+++ /dev/null
-// 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;
-}
projects / bcachefs-tools-debian / blobdiff