--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#include "bcachefs.h"
+#include "bbpos.h"
+#include "alloc_background.h"
+#include "backpointers.h"
+#include "bkey_buf.h"
+#include "btree_cache.h"
+#include "btree_update.h"
+#include "btree_update_interior.h"
+#include "btree_write_buffer.h"
+#include "error.h"
+
+#include <linux/mm.h>
+
+static bool extent_matches_bp(struct bch_fs *c,
+ enum btree_id btree_id, unsigned level,
+ struct bkey_s_c k,
+ struct bpos bucket,
+ struct bch_backpointer bp)
+{
+ struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+ const union bch_extent_entry *entry;
+ struct extent_ptr_decoded p;
+
+ bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
+ struct bpos bucket2;
+ struct bch_backpointer bp2;
+
+ if (p.ptr.cached)
+ continue;
+
+ bch2_extent_ptr_to_bp(c, btree_id, level, k, p,
+ &bucket2, &bp2);
+ if (bpos_eq(bucket, bucket2) &&
+ !memcmp(&bp, &bp2, sizeof(bp)))
+ return true;
+ }
+
+ return false;
+}
+
+int bch2_backpointer_invalid(struct bch_fs *c, struct bkey_s_c k,
+ enum bkey_invalid_flags flags,
+ struct printbuf *err)
+{
+ struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(k);
+ struct bpos bucket = bp_pos_to_bucket(c, bp.k->p);
+ int ret = 0;
+
+ bkey_fsck_err_on(!bpos_eq(bp.k->p, bucket_pos_to_bp(c, bucket, bp.v->bucket_offset)),
+ c, err,
+ backpointer_pos_wrong,
+ "backpointer at wrong pos");
+fsck_err:
+ return ret;
+}
+
+void bch2_backpointer_to_text(struct printbuf *out, const struct bch_backpointer *bp)
+{
+ prt_printf(out, "btree=%s l=%u offset=%llu:%u len=%u pos=",
+ bch2_btree_id_str(bp->btree_id),
+ bp->level,
+ (u64) (bp->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT),
+ (u32) bp->bucket_offset & ~(~0U << MAX_EXTENT_COMPRESS_RATIO_SHIFT),
+ bp->bucket_len);
+ bch2_bpos_to_text(out, bp->pos);
+}
+
+void bch2_backpointer_k_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
+{
+ prt_str(out, "bucket=");
+ bch2_bpos_to_text(out, bp_pos_to_bucket(c, k.k->p));
+ prt_str(out, " ");
+
+ bch2_backpointer_to_text(out, bkey_s_c_to_backpointer(k).v);
+}
+
+void bch2_backpointer_swab(struct bkey_s k)
+{
+ struct bkey_s_backpointer bp = bkey_s_to_backpointer(k);
+
+ bp.v->bucket_offset = swab40(bp.v->bucket_offset);
+ bp.v->bucket_len = swab32(bp.v->bucket_len);
+ bch2_bpos_swab(&bp.v->pos);
+}
+
+static noinline int backpointer_mod_err(struct btree_trans *trans,
+ struct bch_backpointer bp,
+ struct bkey_s_c bp_k,
+ struct bkey_s_c orig_k,
+ bool insert)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+
+ if (insert) {
+ prt_printf(&buf, "existing backpointer found when inserting ");
+ bch2_backpointer_to_text(&buf, &bp);
+ prt_newline(&buf);
+ printbuf_indent_add(&buf, 2);
+
+ prt_printf(&buf, "found ");
+ bch2_bkey_val_to_text(&buf, c, bp_k);
+ prt_newline(&buf);
+
+ prt_printf(&buf, "for ");
+ bch2_bkey_val_to_text(&buf, c, orig_k);
+
+ bch_err(c, "%s", buf.buf);
+ } else if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
+ prt_printf(&buf, "backpointer not found when deleting");
+ prt_newline(&buf);
+ printbuf_indent_add(&buf, 2);
+
+ prt_printf(&buf, "searching for ");
+ bch2_backpointer_to_text(&buf, &bp);
+ prt_newline(&buf);
+
+ prt_printf(&buf, "got ");
+ bch2_bkey_val_to_text(&buf, c, bp_k);
+ prt_newline(&buf);
+
+ prt_printf(&buf, "for ");
+ bch2_bkey_val_to_text(&buf, c, orig_k);
+
+ bch_err(c, "%s", buf.buf);
+ }
+
+ printbuf_exit(&buf);
+
+ if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
+ bch2_inconsistent_error(c);
+ return -EIO;
+ } else {
+ return 0;
+ }
+}
+
+int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans,
+ struct bpos bucket,
+ struct bch_backpointer bp,
+ struct bkey_s_c orig_k,
+ bool insert)
+{
+ struct btree_iter bp_iter;
+ struct bkey_s_c k;
+ struct bkey_i_backpointer *bp_k;
+ int ret;
+
+ bp_k = bch2_trans_kmalloc_nomemzero(trans, sizeof(struct bkey_i_backpointer));
+ ret = PTR_ERR_OR_ZERO(bp_k);
+ if (ret)
+ return ret;
+
+ bkey_backpointer_init(&bp_k->k_i);
+ bp_k->k.p = bucket_pos_to_bp(trans->c, bucket, bp.bucket_offset);
+ bp_k->v = bp;
+
+ if (!insert) {
+ bp_k->k.type = KEY_TYPE_deleted;
+ set_bkey_val_u64s(&bp_k->k, 0);
+ }
+
+ k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
+ bp_k->k.p,
+ BTREE_ITER_INTENT|
+ BTREE_ITER_SLOTS|
+ BTREE_ITER_WITH_UPDATES);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (insert
+ ? k.k->type
+ : (k.k->type != KEY_TYPE_backpointer ||
+ memcmp(bkey_s_c_to_backpointer(k).v, &bp, sizeof(bp)))) {
+ ret = backpointer_mod_err(trans, bp, k, orig_k, insert);
+ if (ret)
+ goto err;
+ }
+
+ ret = bch2_trans_update(trans, &bp_iter, &bp_k->k_i, 0);
+err:
+ bch2_trans_iter_exit(trans, &bp_iter);
+ return ret;
+}
+
+/*
+ * Find the next backpointer >= *bp_offset:
+ */
+int bch2_get_next_backpointer(struct btree_trans *trans,
+ struct bpos bucket, int gen,
+ struct bpos *bp_pos,
+ struct bch_backpointer *bp,
+ unsigned iter_flags)
+{
+ struct bch_fs *c = trans->c;
+ struct bpos bp_end_pos = bucket_pos_to_bp(c, bpos_nosnap_successor(bucket), 0);
+ struct btree_iter alloc_iter = { NULL }, bp_iter = { NULL };
+ struct bkey_s_c k;
+ int ret = 0;
+
+ if (bpos_ge(*bp_pos, bp_end_pos))
+ goto done;
+
+ if (gen >= 0) {
+ k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
+ bucket, BTREE_ITER_CACHED|iter_flags);
+ ret = bkey_err(k);
+ if (ret)
+ goto out;
+
+ if (k.k->type != KEY_TYPE_alloc_v4 ||
+ bkey_s_c_to_alloc_v4(k).v->gen != gen)
+ goto done;
+ }
+
+ *bp_pos = bpos_max(*bp_pos, bucket_pos_to_bp(c, bucket, 0));
+
+ for_each_btree_key_norestart(trans, bp_iter, BTREE_ID_backpointers,
+ *bp_pos, iter_flags, k, ret) {
+ if (bpos_ge(k.k->p, bp_end_pos))
+ break;
+
+ *bp_pos = k.k->p;
+ *bp = *bkey_s_c_to_backpointer(k).v;
+ goto out;
+ }
+done:
+ *bp_pos = SPOS_MAX;
+out:
+ bch2_trans_iter_exit(trans, &bp_iter);
+ bch2_trans_iter_exit(trans, &alloc_iter);
+ return ret;
+}
+
+static void backpointer_not_found(struct btree_trans *trans,
+ struct bpos bp_pos,
+ struct bch_backpointer bp,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct printbuf buf = PRINTBUF;
+ struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
+
+ /*
+ * If we're using the btree write buffer, the backpointer we were
+ * looking at may have already been deleted - failure to find what it
+ * pointed to is not an error:
+ */
+ if (likely(!bch2_backpointers_no_use_write_buffer))
+ return;
+
+ prt_printf(&buf, "backpointer doesn't match %s it points to:\n ",
+ bp.level ? "btree node" : "extent");
+ prt_printf(&buf, "bucket: ");
+ bch2_bpos_to_text(&buf, bucket);
+ prt_printf(&buf, "\n ");
+
+ prt_printf(&buf, "backpointer pos: ");
+ bch2_bpos_to_text(&buf, bp_pos);
+ prt_printf(&buf, "\n ");
+
+ bch2_backpointer_to_text(&buf, &bp);
+ prt_printf(&buf, "\n ");
+ bch2_bkey_val_to_text(&buf, c, k);
+ if (c->curr_recovery_pass >= BCH_RECOVERY_PASS_check_extents_to_backpointers)
+ bch_err_ratelimited(c, "%s", buf.buf);
+ else
+ bch2_trans_inconsistent(trans, "%s", buf.buf);
+
+ printbuf_exit(&buf);
+}
+
+struct bkey_s_c bch2_backpointer_get_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bpos bp_pos,
+ struct bch_backpointer bp,
+ unsigned iter_flags)
+{
+ if (likely(!bp.level)) {
+ struct bch_fs *c = trans->c;
+ struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
+ struct bkey_s_c k;
+
+ bch2_trans_node_iter_init(trans, iter,
+ bp.btree_id,
+ bp.pos,
+ 0, 0,
+ iter_flags);
+ k = bch2_btree_iter_peek_slot(iter);
+ if (bkey_err(k)) {
+ bch2_trans_iter_exit(trans, iter);
+ return k;
+ }
+
+ if (k.k && extent_matches_bp(c, bp.btree_id, bp.level, k, bucket, bp))
+ return k;
+
+ bch2_trans_iter_exit(trans, iter);
+ backpointer_not_found(trans, bp_pos, bp, k);
+ return bkey_s_c_null;
+ } else {
+ struct btree *b = bch2_backpointer_get_node(trans, iter, bp_pos, bp);
+
+ if (IS_ERR_OR_NULL(b)) {
+ bch2_trans_iter_exit(trans, iter);
+ return IS_ERR(b) ? bkey_s_c_err(PTR_ERR(b)) : bkey_s_c_null;
+ }
+ return bkey_i_to_s_c(&b->key);
+ }
+}
+
+struct btree *bch2_backpointer_get_node(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bpos bp_pos,
+ struct bch_backpointer bp)
+{
+ struct bch_fs *c = trans->c;
+ struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
+ struct btree *b;
+
+ BUG_ON(!bp.level);
+
+ bch2_trans_node_iter_init(trans, iter,
+ bp.btree_id,
+ bp.pos,
+ 0,
+ bp.level - 1,
+ 0);
+ b = bch2_btree_iter_peek_node(iter);
+ if (IS_ERR_OR_NULL(b))
+ goto err;
+
+ BUG_ON(b->c.level != bp.level - 1);
+
+ if (extent_matches_bp(c, bp.btree_id, bp.level,
+ bkey_i_to_s_c(&b->key),
+ bucket, bp))
+ return b;
+
+ if (btree_node_will_make_reachable(b)) {
+ b = ERR_PTR(-BCH_ERR_backpointer_to_overwritten_btree_node);
+ } else {
+ backpointer_not_found(trans, bp_pos, bp, bkey_i_to_s_c(&b->key));
+ b = NULL;
+ }
+err:
+ bch2_trans_iter_exit(trans, iter);
+ return b;
+}
+
+static int bch2_check_btree_backpointer(struct btree_trans *trans, struct btree_iter *bp_iter,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter alloc_iter = { NULL };
+ struct bkey_s_c alloc_k;
+ struct printbuf buf = PRINTBUF;
+ int ret = 0;
+
+ if (fsck_err_on(!bch2_dev_exists2(c, k.k->p.inode), c,
+ backpointer_to_missing_device,
+ "backpointer for missing device:\n%s",
+ (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+ ret = bch2_btree_delete_at(trans, bp_iter, 0);
+ goto out;
+ }
+
+ alloc_k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
+ bp_pos_to_bucket(c, k.k->p), 0);
+ ret = bkey_err(alloc_k);
+ if (ret)
+ goto out;
+
+ if (fsck_err_on(alloc_k.k->type != KEY_TYPE_alloc_v4, c,
+ backpointer_to_missing_alloc,
+ "backpointer for nonexistent alloc key: %llu:%llu:0\n%s",
+ alloc_iter.pos.inode, alloc_iter.pos.offset,
+ (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
+ ret = bch2_btree_delete_at(trans, bp_iter, 0);
+ goto out;
+ }
+out:
+fsck_err:
+ bch2_trans_iter_exit(trans, &alloc_iter);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+/* verify that every backpointer has a corresponding alloc key */
+int bch2_check_btree_backpointers(struct bch_fs *c)
+{
+ int ret = bch2_trans_run(c,
+ for_each_btree_key_commit(trans, iter,
+ BTREE_ID_backpointers, POS_MIN, 0, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ bch2_check_btree_backpointer(trans, &iter, k)));
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_bp_exists(struct btree_trans *trans,
+ struct bpos bucket,
+ struct bch_backpointer bp,
+ struct bkey_s_c orig_k,
+ struct bpos bucket_start,
+ struct bpos bucket_end,
+ struct bkey_buf *last_flushed)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter bp_iter = { NULL };
+ struct printbuf buf = PRINTBUF;
+ struct bkey_s_c bp_k;
+ struct bkey_buf tmp;
+ int ret;
+
+ bch2_bkey_buf_init(&tmp);
+
+ if (bpos_lt(bucket, bucket_start) ||
+ bpos_gt(bucket, bucket_end))
+ return 0;
+
+ if (!bch2_dev_bucket_exists(c, bucket))
+ goto missing;
+
+ bp_k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
+ bucket_pos_to_bp(c, bucket, bp.bucket_offset),
+ 0);
+ ret = bkey_err(bp_k);
+ if (ret)
+ goto err;
+
+ if (bp_k.k->type != KEY_TYPE_backpointer ||
+ memcmp(bkey_s_c_to_backpointer(bp_k).v, &bp, sizeof(bp))) {
+ if (!bpos_eq(orig_k.k->p, last_flushed->k->k.p) ||
+ bkey_bytes(orig_k.k) != bkey_bytes(&last_flushed->k->k) ||
+ memcmp(orig_k.v, &last_flushed->k->v, bkey_val_bytes(orig_k.k))) {
+ bch2_bkey_buf_reassemble(&tmp, c, orig_k);
+
+ if (bp.level) {
+ bch2_trans_unlock(trans);
+ bch2_btree_interior_updates_flush(c);
+ }
+
+ ret = bch2_btree_write_buffer_flush_sync(trans);
+ if (ret)
+ goto err;
+
+ bch2_bkey_buf_copy(last_flushed, c, tmp.k);
+ ret = -BCH_ERR_transaction_restart_write_buffer_flush;
+ goto out;
+ }
+ goto missing;
+ }
+out:
+err:
+fsck_err:
+ bch2_trans_iter_exit(trans, &bp_iter);
+ bch2_bkey_buf_exit(&tmp, c);
+ printbuf_exit(&buf);
+ return ret;
+missing:
+ prt_printf(&buf, "missing backpointer for btree=%s l=%u ",
+ bch2_btree_id_str(bp.btree_id), bp.level);
+ bch2_bkey_val_to_text(&buf, c, orig_k);
+ prt_printf(&buf, "\nbp pos ");
+ bch2_bpos_to_text(&buf, bp_iter.pos);
+
+ if (c->opts.reconstruct_alloc ||
+ fsck_err(c, ptr_to_missing_backpointer, "%s", buf.buf))
+ ret = bch2_bucket_backpointer_mod(trans, bucket, bp, orig_k, true);
+
+ goto out;
+}
+
+static int check_extent_to_backpointers(struct btree_trans *trans,
+ enum btree_id btree, unsigned level,
+ struct bpos bucket_start,
+ struct bpos bucket_end,
+ struct bkey_buf *last_flushed,
+ struct bkey_s_c k)
+{
+ struct bch_fs *c = trans->c;
+ struct bkey_ptrs_c ptrs;
+ const union bch_extent_entry *entry;
+ struct extent_ptr_decoded p;
+ int ret;
+
+ ptrs = bch2_bkey_ptrs_c(k);
+ bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
+ struct bpos bucket_pos;
+ struct bch_backpointer bp;
+
+ if (p.ptr.cached)
+ continue;
+
+ bch2_extent_ptr_to_bp(c, btree, level,
+ k, p, &bucket_pos, &bp);
+
+ ret = check_bp_exists(trans, bucket_pos, bp, k,
+ bucket_start, bucket_end,
+ last_flushed);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int check_btree_root_to_backpointers(struct btree_trans *trans,
+ enum btree_id btree_id,
+ struct bpos bucket_start,
+ struct bpos bucket_end,
+ struct bkey_buf *last_flushed,
+ int *level)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct btree *b;
+ struct bkey_s_c k;
+ int ret;
+retry:
+ bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN,
+ 0, bch2_btree_id_root(c, btree_id)->b->c.level, 0);
+ b = bch2_btree_iter_peek_node(&iter);
+ ret = PTR_ERR_OR_ZERO(b);
+ if (ret)
+ goto err;
+
+ if (b != btree_node_root(c, b)) {
+ bch2_trans_iter_exit(trans, &iter);
+ goto retry;
+ }
+
+ *level = b->c.level;
+
+ k = bkey_i_to_s_c(&b->key);
+ ret = check_extent_to_backpointers(trans, btree_id, b->c.level + 1,
+ bucket_start, bucket_end,
+ last_flushed, k);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static inline struct bbpos bp_to_bbpos(struct bch_backpointer bp)
+{
+ return (struct bbpos) {
+ .btree = bp.btree_id,
+ .pos = bp.pos,
+ };
+}
+
+static size_t btree_nodes_fit_in_ram(struct bch_fs *c)
+{
+ struct sysinfo i;
+ u64 mem_bytes;
+
+ si_meminfo(&i);
+ mem_bytes = i.totalram * i.mem_unit;
+ return div_u64(mem_bytes >> 1, btree_bytes(c));
+}
+
+static int bch2_get_btree_in_memory_pos(struct btree_trans *trans,
+ unsigned btree_leaf_mask,
+ unsigned btree_interior_mask,
+ struct bbpos start, struct bbpos *end)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ size_t btree_nodes = btree_nodes_fit_in_ram(trans->c);
+ enum btree_id btree;
+ int ret = 0;
+
+ for (btree = start.btree; btree < BTREE_ID_NR && !ret; btree++) {
+ unsigned depth = ((1U << btree) & btree_leaf_mask) ? 1 : 2;
+
+ if (!((1U << btree) & btree_leaf_mask) &&
+ !((1U << btree) & btree_interior_mask))
+ continue;
+
+ bch2_trans_node_iter_init(trans, &iter, btree,
+ btree == start.btree ? start.pos : POS_MIN,
+ 0, depth, 0);
+ /*
+ * for_each_btree_key_contineu() doesn't check the return value
+ * from bch2_btree_iter_advance(), which is needed when
+ * iterating over interior nodes where we'll see keys at
+ * SPOS_MAX:
+ */
+ do {
+ k = __bch2_btree_iter_peek_and_restart(trans, &iter, 0);
+ ret = bkey_err(k);
+ if (!k.k || ret)
+ break;
+
+ --btree_nodes;
+ if (!btree_nodes) {
+ *end = BBPOS(btree, k.k->p);
+ bch2_trans_iter_exit(trans, &iter);
+ return 0;
+ }
+ } while (bch2_btree_iter_advance(&iter));
+ bch2_trans_iter_exit(trans, &iter);
+ }
+
+ *end = BBPOS_MAX;
+ return ret;
+}
+
+static int bch2_check_extents_to_backpointers_pass(struct btree_trans *trans,
+ struct bpos bucket_start,
+ struct bpos bucket_end)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ enum btree_id btree_id;
+ struct bkey_s_c k;
+ struct bkey_buf last_flushed;
+ int ret = 0;
+
+ bch2_bkey_buf_init(&last_flushed);
+ bkey_init(&last_flushed.k->k);
+
+ for (btree_id = 0; btree_id < btree_id_nr_alive(c); btree_id++) {
+ int level, depth = btree_type_has_ptrs(btree_id) ? 0 : 1;
+
+ ret = commit_do(trans, NULL, NULL,
+ BCH_TRANS_COMMIT_no_enospc,
+ check_btree_root_to_backpointers(trans, btree_id,
+ bucket_start, bucket_end,
+ &last_flushed, &level));
+ if (ret)
+ return ret;
+
+ while (level >= depth) {
+ bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0,
+ level,
+ BTREE_ITER_PREFETCH);
+ while (1) {
+ bch2_trans_begin(trans);
+ k = bch2_btree_iter_peek(&iter);
+ if (!k.k)
+ break;
+ ret = bkey_err(k) ?:
+ check_extent_to_backpointers(trans, btree_id, level,
+ bucket_start, bucket_end,
+ &last_flushed, k) ?:
+ bch2_trans_commit(trans, NULL, NULL,
+ BCH_TRANS_COMMIT_no_enospc);
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
+ ret = 0;
+ continue;
+ }
+ if (ret)
+ break;
+ if (bpos_eq(iter.pos, SPOS_MAX))
+ break;
+ bch2_btree_iter_advance(&iter);
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ if (ret)
+ return ret;
+
+ --level;
+ }
+ }
+
+ bch2_bkey_buf_exit(&last_flushed, c);
+ return 0;
+}
+
+static struct bpos bucket_pos_to_bp_safe(const struct bch_fs *c,
+ struct bpos bucket)
+{
+ return bch2_dev_exists2(c, bucket.inode)
+ ? bucket_pos_to_bp(c, bucket, 0)
+ : bucket;
+}
+
+static int bch2_get_alloc_in_memory_pos(struct btree_trans *trans,
+ struct bpos start, struct bpos *end)
+{
+ struct btree_iter alloc_iter;
+ struct btree_iter bp_iter;
+ struct bkey_s_c alloc_k, bp_k;
+ size_t btree_nodes = btree_nodes_fit_in_ram(trans->c);
+ bool alloc_end = false, bp_end = false;
+ int ret = 0;
+
+ bch2_trans_node_iter_init(trans, &alloc_iter, BTREE_ID_alloc,
+ start, 0, 1, 0);
+ bch2_trans_node_iter_init(trans, &bp_iter, BTREE_ID_backpointers,
+ bucket_pos_to_bp_safe(trans->c, start), 0, 1, 0);
+ while (1) {
+ alloc_k = !alloc_end
+ ? __bch2_btree_iter_peek_and_restart(trans, &alloc_iter, 0)
+ : bkey_s_c_null;
+ bp_k = !bp_end
+ ? __bch2_btree_iter_peek_and_restart(trans, &bp_iter, 0)
+ : bkey_s_c_null;
+
+ ret = bkey_err(alloc_k) ?: bkey_err(bp_k);
+ if ((!alloc_k.k && !bp_k.k) || ret) {
+ *end = SPOS_MAX;
+ break;
+ }
+
+ --btree_nodes;
+ if (!btree_nodes) {
+ *end = alloc_k.k ? alloc_k.k->p : SPOS_MAX;
+ break;
+ }
+
+ if (bpos_lt(alloc_iter.pos, SPOS_MAX) &&
+ bpos_lt(bucket_pos_to_bp_safe(trans->c, alloc_iter.pos), bp_iter.pos)) {
+ if (!bch2_btree_iter_advance(&alloc_iter))
+ alloc_end = true;
+ } else {
+ if (!bch2_btree_iter_advance(&bp_iter))
+ bp_end = true;
+ }
+ }
+ bch2_trans_iter_exit(trans, &bp_iter);
+ bch2_trans_iter_exit(trans, &alloc_iter);
+ return ret;
+}
+
+int bch2_check_extents_to_backpointers(struct bch_fs *c)
+{
+ struct btree_trans *trans = bch2_trans_get(c);
+ struct bpos start = POS_MIN, end;
+ int ret;
+
+ while (1) {
+ ret = bch2_get_alloc_in_memory_pos(trans, start, &end);
+ if (ret)
+ break;
+
+ if (bpos_eq(start, POS_MIN) && !bpos_eq(end, SPOS_MAX))
+ bch_verbose(c, "%s(): alloc info does not fit in ram, running in multiple passes with %zu nodes per pass",
+ __func__, btree_nodes_fit_in_ram(c));
+
+ if (!bpos_eq(start, POS_MIN) || !bpos_eq(end, SPOS_MAX)) {
+ struct printbuf buf = PRINTBUF;
+
+ prt_str(&buf, "check_extents_to_backpointers(): ");
+ bch2_bpos_to_text(&buf, start);
+ prt_str(&buf, "-");
+ bch2_bpos_to_text(&buf, end);
+
+ bch_verbose(c, "%s", buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ ret = bch2_check_extents_to_backpointers_pass(trans, start, end);
+ if (ret || bpos_eq(end, SPOS_MAX))
+ break;
+
+ start = bpos_successor(end);
+ }
+ bch2_trans_put(trans);
+
+ bch_err_fn(c, ret);
+ return ret;
+}
+
+static int check_one_backpointer(struct btree_trans *trans,
+ struct bbpos start,
+ struct bbpos end,
+ struct bkey_s_c_backpointer bp,
+ struct bpos *last_flushed_pos)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bbpos pos = bp_to_bbpos(*bp.v);
+ struct bkey_s_c k;
+ struct printbuf buf = PRINTBUF;
+ int ret;
+
+ if (bbpos_cmp(pos, start) < 0 ||
+ bbpos_cmp(pos, end) > 0)
+ return 0;
+
+ k = bch2_backpointer_get_key(trans, &iter, bp.k->p, *bp.v, 0);
+ ret = bkey_err(k);
+ if (ret == -BCH_ERR_backpointer_to_overwritten_btree_node)
+ return 0;
+ if (ret)
+ return ret;
+
+ if (!k.k && !bpos_eq(*last_flushed_pos, bp.k->p)) {
+ *last_flushed_pos = bp.k->p;
+ ret = bch2_btree_write_buffer_flush_sync(trans) ?:
+ -BCH_ERR_transaction_restart_write_buffer_flush;
+ goto out;
+ }
+
+ if (fsck_err_on(!k.k, c,
+ backpointer_to_missing_ptr,
+ "backpointer for missing %s\n %s",
+ bp.v->level ? "btree node" : "extent",
+ (bch2_bkey_val_to_text(&buf, c, bp.s_c), buf.buf))) {
+ ret = bch2_btree_delete_at_buffered(trans, BTREE_ID_backpointers, bp.k->p);
+ goto out;
+ }
+out:
+fsck_err:
+ bch2_trans_iter_exit(trans, &iter);
+ printbuf_exit(&buf);
+ return ret;
+}
+
+static int bch2_check_backpointers_to_extents_pass(struct btree_trans *trans,
+ struct bbpos start,
+ struct bbpos end)
+{
+ struct bpos last_flushed_pos = SPOS_MAX;
+
+ return for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,
+ POS_MIN, BTREE_ITER_PREFETCH, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ check_one_backpointer(trans, start, end,
+ bkey_s_c_to_backpointer(k),
+ &last_flushed_pos));
+}
+
+int bch2_check_backpointers_to_extents(struct bch_fs *c)
+{
+ struct btree_trans *trans = bch2_trans_get(c);
+ struct bbpos start = (struct bbpos) { .btree = 0, .pos = POS_MIN, }, end;
+ int ret;
+
+ while (1) {
+ ret = bch2_get_btree_in_memory_pos(trans,
+ (1U << BTREE_ID_extents)|
+ (1U << BTREE_ID_reflink),
+ ~0,
+ start, &end);
+ if (ret)
+ break;
+
+ if (!bbpos_cmp(start, BBPOS_MIN) &&
+ bbpos_cmp(end, BBPOS_MAX))
+ bch_verbose(c, "%s(): extents do not fit in ram, running in multiple passes with %zu nodes per pass",
+ __func__, btree_nodes_fit_in_ram(c));
+
+ if (bbpos_cmp(start, BBPOS_MIN) ||
+ bbpos_cmp(end, BBPOS_MAX)) {
+ struct printbuf buf = PRINTBUF;
+
+ prt_str(&buf, "check_backpointers_to_extents(): ");
+ bch2_bbpos_to_text(&buf, start);
+ prt_str(&buf, "-");
+ bch2_bbpos_to_text(&buf, end);
+
+ bch_verbose(c, "%s", buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ ret = bch2_check_backpointers_to_extents_pass(trans, start, end);
+ if (ret || !bbpos_cmp(end, BBPOS_MAX))
+ break;
+
+ start = bbpos_successor(end);
+ }
+ bch2_trans_put(trans);
+
+ bch_err_fn(c, ret);
+ return ret;
+}
projects / bcachefs-tools-debian / blobdiff