From: Kent Overstreet Date: Fri, 2 May 2025 17:23:22 +0000 (-0400) Subject: bcachefs: delete_dead_snapshot_keys_v2() X-Git-Tag: v6.16-rc1~211^2~99 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=88f62ed60ceebf387140c8e59df8db827668d09a;p=thirdparty%2Fkernel%2Flinux.git bcachefs: delete_dead_snapshot_keys_v2() Since extents, dirents and xattrs require an inode with the corresponding snapshot ID to exists, we can avoid a lot of scanning by only scanning those trees for keys to process if the correspending inode exists. Signed-off-by: Kent Overstreet --- diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c index a16fa0d8a2747..9ec3275c7b0ad 100644 --- a/fs/bcachefs/snapshot.c +++ b/fs/bcachefs/snapshot.c @@ -1432,6 +1432,12 @@ static unsigned live_child(struct bch_fs *c, u32 id) return ret; } +static bool snapshot_id_dying(struct snapshot_delete *d, unsigned id) +{ + return snapshot_list_has_id(&d->delete_leaves, id) || + interior_delete_has_id(&d->delete_interior, id) != 0; +} + static int delete_dead_snapshots_process_key(struct btree_trans *trans, struct btree_iter *iter, struct bkey_s_c k) @@ -1500,6 +1506,129 @@ static bool skip_unrelated_snapshot_tree(struct btree_trans *trans, struct btree return ret; } +static int delete_dead_snapshot_keys_v1(struct btree_trans *trans) +{ + struct bch_fs *c = trans->c; + struct snapshot_delete *d = &c->snapshot_delete; + + for (d->pos.btree = 0; d->pos.btree < BTREE_ID_NR; d->pos.btree++) { + struct disk_reservation res = { 0 }; + u64 prev_inum = 0; + + d->pos.pos = POS_MIN; + + if (!btree_type_has_snapshots(d->pos.btree)) + continue; + + int ret = for_each_btree_key_commit(trans, iter, + d->pos.btree, POS_MIN, + BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k, + &res, NULL, BCH_TRANS_COMMIT_no_enospc, ({ + d->pos.pos = iter.pos; + + if (skip_unrelated_snapshot_tree(trans, &iter, &prev_inum)) + continue; + + delete_dead_snapshots_process_key(trans, &iter, k); + })); + + bch2_disk_reservation_put(c, &res); + + if (ret) + return ret; + } + + return 0; +} + +static int delete_dead_snapshot_keys_range(struct btree_trans *trans, enum btree_id btree, + struct bpos start, struct bpos end) +{ + struct bch_fs *c = trans->c; + struct snapshot_delete *d = &c->snapshot_delete; + struct disk_reservation res = { 0 }; + + d->pos.btree = btree; + d->pos.pos = POS_MIN; + + int ret = for_each_btree_key_max_commit(trans, iter, + btree, start, end, + BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k, + &res, NULL, BCH_TRANS_COMMIT_no_enospc, ({ + d->pos.pos = iter.pos; + delete_dead_snapshots_process_key(trans, &iter, k); + })); + + bch2_disk_reservation_put(c, &res); + return ret; +} + +static int delete_dead_snapshot_keys_v2(struct btree_trans *trans) +{ + struct bch_fs *c = trans->c; + struct snapshot_delete *d = &c->snapshot_delete; + struct disk_reservation res = { 0 }; + u64 prev_inum = 0; + int ret = 0; + + struct btree_iter iter; + bch2_trans_iter_init(trans, &iter, BTREE_ID_inodes, POS_MIN, + BTREE_ITER_prefetch|BTREE_ITER_all_snapshots); + + while (1) { + struct bkey_s_c k; + ret = lockrestart_do(trans, + bkey_err(k = bch2_btree_iter_peek(trans, &iter))); + if (ret) + break; + + if (!k.k) + break; + + d->pos.btree = iter.btree_id; + d->pos.pos = iter.pos; + + if (skip_unrelated_snapshot_tree(trans, &iter, &prev_inum)) + continue; + + if (snapshot_id_dying(d, k.k->p.snapshot)) { + struct bpos start = POS(k.k->p.offset, 0); + struct bpos end = POS(k.k->p.offset, U64_MAX); + + ret = delete_dead_snapshot_keys_range(trans, BTREE_ID_extents, start, end) ?: + delete_dead_snapshot_keys_range(trans, BTREE_ID_dirents, start, end) ?: + delete_dead_snapshot_keys_range(trans, BTREE_ID_xattrs, start, end); + if (ret) + break; + + bch2_btree_iter_set_pos(trans, &iter, POS(0, k.k->p.offset + 1)); + } else { + bch2_btree_iter_advance(trans, &iter); + } + } + bch2_trans_iter_exit(trans, &iter); + + if (ret) + goto err; + + prev_inum = 0; + ret = for_each_btree_key_commit(trans, iter, + BTREE_ID_inodes, POS_MIN, + BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k, + &res, NULL, BCH_TRANS_COMMIT_no_enospc, ({ + d->pos.btree = iter.btree_id; + d->pos.pos = iter.pos; + + if (skip_unrelated_snapshot_tree(trans, &iter, &prev_inum)) + continue; + + delete_dead_snapshots_process_key(trans, &iter, k); + })); +err: + bch2_disk_reservation_put(c, &res); + return ret; +} + /* * For a given snapshot, if it doesn't have a subvolume that points to it, and * it doesn't have child snapshot nodes - it's now redundant and we can mark it @@ -1683,34 +1812,13 @@ int bch2_delete_dead_snapshots(struct bch_fs *c) goto err; } - for (d->pos.btree = 0; d->pos.btree < BTREE_ID_NR; d->pos.btree++) { - struct disk_reservation res = { 0 }; - u64 prev_inum = 0; - - d->pos.pos = POS_MIN; - - if (!btree_type_has_snapshots(d->pos.btree)) - continue; - - ret = for_each_btree_key_commit(trans, iter, - d->pos.btree, POS_MIN, - BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k, - &res, NULL, BCH_TRANS_COMMIT_no_enospc, ({ - d->pos.pos = iter.pos; - - if (skip_unrelated_snapshot_tree(trans, &iter, &prev_inum)) - continue; - - delete_dead_snapshots_process_key(trans, &iter, k); - })); - - bch2_disk_reservation_put(c, &res); - - if (!bch2_err_matches(ret, EROFS)) - bch_err_msg(c, ret, "deleting keys from dying snapshots"); - if (ret) - goto err; - } + ret = !bch2_request_incompat_feature(c, bcachefs_metadata_version_snapshot_deletion_v2) + ? delete_dead_snapshot_keys_v2(trans) + : delete_dead_snapshot_keys_v1(trans); + if (!bch2_err_matches(ret, EROFS)) + bch_err_msg(c, ret, "deleting keys from dying snapshots"); + if (ret) + goto err; darray_for_each(d->delete_leaves, i) { ret = commit_do(trans, NULL, NULL, 0,