bcachefs: Fix rcu splat in check_fix_ptrs()

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

diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index e28d28ac2a13d9ce9ec4e708ccf98378eb13cae2..02bb02b70981947bc81719147003afe00e71d000 100644 (file)
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -479,9 +479,8 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
 
        percpu_down_read(&c->mark_lock);
 
-       rcu_read_lock();
        bkey_for_each_ptr_decode(k.k, ptrs_c, p, entry_c) {
-               struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
+               struct bch_dev *ca = bch2_dev_tryget(c, p.ptr.dev);
                if (!ca) {
                        if (fsck_err(c, ptr_to_invalid_device,
                                     "pointer to missing device %u\n"
@@ -558,7 +557,7 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
                        do_update = true;
 
                if (data_type != BCH_DATA_btree && p.ptr.gen != g->gen)
-                       continue;
+                       goto next;
 
                if (fsck_err_on(bucket_data_type_mismatch(g->data_type, data_type),
                                c, ptr_bucket_data_type_mismatch,
@@ -601,8 +600,9 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
                                         bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
                                do_update = true;
                }
+next:
+               bch2_dev_put(ca);
        }
-       rcu_read_unlock();
 
        if (do_update) {
                if (flags & BTREE_TRIGGER_is_root) {
@@ -638,9 +638,10 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
                } else {
                        struct bkey_ptrs ptrs;
                        union bch_extent_entry *entry;
+
+                       rcu_read_lock();
 restart_drop_ptrs:
                        ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
-                       rcu_read_lock();
                        bkey_for_each_ptr_decode(bkey_i_to_s(new).k, ptrs, p, entry) {
                                struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
                                struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);