On Sun, 19 May 2024, Kent Overstreet wrote:
On Wed, May 15, 2024 at 11:19:20PM -0400, Camila Alvarez wrote:
Values were left as the next possible sequence number when there were no
entries.
The fix involves updating the last_seq initial value and
setting last_empty_seq to cur_seq - 1.
I think this is correct, but we should try to come up with some better
assertions or something to make the code clearer; we don't want off by
ones to lurk so easily.
Could you give it some thought?
You're right. I think the code is written in a confusing way. In
particular it seems that cur_seq - 1 is used all over the place.
I believe we can abstract cur_seq - 1 in an independent variable (since
it represents the actual last sequence number), that should make it
clearer.
I'll share an updated version of the patch.
Thanks for the response!
Reported-by: [email protected]
Signed-off-by: Camila Alvarez <[email protected]>
---
fs/bcachefs/journal.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c
index adec8e1ea73e..3835c458eec9 100644
--- a/fs/bcachefs/journal.c
+++ b/fs/bcachefs/journal.c
@@ -1196,7 +1196,7 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
struct journal_replay *i, **_i;
struct genradix_iter iter;
bool had_entries = false;
- u64 last_seq = cur_seq, nr, seq;
+ u64 last_seq = cur_seq - 1, nr, seq;
genradix_for_each_reverse(&c->journal_entries, iter, _i) {
i = *_i;
@@ -1256,7 +1256,7 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
}
if (!had_entries)
- j->last_empty_seq = cur_seq;
+ j->last_empty_seq = cur_seq - 1;
spin_lock(&j->lock);
--
2.34.1
