To help ameloriate issues with peek operations having to skip over deletions in the journal - just bail out if all we're doing is prefetching btree nodes.
Since btree node prefetching runs every time we iterate to a new node, and has to sequentially scan ahead, this avoids another O(n^2). Signed-off-by: Kent Overstreet <[email protected]> --- fs/bcachefs/btree_iter.c | 2 ++ fs/bcachefs/btree_journal_iter.c | 9 ++++++++- fs/bcachefs/btree_journal_iter.h | 1 + 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c index ed74f0655d98..89f9665ce70d 100644 --- a/fs/bcachefs/btree_iter.c +++ b/fs/bcachefs/btree_iter.c @@ -825,6 +825,8 @@ static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *p bch2_bkey_buf_init(&tmp); + jiter->fail_if_too_many_whiteouts = true; + while (nr-- && !ret) { if (!bch2_btree_node_relock(trans, path, path->level)) break; diff --git a/fs/bcachefs/btree_journal_iter.c b/fs/bcachefs/btree_journal_iter.c index dbc9bc233cca..93a5f758d419 100644 --- a/fs/bcachefs/btree_journal_iter.c +++ b/fs/bcachefs/btree_journal_iter.c @@ -426,6 +426,7 @@ static void btree_and_journal_iter_prefetch(struct btree_and_journal_iter *_iter : (level > 1 ? 1 : 16); iter.prefetch = false; + iter.fail_if_too_many_whiteouts = true; bch2_bkey_buf_init(&tmp); while (nr--) { @@ -444,12 +445,18 @@ static void btree_and_journal_iter_prefetch(struct btree_and_journal_iter *_iter struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter) { struct bkey_s_c btree_k, journal_k = bkey_s_c_null, ret; + size_t iters = 0; if (iter->prefetch && iter->journal.level) btree_and_journal_iter_prefetch(iter); -again: + if (iter->at_end) return bkey_s_c_null; +again: + iters++; + + if (iters > 20 && iter->fail_if_too_many_whiteouts) + return bkey_s_c_null; while ((btree_k = bch2_journal_iter_peek_btree(iter)).k && bpos_lt(btree_k.k->p, iter->pos)) diff --git a/fs/bcachefs/btree_journal_iter.h b/fs/bcachefs/btree_journal_iter.h index 118ada4cdd1b..9e8f8ab1c6ff 100644 --- a/fs/bcachefs/btree_journal_iter.h +++ b/fs/bcachefs/btree_journal_iter.h @@ -26,6 +26,7 @@ struct btree_and_journal_iter { struct bpos pos; bool at_end; bool prefetch; + bool fail_if_too_many_whiteouts; }; static inline int __journal_key_btree_cmp(enum btree_id l_btree_id, -- 2.45.2
