The discard path is supposed to issue journal flushes when there's too many buckets empty buckets that need a journal commit before they can be written to again, but at some point this code seems to have been lost.
Bring it back with a new optimization to make sure we don't issue too many journal flushes: the journal now tracks the sequence number of the most recent flush in progress, which the discard path uses when deciding which buckets need a journal flush. Signed-off-by: Kent Overstreet <[email protected]> --- fs/bcachefs/alloc_background.c | 48 ++++++++++++----------- fs/bcachefs/alloc_foreground.c | 10 +++-- fs/bcachefs/alloc_types.h | 1 + fs/bcachefs/buckets_waiting_for_journal.c | 12 +++--- fs/bcachefs/buckets_waiting_for_journal.h | 4 +- fs/bcachefs/journal.c | 1 + fs/bcachefs/journal_types.h | 1 + fs/bcachefs/trace.h | 14 ++++++- 8 files changed, 56 insertions(+), 35 deletions(-) diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c index fc2ef33b67b3..4103dae26239 100644 --- a/fs/bcachefs/alloc_background.c +++ b/fs/bcachefs/alloc_background.c @@ -1803,7 +1803,6 @@ struct discard_buckets_state { u64 open; u64 need_journal_commit; u64 discarded; - u64 need_journal_commit_this_dev; }; static int bch2_discard_one_bucket(struct btree_trans *trans, @@ -1827,11 +1826,11 @@ static int bch2_discard_one_bucket(struct btree_trans *trans, goto out; } - if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal, - c->journal.flushed_seq_ondisk, - pos.inode, pos.offset)) { - s->need_journal_commit++; - s->need_journal_commit_this_dev++; + u64 seq_ready = bch2_bucket_journal_seq_ready(&c->buckets_waiting_for_journal, + pos.inode, pos.offset); + if (seq_ready > c->journal.flushed_seq_ondisk) { + if (seq_ready > c->journal.flushing_seq) + s->need_journal_commit++; goto out; } @@ -1865,23 +1864,24 @@ static int bch2_discard_one_bucket(struct btree_trans *trans, discard_locked = true; } - if (!bkey_eq(*discard_pos_done, iter.pos) && - ca->mi.discard && !c->opts.nochanges) { - /* - * This works without any other locks because this is the only - * thread that removes items from the need_discard tree - */ - bch2_trans_unlock_long(trans); - blkdev_issue_discard(ca->disk_sb.bdev, - k.k->p.offset * ca->mi.bucket_size, - ca->mi.bucket_size, - GFP_KERNEL); - *discard_pos_done = iter.pos; + if (!bkey_eq(*discard_pos_done, iter.pos)) { s->discarded++; + *discard_pos_done = iter.pos; - ret = bch2_trans_relock_notrace(trans); - if (ret) - goto out; + if (ca->mi.discard && !c->opts.nochanges) { + /* + * This works without any other locks because this is the only + * thread that removes items from the need_discard tree + */ + bch2_trans_unlock_long(trans); + blkdev_issue_discard(ca->disk_sb.bdev, + k.k->p.offset * ca->mi.bucket_size, + ca->mi.bucket_size, + GFP_KERNEL); + ret = bch2_trans_relock_notrace(trans); + if (ret) + goto out; + } } SET_BCH_ALLOC_V4_NEED_DISCARD(&a->v, false); @@ -1929,6 +1929,10 @@ static void bch2_do_discards_work(struct work_struct *work) POS(ca->dev_idx, U64_MAX), 0, k, bch2_discard_one_bucket(trans, ca, &iter, &discard_pos_done, &s, false))); + /* XXX ratelimit journal flushes */ + if (s.need_journal_commit > dev_buckets_available(ca, BCH_WATERMARK_normal)) + bch2_journal_flush_async(&c->journal, NULL); + trace_discard_buckets(c, s.seen, s.open, s.need_journal_commit, s.discarded, bch2_err_str(ret)); @@ -2024,7 +2028,7 @@ static void bch2_do_discards_fast_work(struct work_struct *work) break; } - trace_discard_buckets(c, s.seen, s.open, s.need_journal_commit, s.discarded, bch2_err_str(ret)); + trace_discard_buckets_fast(c, s.seen, s.open, s.need_journal_commit, s.discarded, bch2_err_str(ret)); bch2_trans_put(trans); percpu_ref_put(&ca->io_ref); diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c index ecd14962ab01..1759c15a7745 100644 --- a/fs/bcachefs/alloc_foreground.c +++ b/fs/bcachefs/alloc_foreground.c @@ -188,8 +188,12 @@ static inline bool may_alloc_bucket(struct bch_fs *c, return false; } - if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal, - c->journal.flushed_seq_ondisk, bucket.inode, bucket.offset)) { + u64 journal_seq_ready = + bch2_bucket_journal_seq_ready(&c->buckets_waiting_for_journal, + bucket.inode, bucket.offset); + if (journal_seq_ready > c->journal.flushed_seq_ondisk) { + if (journal_seq_ready > c->journal.flushing_seq) + s->need_journal_commit++; s->skipped_need_journal_commit++; return false; } @@ -553,7 +557,7 @@ static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans, ? bch2_bucket_alloc_freelist(trans, ca, watermark, &s, cl) : bch2_bucket_alloc_early(trans, ca, watermark, &s, cl); - if (s.skipped_need_journal_commit * 2 > avail) + if (s.need_journal_commit * 2 > avail) bch2_journal_flush_async(&c->journal, NULL); if (!ob && s.btree_bitmap != BTREE_BITMAP_ANY) { diff --git a/fs/bcachefs/alloc_types.h b/fs/bcachefs/alloc_types.h index 9bbb28e90b93..4aa8ee026cb8 100644 --- a/fs/bcachefs/alloc_types.h +++ b/fs/bcachefs/alloc_types.h @@ -18,6 +18,7 @@ struct bucket_alloc_state { u64 buckets_seen; u64 skipped_open; u64 skipped_need_journal_commit; + u64 need_journal_commit; u64 skipped_nocow; u64 skipped_nouse; u64 skipped_mi_btree_bitmap; diff --git a/fs/bcachefs/buckets_waiting_for_journal.c b/fs/bcachefs/buckets_waiting_for_journal.c index f9fb150eda70..c8a488e6b7b8 100644 --- a/fs/bcachefs/buckets_waiting_for_journal.c +++ b/fs/bcachefs/buckets_waiting_for_journal.c @@ -22,23 +22,21 @@ static void bucket_table_init(struct buckets_waiting_for_journal_table *t, size_ memset(t->d, 0, sizeof(t->d[0]) << t->bits); } -bool bch2_bucket_needs_journal_commit(struct buckets_waiting_for_journal *b, - u64 flushed_seq, - unsigned dev, u64 bucket) +u64 bch2_bucket_journal_seq_ready(struct buckets_waiting_for_journal *b, + unsigned dev, u64 bucket) { struct buckets_waiting_for_journal_table *t; u64 dev_bucket = (u64) dev << 56 | bucket; - bool ret = false; - unsigned i; + u64 ret = 0; mutex_lock(&b->lock); t = b->t; - for (i = 0; i < ARRAY_SIZE(t->hash_seeds); i++) { + for (unsigned i = 0; i < ARRAY_SIZE(t->hash_seeds); i++) { struct bucket_hashed *h = bucket_hash(t, i, dev_bucket); if (h->dev_bucket == dev_bucket) { - ret = h->journal_seq > flushed_seq; + ret = h->journal_seq; break; } } diff --git a/fs/bcachefs/buckets_waiting_for_journal.h b/fs/bcachefs/buckets_waiting_for_journal.h index d2ae19cbe18c..365619ca44c8 100644 --- a/fs/bcachefs/buckets_waiting_for_journal.h +++ b/fs/bcachefs/buckets_waiting_for_journal.h @@ -4,8 +4,8 @@ #include "buckets_waiting_for_journal_types.h" -bool bch2_bucket_needs_journal_commit(struct buckets_waiting_for_journal *, - u64, unsigned, u64); +u64 bch2_bucket_journal_seq_ready(struct buckets_waiting_for_journal *, + unsigned, u64); int bch2_set_bucket_needs_journal_commit(struct buckets_waiting_for_journal *, u64, unsigned, u64, u64); diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c index cb2c3722f674..ee5cb8f7b5a7 100644 --- a/fs/bcachefs/journal.c +++ b/fs/bcachefs/journal.c @@ -783,6 +783,7 @@ int bch2_journal_flush_seq_async(struct journal *j, u64 seq, } buf->must_flush = true; + j->flushing_seq = max(j->flushing_seq, seq); if (parent && !closure_wait(&buf->wait, parent)) BUG(); diff --git a/fs/bcachefs/journal_types.h b/fs/bcachefs/journal_types.h index 3ba433a48eb8..a198a81d7478 100644 --- a/fs/bcachefs/journal_types.h +++ b/fs/bcachefs/journal_types.h @@ -237,6 +237,7 @@ struct journal { /* seq, last_seq from the most recent journal entry successfully written */ u64 seq_ondisk; u64 flushed_seq_ondisk; + u64 flushing_seq; u64 last_seq_ondisk; u64 err_seq; u64 last_empty_seq; diff --git a/fs/bcachefs/trace.h b/fs/bcachefs/trace.h index 56a5a7fbc0fd..c1b51009edf6 100644 --- a/fs/bcachefs/trace.h +++ b/fs/bcachefs/trace.h @@ -727,7 +727,7 @@ DEFINE_EVENT(fs_str, bucket_alloc_fail, TP_ARGS(c, str) ); -TRACE_EVENT(discard_buckets, +DECLARE_EVENT_CLASS(discard_buckets_class, TP_PROTO(struct bch_fs *c, u64 seen, u64 open, u64 need_journal_commit, u64 discarded, const char *err), TP_ARGS(c, seen, open, need_journal_commit, discarded, err), @@ -759,6 +759,18 @@ TRACE_EVENT(discard_buckets, __entry->err) ); +DEFINE_EVENT(discard_buckets_class, discard_buckets, + TP_PROTO(struct bch_fs *c, u64 seen, u64 open, + u64 need_journal_commit, u64 discarded, const char *err), + TP_ARGS(c, seen, open, need_journal_commit, discarded, err) +); + +DEFINE_EVENT(discard_buckets_class, discard_buckets_fast, + TP_PROTO(struct bch_fs *c, u64 seen, u64 open, + u64 need_journal_commit, u64 discarded, const char *err), + TP_ARGS(c, seen, open, need_journal_commit, discarded, err) +); + TRACE_EVENT(bucket_invalidate, TP_PROTO(struct bch_fs *c, unsigned dev, u64 bucket, u32 sectors), TP_ARGS(c, dev, bucket, sectors), -- 2.45.2
