bcachefs: Fix deletion in __bch2_dev_usrdata_drop()

With snapshots, __bch2_dev_usr_data_drop() now uses an ALL_SNAPSHOTS
iterator, which isn't an extent iterator - meaning we shouldn't be
inserting whiteouts with nonzero size to delete. This fixes a bug where
we go RO because we tried to insert an invalid key in the device remove
path.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/migrate.c b/fs/bcachefs/migrate.c
index 9f9eb799337e2ae22197e0d13aa23febae6ac1be..94d5d99ffd2a4634398af0faae7acfd3f90c78d6 100644 (file)
--- a/fs/bcachefs/migrate.c
+++ b/fs/bcachefs/migrate.c
@@ -73,6 +73,15 @@ static int __bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags
                 */
                bch2_extent_normalize(c, bkey_i_to_s(sk.k));
 
+               /*
+                * Since we're not inserting through an extent iterator
+                * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
+                * we aren't using the extent overwrite path to delete, we're
+                * just using the normal key deletion path:
+                */
+               if (bkey_deleted(&sk.k->k))
+                       sk.k->k.size = 0;
+
                ret   = bch2_btree_iter_traverse(&iter) ?:
                        bch2_trans_update(&trans, &iter, sk.k,
                                          BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?: