bcachefs: bch2_bkey_get_mut() now calls bch2_trans_update()

It's safe to call bch2_trans_update with a k/v pair where the value
hasn't been filled out, as long as the key part has been and the value
is filled out by transaction commit time.

This patch folds the bch2_trans_update() call into bch2_bkey_get_mut(),
eliminating a bit of boilerplate.

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

1 files changed, 11 insertions, 24 deletions

diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c
index 48956453340d..cac295afc75f 100644
--- a/fs/bcachefs/subvolume.c
+++ b/fs/bcachefs/subvolume.c
@@ -369,7 +369,7 @@ static int bch2_snapshot_node_set_deleted(struct btree_trans *trans, u32 id)
 	ret = PTR_ERR_OR_ZERO(s);
 	if (unlikely(ret)) {
 		bch2_fs_inconsistent_on(ret == -ENOENT, trans->c, "missing snapshot %u", id);
-		goto err;
+		return ret;
 	}
 
 	/* already deleted? */
@@ -379,10 +379,6 @@ static int bch2_snapshot_node_set_deleted(struct btree_trans *trans, u32 id)
 	SET_BCH_SNAPSHOT_DELETED(&s->v, true);
 	SET_BCH_SNAPSHOT_SUBVOL(&s->v, false);
 	s->v.subvol = 0;
-
-	ret = bch2_trans_update(trans, &iter, &s->k_i, 0);
-	if (ret)
-		goto err;
 err:
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
@@ -434,10 +430,6 @@ static int bch2_snapshot_node_delete(struct btree_trans *trans, u32 id)
 		    le32_to_cpu(parent->v.children[1]))
 			swap(parent->v.children[0],
 			     parent->v.children[1]);
-
-		ret = bch2_trans_update(trans, &p_iter, &parent->k_i, 0);
-		if (ret)
-			goto err;
 	}
 
 	ret = bch2_btree_delete_at(trans, &iter, 0);
@@ -888,30 +880,25 @@ int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
 	struct subvolume_unlink_hook *h;
 	int ret = 0;
 
+	h = bch2_trans_kmalloc(trans, sizeof(*h));
+	ret = PTR_ERR_OR_ZERO(h);
+	if (ret)
+		return ret;
+
+	h->h.fn		= bch2_subvolume_wait_for_pagecache_and_delete_hook;
+	h->subvol	= subvolid;
+	bch2_trans_commit_hook(trans, &h->h);
+
 	n = bch2_bkey_get_mut_typed(trans, &iter,
 			BTREE_ID_subvolumes, POS(0, subvolid),
 			BTREE_ITER_CACHED, subvolume);
 	ret = PTR_ERR_OR_ZERO(n);
 	if (unlikely(ret)) {
 		bch2_fs_inconsistent_on(ret == -ENOENT, trans->c, "missing subvolume %u", subvolid);
-		goto err;
+		return ret;
 	}
 
 	SET_BCH_SUBVOLUME_UNLINKED(&n->v, true);
-
-	ret = bch2_trans_update(trans, &iter, &n->k_i, 0);
-	if (ret)
-		goto err;
-
-	h = bch2_trans_kmalloc(trans, sizeof(*h));
-	ret = PTR_ERR_OR_ZERO(h);
-	if (ret)
-		goto err;
-
-	h->h.fn		= bch2_subvolume_wait_for_pagecache_and_delete_hook;
-	h->subvol	= subvolid;
-	bch2_trans_commit_hook(trans, &h->h);
-err:
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }