diff options
Diffstat (limited to 'c_src/libbcachefs/subvolume.c')
-rw-r--r-- | c_src/libbcachefs/subvolume.c | 444 |
1 files changed, 0 insertions, 444 deletions
diff --git a/c_src/libbcachefs/subvolume.c b/c_src/libbcachefs/subvolume.c deleted file mode 100644 index 7c67c28d..00000000 --- a/c_src/libbcachefs/subvolume.c +++ /dev/null @@ -1,444 +0,0 @@ -// 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 <linux/random.h> - -static int bch2_subvolume_delete(struct btree_trans *, u32); - -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 bch_snapshot snapshot; - 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 (!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) - return ret; - - if (fsck_err_on(le32_to_cpu(st.master_subvol) != subvol.k->p.offset, - c, 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) - return ret; - - SET_BCH_SUBVOLUME_SNAP(&s->v, true); - } - } - -fsck_err: - 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; -} - -/* Subvolumes: */ - -int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k, - enum bkey_invalid_flags flags, struct printbuf *err) -{ - int ret = 0; - - bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) || - bkey_gt(k.k->p, SUBVOL_POS_MAX), c, err, - subvol_pos_bad, - "invalid pos"); -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, parent)) - prt_printf(out, " parent %u", le32_to_cpu(s.v->parent)); -} - -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) -{ - 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(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; -} - -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, parent) && - le32_to_cpu(bkey_s_c_to_subvolume(k).v->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.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.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 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.parent = cpu_to_le32(src_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_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; -} |