// SPDX-License-Identifier: GPL-2.0 #include "bcachefs.h" #include "btree_key_cache.h" #include "btree_update.h" #include "errcode.h" #include "error.h" #include "fs.h" #include "snapshot.h" #include "subvolume.h" #include static int bch2_subvolume_delete(struct btree_trans *, u32); static struct bpos subvolume_children_pos(struct bkey_s_c k) { if (k.k->type != KEY_TYPE_subvolume) return POS_MIN; struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k); if (!s.v->fs_path_parent) return POS_MIN; return POS(le32_to_cpu(s.v->fs_path_parent), s.k->p.offset); } static int check_subvol(struct btree_trans *trans, struct btree_iter *iter, struct bkey_s_c k) { struct bch_fs *c = trans->c; struct bkey_s_c_subvolume subvol; struct btree_iter subvol_children_iter = {}; struct bch_snapshot snapshot; struct printbuf buf = PRINTBUF; unsigned snapid; int ret = 0; if (k.k->type != KEY_TYPE_subvolume) return 0; subvol = bkey_s_c_to_subvolume(k); snapid = le32_to_cpu(subvol.v->snapshot); ret = bch2_snapshot_lookup(trans, snapid, &snapshot); if (bch2_err_matches(ret, ENOENT)) bch_err(c, "subvolume %llu points to nonexistent snapshot %u", k.k->p.offset, snapid); if (ret) return ret; if (BCH_SUBVOLUME_UNLINKED(subvol.v)) { ret = bch2_subvolume_delete(trans, iter->pos.offset); bch_err_msg(c, ret, "deleting subvolume %llu", iter->pos.offset); return ret ?: -BCH_ERR_transaction_restart_nested; } if (fsck_err_on(subvol.k->p.offset == BCACHEFS_ROOT_SUBVOL && subvol.v->fs_path_parent, trans, subvol_root_fs_path_parent_nonzero, "root subvolume has nonzero fs_path_parent\n%s", (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) { struct bkey_i_subvolume *n = bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume); ret = PTR_ERR_OR_ZERO(n); if (ret) goto err; n->v.fs_path_parent = 0; } if (subvol.v->fs_path_parent) { struct bpos pos = subvolume_children_pos(k); struct bkey_s_c subvol_children_k = bch2_bkey_get_iter(trans, &subvol_children_iter, BTREE_ID_subvolume_children, pos, 0); ret = bkey_err(subvol_children_k); if (ret) goto err; if (fsck_err_on(subvol_children_k.k->type != KEY_TYPE_set, trans, subvol_children_not_set, "subvolume not set in subvolume_children btree at %llu:%llu\n%s", pos.inode, pos.offset, (printbuf_reset(&buf), bch2_bkey_val_to_text(&buf, c, k), buf.buf))) { ret = bch2_btree_bit_mod(trans, BTREE_ID_subvolume_children, pos, true); if (ret) goto err; } } struct bch_inode_unpacked inode; ret = bch2_inode_find_by_inum_nowarn_trans(trans, (subvol_inum) { k.k->p.offset, le64_to_cpu(subvol.v->inode) }, &inode); if (!ret) { if (fsck_err_on(inode.bi_subvol != subvol.k->p.offset, trans, subvol_root_wrong_bi_subvol, "subvol root %llu:%u has wrong bi_subvol field: got %u, should be %llu", inode.bi_inum, inode.bi_snapshot, inode.bi_subvol, subvol.k->p.offset)) { inode.bi_subvol = subvol.k->p.offset; inode.bi_snapshot = le32_to_cpu(subvol.v->snapshot); ret = __bch2_fsck_write_inode(trans, &inode); if (ret) goto err; } } else if (bch2_err_matches(ret, ENOENT)) { if (fsck_err(trans, subvol_to_missing_root, "subvolume %llu points to missing subvolume root %llu:%u", k.k->p.offset, le64_to_cpu(subvol.v->inode), le32_to_cpu(subvol.v->snapshot))) { ret = bch2_subvolume_delete(trans, iter->pos.offset); bch_err_msg(c, ret, "deleting subvolume %llu", iter->pos.offset); ret = ret ?: -BCH_ERR_transaction_restart_nested; goto err; } } else { goto err; } if (!BCH_SUBVOLUME_SNAP(subvol.v)) { u32 snapshot_root = bch2_snapshot_root(c, le32_to_cpu(subvol.v->snapshot)); u32 snapshot_tree; struct bch_snapshot_tree st; rcu_read_lock(); snapshot_tree = snapshot_t(c, snapshot_root)->tree; rcu_read_unlock(); ret = bch2_snapshot_tree_lookup(trans, snapshot_tree, &st); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c, "%s: snapshot tree %u not found", __func__, snapshot_tree); if (ret) goto err; if (fsck_err_on(le32_to_cpu(st.master_subvol) != subvol.k->p.offset, trans, subvol_not_master_and_not_snapshot, "subvolume %llu is not set as snapshot but is not master subvolume", k.k->p.offset)) { struct bkey_i_subvolume *s = bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume); ret = PTR_ERR_OR_ZERO(s); if (ret) goto err; SET_BCH_SUBVOLUME_SNAP(&s->v, true); } } err: fsck_err: bch2_trans_iter_exit(trans, &subvol_children_iter); printbuf_exit(&buf); return ret; } int bch2_check_subvols(struct bch_fs *c) { int ret = bch2_trans_run(c, for_each_btree_key_commit(trans, iter, BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, check_subvol(trans, &iter, k))); bch_err_fn(c, ret); return ret; } static int check_subvol_child(struct btree_trans *trans, struct btree_iter *child_iter, struct bkey_s_c child_k) { struct bch_subvolume s; int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, child_k.k->p.offset), 0, subvolume, &s); if (ret && !bch2_err_matches(ret, ENOENT)) return ret; if (fsck_err_on(ret || le32_to_cpu(s.fs_path_parent) != child_k.k->p.inode, trans, subvol_children_bad, "incorrect entry in subvolume_children btree %llu:%llu", child_k.k->p.inode, child_k.k->p.offset)) { ret = bch2_btree_delete_at(trans, child_iter, 0); if (ret) goto err; } err: fsck_err: return ret; } int bch2_check_subvol_children(struct bch_fs *c) { int ret = bch2_trans_run(c, for_each_btree_key_commit(trans, iter, BTREE_ID_subvolume_children, POS_MIN, BTREE_ITER_prefetch, k, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, check_subvol_child(trans, &iter, k))); bch_err_fn(c, ret); return 0; } /* Subvolumes: */ int bch2_subvolume_validate(struct bch_fs *c, struct bkey_s_c k, enum bch_validate_flags flags) { struct bkey_s_c_subvolume subvol = bkey_s_c_to_subvolume(k); int ret = 0; bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) || bkey_gt(k.k->p, SUBVOL_POS_MAX), c, subvol_pos_bad, "invalid pos"); bkey_fsck_err_on(!subvol.v->snapshot, c, subvol_snapshot_bad, "invalid snapshot"); bkey_fsck_err_on(!subvol.v->inode, c, subvol_inode_bad, "invalid inode"); fsck_err: return ret; } void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k) { struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k); prt_printf(out, "root %llu snapshot id %u", le64_to_cpu(s.v->inode), le32_to_cpu(s.v->snapshot)); if (bkey_val_bytes(s.k) > offsetof(struct bch_subvolume, creation_parent)) { prt_printf(out, " creation_parent %u", le32_to_cpu(s.v->creation_parent)); prt_printf(out, " fs_parent %u", le32_to_cpu(s.v->fs_path_parent)); } } static int subvolume_children_mod(struct btree_trans *trans, struct bpos pos, bool set) { return !bpos_eq(pos, POS_MIN) ? bch2_btree_bit_mod(trans, BTREE_ID_subvolume_children, pos, set) : 0; } int bch2_subvolume_trigger(struct btree_trans *trans, enum btree_id btree_id, unsigned level, struct bkey_s_c old, struct bkey_s new, enum btree_iter_update_trigger_flags flags) { if (flags & BTREE_TRIGGER_transactional) { struct bpos children_pos_old = subvolume_children_pos(old); struct bpos children_pos_new = subvolume_children_pos(new.s_c); if (!bpos_eq(children_pos_old, children_pos_new)) { int ret = subvolume_children_mod(trans, children_pos_old, false) ?: subvolume_children_mod(trans, children_pos_new, true); if (ret) return ret; } } return 0; } int bch2_subvol_has_children(struct btree_trans *trans, u32 subvol) { struct btree_iter iter; bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolume_children, POS(subvol, 0), 0); struct bkey_s_c k = bch2_btree_iter_peek(&iter); bch2_trans_iter_exit(trans, &iter); return bkey_err(k) ?: k.k && k.k->p.inode == subvol ? -BCH_ERR_ENOTEMPTY_subvol_not_empty : 0; } static __always_inline int bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol, bool inconsistent_if_not_found, int iter_flags, struct bch_subvolume *s) { int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, subvol), iter_flags, subvolume, s); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT) && inconsistent_if_not_found, trans->c, "missing subvolume %u", subvol); return ret; } int bch2_subvolume_get(struct btree_trans *trans, unsigned subvol, bool inconsistent_if_not_found, int iter_flags, struct bch_subvolume *s) { return bch2_subvolume_get_inlined(trans, subvol, inconsistent_if_not_found, iter_flags, s); } int bch2_subvol_is_ro_trans(struct btree_trans *trans, u32 subvol) { struct bch_subvolume s; int ret = bch2_subvolume_get_inlined(trans, subvol, true, 0, &s); if (ret) return ret; if (BCH_SUBVOLUME_RO(&s)) return -EROFS; return 0; } int bch2_subvol_is_ro(struct bch_fs *c, u32 subvol) { return bch2_trans_do(c, NULL, NULL, 0, bch2_subvol_is_ro_trans(trans, subvol)); } int bch2_snapshot_get_subvol(struct btree_trans *trans, u32 snapshot, struct bch_subvolume *subvol) { struct bch_snapshot snap; return bch2_snapshot_lookup(trans, snapshot, &snap) ?: bch2_subvolume_get(trans, le32_to_cpu(snap.subvol), true, 0, subvol); } int __bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid, u32 *snapid, bool warn) { struct btree_iter iter; struct bkey_s_c_subvolume subvol; int ret; subvol = bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_subvolumes, POS(0, subvolid), BTREE_ITER_cached|BTREE_ITER_with_updates, subvolume); ret = bkey_err(subvol); bch2_fs_inconsistent_on(warn && bch2_err_matches(ret, ENOENT), trans->c, "missing subvolume %u", subvolid); if (likely(!ret)) *snapid = le32_to_cpu(subvol.v->snapshot); bch2_trans_iter_exit(trans, &iter); return ret; } int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid, u32 *snapid) { return __bch2_subvolume_get_snapshot(trans, subvolid, snapid, true); } static int bch2_subvolume_reparent(struct btree_trans *trans, struct btree_iter *iter, struct bkey_s_c k, u32 old_parent, u32 new_parent) { struct bkey_i_subvolume *s; int ret; if (k.k->type != KEY_TYPE_subvolume) return 0; if (bkey_val_bytes(k.k) > offsetof(struct bch_subvolume, creation_parent) && le32_to_cpu(bkey_s_c_to_subvolume(k).v->creation_parent) != old_parent) return 0; s = bch2_bkey_make_mut_typed(trans, iter, &k, 0, subvolume); ret = PTR_ERR_OR_ZERO(s); if (ret) return ret; s->v.creation_parent = cpu_to_le32(new_parent); return 0; } /* * Separate from the snapshot tree in the snapshots btree, we record the tree * structure of how snapshot subvolumes were created - the parent subvolume of * each snapshot subvolume. * * When a subvolume is deleted, we scan for child subvolumes and reparant them, * to avoid dangling references: */ static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_delete) { struct bch_subvolume s; return lockrestart_do(trans, bch2_subvolume_get(trans, subvolid_to_delete, true, BTREE_ITER_cached, &s)) ?: for_each_btree_key_commit(trans, iter, BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, bch2_subvolume_reparent(trans, &iter, k, subvolid_to_delete, le32_to_cpu(s.creation_parent))); } /* * Delete subvolume, mark snapshot ID as deleted, queue up snapshot * deletion/cleanup: */ static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid) { struct btree_iter iter; struct bkey_s_c_subvolume subvol; u32 snapid; int ret = 0; subvol = bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_subvolumes, POS(0, subvolid), BTREE_ITER_cached|BTREE_ITER_intent, subvolume); ret = bkey_err(subvol); bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, "missing subvolume %u", subvolid); if (ret) return ret; snapid = le32_to_cpu(subvol.v->snapshot); ret = bch2_btree_delete_at(trans, &iter, 0) ?: bch2_snapshot_node_set_deleted(trans, snapid); bch2_trans_iter_exit(trans, &iter); return ret; } static int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid) { return bch2_subvolumes_reparent(trans, subvolid) ?: commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc, __bch2_subvolume_delete(trans, subvolid)); } static 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_run(c, bch2_subvolume_delete(trans, *id)); bch_err_msg(c, ret, "deleting subvolume %u", *id); if (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; }; static 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; 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(bch2_err_matches(ret, ENOENT), trans->c, "missing subvolume %u", subvolid); return ret; } SET_BCH_SUBVOLUME_UNLINKED(&n->v, true); bch2_trans_iter_exit(trans, &iter); return ret; } int bch2_subvolume_create(struct btree_trans *trans, u64 inode, u32 parent_subvolid, u32 src_subvolid, u32 *new_subvolid, u32 *new_snapshotid, bool ro) { struct bch_fs *c = trans->c; struct btree_iter dst_iter, src_iter = (struct btree_iter) { NULL }; struct bkey_i_subvolume *new_subvol = NULL; struct bkey_i_subvolume *src_subvol = NULL; u32 parent = 0, new_nodes[2], snapshot_subvols[2]; int ret = 0; ret = bch2_bkey_get_empty_slot(trans, &dst_iter, BTREE_ID_subvolumes, POS(0, U32_MAX)); if (ret == -BCH_ERR_ENOSPC_btree_slot) ret = -BCH_ERR_ENOSPC_subvolume_create; if (ret) return ret; snapshot_subvols[0] = dst_iter.pos.offset; snapshot_subvols[1] = src_subvolid; if (src_subvolid) { /* Creating a snapshot: */ src_subvol = bch2_bkey_get_mut_typed(trans, &src_iter, BTREE_ID_subvolumes, POS(0, src_subvolid), BTREE_ITER_cached, subvolume); ret = PTR_ERR_OR_ZERO(src_subvol); if (unlikely(ret)) { bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c, "subvolume %u not found", src_subvolid); goto err; } parent = le32_to_cpu(src_subvol->v.snapshot); } ret = bch2_snapshot_node_create(trans, parent, new_nodes, snapshot_subvols, src_subvolid ? 2 : 1); if (ret) goto err; if (src_subvolid) { src_subvol->v.snapshot = cpu_to_le32(new_nodes[1]); ret = bch2_trans_update(trans, &src_iter, &src_subvol->k_i, 0); if (ret) goto err; } new_subvol = bch2_bkey_alloc(trans, &dst_iter, 0, subvolume); ret = PTR_ERR_OR_ZERO(new_subvol); if (ret) goto err; new_subvol->v.flags = 0; new_subvol->v.snapshot = cpu_to_le32(new_nodes[0]); new_subvol->v.inode = cpu_to_le64(inode); new_subvol->v.creation_parent = cpu_to_le32(src_subvolid); new_subvol->v.fs_path_parent = cpu_to_le32(parent_subvolid); new_subvol->v.otime.lo = cpu_to_le64(bch2_current_time(c)); new_subvol->v.otime.hi = 0; SET_BCH_SUBVOLUME_RO(&new_subvol->v, ro); SET_BCH_SUBVOLUME_SNAP(&new_subvol->v, src_subvolid != 0); *new_subvolid = new_subvol->k.p.offset; *new_snapshotid = new_nodes[0]; err: bch2_trans_iter_exit(trans, &src_iter); bch2_trans_iter_exit(trans, &dst_iter); return ret; } int bch2_initialize_subvolumes(struct bch_fs *c) { struct bkey_i_snapshot_tree root_tree; struct bkey_i_snapshot root_snapshot; struct bkey_i_subvolume root_volume; int ret; bkey_snapshot_tree_init(&root_tree.k_i); root_tree.k.p.offset = 1; root_tree.v.master_subvol = cpu_to_le32(1); root_tree.v.root_snapshot = cpu_to_le32(U32_MAX); bkey_snapshot_init(&root_snapshot.k_i); root_snapshot.k.p.offset = U32_MAX; root_snapshot.v.flags = 0; root_snapshot.v.parent = 0; root_snapshot.v.subvol = cpu_to_le32(BCACHEFS_ROOT_SUBVOL); root_snapshot.v.tree = cpu_to_le32(1); SET_BCH_SNAPSHOT_SUBVOL(&root_snapshot.v, true); bkey_subvolume_init(&root_volume.k_i); root_volume.k.p.offset = BCACHEFS_ROOT_SUBVOL; root_volume.v.flags = 0; root_volume.v.snapshot = cpu_to_le32(U32_MAX); root_volume.v.inode = cpu_to_le64(BCACHEFS_ROOT_INO); ret = bch2_btree_insert(c, BTREE_ID_snapshot_trees, &root_tree.k_i, NULL, 0, 0) ?: bch2_btree_insert(c, BTREE_ID_snapshots, &root_snapshot.k_i, NULL, 0, 0) ?: bch2_btree_insert(c, BTREE_ID_subvolumes, &root_volume.k_i, NULL, 0, 0); bch_err_fn(c, ret); return ret; } static int __bch2_fs_upgrade_for_subvolumes(struct btree_trans *trans) { struct btree_iter iter; struct bkey_s_c k; struct bch_inode_unpacked inode; int ret; k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes, SPOS(0, BCACHEFS_ROOT_INO, U32_MAX), 0); ret = bkey_err(k); if (ret) return ret; if (!bkey_is_inode(k.k)) { bch_err(trans->c, "root inode not found"); ret = -BCH_ERR_ENOENT_inode; goto err; } ret = bch2_inode_unpack(k, &inode); BUG_ON(ret); inode.bi_subvol = BCACHEFS_ROOT_SUBVOL; ret = bch2_inode_write(trans, &iter, &inode); err: bch2_trans_iter_exit(trans, &iter); return ret; } /* set bi_subvol on root inode */ int bch2_fs_upgrade_for_subvolumes(struct bch_fs *c) { int ret = bch2_trans_do(c, NULL, NULL, BCH_TRANS_COMMIT_lazy_rw, __bch2_fs_upgrade_for_subvolumes(trans)); bch_err_fn(c, ret); return ret; } int bch2_fs_subvolumes_init(struct bch_fs *c) { INIT_WORK(&c->snapshot_delete_work, bch2_delete_dead_snapshots_work); INIT_WORK(&c->snapshot_wait_for_pagecache_and_delete_work, bch2_subvolume_wait_for_pagecache_and_delete); mutex_init(&c->snapshots_unlinked_lock); return 0; }