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-rw-r--r--fs/bcachefs/fsck.c3196
1 files changed, 3196 insertions, 0 deletions
diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
new file mode 100644
index 000000000000..7b3b63ed747c
--- /dev/null
+++ b/fs/bcachefs/fsck.c
@@ -0,0 +1,3196 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "bkey_buf.h"
+#include "btree_cache.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "darray.h"
+#include "dirent.h"
+#include "error.h"
+#include "fs.h"
+#include "fs-common.h"
+#include "fsck.h"
+#include "inode.h"
+#include "keylist.h"
+#include "recovery_passes.h"
+#include "snapshot.h"
+#include "super.h"
+#include "xattr.h"
+
+#include <linux/bsearch.h>
+#include <linux/dcache.h> /* struct qstr */
+
+static bool inode_points_to_dirent(struct bch_inode_unpacked *inode,
+ struct bkey_s_c_dirent d)
+{
+ return inode->bi_dir == d.k->p.inode &&
+ inode->bi_dir_offset == d.k->p.offset;
+}
+
+static int dirent_points_to_inode_nowarn(struct bkey_s_c_dirent d,
+ struct bch_inode_unpacked *inode)
+{
+ if (d.v->d_type == DT_SUBVOL
+ ? le32_to_cpu(d.v->d_child_subvol) == inode->bi_subvol
+ : le64_to_cpu(d.v->d_inum) == inode->bi_inum)
+ return 0;
+ return -BCH_ERR_ENOENT_dirent_doesnt_match_inode;
+}
+
+static void dirent_inode_mismatch_msg(struct printbuf *out,
+ struct bch_fs *c,
+ struct bkey_s_c_dirent dirent,
+ struct bch_inode_unpacked *inode)
+{
+ prt_str(out, "inode points to dirent that does not point back:");
+ prt_newline(out);
+ bch2_bkey_val_to_text(out, c, dirent.s_c);
+ prt_newline(out);
+ bch2_inode_unpacked_to_text(out, inode);
+}
+
+static int dirent_points_to_inode(struct bch_fs *c,
+ struct bkey_s_c_dirent dirent,
+ struct bch_inode_unpacked *inode)
+{
+ int ret = dirent_points_to_inode_nowarn(dirent, inode);
+ if (ret) {
+ struct printbuf buf = PRINTBUF;
+ dirent_inode_mismatch_msg(&buf, c, dirent, inode);
+ bch_warn(c, "%s", buf.buf);
+ printbuf_exit(&buf);
+ }
+ return ret;
+}
+
+/*
+ * XXX: this is handling transaction restarts without returning
+ * -BCH_ERR_transaction_restart_nested, this is not how we do things anymore:
+ */
+static s64 bch2_count_inode_sectors(struct btree_trans *trans, u64 inum,
+ u32 snapshot)
+{
+ u64 sectors = 0;
+
+ int ret = for_each_btree_key_upto(trans, iter, BTREE_ID_extents,
+ SPOS(inum, 0, snapshot),
+ POS(inum, U64_MAX),
+ 0, k, ({
+ if (bkey_extent_is_allocation(k.k))
+ sectors += k.k->size;
+ 0;
+ }));
+
+ return ret ?: sectors;
+}
+
+static s64 bch2_count_subdirs(struct btree_trans *trans, u64 inum,
+ u32 snapshot)
+{
+ u64 subdirs = 0;
+
+ int ret = for_each_btree_key_upto(trans, iter, BTREE_ID_dirents,
+ SPOS(inum, 0, snapshot),
+ POS(inum, U64_MAX),
+ 0, k, ({
+ if (k.k->type == KEY_TYPE_dirent &&
+ bkey_s_c_to_dirent(k).v->d_type == DT_DIR)
+ subdirs++;
+ 0;
+ }));
+
+ return ret ?: subdirs;
+}
+
+static int subvol_lookup(struct btree_trans *trans, u32 subvol,
+ u32 *snapshot, u64 *inum)
+{
+ struct bch_subvolume s;
+ int ret = bch2_subvolume_get(trans, subvol, false, 0, &s);
+
+ *snapshot = le32_to_cpu(s.snapshot);
+ *inum = le64_to_cpu(s.inode);
+ return ret;
+}
+
+static int lookup_first_inode(struct btree_trans *trans, u64 inode_nr,
+ struct bch_inode_unpacked *inode)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ for_each_btree_key_norestart(trans, iter, BTREE_ID_inodes, POS(0, inode_nr),
+ BTREE_ITER_all_snapshots, k, ret) {
+ if (k.k->p.offset != inode_nr)
+ break;
+ if (!bkey_is_inode(k.k))
+ continue;
+ ret = bch2_inode_unpack(k, inode);
+ goto found;
+ }
+ ret = -BCH_ERR_ENOENT_inode;
+found:
+ bch_err_msg(trans->c, ret, "fetching inode %llu", inode_nr);
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int lookup_inode(struct btree_trans *trans, u64 inode_nr, u32 snapshot,
+ struct bch_inode_unpacked *inode)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
+ SPOS(0, inode_nr, snapshot), 0);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ ret = bkey_is_inode(k.k)
+ ? bch2_inode_unpack(k, inode)
+ : -BCH_ERR_ENOENT_inode;
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int lookup_dirent_in_snapshot(struct btree_trans *trans,
+ struct bch_hash_info hash_info,
+ subvol_inum dir, struct qstr *name,
+ u64 *target, unsigned *type, u32 snapshot)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k = bch2_hash_lookup_in_snapshot(trans, &iter, bch2_dirent_hash_desc,
+ &hash_info, dir, name, 0, snapshot);
+ int ret = bkey_err(k);
+ if (ret)
+ return ret;
+
+ struct bkey_s_c_dirent d = bkey_s_c_to_dirent(bch2_btree_iter_peek_slot(&iter));
+ *target = le64_to_cpu(d.v->d_inum);
+ *type = d.v->d_type;
+ bch2_trans_iter_exit(trans, &iter);
+ return 0;
+}
+
+static int __remove_dirent(struct btree_trans *trans, struct bpos pos)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bch_inode_unpacked dir_inode;
+ struct bch_hash_info dir_hash_info;
+ int ret;
+
+ ret = lookup_first_inode(trans, pos.inode, &dir_inode);
+ if (ret)
+ goto err;
+
+ dir_hash_info = bch2_hash_info_init(c, &dir_inode);
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_dirents, pos, BTREE_ITER_intent);
+
+ ret = bch2_btree_iter_traverse(&iter) ?:
+ bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
+ &dir_hash_info, &iter,
+ BTREE_UPDATE_internal_snapshot_node);
+ bch2_trans_iter_exit(trans, &iter);
+err:
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+/* Get lost+found, create if it doesn't exist: */
+static int lookup_lostfound(struct btree_trans *trans, u32 snapshot,
+ struct bch_inode_unpacked *lostfound,
+ u64 reattaching_inum)
+{
+ struct bch_fs *c = trans->c;
+ struct qstr lostfound_str = QSTR("lost+found");
+ u64 inum = 0;
+ unsigned d_type = 0;
+ int ret;
+
+ struct bch_snapshot_tree st;
+ ret = bch2_snapshot_tree_lookup(trans,
+ bch2_snapshot_tree(c, snapshot), &st);
+ if (ret)
+ return ret;
+
+ subvol_inum root_inum = { .subvol = le32_to_cpu(st.master_subvol) };
+
+ struct bch_subvolume subvol;
+ ret = bch2_subvolume_get(trans, le32_to_cpu(st.master_subvol),
+ false, 0, &subvol);
+ bch_err_msg(c, ret, "looking up root subvol %u for snapshot %u",
+ le32_to_cpu(st.master_subvol), snapshot);
+ if (ret)
+ return ret;
+
+ if (!subvol.inode) {
+ struct btree_iter iter;
+ struct bkey_i_subvolume *subvol = bch2_bkey_get_mut_typed(trans, &iter,
+ BTREE_ID_subvolumes, POS(0, le32_to_cpu(st.master_subvol)),
+ 0, subvolume);
+ ret = PTR_ERR_OR_ZERO(subvol);
+ if (ret)
+ return ret;
+
+ subvol->v.inode = cpu_to_le64(reattaching_inum);
+ bch2_trans_iter_exit(trans, &iter);
+ }
+
+ root_inum.inum = le64_to_cpu(subvol.inode);
+
+ struct bch_inode_unpacked root_inode;
+ struct bch_hash_info root_hash_info;
+ ret = lookup_inode(trans, root_inum.inum, snapshot, &root_inode);
+ bch_err_msg(c, ret, "looking up root inode %llu for subvol %u",
+ root_inum.inum, le32_to_cpu(st.master_subvol));
+ if (ret)
+ return ret;
+
+ root_hash_info = bch2_hash_info_init(c, &root_inode);
+
+ ret = lookup_dirent_in_snapshot(trans, root_hash_info, root_inum,
+ &lostfound_str, &inum, &d_type, snapshot);
+ if (bch2_err_matches(ret, ENOENT))
+ goto create_lostfound;
+
+ bch_err_fn(c, ret);
+ if (ret)
+ return ret;
+
+ if (d_type != DT_DIR) {
+ bch_err(c, "error looking up lost+found: not a directory");
+ return -BCH_ERR_ENOENT_not_directory;
+ }
+
+ /*
+ * The bch2_check_dirents pass has already run, dangling dirents
+ * shouldn't exist here:
+ */
+ ret = lookup_inode(trans, inum, snapshot, lostfound);
+ bch_err_msg(c, ret, "looking up lost+found %llu:%u in (root inode %llu, snapshot root %u)",
+ inum, snapshot, root_inum.inum, bch2_snapshot_root(c, snapshot));
+ return ret;
+
+create_lostfound:
+ /*
+ * we always create lost+found in the root snapshot; we don't want
+ * different branches of the snapshot tree to have different lost+found
+ */
+ snapshot = le32_to_cpu(st.root_snapshot);
+ /*
+ * XXX: we could have a nicer log message here if we had a nice way to
+ * walk backpointers to print a path
+ */
+ bch_notice(c, "creating lost+found in subvol %llu snapshot %u",
+ root_inum.subvol, le32_to_cpu(st.root_snapshot));
+
+ u64 now = bch2_current_time(c);
+ struct btree_iter lostfound_iter = { NULL };
+ u64 cpu = raw_smp_processor_id();
+
+ bch2_inode_init_early(c, lostfound);
+ bch2_inode_init_late(lostfound, now, 0, 0, S_IFDIR|0700, 0, &root_inode);
+ lostfound->bi_dir = root_inode.bi_inum;
+ lostfound->bi_snapshot = le32_to_cpu(st.root_snapshot);
+
+ root_inode.bi_nlink++;
+
+ ret = bch2_inode_create(trans, &lostfound_iter, lostfound, snapshot, cpu);
+ if (ret)
+ goto err;
+
+ bch2_btree_iter_set_snapshot(&lostfound_iter, snapshot);
+ ret = bch2_btree_iter_traverse(&lostfound_iter);
+ if (ret)
+ goto err;
+
+ ret = bch2_dirent_create_snapshot(trans,
+ 0, root_inode.bi_inum, snapshot, &root_hash_info,
+ mode_to_type(lostfound->bi_mode),
+ &lostfound_str,
+ lostfound->bi_inum,
+ &lostfound->bi_dir_offset,
+ STR_HASH_must_create) ?:
+ bch2_inode_write_flags(trans, &lostfound_iter, lostfound,
+ BTREE_UPDATE_internal_snapshot_node);
+err:
+ bch_err_msg(c, ret, "creating lost+found");
+ bch2_trans_iter_exit(trans, &lostfound_iter);
+ return ret;
+}
+
+static inline bool inode_should_reattach(struct bch_inode_unpacked *inode)
+{
+ if (inode->bi_inum == BCACHEFS_ROOT_INO &&
+ inode->bi_subvol == BCACHEFS_ROOT_SUBVOL)
+ return false;
+
+ return !inode->bi_dir && !(inode->bi_flags & BCH_INODE_unlinked);
+}
+
+static int maybe_delete_dirent(struct btree_trans *trans, struct bpos d_pos, u32 snapshot)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_dirents,
+ SPOS(d_pos.inode, d_pos.offset, snapshot),
+ BTREE_ITER_intent|
+ BTREE_ITER_with_updates);
+ int ret = bkey_err(k);
+ if (ret)
+ return ret;
+
+ if (bpos_eq(k.k->p, d_pos)) {
+ /*
+ * delet_at() doesn't work because the update path doesn't
+ * internally use BTREE_ITER_with_updates yet
+ */
+ struct bkey_i *k = bch2_trans_kmalloc(trans, sizeof(*k));
+ ret = PTR_ERR_OR_ZERO(k);
+ if (ret)
+ goto err;
+
+ bkey_init(&k->k);
+ k->k.type = KEY_TYPE_whiteout;
+ k->k.p = iter.pos;
+ ret = bch2_trans_update(trans, &iter, k, BTREE_UPDATE_internal_snapshot_node);
+ }
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int reattach_inode(struct btree_trans *trans, struct bch_inode_unpacked *inode)
+{
+ struct bch_fs *c = trans->c;
+ struct bch_inode_unpacked lostfound;
+ char name_buf[20];
+ int ret;
+
+ u32 dirent_snapshot = inode->bi_snapshot;
+ if (inode->bi_subvol) {
+ inode->bi_parent_subvol = BCACHEFS_ROOT_SUBVOL;
+
+ u64 root_inum;
+ ret = subvol_lookup(trans, inode->bi_parent_subvol,
+ &dirent_snapshot, &root_inum);
+ if (ret)
+ return ret;
+
+ snprintf(name_buf, sizeof(name_buf), "subvol-%u", inode->bi_subvol);
+ } else {
+ snprintf(name_buf, sizeof(name_buf), "%llu", inode->bi_inum);
+ }
+
+ ret = lookup_lostfound(trans, dirent_snapshot, &lostfound, inode->bi_inum);
+ if (ret)
+ return ret;
+
+ lostfound.bi_nlink += S_ISDIR(inode->bi_mode);
+
+ /* ensure lost+found inode is also present in inode snapshot */
+ if (!inode->bi_subvol) {
+ BUG_ON(!bch2_snapshot_is_ancestor(c, inode->bi_snapshot, lostfound.bi_snapshot));
+ lostfound.bi_snapshot = inode->bi_snapshot;
+ }
+
+ ret = __bch2_fsck_write_inode(trans, &lostfound);
+ if (ret)
+ return ret;
+
+ struct bch_hash_info dir_hash = bch2_hash_info_init(c, &lostfound);
+ struct qstr name = QSTR(name_buf);
+
+ inode->bi_dir = lostfound.bi_inum;
+
+ ret = bch2_dirent_create_snapshot(trans,
+ inode->bi_parent_subvol, lostfound.bi_inum,
+ dirent_snapshot,
+ &dir_hash,
+ inode_d_type(inode),
+ &name,
+ inode->bi_subvol ?: inode->bi_inum,
+ &inode->bi_dir_offset,
+ STR_HASH_must_create);
+ if (ret) {
+ bch_err_msg(c, ret, "error creating dirent");
+ return ret;
+ }
+
+ ret = __bch2_fsck_write_inode(trans, inode);
+ if (ret)
+ return ret;
+
+ /*
+ * Fix up inodes in child snapshots: if they should also be reattached
+ * update the backpointer field, if they should not be we need to emit
+ * whiteouts for the dirent we just created.
+ */
+ if (!inode->bi_subvol && bch2_snapshot_is_leaf(c, inode->bi_snapshot) <= 0) {
+ snapshot_id_list whiteouts_done;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+
+ darray_init(&whiteouts_done);
+
+ for_each_btree_key_reverse_norestart(trans, iter,
+ BTREE_ID_inodes, SPOS(0, inode->bi_inum, inode->bi_snapshot - 1),
+ BTREE_ITER_all_snapshots|BTREE_ITER_intent, k, ret) {
+ if (k.k->p.offset != inode->bi_inum)
+ break;
+
+ if (!bkey_is_inode(k.k) ||
+ !bch2_snapshot_is_ancestor(c, k.k->p.snapshot, inode->bi_snapshot) ||
+ snapshot_list_has_ancestor(c, &whiteouts_done, k.k->p.snapshot))
+ continue;
+
+ struct bch_inode_unpacked child_inode;
+ bch2_inode_unpack(k, &child_inode);
+
+ if (!inode_should_reattach(&child_inode)) {
+ ret = maybe_delete_dirent(trans,
+ SPOS(lostfound.bi_inum, inode->bi_dir_offset,
+ dirent_snapshot),
+ k.k->p.snapshot);
+ if (ret)
+ break;
+
+ ret = snapshot_list_add(c, &whiteouts_done, k.k->p.snapshot);
+ if (ret)
+ break;
+ } else {
+ iter.snapshot = k.k->p.snapshot;
+ child_inode.bi_dir = inode->bi_dir;
+ child_inode.bi_dir_offset = inode->bi_dir_offset;
+
+ ret = bch2_inode_write_flags(trans, &iter, &child_inode,
+ BTREE_UPDATE_internal_snapshot_node);
+ if (ret)
+ break;
+ }
+ }
+ darray_exit(&whiteouts_done);
+ bch2_trans_iter_exit(trans, &iter);
+ }
+
+ return ret;
+}
+
+static int remove_backpointer(struct btree_trans *trans,
+ struct bch_inode_unpacked *inode)
+{
+ if (!inode->bi_dir)
+ return 0;
+
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c_dirent d =
+ bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_dirents,
+ SPOS(inode->bi_dir, inode->bi_dir_offset, inode->bi_snapshot), 0,
+ dirent);
+ int ret = bkey_err(d) ?:
+ dirent_points_to_inode(c, d, inode) ?:
+ __remove_dirent(trans, d.k->p);
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int reattach_subvol(struct btree_trans *trans, struct bkey_s_c_subvolume s)
+{
+ struct bch_fs *c = trans->c;
+
+ struct bch_inode_unpacked inode;
+ int ret = bch2_inode_find_by_inum_trans(trans,
+ (subvol_inum) { s.k->p.offset, le64_to_cpu(s.v->inode) },
+ &inode);
+ if (ret)
+ return ret;
+
+ ret = remove_backpointer(trans, &inode);
+ if (!bch2_err_matches(ret, ENOENT))
+ bch_err_msg(c, ret, "removing dirent");
+ if (ret)
+ return ret;
+
+ ret = reattach_inode(trans, &inode);
+ bch_err_msg(c, ret, "reattaching inode %llu", inode.bi_inum);
+ return ret;
+}
+
+static int reconstruct_subvol(struct btree_trans *trans, u32 snapshotid, u32 subvolid, u64 inum)
+{
+ struct bch_fs *c = trans->c;
+
+ if (!bch2_snapshot_is_leaf(c, snapshotid)) {
+ bch_err(c, "need to reconstruct subvol, but have interior node snapshot");
+ return -BCH_ERR_fsck_repair_unimplemented;
+ }
+
+ /*
+ * If inum isn't set, that means we're being called from check_dirents,
+ * not check_inodes - the root of this subvolume doesn't exist or we
+ * would have found it there:
+ */
+ if (!inum) {
+ struct btree_iter inode_iter = {};
+ struct bch_inode_unpacked new_inode;
+ u64 cpu = raw_smp_processor_id();
+
+ bch2_inode_init_early(c, &new_inode);
+ bch2_inode_init_late(&new_inode, bch2_current_time(c), 0, 0, S_IFDIR|0755, 0, NULL);
+
+ new_inode.bi_subvol = subvolid;
+
+ int ret = bch2_inode_create(trans, &inode_iter, &new_inode, snapshotid, cpu) ?:
+ bch2_btree_iter_traverse(&inode_iter) ?:
+ bch2_inode_write(trans, &inode_iter, &new_inode);
+ bch2_trans_iter_exit(trans, &inode_iter);
+ if (ret)
+ return ret;
+
+ inum = new_inode.bi_inum;
+ }
+
+ bch_info(c, "reconstructing subvol %u with root inode %llu", subvolid, inum);
+
+ struct bkey_i_subvolume *new_subvol = bch2_trans_kmalloc(trans, sizeof(*new_subvol));
+ int ret = PTR_ERR_OR_ZERO(new_subvol);
+ if (ret)
+ return ret;
+
+ bkey_subvolume_init(&new_subvol->k_i);
+ new_subvol->k.p.offset = subvolid;
+ new_subvol->v.snapshot = cpu_to_le32(snapshotid);
+ new_subvol->v.inode = cpu_to_le64(inum);
+ ret = bch2_btree_insert_trans(trans, BTREE_ID_subvolumes, &new_subvol->k_i, 0);
+ if (ret)
+ return ret;
+
+ struct btree_iter iter;
+ struct bkey_i_snapshot *s = bch2_bkey_get_mut_typed(trans, &iter,
+ BTREE_ID_snapshots, POS(0, snapshotid),
+ 0, snapshot);
+ ret = PTR_ERR_OR_ZERO(s);
+ bch_err_msg(c, ret, "getting snapshot %u", snapshotid);
+ if (ret)
+ return ret;
+
+ u32 snapshot_tree = le32_to_cpu(s->v.tree);
+
+ s->v.subvol = cpu_to_le32(subvolid);
+ SET_BCH_SNAPSHOT_SUBVOL(&s->v, true);
+ bch2_trans_iter_exit(trans, &iter);
+
+ struct bkey_i_snapshot_tree *st = bch2_bkey_get_mut_typed(trans, &iter,
+ BTREE_ID_snapshot_trees, POS(0, snapshot_tree),
+ 0, snapshot_tree);
+ ret = PTR_ERR_OR_ZERO(st);
+ bch_err_msg(c, ret, "getting snapshot tree %u", snapshot_tree);
+ if (ret)
+ return ret;
+
+ if (!st->v.master_subvol)
+ st->v.master_subvol = cpu_to_le32(subvolid);
+
+ bch2_trans_iter_exit(trans, &iter);
+ return 0;
+}
+
+static int reconstruct_inode(struct btree_trans *trans, enum btree_id btree, u32 snapshot, u64 inum)
+{
+ struct bch_fs *c = trans->c;
+ unsigned i_mode = S_IFREG;
+ u64 i_size = 0;
+
+ switch (btree) {
+ case BTREE_ID_extents: {
+ struct btree_iter iter = {};
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_extents, SPOS(inum, U64_MAX, snapshot), 0);
+ struct bkey_s_c k = bch2_btree_iter_peek_prev(&iter);
+ bch2_trans_iter_exit(trans, &iter);
+ int ret = bkey_err(k);
+ if (ret)
+ return ret;
+
+ i_size = k.k->p.offset << 9;
+ break;
+ }
+ case BTREE_ID_dirents:
+ i_mode = S_IFDIR;
+ break;
+ case BTREE_ID_xattrs:
+ break;
+ default:
+ BUG();
+ }
+
+ struct bch_inode_unpacked new_inode;
+ bch2_inode_init_early(c, &new_inode);
+ bch2_inode_init_late(&new_inode, bch2_current_time(c), 0, 0, i_mode|0600, 0, NULL);
+ new_inode.bi_size = i_size;
+ new_inode.bi_inum = inum;
+ new_inode.bi_snapshot = snapshot;
+
+ return __bch2_fsck_write_inode(trans, &new_inode);
+}
+
+struct snapshots_seen {
+ struct bpos pos;
+ snapshot_id_list ids;
+};
+
+static inline void snapshots_seen_exit(struct snapshots_seen *s)
+{
+ darray_exit(&s->ids);
+}
+
+static inline void snapshots_seen_init(struct snapshots_seen *s)
+{
+ memset(s, 0, sizeof(*s));
+}
+
+static int snapshots_seen_add_inorder(struct bch_fs *c, struct snapshots_seen *s, u32 id)
+{
+ u32 *i;
+ __darray_for_each(s->ids, i) {
+ if (*i == id)
+ return 0;
+ if (*i > id)
+ break;
+ }
+
+ int ret = darray_insert_item(&s->ids, i - s->ids.data, id);
+ if (ret)
+ bch_err(c, "error reallocating snapshots_seen table (size %zu)",
+ s->ids.size);
+ return ret;
+}
+
+static int snapshots_seen_update(struct bch_fs *c, struct snapshots_seen *s,
+ enum btree_id btree_id, struct bpos pos)
+{
+ if (!bkey_eq(s->pos, pos))
+ s->ids.nr = 0;
+ s->pos = pos;
+
+ return snapshot_list_add_nodup(c, &s->ids, pos.snapshot);
+}
+
+/**
+ * key_visible_in_snapshot - returns true if @id is a descendent of @ancestor,
+ * and @ancestor hasn't been overwritten in @seen
+ *
+ * @c: filesystem handle
+ * @seen: list of snapshot ids already seen at current position
+ * @id: descendent snapshot id
+ * @ancestor: ancestor snapshot id
+ *
+ * Returns: whether key in @ancestor snapshot is visible in @id snapshot
+ */
+static bool key_visible_in_snapshot(struct bch_fs *c, struct snapshots_seen *seen,
+ u32 id, u32 ancestor)
+{
+ ssize_t i;
+
+ EBUG_ON(id > ancestor);
+
+ /* @ancestor should be the snapshot most recently added to @seen */
+ EBUG_ON(ancestor != seen->pos.snapshot);
+ EBUG_ON(ancestor != darray_last(seen->ids));
+
+ if (id == ancestor)
+ return true;
+
+ if (!bch2_snapshot_is_ancestor(c, id, ancestor))
+ return false;
+
+ /*
+ * We know that @id is a descendant of @ancestor, we're checking if
+ * we've seen a key that overwrote @ancestor - i.e. also a descendent of
+ * @ascestor and with @id as a descendent.
+ *
+ * But we already know that we're scanning IDs between @id and @ancestor
+ * numerically, since snapshot ID lists are kept sorted, so if we find
+ * an id that's an ancestor of @id we're done:
+ */
+
+ for (i = seen->ids.nr - 2;
+ i >= 0 && seen->ids.data[i] >= id;
+ --i)
+ if (bch2_snapshot_is_ancestor(c, id, seen->ids.data[i]))
+ return false;
+
+ return true;
+}
+
+/**
+ * ref_visible - given a key with snapshot id @src that points to a key with
+ * snapshot id @dst, test whether there is some snapshot in which @dst is
+ * visible.
+ *
+ * @c: filesystem handle
+ * @s: list of snapshot IDs already seen at @src
+ * @src: snapshot ID of src key
+ * @dst: snapshot ID of dst key
+ * Returns: true if there is some snapshot in which @dst is visible
+ *
+ * Assumes we're visiting @src keys in natural key order
+ */
+static bool ref_visible(struct bch_fs *c, struct snapshots_seen *s,
+ u32 src, u32 dst)
+{
+ return dst <= src
+ ? key_visible_in_snapshot(c, s, dst, src)
+ : bch2_snapshot_is_ancestor(c, src, dst);
+}
+
+static int ref_visible2(struct bch_fs *c,
+ u32 src, struct snapshots_seen *src_seen,
+ u32 dst, struct snapshots_seen *dst_seen)
+{
+ if (dst > src) {
+ swap(dst, src);
+ swap(dst_seen, src_seen);
+ }
+ return key_visible_in_snapshot(c, src_seen, dst, src);
+}
+
+#define for_each_visible_inode(_c, _s, _w, _snapshot, _i) \
+ for (_i = (_w)->inodes.data; _i < (_w)->inodes.data + (_w)->inodes.nr && \
+ (_i)->snapshot <= (_snapshot); _i++) \
+ if (key_visible_in_snapshot(_c, _s, _i->snapshot, _snapshot))
+
+struct inode_walker_entry {
+ struct bch_inode_unpacked inode;
+ u32 snapshot;
+ u64 count;
+};
+
+struct inode_walker {
+ bool first_this_inode;
+ bool have_inodes;
+ bool recalculate_sums;
+ struct bpos last_pos;
+
+ DARRAY(struct inode_walker_entry) inodes;
+};
+
+static void inode_walker_exit(struct inode_walker *w)
+{
+ darray_exit(&w->inodes);
+}
+
+static struct inode_walker inode_walker_init(void)
+{
+ return (struct inode_walker) { 0, };
+}
+
+static int add_inode(struct bch_fs *c, struct inode_walker *w,
+ struct bkey_s_c inode)
+{
+ struct bch_inode_unpacked u;
+
+ BUG_ON(bch2_inode_unpack(inode, &u));
+
+ return darray_push(&w->inodes, ((struct inode_walker_entry) {
+ .inode = u,
+ .snapshot = inode.k->p.snapshot,
+ }));
+}
+
+static int get_inodes_all_snapshots(struct btree_trans *trans,
+ struct inode_walker *w, u64 inum)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ /*
+ * We no longer have inodes for w->last_pos; clear this to avoid
+ * screwing up check_i_sectors/check_subdir_count if we take a
+ * transaction restart here:
+ */
+ w->have_inodes = false;
+ w->recalculate_sums = false;
+ w->inodes.nr = 0;
+
+ for_each_btree_key_norestart(trans, iter, BTREE_ID_inodes, POS(0, inum),
+ BTREE_ITER_all_snapshots, k, ret) {
+ if (k.k->p.offset != inum)
+ break;
+
+ if (bkey_is_inode(k.k))
+ add_inode(c, w, k);
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ if (ret)
+ return ret;
+
+ w->first_this_inode = true;
+ w->have_inodes = true;
+ return 0;
+}
+
+static struct inode_walker_entry *
+lookup_inode_for_snapshot(struct bch_fs *c, struct inode_walker *w, struct bkey_s_c k)
+{
+ bool is_whiteout = k.k->type == KEY_TYPE_whiteout;
+
+ struct inode_walker_entry *i;
+ __darray_for_each(w->inodes, i)
+ if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, i->snapshot))
+ goto found;
+
+ return NULL;
+found:
+ BUG_ON(k.k->p.snapshot > i->snapshot);
+
+ if (k.k->p.snapshot != i->snapshot && !is_whiteout) {
+ struct inode_walker_entry new = *i;
+
+ new.snapshot = k.k->p.snapshot;
+ new.count = 0;
+
+ struct printbuf buf = PRINTBUF;
+ bch2_bkey_val_to_text(&buf, c, k);
+
+ bch_info(c, "have key for inode %llu:%u but have inode in ancestor snapshot %u\n"
+ "unexpected because we should always update the inode when we update a key in that inode\n"
+ "%s",
+ w->last_pos.inode, k.k->p.snapshot, i->snapshot, buf.buf);
+ printbuf_exit(&buf);
+
+ while (i > w->inodes.data && i[-1].snapshot > k.k->p.snapshot)
+ --i;
+
+ size_t pos = i - w->inodes.data;
+ int ret = darray_insert_item(&w->inodes, pos, new);
+ if (ret)
+ return ERR_PTR(ret);
+
+ i = w->inodes.data + pos;
+ }
+
+ return i;
+}
+
+static struct inode_walker_entry *walk_inode(struct btree_trans *trans,
+ struct inode_walker *w,
+ struct bkey_s_c k)
+{
+ if (w->last_pos.inode != k.k->p.inode) {
+ int ret = get_inodes_all_snapshots(trans, w, k.k->p.inode);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ w->last_pos = k.k->p;
+
+ return lookup_inode_for_snapshot(trans->c, w, k);
+}
+
+static int get_visible_inodes(struct btree_trans *trans,
+ struct inode_walker *w,
+ struct snapshots_seen *s,
+ u64 inum)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ w->inodes.nr = 0;
+
+ for_each_btree_key_norestart(trans, iter, BTREE_ID_inodes, POS(0, inum),
+ BTREE_ITER_all_snapshots, k, ret) {
+ if (k.k->p.offset != inum)
+ break;
+
+ if (!ref_visible(c, s, s->pos.snapshot, k.k->p.snapshot))
+ continue;
+
+ if (bkey_is_inode(k.k))
+ add_inode(c, w, k);
+
+ if (k.k->p.snapshot >= s->pos.snapshot)
+ break;
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ return ret;
+}
+
+static int dirent_has_target(struct btree_trans *trans, struct bkey_s_c_dirent d)
+{
+ if (d.v->d_type == DT_SUBVOL) {
+ u32 snap;
+ u64 inum;
+ int ret = subvol_lookup(trans, le32_to_cpu(d.v->d_child_subvol), &snap, &inum);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+ return !ret;
+ } else {
+ struct btree_iter iter;
+ struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
+ SPOS(0, le64_to_cpu(d.v->d_inum), d.k->p.snapshot), 0);
+ int ret = bkey_err(k);
+ if (ret)
+ return ret;
+
+ ret = bkey_is_inode(k.k);
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+ }
+}
+
+/*
+ * Prefer to delete the first one, since that will be the one at the wrong
+ * offset:
+ * return value: 0 -> delete k1, 1 -> delete k2
+ */
+static int hash_pick_winner(struct btree_trans *trans,
+ const struct bch_hash_desc desc,
+ struct bch_hash_info *hash_info,
+ struct bkey_s_c k1,
+ struct bkey_s_c k2)
+{
+ if (bkey_val_bytes(k1.k) == bkey_val_bytes(k2.k) &&
+ !memcmp(k1.v, k2.v, bkey_val_bytes(k1.k)))
+ return 0;
+
+ switch (desc.btree_id) {
+ case BTREE_ID_dirents: {
+ int ret = dirent_has_target(trans, bkey_s_c_to_dirent(k1));
+ if (ret < 0)
+ return ret;
+ if (!ret)
+ return 0;
+
+ ret = dirent_has_target(trans, bkey_s_c_to_dirent(k2));
+ if (ret < 0)
+ return ret;
+ if (!ret)
+ return 1;
+ return 2;
+ }
+ default:
+ return 0;
+ }
+}
+
+static int fsck_update_backpointers(struct btree_trans *trans,
+ struct snapshots_seen *s,
+ const struct bch_hash_desc desc,
+ struct bch_hash_info *hash_info,
+ struct bkey_i *new)
+{
+ if (new->k.type != KEY_TYPE_dirent)
+ return 0;
+
+ struct bkey_i_dirent *d = bkey_i_to_dirent(new);
+ struct inode_walker target = inode_walker_init();
+ int ret = 0;
+
+ if (d->v.d_type == DT_SUBVOL) {
+ BUG();
+ } else {
+ ret = get_visible_inodes(trans, &target, s, le64_to_cpu(d->v.d_inum));
+ if (ret)
+ goto err;
+
+ darray_for_each(target.inodes, i) {
+ i->inode.bi_dir_offset = d->k.p.offset;
+ ret = __bch2_fsck_write_inode(trans, &i->inode);
+ if (ret)
+ goto err;
+ }
+ }
+err:
+ inode_walker_exit(&target);
+ return ret;
+}
+
+static int fsck_rename_dirent(struct btree_trans *trans,
+ struct snapshots_seen *s,
+ const struct bch_hash_desc desc,
+ struct bch_hash_info *hash_info,
+ struct bkey_s_c_dirent old)
+{
+ struct qstr old_name = bch2_dirent_get_name(old);
+ struct bkey_i_dirent *new = bch2_trans_kmalloc(trans, bkey_bytes(old.k) + 32);
+ int ret = PTR_ERR_OR_ZERO(new);
+ if (ret)
+ return ret;
+
+ bkey_dirent_init(&new->k_i);
+ dirent_copy_target(new, old);
+ new->k.p = old.k->p;
+
+ for (unsigned i = 0; i < 1000; i++) {
+ unsigned len = sprintf(new->v.d_name, "%.*s.fsck_renamed-%u",
+ old_name.len, old_name.name, i);
+ unsigned u64s = BKEY_U64s + dirent_val_u64s(len);
+
+ if (u64s > U8_MAX)
+ return -EINVAL;
+
+ new->k.u64s = u64s;
+
+ ret = bch2_hash_set_in_snapshot(trans, bch2_dirent_hash_desc, hash_info,
+ (subvol_inum) { 0, old.k->p.inode },
+ old.k->p.snapshot, &new->k_i,
+ BTREE_UPDATE_internal_snapshot_node);
+ if (!bch2_err_matches(ret, EEXIST))
+ break;
+ }
+
+ if (ret)
+ return ret;
+
+ return fsck_update_backpointers(trans, s, desc, hash_info, &new->k_i);
+}
+
+static int hash_check_key(struct btree_trans *trans,
+ struct snapshots_seen *s,
+ const struct bch_hash_desc desc,
+ struct bch_hash_info *hash_info,
+ struct btree_iter *k_iter, struct bkey_s_c hash_k)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter = { NULL };
+ struct printbuf buf = PRINTBUF;
+ struct bkey_s_c k;
+ u64 hash;
+ int ret = 0;
+
+ if (hash_k.k->type != desc.key_type)
+ return 0;
+
+ hash = desc.hash_bkey(hash_info, hash_k);
+
+ if (likely(hash == hash_k.k->p.offset))
+ return 0;
+
+ if (hash_k.k->p.offset < hash)
+ goto bad_hash;
+
+ for_each_btree_key_norestart(trans, iter, desc.btree_id,
+ SPOS(hash_k.k->p.inode, hash, hash_k.k->p.snapshot),
+ BTREE_ITER_slots, k, ret) {
+ if (bkey_eq(k.k->p, hash_k.k->p))
+ break;
+
+ if (k.k->type == desc.key_type &&
+ !desc.cmp_bkey(k, hash_k))
+ goto duplicate_entries;
+
+ if (bkey_deleted(k.k)) {
+ bch2_trans_iter_exit(trans, &iter);
+ goto bad_hash;
+ }
+ }
+out:
+ bch2_trans_iter_exit(trans, &iter);
+ printbuf_exit(&buf);
+ return ret;
+bad_hash:
+ if (fsck_err(trans, hash_table_key_wrong_offset,
+ "hash table key at wrong offset: btree %s inode %llu offset %llu, hashed to %llu\n %s",
+ bch2_btree_id_str(desc.btree_id), hash_k.k->p.inode, hash_k.k->p.offset, hash,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, hash_k), buf.buf))) {
+ struct bkey_i *new = bch2_bkey_make_mut_noupdate(trans, hash_k);
+ if (IS_ERR(new))
+ return PTR_ERR(new);
+
+ k = bch2_hash_set_or_get_in_snapshot(trans, &iter, desc, hash_info,
+ (subvol_inum) { 0, hash_k.k->p.inode },
+ hash_k.k->p.snapshot, new,
+ STR_HASH_must_create|
+ BTREE_ITER_with_updates|
+ BTREE_UPDATE_internal_snapshot_node);
+ ret = bkey_err(k);
+ if (ret)
+ goto out;
+ if (k.k)
+ goto duplicate_entries;
+
+ ret = bch2_hash_delete_at(trans, desc, hash_info, k_iter,
+ BTREE_UPDATE_internal_snapshot_node) ?:
+ fsck_update_backpointers(trans, s, desc, hash_info, new) ?:
+ bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc) ?:
+ -BCH_ERR_transaction_restart_nested;
+ goto out;
+ }
+fsck_err:
+ goto out;
+duplicate_entries:
+ ret = hash_pick_winner(trans, desc, hash_info, hash_k, k);
+ if (ret < 0)
+ goto out;
+
+ if (!fsck_err(trans, hash_table_key_duplicate,
+ "duplicate hash table keys%s:\n%s",
+ ret != 2 ? "" : ", both point to valid inodes",
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, hash_k),
+ prt_newline(&buf),
+ bch2_bkey_val_to_text(&buf, c, k),
+ buf.buf)))
+ goto out;
+
+ switch (ret) {
+ case 0:
+ ret = bch2_hash_delete_at(trans, desc, hash_info, k_iter, 0);
+ break;
+ case 1:
+ ret = bch2_hash_delete_at(trans, desc, hash_info, &iter, 0);
+ break;
+ case 2:
+ ret = fsck_rename_dirent(trans, s, desc, hash_info, bkey_s_c_to_dirent(hash_k)) ?:
+ bch2_hash_delete_at(trans, desc, hash_info, k_iter, 0);
+ goto out;
+ }
+
+ ret = bch2_trans_commit(trans, NULL, NULL, 0) ?:
+ -BCH_ERR_transaction_restart_nested;
+ goto out;
+}
+
+static struct bkey_s_c_dirent dirent_get_by_pos(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bpos pos)
+{
+ return bch2_bkey_get_iter_typed(trans, iter, BTREE_ID_dirents, pos, 0, dirent);
+}
+
+static struct bkey_s_c_dirent inode_get_dirent(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bch_inode_unpacked *inode,
+ u32 *snapshot)
+{
+ if (inode->bi_subvol) {
+ u64 inum;
+ int ret = subvol_lookup(trans, inode->bi_parent_subvol, snapshot, &inum);
+ if (ret)
+ return ((struct bkey_s_c_dirent) { .k = ERR_PTR(ret) });
+ }
+
+ return dirent_get_by_pos(trans, iter, SPOS(inode->bi_dir, inode->bi_dir_offset, *snapshot));
+}
+
+static int check_inode_deleted_list(struct btree_trans *trans, struct bpos p)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_deleted_inodes, p, 0);
+ int ret = bkey_err(k) ?: k.k->type == KEY_TYPE_set;
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int check_inode_dirent_inode(struct btree_trans *trans,
+ struct bch_inode_unpacked *inode,
+ bool *write_inode)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+
+ u32 inode_snapshot = inode->bi_snapshot;
+ struct btree_iter dirent_iter = {};
+ struct bkey_s_c_dirent d = inode_get_dirent(trans, &dirent_iter, inode, &inode_snapshot);
+ int ret = bkey_err(d);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+
+ if (fsck_err_on(ret,
+ trans, inode_points_to_missing_dirent,
+ "inode points to missing dirent\n%s",
+ (bch2_inode_unpacked_to_text(&buf, inode), buf.buf)) ||
+ fsck_err_on(!ret && dirent_points_to_inode_nowarn(d, inode),
+ trans, inode_points_to_wrong_dirent,
+ "%s",
+ (printbuf_reset(&buf),
+ dirent_inode_mismatch_msg(&buf, c, d, inode),
+ buf.buf))) {
+ /*
+ * We just clear the backpointer fields for now. If we find a
+ * dirent that points to this inode in check_dirents(), we'll
+ * update it then; then when we get to check_path() if the
+ * backpointer is still 0 we'll reattach it.
+ */
+ inode->bi_dir = 0;
+ inode->bi_dir_offset = 0;
+ *write_inode = true;
+ }
+
+ ret = 0;
+fsck_err:
+ bch2_trans_iter_exit(trans, &dirent_iter);
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int get_snapshot_root_inode(struct btree_trans *trans,
+ struct bch_inode_unpacked *root,
+ u64 inum)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret = 0;
+
+ for_each_btree_key_reverse_norestart(trans, iter, BTREE_ID_inodes,
+ SPOS(0, inum, U32_MAX),
+ BTREE_ITER_all_snapshots, k, ret) {
+ if (k.k->p.offset != inum)
+ break;
+ if (bkey_is_inode(k.k))
+ goto found_root;
+ }
+ if (ret)
+ goto err;
+ BUG();
+found_root:
+ BUG_ON(bch2_inode_unpack(k, root));
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int check_inode(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k,
+ struct bch_inode_unpacked *snapshot_root,
+ struct snapshots_seen *s)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ struct bch_inode_unpacked u;
+ bool do_update = false;
+ int ret;
+
+ ret = bch2_check_key_has_snapshot(trans, iter, k);
+ if (ret < 0)
+ goto err;
+ if (ret)
+ return 0;
+
+ ret = snapshots_seen_update(c, s, iter->btree_id, k.k->p);
+ if (ret)
+ goto err;
+
+ if (!bkey_is_inode(k.k))
+ return 0;
+
+ BUG_ON(bch2_inode_unpack(k, &u));
+
+ if (snapshot_root->bi_inum != u.bi_inum) {
+ ret = get_snapshot_root_inode(trans, snapshot_root, u.bi_inum);
+ if (ret)
+ goto err;
+ }
+
+ if (fsck_err_on(u.bi_hash_seed != snapshot_root->bi_hash_seed ||
+ INODE_STR_HASH(&u) != INODE_STR_HASH(snapshot_root),
+ trans, inode_snapshot_mismatch,
+ "inodes in different snapshots don't match")) {
+ u.bi_hash_seed = snapshot_root->bi_hash_seed;
+ SET_INODE_STR_HASH(&u, INODE_STR_HASH(snapshot_root));
+ do_update = true;
+ }
+
+ if (u.bi_dir || u.bi_dir_offset) {
+ ret = check_inode_dirent_inode(trans, &u, &do_update);
+ if (ret)
+ goto err;
+ }
+
+ if (fsck_err_on(u.bi_dir && (u.bi_flags & BCH_INODE_unlinked),
+ trans, inode_unlinked_but_has_dirent,
+ "inode unlinked but has dirent\n%s",
+ (printbuf_reset(&buf),
+ bch2_inode_unpacked_to_text(&buf, &u),
+ buf.buf))) {
+ u.bi_flags &= ~BCH_INODE_unlinked;
+ do_update = true;
+ }
+
+ if (S_ISDIR(u.bi_mode) && (u.bi_flags & BCH_INODE_unlinked)) {
+ /* Check for this early so that check_unreachable_inode() will reattach it */
+
+ ret = bch2_empty_dir_snapshot(trans, k.k->p.offset, 0, k.k->p.snapshot);
+ if (ret && ret != -BCH_ERR_ENOTEMPTY_dir_not_empty)
+ goto err;
+
+ fsck_err_on(ret, trans, inode_dir_unlinked_but_not_empty,
+ "dir unlinked but not empty\n%s",
+ (printbuf_reset(&buf),
+ bch2_inode_unpacked_to_text(&buf, &u),
+ buf.buf));
+ u.bi_flags &= ~BCH_INODE_unlinked;
+ do_update = true;
+ ret = 0;
+ }
+
+ ret = bch2_inode_has_child_snapshots(trans, k.k->p);
+ if (ret < 0)
+ goto err;
+
+ if (fsck_err_on(ret != !!(u.bi_flags & BCH_INODE_has_child_snapshot),
+ trans, inode_has_child_snapshots_wrong,
+ "inode has_child_snapshots flag wrong (should be %u)\n%s",
+ ret,
+ (printbuf_reset(&buf),
+ bch2_inode_unpacked_to_text(&buf, &u),
+ buf.buf))) {
+ if (ret)
+ u.bi_flags |= BCH_INODE_has_child_snapshot;
+ else
+ u.bi_flags &= ~BCH_INODE_has_child_snapshot;
+ do_update = true;
+ }
+ ret = 0;
+
+ if ((u.bi_flags & BCH_INODE_unlinked) &&
+ !(u.bi_flags & BCH_INODE_has_child_snapshot)) {
+ if (!test_bit(BCH_FS_started, &c->flags)) {
+ /*
+ * If we're not in online fsck, don't delete unlinked
+ * inodes, just make sure they're on the deleted list.
+ *
+ * They might be referred to by a logged operation -
+ * i.e. we might have crashed in the middle of a
+ * truncate on an unlinked but open file - so we want to
+ * let the delete_dead_inodes kill it after resuming
+ * logged ops.
+ */
+ ret = check_inode_deleted_list(trans, k.k->p);
+ if (ret < 0)
+ goto err_noprint;
+
+ fsck_err_on(!ret,
+ trans, unlinked_inode_not_on_deleted_list,
+ "inode %llu:%u unlinked, but not on deleted list",
+ u.bi_inum, k.k->p.snapshot);
+
+ ret = bch2_btree_bit_mod_buffered(trans, BTREE_ID_deleted_inodes, k.k->p, 1);
+ if (ret)
+ goto err;
+ } else {
+ ret = bch2_inode_or_descendents_is_open(trans, k.k->p);
+ if (ret < 0)
+ goto err;
+
+ if (fsck_err_on(!ret,
+ trans, inode_unlinked_and_not_open,
+ "inode %llu%u unlinked and not open",
+ u.bi_inum, u.bi_snapshot)) {
+ ret = bch2_inode_rm_snapshot(trans, u.bi_inum, iter->pos.snapshot);
+ bch_err_msg(c, ret, "in fsck deleting inode");
+ goto err_noprint;
+ }
+ ret = 0;
+ }
+ }
+
+ if (fsck_err_on(u.bi_parent_subvol &&
+ (u.bi_subvol == 0 ||
+ u.bi_subvol == BCACHEFS_ROOT_SUBVOL),
+ trans, inode_bi_parent_nonzero,
+ "inode %llu:%u has subvol %u but nonzero parent subvol %u",
+ u.bi_inum, k.k->p.snapshot, u.bi_subvol, u.bi_parent_subvol)) {
+ u.bi_parent_subvol = 0;
+ do_update = true;
+ }
+
+ if (u.bi_subvol) {
+ struct bch_subvolume s;
+
+ ret = bch2_subvolume_get(trans, u.bi_subvol, false, 0, &s);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ goto err;
+
+ if (ret && (c->sb.btrees_lost_data & BIT_ULL(BTREE_ID_subvolumes))) {
+ ret = reconstruct_subvol(trans, k.k->p.snapshot, u.bi_subvol, u.bi_inum);
+ goto do_update;
+ }
+
+ if (fsck_err_on(ret,
+ trans, inode_bi_subvol_missing,
+ "inode %llu:%u bi_subvol points to missing subvolume %u",
+ u.bi_inum, k.k->p.snapshot, u.bi_subvol) ||
+ fsck_err_on(le64_to_cpu(s.inode) != u.bi_inum ||
+ !bch2_snapshot_is_ancestor(c, le32_to_cpu(s.snapshot),
+ k.k->p.snapshot),
+ trans, inode_bi_subvol_wrong,
+ "inode %llu:%u points to subvol %u, but subvol points to %llu:%u",
+ u.bi_inum, k.k->p.snapshot, u.bi_subvol,
+ le64_to_cpu(s.inode),
+ le32_to_cpu(s.snapshot))) {
+ u.bi_subvol = 0;
+ u.bi_parent_subvol = 0;
+ do_update = true;
+ }
+ }
+do_update:
+ if (do_update) {
+ ret = __bch2_fsck_write_inode(trans, &u);
+ bch_err_msg(c, ret, "in fsck updating inode");
+ if (ret)
+ goto err_noprint;
+ }
+err:
+fsck_err:
+ bch_err_fn(c, ret);
+err_noprint:
+ printbuf_exit(&buf);
+ return ret;
+}
+
+int bch2_check_inodes(struct bch_fs *c)
+{
+ struct bch_inode_unpacked snapshot_root = {};
+ struct snapshots_seen s;
+
+ snapshots_seen_init(&s);
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter, BTREE_ID_inodes,
+ POS_MIN,
+ BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ check_inode(trans, &iter, k, &snapshot_root, &s)));
+
+ snapshots_seen_exit(&s);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int find_oldest_inode_needs_reattach(struct btree_trans *trans,
+ struct bch_inode_unpacked *inode)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret = 0;
+
+ /*
+ * We look for inodes to reattach in natural key order, leaves first,
+ * but we should do the reattach at the oldest version that needs to be
+ * reattached:
+ */
+ for_each_btree_key_norestart(trans, iter,
+ BTREE_ID_inodes,
+ SPOS(0, inode->bi_inum, inode->bi_snapshot + 1),
+ BTREE_ITER_all_snapshots, k, ret) {
+ if (k.k->p.offset != inode->bi_inum)
+ break;
+
+ if (!bch2_snapshot_is_ancestor(c, inode->bi_snapshot, k.k->p.snapshot))
+ continue;
+
+ if (!bkey_is_inode(k.k))
+ break;
+
+ struct bch_inode_unpacked parent_inode;
+ bch2_inode_unpack(k, &parent_inode);
+
+ if (!inode_should_reattach(&parent_inode))
+ break;
+
+ *inode = parent_inode;
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ return ret;
+}
+
+static int check_unreachable_inode(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ if (!bkey_is_inode(k.k))
+ return 0;
+
+ struct bch_inode_unpacked inode;
+ BUG_ON(bch2_inode_unpack(k, &inode));
+
+ if (!inode_should_reattach(&inode))
+ return 0;
+
+ ret = find_oldest_inode_needs_reattach(trans, &inode);
+ if (ret)
+ return ret;
+
+ if (fsck_err(trans, inode_unreachable,
+ "unreachable inode:\n%s",
+ (bch2_inode_unpacked_to_text(&buf, &inode),
+ buf.buf)))
+ ret = reattach_inode(trans, &inode);
+fsck_err:
+ printbuf_exit(&buf);
+ return ret;
+}
+
+/*
+ * Reattach unreachable (but not unlinked) inodes
+ *
+ * Run after check_inodes() and check_dirents(), so we node that inode
+ * backpointer fields point to valid dirents, and every inode that has a dirent
+ * that points to it has its backpointer field set - so we're just looking for
+ * non-unlinked inodes without backpointers:
+ *
+ * XXX: this is racy w.r.t. hardlink removal in online fsck
+ */
+int bch2_check_unreachable_inodes(struct bch_fs *c)
+{
+ int ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter, BTREE_ID_inodes,
+ POS_MIN,
+ BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ check_unreachable_inode(trans, &iter, k)));
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static inline bool btree_matches_i_mode(enum btree_id btree, unsigned mode)
+{
+ switch (btree) {
+ case BTREE_ID_extents:
+ return S_ISREG(mode) || S_ISLNK(mode);
+ case BTREE_ID_dirents:
+ return S_ISDIR(mode);
+ case BTREE_ID_xattrs:
+ return true;
+ default:
+ BUG();
+ }
+}
+
+static int check_key_has_inode(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct inode_walker *inode,
+ struct inode_walker_entry *i,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ int ret = PTR_ERR_OR_ZERO(i);
+ if (ret)
+ return ret;
+
+ if (k.k->type == KEY_TYPE_whiteout)
+ goto out;
+
+ if (!i && (c->sb.btrees_lost_data & BIT_ULL(BTREE_ID_inodes))) {
+ ret = reconstruct_inode(trans, iter->btree_id, k.k->p.snapshot, k.k->p.inode) ?:
+ bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
+ if (ret)
+ goto err;
+
+ inode->last_pos.inode--;
+ ret = -BCH_ERR_transaction_restart_nested;
+ goto err;
+ }
+
+ if (fsck_err_on(!i,
+ trans, key_in_missing_inode,
+ "key in missing inode:\n %s",
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+ goto delete;
+
+ if (fsck_err_on(i && !btree_matches_i_mode(iter->btree_id, i->inode.bi_mode),
+ trans, key_in_wrong_inode_type,
+ "key for wrong inode mode %o:\n %s",
+ i->inode.bi_mode,
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+ goto delete;
+out:
+err:
+fsck_err:
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+delete:
+ ret = bch2_btree_delete_at(trans, iter, BTREE_UPDATE_internal_snapshot_node);
+ goto out;
+}
+
+static int check_i_sectors_notnested(struct btree_trans *trans, struct inode_walker *w)
+{
+ struct bch_fs *c = trans->c;
+ int ret = 0;
+ s64 count2;
+
+ darray_for_each(w->inodes, i) {
+ if (i->inode.bi_sectors == i->count)
+ continue;
+
+ count2 = bch2_count_inode_sectors(trans, w->last_pos.inode, i->snapshot);
+
+ if (w->recalculate_sums)
+ i->count = count2;
+
+ if (i->count != count2) {
+ bch_err_ratelimited(c, "fsck counted i_sectors wrong for inode %llu:%u: got %llu should be %llu",
+ w->last_pos.inode, i->snapshot, i->count, count2);
+ return -BCH_ERR_internal_fsck_err;
+ }
+
+ if (fsck_err_on(!(i->inode.bi_flags & BCH_INODE_i_sectors_dirty),
+ trans, inode_i_sectors_wrong,
+ "inode %llu:%u has incorrect i_sectors: got %llu, should be %llu",
+ w->last_pos.inode, i->snapshot,
+ i->inode.bi_sectors, i->count)) {
+ i->inode.bi_sectors = i->count;
+ ret = bch2_fsck_write_inode(trans, &i->inode);
+ if (ret)
+ break;
+ }
+ }
+fsck_err:
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_i_sectors(struct btree_trans *trans, struct inode_walker *w)
+{
+ u32 restart_count = trans->restart_count;
+ return check_i_sectors_notnested(trans, w) ?:
+ trans_was_restarted(trans, restart_count);
+}
+
+struct extent_end {
+ u32 snapshot;
+ u64 offset;
+ struct snapshots_seen seen;
+};
+
+struct extent_ends {
+ struct bpos last_pos;
+ DARRAY(struct extent_end) e;
+};
+
+static void extent_ends_reset(struct extent_ends *extent_ends)
+{
+ darray_for_each(extent_ends->e, i)
+ snapshots_seen_exit(&i->seen);
+ extent_ends->e.nr = 0;
+}
+
+static void extent_ends_exit(struct extent_ends *extent_ends)
+{
+ extent_ends_reset(extent_ends);
+ darray_exit(&extent_ends->e);
+}
+
+static void extent_ends_init(struct extent_ends *extent_ends)
+{
+ memset(extent_ends, 0, sizeof(*extent_ends));
+}
+
+static int extent_ends_at(struct bch_fs *c,
+ struct extent_ends *extent_ends,
+ struct snapshots_seen *seen,
+ struct bkey_s_c k)
+{
+ struct extent_end *i, n = (struct extent_end) {
+ .offset = k.k->p.offset,
+ .snapshot = k.k->p.snapshot,
+ .seen = *seen,
+ };
+
+ n.seen.ids.data = kmemdup(seen->ids.data,
+ sizeof(seen->ids.data[0]) * seen->ids.size,
+ GFP_KERNEL);
+ if (!n.seen.ids.data)
+ return -BCH_ERR_ENOMEM_fsck_extent_ends_at;
+
+ __darray_for_each(extent_ends->e, i) {
+ if (i->snapshot == k.k->p.snapshot) {
+ snapshots_seen_exit(&i->seen);
+ *i = n;
+ return 0;
+ }
+
+ if (i->snapshot >= k.k->p.snapshot)
+ break;
+ }
+
+ return darray_insert_item(&extent_ends->e, i - extent_ends->e.data, n);
+}
+
+static int overlapping_extents_found(struct btree_trans *trans,
+ enum btree_id btree,
+ struct bpos pos1, struct snapshots_seen *pos1_seen,
+ struct bkey pos2,
+ bool *fixed,
+ struct extent_end *extent_end)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ struct btree_iter iter1, iter2 = { NULL };
+ struct bkey_s_c k1, k2;
+ int ret;
+
+ BUG_ON(bkey_le(pos1, bkey_start_pos(&pos2)));
+
+ bch2_trans_iter_init(trans, &iter1, btree, pos1,
+ BTREE_ITER_all_snapshots|
+ BTREE_ITER_not_extents);
+ k1 = bch2_btree_iter_peek_upto(&iter1, POS(pos1.inode, U64_MAX));
+ ret = bkey_err(k1);
+ if (ret)
+ goto err;
+
+ prt_str(&buf, "\n ");
+ bch2_bkey_val_to_text(&buf, c, k1);
+
+ if (!bpos_eq(pos1, k1.k->p)) {
+ prt_str(&buf, "\n wanted\n ");
+ bch2_bpos_to_text(&buf, pos1);
+ prt_str(&buf, "\n ");
+ bch2_bkey_to_text(&buf, &pos2);
+
+ bch_err(c, "%s: error finding first overlapping extent when repairing, got%s",
+ __func__, buf.buf);
+ ret = -BCH_ERR_internal_fsck_err;
+ goto err;
+ }
+
+ bch2_trans_copy_iter(&iter2, &iter1);
+
+ while (1) {
+ bch2_btree_iter_advance(&iter2);
+
+ k2 = bch2_btree_iter_peek_upto(&iter2, POS(pos1.inode, U64_MAX));
+ ret = bkey_err(k2);
+ if (ret)
+ goto err;
+
+ if (bpos_ge(k2.k->p, pos2.p))
+ break;
+ }
+
+ prt_str(&buf, "\n ");
+ bch2_bkey_val_to_text(&buf, c, k2);
+
+ if (bpos_gt(k2.k->p, pos2.p) ||
+ pos2.size != k2.k->size) {
+ bch_err(c, "%s: error finding seconding overlapping extent when repairing%s",
+ __func__, buf.buf);
+ ret = -BCH_ERR_internal_fsck_err;
+ goto err;
+ }
+
+ prt_printf(&buf, "\n overwriting %s extent",
+ pos1.snapshot >= pos2.p.snapshot ? "first" : "second");
+
+ if (fsck_err(trans, extent_overlapping,
+ "overlapping extents%s", buf.buf)) {
+ struct btree_iter *old_iter = &iter1;
+ struct disk_reservation res = { 0 };
+
+ if (pos1.snapshot < pos2.p.snapshot) {
+ old_iter = &iter2;
+ swap(k1, k2);
+ }
+
+ trans->extra_disk_res += bch2_bkey_sectors_compressed(k2);
+
+ ret = bch2_trans_update_extent_overwrite(trans, old_iter,
+ BTREE_UPDATE_internal_snapshot_node,
+ k1, k2) ?:
+ bch2_trans_commit(trans, &res, NULL, BCH_TRANS_COMMIT_no_enospc);
+ bch2_disk_reservation_put(c, &res);
+
+ if (ret)
+ goto err;
+
+ *fixed = true;
+
+ if (pos1.snapshot == pos2.p.snapshot) {
+ /*
+ * We overwrote the first extent, and did the overwrite
+ * in the same snapshot:
+ */
+ extent_end->offset = bkey_start_offset(&pos2);
+ } else if (pos1.snapshot > pos2.p.snapshot) {
+ /*
+ * We overwrote the first extent in pos2's snapshot:
+ */
+ ret = snapshots_seen_add_inorder(c, pos1_seen, pos2.p.snapshot);
+ } else {
+ /*
+ * We overwrote the second extent - restart
+ * check_extent() from the top:
+ */
+ ret = -BCH_ERR_transaction_restart_nested;
+ }
+ }
+fsck_err:
+err:
+ bch2_trans_iter_exit(trans, &iter2);
+ bch2_trans_iter_exit(trans, &iter1);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int check_overlapping_extents(struct btree_trans *trans,
+ struct snapshots_seen *seen,
+ struct extent_ends *extent_ends,
+ struct bkey_s_c k,
+ struct btree_iter *iter,
+ bool *fixed)
+{
+ struct bch_fs *c = trans->c;
+ int ret = 0;
+
+ /* transaction restart, running again */
+ if (bpos_eq(extent_ends->last_pos, k.k->p))
+ return 0;
+
+ if (extent_ends->last_pos.inode != k.k->p.inode)
+ extent_ends_reset(extent_ends);
+
+ darray_for_each(extent_ends->e, i) {
+ if (i->offset <= bkey_start_offset(k.k))
+ continue;
+
+ if (!ref_visible2(c,
+ k.k->p.snapshot, seen,
+ i->snapshot, &i->seen))
+ continue;
+
+ ret = overlapping_extents_found(trans, iter->btree_id,
+ SPOS(iter->pos.inode,
+ i->offset,
+ i->snapshot),
+ &i->seen,
+ *k.k, fixed, i);
+ if (ret)
+ goto err;
+ }
+
+ extent_ends->last_pos = k.k->p;
+err:
+ return ret;
+}
+
+static int check_extent_overbig(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+ struct bch_extent_crc_unpacked crc;
+ const union bch_extent_entry *i;
+ unsigned encoded_extent_max_sectors = c->opts.encoded_extent_max >> 9;
+
+ bkey_for_each_crc(k.k, ptrs, crc, i)
+ if (crc_is_encoded(crc) &&
+ crc.uncompressed_size > encoded_extent_max_sectors) {
+ struct printbuf buf = PRINTBUF;
+
+ bch2_bkey_val_to_text(&buf, c, k);
+ bch_err(c, "overbig encoded extent, please report this:\n %s", buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ return 0;
+}
+
+static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k,
+ struct inode_walker *inode,
+ struct snapshots_seen *s,
+ struct extent_ends *extent_ends,
+ struct disk_reservation *res)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ ret = bch2_check_key_has_snapshot(trans, iter, k);
+ if (ret) {
+ ret = ret < 0 ? ret : 0;
+ goto out;
+ }
+
+ if (inode->last_pos.inode != k.k->p.inode && inode->have_inodes) {
+ ret = check_i_sectors(trans, inode);
+ if (ret)
+ goto err;
+ }
+
+ ret = snapshots_seen_update(c, s, iter->btree_id, k.k->p);
+ if (ret)
+ goto err;
+
+ struct inode_walker_entry *extent_i = walk_inode(trans, inode, k);
+ ret = PTR_ERR_OR_ZERO(extent_i);
+ if (ret)
+ goto err;
+
+ ret = check_key_has_inode(trans, iter, inode, extent_i, k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_whiteout) {
+ ret = check_overlapping_extents(trans, s, extent_ends, k, iter,
+ &inode->recalculate_sums);
+ if (ret)
+ goto err;
+
+ /*
+ * Check inodes in reverse order, from oldest snapshots to
+ * newest, starting from the inode that matches this extent's
+ * snapshot. If we didn't have one, iterate over all inodes:
+ */
+ for (struct inode_walker_entry *i = extent_i ?: &darray_last(inode->inodes);
+ inode->inodes.data && i >= inode->inodes.data;
+ --i) {
+ if (i->snapshot > k.k->p.snapshot ||
+ !key_visible_in_snapshot(c, s, i->snapshot, k.k->p.snapshot))
+ continue;
+
+ if (fsck_err_on(k.k->p.offset > round_up(i->inode.bi_size, block_bytes(c)) >> 9 &&
+ !bkey_extent_is_reservation(k),
+ trans, extent_past_end_of_inode,
+ "extent type past end of inode %llu:%u, i_size %llu\n %s",
+ i->inode.bi_inum, i->snapshot, i->inode.bi_size,
+ (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+ struct btree_iter iter2;
+
+ bch2_trans_copy_iter(&iter2, iter);
+ bch2_btree_iter_set_snapshot(&iter2, i->snapshot);
+ ret = bch2_btree_iter_traverse(&iter2) ?:
+ bch2_btree_delete_at(trans, &iter2,
+ BTREE_UPDATE_internal_snapshot_node);
+ bch2_trans_iter_exit(trans, &iter2);
+ if (ret)
+ goto err;
+
+ iter->k.type = KEY_TYPE_whiteout;
+ break;
+ }
+ }
+ }
+
+ ret = bch2_trans_commit(trans, res, NULL, BCH_TRANS_COMMIT_no_enospc);
+ if (ret)
+ goto err;
+
+ if (bkey_extent_is_allocation(k.k)) {
+ for (struct inode_walker_entry *i = extent_i ?: &darray_last(inode->inodes);
+ inode->inodes.data && i >= inode->inodes.data;
+ --i) {
+ if (i->snapshot > k.k->p.snapshot ||
+ !key_visible_in_snapshot(c, s, i->snapshot, k.k->p.snapshot))
+ continue;
+
+ i->count += k.k->size;
+ }
+ }
+
+ if (k.k->type != KEY_TYPE_whiteout) {
+ ret = extent_ends_at(c, extent_ends, s, k);
+ if (ret)
+ goto err;
+ }
+out:
+err:
+fsck_err:
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+/*
+ * Walk extents: verify that extents have a corresponding S_ISREG inode, and
+ * that i_size an i_sectors are consistent
+ */
+int bch2_check_extents(struct bch_fs *c)
+{
+ struct inode_walker w = inode_walker_init();
+ struct snapshots_seen s;
+ struct extent_ends extent_ends;
+ struct disk_reservation res = { 0 };
+
+ snapshots_seen_init(&s);
+ extent_ends_init(&extent_ends);
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key(trans, iter, BTREE_ID_extents,
+ POS(BCACHEFS_ROOT_INO, 0),
+ BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k, ({
+ bch2_disk_reservation_put(c, &res);
+ check_extent(trans, &iter, k, &w, &s, &extent_ends, &res) ?:
+ check_extent_overbig(trans, &iter, k);
+ })) ?:
+ check_i_sectors_notnested(trans, &w));
+
+ bch2_disk_reservation_put(c, &res);
+ extent_ends_exit(&extent_ends);
+ inode_walker_exit(&w);
+ snapshots_seen_exit(&s);
+
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+int bch2_check_indirect_extents(struct bch_fs *c)
+{
+ struct disk_reservation res = { 0 };
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter, BTREE_ID_reflink,
+ POS_MIN,
+ BTREE_ITER_prefetch, k,
+ &res, NULL,
+ BCH_TRANS_COMMIT_no_enospc, ({
+ bch2_disk_reservation_put(c, &res);
+ check_extent_overbig(trans, &iter, k);
+ })));
+
+ bch2_disk_reservation_put(c, &res);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_subdir_count_notnested(struct btree_trans *trans, struct inode_walker *w)
+{
+ struct bch_fs *c = trans->c;
+ int ret = 0;
+ s64 count2;
+
+ darray_for_each(w->inodes, i) {
+ if (i->inode.bi_nlink == i->count)
+ continue;
+
+ count2 = bch2_count_subdirs(trans, w->last_pos.inode, i->snapshot);
+ if (count2 < 0)
+ return count2;
+
+ if (i->count != count2) {
+ bch_err_ratelimited(c, "fsck counted subdirectories wrong for inum %llu:%u: got %llu should be %llu",
+ w->last_pos.inode, i->snapshot, i->count, count2);
+ i->count = count2;
+ if (i->inode.bi_nlink == i->count)
+ continue;
+ }
+
+ if (fsck_err_on(i->inode.bi_nlink != i->count,
+ trans, inode_dir_wrong_nlink,
+ "directory %llu:%u with wrong i_nlink: got %u, should be %llu",
+ w->last_pos.inode, i->snapshot, i->inode.bi_nlink, i->count)) {
+ i->inode.bi_nlink = i->count;
+ ret = bch2_fsck_write_inode(trans, &i->inode);
+ if (ret)
+ break;
+ }
+ }
+fsck_err:
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_subdir_count(struct btree_trans *trans, struct inode_walker *w)
+{
+ u32 restart_count = trans->restart_count;
+ return check_subdir_count_notnested(trans, w) ?:
+ trans_was_restarted(trans, restart_count);
+}
+
+noinline_for_stack
+static int check_dirent_inode_dirent(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c_dirent d,
+ struct bch_inode_unpacked *target)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ struct btree_iter bp_iter = { NULL };
+ int ret = 0;
+
+ if (inode_points_to_dirent(target, d))
+ return 0;
+
+ if (!target->bi_dir &&
+ !target->bi_dir_offset) {
+ fsck_err_on(S_ISDIR(target->bi_mode),
+ trans, inode_dir_missing_backpointer,
+ "directory with missing backpointer\n%s",
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, d.s_c),
+ prt_printf(&buf, "\n"),
+ bch2_inode_unpacked_to_text(&buf, target),
+ buf.buf));
+
+ fsck_err_on(target->bi_flags & BCH_INODE_unlinked,
+ trans, inode_unlinked_but_has_dirent,
+ "inode unlinked but has dirent\n%s",
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, d.s_c),
+ prt_printf(&buf, "\n"),
+ bch2_inode_unpacked_to_text(&buf, target),
+ buf.buf));
+
+ target->bi_flags &= ~BCH_INODE_unlinked;
+ target->bi_dir = d.k->p.inode;
+ target->bi_dir_offset = d.k->p.offset;
+ return __bch2_fsck_write_inode(trans, target);
+ }
+
+ if (bch2_inode_should_have_bp(target) &&
+ !fsck_err(trans, inode_wrong_backpointer,
+ "dirent points to inode that does not point back:\n %s",
+ (bch2_bkey_val_to_text(&buf, c, d.s_c),
+ prt_printf(&buf, "\n "),
+ bch2_inode_unpacked_to_text(&buf, target),
+ buf.buf)))
+ goto err;
+
+ struct bkey_s_c_dirent bp_dirent = dirent_get_by_pos(trans, &bp_iter,
+ SPOS(target->bi_dir, target->bi_dir_offset, target->bi_snapshot));
+ ret = bkey_err(bp_dirent);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ goto err;
+
+ bool backpointer_exists = !ret;
+ ret = 0;
+
+ if (fsck_err_on(!backpointer_exists,
+ trans, inode_wrong_backpointer,
+ "inode %llu:%u has wrong backpointer:\n"
+ "got %llu:%llu\n"
+ "should be %llu:%llu",
+ target->bi_inum, target->bi_snapshot,
+ target->bi_dir,
+ target->bi_dir_offset,
+ d.k->p.inode,
+ d.k->p.offset)) {
+ target->bi_dir = d.k->p.inode;
+ target->bi_dir_offset = d.k->p.offset;
+ ret = __bch2_fsck_write_inode(trans, target);
+ goto out;
+ }
+
+ bch2_bkey_val_to_text(&buf, c, d.s_c);
+ prt_newline(&buf);
+ if (backpointer_exists)
+ bch2_bkey_val_to_text(&buf, c, bp_dirent.s_c);
+
+ if (fsck_err_on(backpointer_exists &&
+ (S_ISDIR(target->bi_mode) ||
+ target->bi_subvol),
+ trans, inode_dir_multiple_links,
+ "%s %llu:%u with multiple links\n%s",
+ S_ISDIR(target->bi_mode) ? "directory" : "subvolume",
+ target->bi_inum, target->bi_snapshot, buf.buf)) {
+ ret = __remove_dirent(trans, d.k->p);
+ goto out;
+ }
+
+ /*
+ * hardlinked file with nlink 0:
+ * We're just adjusting nlink here so check_nlinks() will pick
+ * it up, it ignores inodes with nlink 0
+ */
+ if (fsck_err_on(backpointer_exists && !target->bi_nlink,
+ trans, inode_multiple_links_but_nlink_0,
+ "inode %llu:%u type %s has multiple links but i_nlink 0\n%s",
+ target->bi_inum, target->bi_snapshot, bch2_d_types[d.v->d_type], buf.buf)) {
+ target->bi_nlink++;
+ target->bi_flags &= ~BCH_INODE_unlinked;
+ ret = __bch2_fsck_write_inode(trans, target);
+ if (ret)
+ goto err;
+ }
+out:
+err:
+fsck_err:
+ bch2_trans_iter_exit(trans, &bp_iter);
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+noinline_for_stack
+static int check_dirent_target(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c_dirent d,
+ struct bch_inode_unpacked *target)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_i_dirent *n;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ ret = check_dirent_inode_dirent(trans, iter, d, target);
+ if (ret)
+ goto err;
+
+ if (fsck_err_on(d.v->d_type != inode_d_type(target),
+ trans, dirent_d_type_wrong,
+ "incorrect d_type: got %s, should be %s:\n%s",
+ bch2_d_type_str(d.v->d_type),
+ bch2_d_type_str(inode_d_type(target)),
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, d.s_c), buf.buf))) {
+ n = bch2_trans_kmalloc(trans, bkey_bytes(d.k));
+ ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ goto err;
+
+ bkey_reassemble(&n->k_i, d.s_c);
+ n->v.d_type = inode_d_type(target);
+ if (n->v.d_type == DT_SUBVOL) {
+ n->v.d_parent_subvol = cpu_to_le32(target->bi_parent_subvol);
+ n->v.d_child_subvol = cpu_to_le32(target->bi_subvol);
+ } else {
+ n->v.d_inum = cpu_to_le64(target->bi_inum);
+ }
+
+ ret = bch2_trans_update(trans, iter, &n->k_i, 0);
+ if (ret)
+ goto err;
+
+ d = dirent_i_to_s_c(n);
+ }
+err:
+fsck_err:
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+/* find a subvolume that's a descendent of @snapshot: */
+static int find_snapshot_subvol(struct btree_trans *trans, u32 snapshot, u32 *subvolid)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ for_each_btree_key_norestart(trans, iter, BTREE_ID_subvolumes, POS_MIN, 0, k, ret) {
+ if (k.k->type != KEY_TYPE_subvolume)
+ continue;
+
+ struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
+ if (bch2_snapshot_is_ancestor(trans->c, le32_to_cpu(s.v->snapshot), snapshot)) {
+ bch2_trans_iter_exit(trans, &iter);
+ *subvolid = k.k->p.offset;
+ goto found;
+ }
+ }
+ if (!ret)
+ ret = -ENOENT;
+found:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+noinline_for_stack
+static int check_dirent_to_subvol(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c_dirent d)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter subvol_iter = {};
+ struct bch_inode_unpacked subvol_root;
+ u32 parent_subvol = le32_to_cpu(d.v->d_parent_subvol);
+ u32 target_subvol = le32_to_cpu(d.v->d_child_subvol);
+ u32 parent_snapshot;
+ u32 new_parent_subvol = 0;
+ u64 parent_inum;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ ret = subvol_lookup(trans, parent_subvol, &parent_snapshot, &parent_inum);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+
+ if (ret ||
+ (!ret && !bch2_snapshot_is_ancestor(c, parent_snapshot, d.k->p.snapshot))) {
+ int ret2 = find_snapshot_subvol(trans, d.k->p.snapshot, &new_parent_subvol);
+ if (ret2 && !bch2_err_matches(ret, ENOENT))
+ return ret2;
+ }
+
+ if (ret &&
+ !new_parent_subvol &&
+ (c->sb.btrees_lost_data & BIT_ULL(BTREE_ID_subvolumes))) {
+ /*
+ * Couldn't find a subvol for dirent's snapshot - but we lost
+ * subvols, so we need to reconstruct:
+ */
+ ret = reconstruct_subvol(trans, d.k->p.snapshot, parent_subvol, 0);
+ if (ret)
+ return ret;
+
+ parent_snapshot = d.k->p.snapshot;
+ }
+
+ if (fsck_err_on(ret,
+ trans, dirent_to_missing_parent_subvol,
+ "dirent parent_subvol points to missing subvolume\n%s",
+ (bch2_bkey_val_to_text(&buf, c, d.s_c), buf.buf)) ||
+ fsck_err_on(!ret && !bch2_snapshot_is_ancestor(c, parent_snapshot, d.k->p.snapshot),
+ trans, dirent_not_visible_in_parent_subvol,
+ "dirent not visible in parent_subvol (not an ancestor of subvol snap %u)\n%s",
+ parent_snapshot,
+ (bch2_bkey_val_to_text(&buf, c, d.s_c), buf.buf))) {
+ if (!new_parent_subvol) {
+ bch_err(c, "could not find a subvol for snapshot %u", d.k->p.snapshot);
+ return -BCH_ERR_fsck_repair_unimplemented;
+ }
+
+ struct bkey_i_dirent *new_dirent = bch2_bkey_make_mut_typed(trans, iter, &d.s_c, 0, dirent);
+ ret = PTR_ERR_OR_ZERO(new_dirent);
+ if (ret)
+ goto err;
+
+ new_dirent->v.d_parent_subvol = cpu_to_le32(new_parent_subvol);
+ }
+
+ struct bkey_s_c_subvolume s =
+ bch2_bkey_get_iter_typed(trans, &subvol_iter,
+ BTREE_ID_subvolumes, POS(0, target_subvol),
+ 0, subvolume);
+ ret = bkey_err(s.s_c);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+
+ if (ret) {
+ if (fsck_err(trans, dirent_to_missing_subvol,
+ "dirent points to missing subvolume\n%s",
+ (bch2_bkey_val_to_text(&buf, c, d.s_c), buf.buf)))
+ return __remove_dirent(trans, d.k->p);
+ ret = 0;
+ goto out;
+ }
+
+ if (fsck_err_on(le32_to_cpu(s.v->fs_path_parent) != parent_subvol,
+ trans, subvol_fs_path_parent_wrong,
+ "subvol with wrong fs_path_parent, should be be %u\n%s",
+ parent_subvol,
+ (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
+ struct bkey_i_subvolume *n =
+ bch2_bkey_make_mut_typed(trans, &subvol_iter, &s.s_c, 0, subvolume);
+ ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ goto err;
+
+ n->v.fs_path_parent = cpu_to_le32(parent_subvol);
+ }
+
+ u64 target_inum = le64_to_cpu(s.v->inode);
+ u32 target_snapshot = le32_to_cpu(s.v->snapshot);
+
+ ret = lookup_inode(trans, target_inum, target_snapshot, &subvol_root);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ goto err;
+
+ if (ret) {
+ bch_err(c, "subvol %u points to missing inode root %llu", target_subvol, target_inum);
+ ret = -BCH_ERR_fsck_repair_unimplemented;
+ goto err;
+ }
+
+ if (fsck_err_on(!ret && parent_subvol != subvol_root.bi_parent_subvol,
+ trans, inode_bi_parent_wrong,
+ "subvol root %llu has wrong bi_parent_subvol: got %u, should be %u",
+ target_inum,
+ subvol_root.bi_parent_subvol, parent_subvol)) {
+ subvol_root.bi_parent_subvol = parent_subvol;
+ subvol_root.bi_snapshot = le32_to_cpu(s.v->snapshot);
+ ret = __bch2_fsck_write_inode(trans, &subvol_root);
+ if (ret)
+ goto err;
+ }
+
+ ret = check_dirent_target(trans, iter, d, &subvol_root);
+ if (ret)
+ goto err;
+out:
+err:
+fsck_err:
+ bch2_trans_iter_exit(trans, &subvol_iter);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k,
+ struct bch_hash_info *hash_info,
+ struct inode_walker *dir,
+ struct inode_walker *target,
+ struct snapshots_seen *s)
+{
+ struct bch_fs *c = trans->c;
+ struct inode_walker_entry *i;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ ret = bch2_check_key_has_snapshot(trans, iter, k);
+ if (ret) {
+ ret = ret < 0 ? ret : 0;
+ goto out;
+ }
+
+ ret = snapshots_seen_update(c, s, iter->btree_id, k.k->p);
+ if (ret)
+ goto err;
+
+ if (k.k->type == KEY_TYPE_whiteout)
+ goto out;
+
+ if (dir->last_pos.inode != k.k->p.inode && dir->have_inodes) {
+ ret = check_subdir_count(trans, dir);
+ if (ret)
+ goto err;
+ }
+
+ i = walk_inode(trans, dir, k);
+ ret = PTR_ERR_OR_ZERO(i);
+ if (ret < 0)
+ goto err;
+
+ ret = check_key_has_inode(trans, iter, dir, i, k);
+ if (ret)
+ goto err;
+
+ if (!i)
+ goto out;
+
+ if (dir->first_this_inode)
+ *hash_info = bch2_hash_info_init(c, &i->inode);
+ dir->first_this_inode = false;
+
+ ret = hash_check_key(trans, s, bch2_dirent_hash_desc, hash_info, iter, k);
+ if (ret < 0)
+ goto err;
+ if (ret) {
+ /* dirent has been deleted */
+ ret = 0;
+ goto out;
+ }
+
+ if (k.k->type != KEY_TYPE_dirent)
+ goto out;
+
+ struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
+
+ if (d.v->d_type == DT_SUBVOL) {
+ ret = check_dirent_to_subvol(trans, iter, d);
+ if (ret)
+ goto err;
+ } else {
+ ret = get_visible_inodes(trans, target, s, le64_to_cpu(d.v->d_inum));
+ if (ret)
+ goto err;
+
+ if (fsck_err_on(!target->inodes.nr,
+ trans, dirent_to_missing_inode,
+ "dirent points to missing inode:\n%s",
+ (printbuf_reset(&buf),
+ bch2_bkey_val_to_text(&buf, c, k),
+ buf.buf))) {
+ ret = __remove_dirent(trans, d.k->p);
+ if (ret)
+ goto err;
+ }
+
+ darray_for_each(target->inodes, i) {
+ ret = check_dirent_target(trans, iter, d, &i->inode);
+ if (ret)
+ goto err;
+ }
+ }
+
+ ret = bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
+ if (ret)
+ goto err;
+
+ if (d.v->d_type == DT_DIR)
+ for_each_visible_inode(c, s, dir, d.k->p.snapshot, i)
+ i->count++;
+out:
+err:
+fsck_err:
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+/*
+ * Walk dirents: verify that they all have a corresponding S_ISDIR inode,
+ * validate d_type
+ */
+int bch2_check_dirents(struct bch_fs *c)
+{
+ struct inode_walker dir = inode_walker_init();
+ struct inode_walker target = inode_walker_init();
+ struct snapshots_seen s;
+ struct bch_hash_info hash_info;
+
+ snapshots_seen_init(&s);
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key(trans, iter, BTREE_ID_dirents,
+ POS(BCACHEFS_ROOT_INO, 0),
+ BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
+ check_dirent(trans, &iter, k, &hash_info, &dir, &target, &s)) ?:
+ check_subdir_count_notnested(trans, &dir));
+
+ snapshots_seen_exit(&s);
+ inode_walker_exit(&dir);
+ inode_walker_exit(&target);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_xattr(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k,
+ struct bch_hash_info *hash_info,
+ struct inode_walker *inode)
+{
+ struct bch_fs *c = trans->c;
+ struct inode_walker_entry *i;
+ int ret;
+
+ ret = bch2_check_key_has_snapshot(trans, iter, k);
+ if (ret < 0)
+ return ret;
+ if (ret)
+ return 0;
+
+ i = walk_inode(trans, inode, k);
+ ret = PTR_ERR_OR_ZERO(i);
+ if (ret)
+ return ret;
+
+ ret = check_key_has_inode(trans, iter, inode, i, k);
+ if (ret)
+ return ret;
+
+ if (!i)
+ return 0;
+
+ if (inode->first_this_inode)
+ *hash_info = bch2_hash_info_init(c, &i->inode);
+ inode->first_this_inode = false;
+
+ ret = hash_check_key(trans, NULL, bch2_xattr_hash_desc, hash_info, iter, k);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+/*
+ * Walk xattrs: verify that they all have a corresponding inode
+ */
+int bch2_check_xattrs(struct bch_fs *c)
+{
+ struct inode_walker inode = inode_walker_init();
+ struct bch_hash_info hash_info;
+ int ret = 0;
+
+ ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter, BTREE_ID_xattrs,
+ POS(BCACHEFS_ROOT_INO, 0),
+ BTREE_ITER_prefetch|BTREE_ITER_all_snapshots,
+ k,
+ NULL, NULL,
+ BCH_TRANS_COMMIT_no_enospc,
+ check_xattr(trans, &iter, k, &hash_info, &inode)));
+
+ inode_walker_exit(&inode);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_root_trans(struct btree_trans *trans)
+{
+ struct bch_fs *c = trans->c;
+ struct bch_inode_unpacked root_inode;
+ u32 snapshot;
+ u64 inum;
+ int ret;
+
+ ret = subvol_lookup(trans, BCACHEFS_ROOT_SUBVOL, &snapshot, &inum);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+
+ if (mustfix_fsck_err_on(ret, trans, root_subvol_missing,
+ "root subvol missing")) {
+ struct bkey_i_subvolume *root_subvol =
+ bch2_trans_kmalloc(trans, sizeof(*root_subvol));
+ ret = PTR_ERR_OR_ZERO(root_subvol);
+ if (ret)
+ goto err;
+
+ snapshot = U32_MAX;
+ inum = BCACHEFS_ROOT_INO;
+
+ bkey_subvolume_init(&root_subvol->k_i);
+ root_subvol->k.p.offset = BCACHEFS_ROOT_SUBVOL;
+ root_subvol->v.flags = 0;
+ root_subvol->v.snapshot = cpu_to_le32(snapshot);
+ root_subvol->v.inode = cpu_to_le64(inum);
+ ret = bch2_btree_insert_trans(trans, BTREE_ID_subvolumes, &root_subvol->k_i, 0);
+ bch_err_msg(c, ret, "writing root subvol");
+ if (ret)
+ goto err;
+ }
+
+ ret = lookup_inode(trans, BCACHEFS_ROOT_INO, snapshot, &root_inode);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ return ret;
+
+ if (mustfix_fsck_err_on(ret,
+ trans, root_dir_missing,
+ "root directory missing") ||
+ mustfix_fsck_err_on(!S_ISDIR(root_inode.bi_mode),
+ trans, root_inode_not_dir,
+ "root inode not a directory")) {
+ bch2_inode_init(c, &root_inode, 0, 0, S_IFDIR|0755,
+ 0, NULL);
+ root_inode.bi_inum = inum;
+ root_inode.bi_snapshot = snapshot;
+
+ ret = __bch2_fsck_write_inode(trans, &root_inode);
+ bch_err_msg(c, ret, "writing root inode");
+ }
+err:
+fsck_err:
+ return ret;
+}
+
+/* Get root directory, create if it doesn't exist: */
+int bch2_check_root(struct bch_fs *c)
+{
+ int ret = bch2_trans_commit_do(c, NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ check_root_trans(trans));
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+typedef DARRAY(u32) darray_u32;
+
+static bool darray_u32_has(darray_u32 *d, u32 v)
+{
+ darray_for_each(*d, i)
+ if (*i == v)
+ return true;
+ return false;
+}
+
+static int check_subvol_path(struct btree_trans *trans, struct btree_iter *iter, struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter parent_iter = {};
+ darray_u32 subvol_path = {};
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ if (k.k->type != KEY_TYPE_subvolume)
+ return 0;
+
+ while (k.k->p.offset != BCACHEFS_ROOT_SUBVOL) {
+ ret = darray_push(&subvol_path, k.k->p.offset);
+ if (ret)
+ goto err;
+
+ struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
+
+ struct bch_inode_unpacked subvol_root;
+ ret = bch2_inode_find_by_inum_trans(trans,
+ (subvol_inum) { s.k->p.offset, le64_to_cpu(s.v->inode) },
+ &subvol_root);
+ if (ret)
+ break;
+
+ u32 parent = le32_to_cpu(s.v->fs_path_parent);
+
+ if (darray_u32_has(&subvol_path, parent)) {
+ if (fsck_err(c, subvol_loop, "subvolume loop"))
+ ret = reattach_subvol(trans, s);
+ break;
+ }
+
+ bch2_trans_iter_exit(trans, &parent_iter);
+ bch2_trans_iter_init(trans, &parent_iter,
+ BTREE_ID_subvolumes, POS(0, parent), 0);
+ k = bch2_btree_iter_peek_slot(&parent_iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (fsck_err_on(k.k->type != KEY_TYPE_subvolume,
+ trans, subvol_unreachable,
+ "unreachable subvolume %s",
+ (bch2_bkey_val_to_text(&buf, c, s.s_c),
+ buf.buf))) {
+ ret = reattach_subvol(trans, s);
+ break;
+ }
+ }
+fsck_err:
+err:
+ printbuf_exit(&buf);
+ darray_exit(&subvol_path);
+ bch2_trans_iter_exit(trans, &parent_iter);
+ return ret;
+}
+
+int bch2_check_subvolume_structure(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_path(trans, &iter, k)));
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+struct pathbuf_entry {
+ u64 inum;
+ u32 snapshot;
+};
+
+typedef DARRAY(struct pathbuf_entry) pathbuf;
+
+static bool path_is_dup(pathbuf *p, u64 inum, u32 snapshot)
+{
+ darray_for_each(*p, i)
+ if (i->inum == inum &&
+ i->snapshot == snapshot)
+ return true;
+ return false;
+}
+
+static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c inode_k)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter inode_iter = {};
+ struct bch_inode_unpacked inode;
+ struct printbuf buf = PRINTBUF;
+ u32 snapshot = inode_k.k->p.snapshot;
+ int ret = 0;
+
+ p->nr = 0;
+
+ BUG_ON(bch2_inode_unpack(inode_k, &inode));
+
+ if (!S_ISDIR(inode.bi_mode))
+ return 0;
+
+ while (!inode.bi_subvol) {
+ struct btree_iter dirent_iter;
+ struct bkey_s_c_dirent d;
+ u32 parent_snapshot = snapshot;
+
+ d = inode_get_dirent(trans, &dirent_iter, &inode, &parent_snapshot);
+ ret = bkey_err(d.s_c);
+ if (ret && !bch2_err_matches(ret, ENOENT))
+ break;
+
+ if (!ret && (ret = dirent_points_to_inode(c, d, &inode)))
+ bch2_trans_iter_exit(trans, &dirent_iter);
+
+ if (bch2_err_matches(ret, ENOENT)) {
+ printbuf_reset(&buf);
+ bch2_bkey_val_to_text(&buf, c, inode_k);
+ bch_err(c, "unreachable inode in check_directory_structure: %s\n%s",
+ bch2_err_str(ret), buf.buf);
+ goto out;
+ }
+
+ bch2_trans_iter_exit(trans, &dirent_iter);
+
+ ret = darray_push(p, ((struct pathbuf_entry) {
+ .inum = inode.bi_inum,
+ .snapshot = snapshot,
+ }));
+ if (ret)
+ return ret;
+
+ snapshot = parent_snapshot;
+
+ bch2_trans_iter_exit(trans, &inode_iter);
+ inode_k = bch2_bkey_get_iter(trans, &inode_iter, BTREE_ID_inodes,
+ SPOS(0, inode.bi_dir, snapshot), 0);
+ ret = bkey_err(inode_k) ?:
+ !bkey_is_inode(inode_k.k) ? -BCH_ERR_ENOENT_inode
+ : bch2_inode_unpack(inode_k, &inode);
+ if (ret) {
+ /* Should have been caught in dirents pass */
+ bch_err_msg(c, ret, "error looking up parent directory");
+ break;
+ }
+
+ snapshot = inode_k.k->p.snapshot;
+
+ if (path_is_dup(p, inode.bi_inum, snapshot)) {
+ /* XXX print path */
+ bch_err(c, "directory structure loop");
+
+ darray_for_each(*p, i)
+ pr_err("%llu:%u", i->inum, i->snapshot);
+ pr_err("%llu:%u", inode.bi_inum, snapshot);
+
+ if (fsck_err(trans, dir_loop, "directory structure loop")) {
+ ret = remove_backpointer(trans, &inode);
+ bch_err_msg(c, ret, "removing dirent");
+ if (ret)
+ break;
+
+ ret = reattach_inode(trans, &inode);
+ bch_err_msg(c, ret, "reattaching inode %llu", inode.bi_inum);
+ }
+ break;
+ }
+ }
+out:
+fsck_err:
+ bch2_trans_iter_exit(trans, &inode_iter);
+ printbuf_exit(&buf);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+/*
+ * Check for loops in the directory structure: all other connectivity issues
+ * have been fixed by prior passes
+ */
+int bch2_check_directory_structure(struct bch_fs *c)
+{
+ pathbuf path = { 0, };
+ int ret;
+
+ ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter, BTREE_ID_inodes, POS_MIN,
+ BTREE_ITER_intent|
+ BTREE_ITER_prefetch|
+ BTREE_ITER_all_snapshots, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
+ if (!bkey_is_inode(k.k))
+ continue;
+
+ if (bch2_inode_flags(k) & BCH_INODE_unlinked)
+ continue;
+
+ check_path(trans, &path, k);
+ })));
+ darray_exit(&path);
+
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+struct nlink_table {
+ size_t nr;
+ size_t size;
+
+ struct nlink {
+ u64 inum;
+ u32 snapshot;
+ u32 count;
+ } *d;
+};
+
+static int add_nlink(struct bch_fs *c, struct nlink_table *t,
+ u64 inum, u32 snapshot)
+{
+ if (t->nr == t->size) {
+ size_t new_size = max_t(size_t, 128UL, t->size * 2);
+ void *d = kvmalloc_array(new_size, sizeof(t->d[0]), GFP_KERNEL);
+
+ if (!d) {
+ bch_err(c, "fsck: error allocating memory for nlink_table, size %zu",
+ new_size);
+ return -BCH_ERR_ENOMEM_fsck_add_nlink;
+ }
+
+ if (t->d)
+ memcpy(d, t->d, t->size * sizeof(t->d[0]));
+ kvfree(t->d);
+
+ t->d = d;
+ t->size = new_size;
+ }
+
+
+ t->d[t->nr++] = (struct nlink) {
+ .inum = inum,
+ .snapshot = snapshot,
+ };
+
+ return 0;
+}
+
+static int nlink_cmp(const void *_l, const void *_r)
+{
+ const struct nlink *l = _l;
+ const struct nlink *r = _r;
+
+ return cmp_int(l->inum, r->inum);
+}
+
+static void inc_link(struct bch_fs *c, struct snapshots_seen *s,
+ struct nlink_table *links,
+ u64 range_start, u64 range_end, u64 inum, u32 snapshot)
+{
+ struct nlink *link, key = {
+ .inum = inum, .snapshot = U32_MAX,
+ };
+
+ if (inum < range_start || inum >= range_end)
+ return;
+
+ link = __inline_bsearch(&key, links->d, links->nr,
+ sizeof(links->d[0]), nlink_cmp);
+ if (!link)
+ return;
+
+ while (link > links->d && link[0].inum == link[-1].inum)
+ --link;
+
+ for (; link < links->d + links->nr && link->inum == inum; link++)
+ if (ref_visible(c, s, snapshot, link->snapshot)) {
+ link->count++;
+ if (link->snapshot >= snapshot)
+ break;
+ }
+}
+
+noinline_for_stack
+static int check_nlinks_find_hardlinks(struct bch_fs *c,
+ struct nlink_table *t,
+ u64 start, u64 *end)
+{
+ int ret = bch2_trans_run(c,
+ for_each_btree_key(trans, iter, BTREE_ID_inodes,
+ POS(0, start),
+ BTREE_ITER_intent|
+ BTREE_ITER_prefetch|
+ BTREE_ITER_all_snapshots, k, ({
+ if (!bkey_is_inode(k.k))
+ continue;
+
+ /* Should never fail, checked by bch2_inode_invalid: */
+ struct bch_inode_unpacked u;
+ BUG_ON(bch2_inode_unpack(k, &u));
+
+ /*
+ * Backpointer and directory structure checks are sufficient for
+ * directories, since they can't have hardlinks:
+ */
+ if (S_ISDIR(u.bi_mode))
+ continue;
+
+ /*
+ * Previous passes ensured that bi_nlink is nonzero if
+ * it had multiple hardlinks:
+ */
+ if (!u.bi_nlink)
+ continue;
+
+ ret = add_nlink(c, t, k.k->p.offset, k.k->p.snapshot);
+ if (ret) {
+ *end = k.k->p.offset;
+ ret = 0;
+ break;
+ }
+ 0;
+ })));
+
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+noinline_for_stack
+static int check_nlinks_walk_dirents(struct bch_fs *c, struct nlink_table *links,
+ u64 range_start, u64 range_end)
+{
+ struct snapshots_seen s;
+
+ snapshots_seen_init(&s);
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key(trans, iter, BTREE_ID_dirents, POS_MIN,
+ BTREE_ITER_intent|
+ BTREE_ITER_prefetch|
+ BTREE_ITER_all_snapshots, k, ({
+ ret = snapshots_seen_update(c, &s, iter.btree_id, k.k->p);
+ if (ret)
+ break;
+
+ if (k.k->type == KEY_TYPE_dirent) {
+ struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
+
+ if (d.v->d_type != DT_DIR &&
+ d.v->d_type != DT_SUBVOL)
+ inc_link(c, &s, links, range_start, range_end,
+ le64_to_cpu(d.v->d_inum), d.k->p.snapshot);
+ }
+ 0;
+ })));
+
+ snapshots_seen_exit(&s);
+
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_nlinks_update_inode(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k,
+ struct nlink_table *links,
+ size_t *idx, u64 range_end)
+{
+ struct bch_inode_unpacked u;
+ struct nlink *link = &links->d[*idx];
+ int ret = 0;
+
+ if (k.k->p.offset >= range_end)
+ return 1;
+
+ if (!bkey_is_inode(k.k))
+ return 0;
+
+ BUG_ON(bch2_inode_unpack(k, &u));
+
+ if (S_ISDIR(u.bi_mode))
+ return 0;
+
+ if (!u.bi_nlink)
+ return 0;
+
+ while ((cmp_int(link->inum, k.k->p.offset) ?:
+ cmp_int(link->snapshot, k.k->p.snapshot)) < 0) {
+ BUG_ON(*idx == links->nr);
+ link = &links->d[++*idx];
+ }
+
+ if (fsck_err_on(bch2_inode_nlink_get(&u) != link->count,
+ trans, inode_wrong_nlink,
+ "inode %llu type %s has wrong i_nlink (%u, should be %u)",
+ u.bi_inum, bch2_d_types[mode_to_type(u.bi_mode)],
+ bch2_inode_nlink_get(&u), link->count)) {
+ bch2_inode_nlink_set(&u, link->count);
+ ret = __bch2_fsck_write_inode(trans, &u);
+ }
+fsck_err:
+ return ret;
+}
+
+noinline_for_stack
+static int check_nlinks_update_hardlinks(struct bch_fs *c,
+ struct nlink_table *links,
+ u64 range_start, u64 range_end)
+{
+ size_t idx = 0;
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter, BTREE_ID_inodes,
+ POS(0, range_start),
+ BTREE_ITER_intent|BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ check_nlinks_update_inode(trans, &iter, k, links, &idx, range_end)));
+ if (ret < 0) {
+ bch_err(c, "error in fsck walking inodes: %s", bch2_err_str(ret));
+ return ret;
+ }
+
+ return 0;
+}
+
+int bch2_check_nlinks(struct bch_fs *c)
+{
+ struct nlink_table links = { 0 };
+ u64 this_iter_range_start, next_iter_range_start = 0;
+ int ret = 0;
+
+ do {
+ this_iter_range_start = next_iter_range_start;
+ next_iter_range_start = U64_MAX;
+
+ ret = check_nlinks_find_hardlinks(c, &links,
+ this_iter_range_start,
+ &next_iter_range_start);
+
+ ret = check_nlinks_walk_dirents(c, &links,
+ this_iter_range_start,
+ next_iter_range_start);
+ if (ret)
+ break;
+
+ ret = check_nlinks_update_hardlinks(c, &links,
+ this_iter_range_start,
+ next_iter_range_start);
+ if (ret)
+ break;
+
+ links.nr = 0;
+ } while (next_iter_range_start != U64_MAX);
+
+ kvfree(links.d);
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int fix_reflink_p_key(struct btree_trans *trans, struct btree_iter *iter,
+ struct bkey_s_c k)
+{
+ struct bkey_s_c_reflink_p p;
+ struct bkey_i_reflink_p *u;
+
+ if (k.k->type != KEY_TYPE_reflink_p)
+ return 0;
+
+ p = bkey_s_c_to_reflink_p(k);
+
+ if (!p.v->front_pad && !p.v->back_pad)
+ return 0;
+
+ u = bch2_trans_kmalloc(trans, sizeof(*u));
+ int ret = PTR_ERR_OR_ZERO(u);
+ if (ret)
+ return ret;
+
+ bkey_reassemble(&u->k_i, k);
+ u->v.front_pad = 0;
+ u->v.back_pad = 0;
+
+ return bch2_trans_update(trans, iter, &u->k_i, BTREE_TRIGGER_norun);
+}
+
+int bch2_fix_reflink_p(struct bch_fs *c)
+{
+ if (c->sb.version >= bcachefs_metadata_version_reflink_p_fix)
+ return 0;
+
+ int ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter,
+ BTREE_ID_extents, POS_MIN,
+ BTREE_ITER_intent|BTREE_ITER_prefetch|
+ BTREE_ITER_all_snapshots, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ fix_reflink_p_key(trans, &iter, k)));
+ bch_err_fn(c, ret);
+ return ret;
+}
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-29 20:44:27 +0300