bcachefs: Minor bucket alloc optimization

Check open buckets and buckets waiting for journal commit before doing
other expensive lookups.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index 49c9275465f9d1934ad5d21c71cf8d5a3332d07e..57d5f14c93d07ed205d85630d9bb5aba2eb5233f 100644 (file)
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -200,14 +200,35 @@ static inline unsigned open_buckets_reserved(enum bch_watermark watermark)
        }
 }
 
+static inline bool may_alloc_bucket(struct bch_fs *c,
+                                   struct bpos bucket,
+                                   struct bucket_alloc_state *s)
+{
+       if (bch2_bucket_is_open(c, bucket.inode, bucket.offset)) {
+               s->skipped_open++;
+               return false;
+       }
+
+       if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
+                       c->journal.flushed_seq_ondisk, bucket.inode, bucket.offset)) {
+               s->skipped_need_journal_commit++;
+               return false;
+       }
+
+       if (bch2_bucket_nocow_is_locked(&c->nocow_locks, bucket)) {
+               s->skipped_nocow++;
+               return false;
+       }
+
+       return true;
+}
+
 static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *ca,
                                              u64 bucket, u8 gen,
                                              enum bch_watermark watermark,
                                              struct bucket_alloc_state *s,
                                              struct closure *cl)
 {
-       struct open_bucket *ob;
-
        if (unlikely(is_superblock_bucket(c, ca, bucket)))
                return NULL;
 
@@ -216,22 +237,6 @@ static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *
                return NULL;
        }
 
-       if (bch2_bucket_is_open(c, ca->dev_idx, bucket)) {
-               s->skipped_open++;
-               return NULL;
-       }
-
-       if (bch2_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
-                       c->journal.flushed_seq_ondisk, ca->dev_idx, bucket)) {
-               s->skipped_need_journal_commit++;
-               return NULL;
-       }
-
-       if (bch2_bucket_nocow_is_locked(&c->nocow_locks, POS(ca->dev_idx, bucket))) {
-               s->skipped_nocow++;
-               return NULL;
-       }
-
        spin_lock(&c->freelist_lock);
 
        if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(watermark))) {
@@ -250,10 +255,9 @@ static struct open_bucket *__try_alloc_bucket(struct bch_fs *c, struct bch_dev *
                return NULL;
        }
 
-       ob = bch2_open_bucket_alloc(c);
+       struct open_bucket *ob = bch2_open_bucket_alloc(c);
 
        spin_lock(&ob->lock);
-
        ob->valid       = true;
        ob->sectors_free = ca->mi.bucket_size;
        ob->dev         = ca->dev_idx;
@@ -279,8 +283,11 @@ static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bc
 {
        struct bch_fs *c = trans->c;
        u64 b = freespace_iter->pos.offset & ~(~0ULL << 56);
-       u8 gen;
 
+       if (!may_alloc_bucket(c, POS(ca->dev_idx, b), s))
+               return NULL;
+
+       u8 gen;
        int ret = bch2_check_discard_freespace_key(trans, freespace_iter, &gen, true);
        if (ret < 0)
                return ERR_PTR(ret);
@@ -300,6 +307,7 @@ bch2_bucket_alloc_early(struct btree_trans *trans,
                        struct bucket_alloc_state *s,
                        struct closure *cl)
 {
+       struct bch_fs *c = trans->c;
        struct btree_iter iter, citer;
        struct bkey_s_c k, ck;
        struct open_bucket *ob = NULL;
@@ -359,7 +367,10 @@ again:
 
                s->buckets_seen++;
 
-               ob = __try_alloc_bucket(trans->c, ca, k.k->p.offset, a->gen, watermark, s, cl);
+               ob = may_alloc_bucket(c, k.k->p, s)
+                       ? __try_alloc_bucket(c, ca, k.k->p.offset, a->gen,
+                                            watermark, s, cl)
+                       : NULL;
 next:
                bch2_set_btree_iter_dontneed(&citer);
                bch2_trans_iter_exit(trans, &citer);