+ h->fn = bch2_delete_dead_snapshots_hook;
+ bch2_trans_commit_hook(trans, h);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work)
+{
+ struct bch_fs *c = container_of(work, struct bch_fs,
+ snapshot_wait_for_pagecache_and_delete_work);
+ snapshot_id_list s;
+ u32 *id;
+ int ret = 0;
+
+ while (!ret) {
+ mutex_lock(&c->snapshots_unlinked_lock);
+ s = c->snapshots_unlinked;
+ darray_init(&c->snapshots_unlinked);
+ mutex_unlock(&c->snapshots_unlinked_lock);
+
+ if (!s.nr)
+ break;
+
+ bch2_evict_subvolume_inodes(c, &s);
+
+ for (id = s.data; id < s.data + s.nr; id++) {
+ ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_NOFAIL,
+ bch2_subvolume_delete(&trans, *id));
+ if (ret) {
+ bch_err(c, "error deleting subvolume %u: %s", *id, bch2_err_str(ret));
+ break;
+ }
+ }
+
+ darray_exit(&s);
+ }
+
+ bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache);
+}
+
+struct subvolume_unlink_hook {
+ struct btree_trans_commit_hook h;
+ u32 subvol;
+};
+
+int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans,
+ struct btree_trans_commit_hook *_h)
+{
+ struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h);
+ struct bch_fs *c = trans->c;
+ int ret = 0;
+
+ mutex_lock(&c->snapshots_unlinked_lock);
+ if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol))
+ ret = snapshot_list_add(c, &c->snapshots_unlinked, h->subvol);
+ mutex_unlock(&c->snapshots_unlinked_lock);
+
+ if (ret)
+ return ret;
+
+ if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_snapshot_delete_pagecache))
+ return -EROFS;
+
+ if (!queue_work(c->write_ref_wq, &c->snapshot_wait_for_pagecache_and_delete_work))
+ bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache);
+ return 0;
+}
+
+int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
+{
+ struct btree_iter iter;
+ struct bkey_i_subvolume *n;
+ struct subvolume_unlink_hook *h;
+ int ret = 0;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,
+ POS(0, subvolid),
+ BTREE_ITER_CACHED|
+ BTREE_ITER_INTENT);
+ n = bch2_bkey_get_mut_typed(trans, &iter, subvolume);
+ ret = PTR_ERR_OR_ZERO(n);
+ if (unlikely(ret)) {
+ bch2_fs_inconsistent_on(ret == -ENOENT, trans->c, "missing subvolume %u", subvolid);
+ goto err;
+ }
+
+ SET_BCH_SUBVOLUME_UNLINKED(&n->v, true);
+
+ ret = bch2_trans_update(trans, &iter, &n->k_i, 0);
+ if (ret)
+ goto err;