bcachefs: "buckets with backpointer mismatches" now allocated on demand

More self healing work: we're going to be calling
check_bucket_backpointer_mismatch() at runtime, outside of fsck.

Then when we need to we'll kick off the full
check_extents_to_backpointers recovery pass.

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

1 files changed, 22 insertions, 0 deletions

diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index 596edc7bba2f..8d6955ef631b 100644
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -1324,6 +1324,28 @@ int bch2_dev_buckets_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 		       sizeof(bucket_gens->b[0]) * copy);
 	}
 
+	for (unsigned i = 0; i < ARRAY_SIZE(ca->bucket_backpointer_mismatches); i++) {
+		struct bucket_bitmap *bitmap = &ca->bucket_backpointer_mismatches[i];
+
+		mutex_lock(&bitmap->lock);
+		if (bitmap->buckets) {
+			unsigned long *n = kvcalloc(BITS_TO_LONGS(nbuckets),
+						    sizeof(unsigned long), GFP_KERNEL);
+			if (!n) {
+				mutex_unlock(&bitmap->lock);
+				ret = -BCH_ERR_ENOMEM_backpointer_mismatches_bitmap;
+				goto err;
+			}
+
+			memcpy(n, bitmap->buckets,
+			       BITS_TO_LONGS(ca->mi.nbuckets) * sizeof(unsigned long));
+			kvfree(bitmap->buckets);
+			bitmap->buckets = n;
+
+		}
+		mutex_unlock(&bitmap->lock);
+	}
+
 	rcu_assign_pointer(ca->bucket_gens, bucket_gens);
 	bucket_gens	= old_bucket_gens;