diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-11-17 14:39:46 -0500 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-12-21 01:36:18 -0500 |
| commit | 854724d116cbd1145cd3888239a5cc7ea44d8cdc (patch) | |
| tree | 90e201455f947ff44b43abc0ed560ec97ecd8f95 | |
| parent | 06d7a56fe0bfc4f8c17bff6ca12d8bdd33e9f7e8 (diff) | |
bcachefs: btree_and_journal_iter: don't iterate over too many whiteouts when prefetching
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 <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/btree_iter.c | 2 | ||||
| -rw-r--r-- | fs/bcachefs/btree_journal_iter.c | 7 | ||||
| -rw-r--r-- | fs/bcachefs/btree_journal_iter.h | 1 |
3 files changed, 10 insertions, 0 deletions
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..cc7f5fad90c6 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--) { @@ -444,6 +445,7 @@ 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); @@ -451,6 +453,11 @@ again: if (iter->at_end) return bkey_s_c_null; + 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)) bch2_journal_iter_advance_btree(iter); 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, |