bcachefs: Extents may now cross btree node boundaries

When snapshots arrive, we won't necessarily be able to arbitrarily split
existis - when we need to split an existing extent, we'll have to check
if the extent was overwritten in child snapshots and if so emit a
whiteout for the split in the child snapshot.

Because extents couldn't span btree nodes previously, journal replay
would sometimes have to split existing extents. That's no good anymore,
but fortunately since extent handling has already been lifted above most
of the btree code there's no real need for that rule anymore.

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

1 files changed, 1 insertions, 112 deletions

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 8560023b4c7a..54ac9cc470af 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -506,115 +506,6 @@ static void replay_now_at(struct journal *j, u64 seq)
 		bch2_journal_pin_put(j, j->replay_journal_seq++);
 }
 
-static int bch2_extent_replay_key(struct bch_fs *c, enum btree_id btree_id,
-				  struct bkey_i *k)
-{
-	struct btree_trans trans;
-	struct btree_iter *iter, *split_iter;
-	/*
-	 * We might cause compressed extents to be split, so we need to pass in
-	 * a disk_reservation:
-	 */
-	struct disk_reservation disk_res =
-		bch2_disk_reservation_init(c, 0);
-	struct bkey_i *split;
-	struct bpos atomic_end;
-	/*
-	 * Some extents aren't equivalent - w.r.t. what the triggers do
-	 * - if they're split:
-	 */
-	bool remark_if_split = bch2_bkey_sectors_compressed(bkey_i_to_s_c(k)) ||
-		k->k.type == KEY_TYPE_reflink_p;
-	bool remark = false;
-	int ret;
-
-	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
-retry:
-	bch2_trans_begin(&trans);
-
-	iter = bch2_trans_get_iter(&trans, btree_id,
-				   bkey_start_pos(&k->k),
-				   BTREE_ITER_INTENT);
-
-	do {
-		ret = bch2_btree_iter_traverse(iter);
-		if (ret)
-			goto err;
-
-		atomic_end = bpos_min(k->k.p, iter->l[0].b->key.k.p);
-
-		split = bch2_trans_kmalloc(&trans, bkey_bytes(&k->k));
-		ret = PTR_ERR_OR_ZERO(split);
-		if (ret)
-			goto err;
-
-		if (!remark &&
-		    remark_if_split &&
-		    bkey_cmp(atomic_end, k->k.p) < 0) {
-			ret = bch2_disk_reservation_add(c, &disk_res,
-					k->k.size *
-					bch2_bkey_nr_ptrs_allocated(bkey_i_to_s_c(k)),
-					BCH_DISK_RESERVATION_NOFAIL);
-			BUG_ON(ret);
-
-			remark = true;
-		}
-
-		bkey_copy(split, k);
-		bch2_cut_front(iter->pos, split);
-		bch2_cut_back(atomic_end, split);
-
-		split_iter = bch2_trans_copy_iter(&trans, iter);
-
-		/*
-		 * It's important that we don't go through the
-		 * extent_handle_overwrites() and extent_update_to_keys() path
-		 * here: journal replay is supposed to treat extents like
-		 * regular keys
-		 */
-		__bch2_btree_iter_set_pos(split_iter, split->k.p, false);
-		bch2_trans_update(&trans, split_iter, split,
-				  BTREE_TRIGGER_NORUN);
-		bch2_trans_iter_put(&trans, split_iter);
-
-		bch2_btree_iter_set_pos(iter, split->k.p);
-
-		if (remark) {
-			ret = bch2_trans_mark_key(&trans,
-						  bkey_s_c_null,
-						  bkey_i_to_s_c(split),
-						  0, split->k.size,
-						  BTREE_TRIGGER_INSERT);
-			if (ret)
-				goto err;
-		}
-	} while (bkey_cmp(iter->pos, k->k.p) < 0);
-
-	if (remark) {
-		ret = bch2_trans_mark_key(&trans,
-					  bkey_i_to_s_c(k),
-					  bkey_s_c_null,
-					  0, -((s64) k->k.size),
-					  BTREE_TRIGGER_OVERWRITE);
-		if (ret)
-			goto err;
-	}
-
-	ret = bch2_trans_commit(&trans, &disk_res, NULL,
-				BTREE_INSERT_NOFAIL|
-				BTREE_INSERT_LAZY_RW|
-				BTREE_INSERT_JOURNAL_REPLAY);
-err:
-	bch2_trans_iter_put(&trans, iter);
-
-	if (ret == -EINTR)
-		goto retry;
-
-	bch2_disk_reservation_put(c, &disk_res);
-
-	return bch2_trans_exit(&trans) ?: ret;
-}
-
 static int __bch2_journal_replay_key(struct btree_trans *trans,
 				     enum btree_id id, unsigned level,
 				     struct bkey_i *k)
@@ -753,9 +644,7 @@ static int bch2_journal_replay(struct bch_fs *c,
 
 		replay_now_at(j, keys.journal_seq_base + i->journal_seq);
 
-		ret = i->k->k.size
-			? bch2_extent_replay_key(c, i->btree_id, i->k)
-			: bch2_journal_replay_key(c, i);
+		ret = bch2_journal_replay_key(c, i);
 		if (ret)
 			goto err;
 	}