445 lines
12 KiB
C
445 lines
12 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include "bcachefs.h"
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#include "btree_key_cache.h"
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#include "btree_update.h"
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#include "errcode.h"
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#include "error.h"
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#include "fs.h"
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#include "snapshot.h"
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#include "subvolume.h"
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#include <linux/random.h>
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static int bch2_subvolume_delete(struct btree_trans *, u32);
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static int check_subvol(struct btree_trans *trans,
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struct btree_iter *iter,
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struct bkey_s_c k)
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{
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struct bch_fs *c = trans->c;
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struct bkey_s_c_subvolume subvol;
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struct bch_snapshot snapshot;
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unsigned snapid;
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int ret = 0;
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if (k.k->type != KEY_TYPE_subvolume)
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return 0;
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subvol = bkey_s_c_to_subvolume(k);
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snapid = le32_to_cpu(subvol.v->snapshot);
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ret = bch2_snapshot_lookup(trans, snapid, &snapshot);
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if (bch2_err_matches(ret, ENOENT))
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bch_err(c, "subvolume %llu points to nonexistent snapshot %u",
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k.k->p.offset, snapid);
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if (ret)
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return ret;
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if (BCH_SUBVOLUME_UNLINKED(subvol.v)) {
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ret = bch2_subvolume_delete(trans, iter->pos.offset);
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bch_err_msg(c, ret, "deleting subvolume %llu", iter->pos.offset);
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return ret ?: -BCH_ERR_transaction_restart_nested;
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}
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if (!BCH_SUBVOLUME_SNAP(subvol.v)) {
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u32 snapshot_root = bch2_snapshot_root(c, le32_to_cpu(subvol.v->snapshot));
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u32 snapshot_tree;
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struct bch_snapshot_tree st;
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rcu_read_lock();
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snapshot_tree = snapshot_t(c, snapshot_root)->tree;
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rcu_read_unlock();
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ret = bch2_snapshot_tree_lookup(trans, snapshot_tree, &st);
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bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
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"%s: snapshot tree %u not found", __func__, snapshot_tree);
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if (ret)
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return ret;
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if (fsck_err_on(le32_to_cpu(st.master_subvol) != subvol.k->p.offset,
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c, subvol_not_master_and_not_snapshot,
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"subvolume %llu is not set as snapshot but is not master subvolume",
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k.k->p.offset)) {
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struct bkey_i_subvolume *s =
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bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume);
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ret = PTR_ERR_OR_ZERO(s);
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if (ret)
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return ret;
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SET_BCH_SUBVOLUME_SNAP(&s->v, true);
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}
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}
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fsck_err:
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return ret;
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}
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int bch2_check_subvols(struct bch_fs *c)
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{
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int ret = bch2_trans_run(c,
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for_each_btree_key_commit(trans, iter,
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BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k,
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NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
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check_subvol(trans, &iter, k)));
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bch_err_fn(c, ret);
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return ret;
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}
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/* Subvolumes: */
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int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k,
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enum bkey_invalid_flags flags, struct printbuf *err)
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{
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int ret = 0;
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bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) ||
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bkey_gt(k.k->p, SUBVOL_POS_MAX), c, err,
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subvol_pos_bad,
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"invalid pos");
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fsck_err:
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return ret;
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}
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void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c,
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struct bkey_s_c k)
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{
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struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
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prt_printf(out, "root %llu snapshot id %u",
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le64_to_cpu(s.v->inode),
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le32_to_cpu(s.v->snapshot));
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if (bkey_val_bytes(s.k) > offsetof(struct bch_subvolume, parent))
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prt_printf(out, " parent %u", le32_to_cpu(s.v->parent));
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}
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static __always_inline int
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bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol,
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bool inconsistent_if_not_found,
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int iter_flags,
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struct bch_subvolume *s)
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{
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int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, subvol),
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iter_flags, subvolume, s);
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bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT) &&
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inconsistent_if_not_found,
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trans->c, "missing subvolume %u", subvol);
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return ret;
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}
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int bch2_subvolume_get(struct btree_trans *trans, unsigned subvol,
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bool inconsistent_if_not_found,
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int iter_flags,
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struct bch_subvolume *s)
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{
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return bch2_subvolume_get_inlined(trans, subvol, inconsistent_if_not_found, iter_flags, s);
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}
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int bch2_subvol_is_ro_trans(struct btree_trans *trans, u32 subvol)
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{
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struct bch_subvolume s;
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int ret = bch2_subvolume_get_inlined(trans, subvol, true, 0, &s);
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if (ret)
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return ret;
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if (BCH_SUBVOLUME_RO(&s))
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return -EROFS;
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return 0;
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}
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int bch2_subvol_is_ro(struct bch_fs *c, u32 subvol)
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{
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return bch2_trans_do(c, NULL, NULL, 0,
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bch2_subvol_is_ro_trans(trans, subvol));
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}
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int bch2_snapshot_get_subvol(struct btree_trans *trans, u32 snapshot,
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struct bch_subvolume *subvol)
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{
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struct bch_snapshot snap;
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return bch2_snapshot_lookup(trans, snapshot, &snap) ?:
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bch2_subvolume_get(trans, le32_to_cpu(snap.subvol), true, 0, subvol);
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}
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int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid,
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u32 *snapid)
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{
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struct btree_iter iter;
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struct bkey_s_c_subvolume subvol;
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int ret;
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subvol = bch2_bkey_get_iter_typed(trans, &iter,
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BTREE_ID_subvolumes, POS(0, subvolid),
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BTREE_ITER_CACHED|BTREE_ITER_WITH_UPDATES,
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subvolume);
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ret = bkey_err(subvol);
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bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
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"missing subvolume %u", subvolid);
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if (likely(!ret))
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*snapid = le32_to_cpu(subvol.v->snapshot);
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bch2_trans_iter_exit(trans, &iter);
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return ret;
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}
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static int bch2_subvolume_reparent(struct btree_trans *trans,
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struct btree_iter *iter,
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struct bkey_s_c k,
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u32 old_parent, u32 new_parent)
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{
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struct bkey_i_subvolume *s;
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int ret;
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if (k.k->type != KEY_TYPE_subvolume)
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return 0;
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if (bkey_val_bytes(k.k) > offsetof(struct bch_subvolume, parent) &&
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le32_to_cpu(bkey_s_c_to_subvolume(k).v->parent) != old_parent)
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return 0;
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s = bch2_bkey_make_mut_typed(trans, iter, &k, 0, subvolume);
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ret = PTR_ERR_OR_ZERO(s);
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if (ret)
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return ret;
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s->v.parent = cpu_to_le32(new_parent);
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return 0;
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}
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/*
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* Separate from the snapshot tree in the snapshots btree, we record the tree
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* structure of how snapshot subvolumes were created - the parent subvolume of
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* each snapshot subvolume.
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*
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* When a subvolume is deleted, we scan for child subvolumes and reparant them,
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* to avoid dangling references:
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*/
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static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_delete)
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{
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struct bch_subvolume s;
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return lockrestart_do(trans,
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bch2_subvolume_get(trans, subvolid_to_delete, true,
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BTREE_ITER_CACHED, &s)) ?:
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for_each_btree_key_commit(trans, iter,
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BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k,
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NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
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bch2_subvolume_reparent(trans, &iter, k,
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subvolid_to_delete, le32_to_cpu(s.parent)));
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}
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/*
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* Delete subvolume, mark snapshot ID as deleted, queue up snapshot
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* deletion/cleanup:
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*/
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static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
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{
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struct btree_iter iter;
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struct bkey_s_c_subvolume subvol;
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u32 snapid;
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int ret = 0;
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subvol = bch2_bkey_get_iter_typed(trans, &iter,
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BTREE_ID_subvolumes, POS(0, subvolid),
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BTREE_ITER_CACHED|BTREE_ITER_INTENT,
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subvolume);
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ret = bkey_err(subvol);
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bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
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"missing subvolume %u", subvolid);
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if (ret)
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return ret;
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snapid = le32_to_cpu(subvol.v->snapshot);
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ret = bch2_btree_delete_at(trans, &iter, 0) ?:
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bch2_snapshot_node_set_deleted(trans, snapid);
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bch2_trans_iter_exit(trans, &iter);
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return ret;
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}
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static int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
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{
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return bch2_subvolumes_reparent(trans, subvolid) ?:
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commit_do(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
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__bch2_subvolume_delete(trans, subvolid));
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}
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static void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work)
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{
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struct bch_fs *c = container_of(work, struct bch_fs,
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snapshot_wait_for_pagecache_and_delete_work);
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snapshot_id_list s;
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u32 *id;
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int ret = 0;
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while (!ret) {
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mutex_lock(&c->snapshots_unlinked_lock);
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s = c->snapshots_unlinked;
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darray_init(&c->snapshots_unlinked);
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mutex_unlock(&c->snapshots_unlinked_lock);
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if (!s.nr)
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break;
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bch2_evict_subvolume_inodes(c, &s);
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for (id = s.data; id < s.data + s.nr; id++) {
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ret = bch2_trans_run(c, bch2_subvolume_delete(trans, *id));
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bch_err_msg(c, ret, "deleting subvolume %u", *id);
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if (ret)
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break;
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}
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darray_exit(&s);
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}
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bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache);
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}
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struct subvolume_unlink_hook {
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struct btree_trans_commit_hook h;
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u32 subvol;
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};
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static int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans,
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struct btree_trans_commit_hook *_h)
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{
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struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h);
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struct bch_fs *c = trans->c;
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int ret = 0;
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mutex_lock(&c->snapshots_unlinked_lock);
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if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol))
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ret = snapshot_list_add(c, &c->snapshots_unlinked, h->subvol);
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mutex_unlock(&c->snapshots_unlinked_lock);
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if (ret)
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return ret;
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if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_snapshot_delete_pagecache))
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return -EROFS;
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if (!queue_work(c->write_ref_wq, &c->snapshot_wait_for_pagecache_and_delete_work))
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bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache);
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return 0;
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}
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int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
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{
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struct btree_iter iter;
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struct bkey_i_subvolume *n;
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struct subvolume_unlink_hook *h;
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int ret = 0;
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h = bch2_trans_kmalloc(trans, sizeof(*h));
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ret = PTR_ERR_OR_ZERO(h);
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if (ret)
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return ret;
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h->h.fn = bch2_subvolume_wait_for_pagecache_and_delete_hook;
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h->subvol = subvolid;
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bch2_trans_commit_hook(trans, &h->h);
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n = bch2_bkey_get_mut_typed(trans, &iter,
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BTREE_ID_subvolumes, POS(0, subvolid),
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||
|
|
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;
|
||
|
|
}
|