY_INODE_MAX) {
+ k = bkey_s_c_null;
+ goto out2;
+ }
bch2_btree_iter_set_pos(trans, iter,
bpos_nosnap_successor(iter->pos));
}
@@ -2785,8 +2827,10 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct
btree_trans *trans, struct btre
}
struct btree_path *path = btree_iter_path(trans, iter);
- if (unlikely(!btree_path_node(path, path->level)))
- return bkey_s_c_null;
+ if (unlikely(!btree_path_node(path, path->level))) {
+ k = bkey_s_c_null;
+ goto out2;
+ }
btree_path_set_should_be_locked(trans, path);
@@ -2879,7 +2923,20 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct
btree_trans *trans, struct btre
bch2_btree_iter_verify(trans, iter);
ret = bch2_btree_iter_verify_ret(trans, iter, k);
if (unlikely(ret))
- return bkey_s_c_err(ret);
+ k = bkey_s_c_err(ret);
+out2:
+ if (trace_btree_iter_peek_slot_enabled()) {
+ CLASS(printbuf, buf)();
+
+ int ret = bkey_err(k);
+ if (ret)
+ prt_str(&buf, bch2_err_str(ret));
+ else if (k.k)
+ bch2_bkey_val_to_text(&buf, trans->c, k);
+ else
+ prt_str(&buf, "(null)");
+ trace_btree_iter_peek_slot(trans->c, buf.buf);
+ }
return k;
}
diff --git a/fs/bcachefs/trace.h b/fs/bcachefs/trace.h
index 41efebdd06ef..e759c9ff3965 100644
--- a/fs/bcachefs/trace.h
+++ b/fs/bcachefs/trace.h
@@ -1495,6 +1495,26 @@ DEFINE_EVENT(fs_str, extent_trim_atomic,
TP_ARGS(c, str)
);
+DEFINE_EVENT(fs_str, btree_iter_peek_slot,
+ TP_PROTO(struct bch_fs *c, const char *str),
+ TP_ARGS(c, str)
+);
+
+DEFINE_EVENT(fs_str, __btree_iter_peek,
+ TP_PROTO(struct bch_fs *c, const char *str),
+ TP_ARGS(c, str)
+);
+
+DEFINE_EVENT(fs_str, btree_iter_peek_max,
+ TP_PROTO(struct bch_fs *c, const char *str),
+ TP_ARGS(c, str)
+);
+
+DEFINE_EVENT(fs_str, btree_iter_peek_prev_min,
+ TP_PROTO(struct bch_fs *c, const char *str),
+ TP_ARGS(c, str)
+);
+
#ifdef CONFIG_BCACHEFS_PATH_TRACEPOINTS
TRACE_EVENT(update_by_path,
--
2.50.0
