diff options
Diffstat (limited to 'fs/bcachefs/backpointers.c')
| -rw-r--r-- | fs/bcachefs/backpointers.c | 860 |
1 files changed, 860 insertions, 0 deletions
diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c new file mode 100644 index 0000000000..23c0834a97 --- /dev/null +++ b/fs/bcachefs/backpointers.c @@ -0,0 +1,860 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "bcachefs.h" +#include "bbpos.h" +#include "alloc_background.h" +#include "backpointers.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 bkey_i_backpointer *bp_k, + struct bch_backpointer bp, + struct bkey_s_c orig_k, + bool insert) +{ + struct btree_iter bp_iter; + struct bkey_s_c k; + int ret; + + 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) +{ + struct btree_iter iter; + struct bkey_s_c k; + int ret; + + ret = bch2_trans_run(c, + for_each_btree_key_commit(trans, iter, + BTREE_ID_backpointers, POS_MIN, 0, k, + NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL, + bch2_check_btree_backpointer(trans, &iter, k))); + if (ret) + bch_err_fn(c, ret); + return ret; +} + +struct bpos_level { + unsigned level; + struct bpos pos; +}; + +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 bpos_level *last_flushed) +{ + struct bch_fs *c = trans->c; + struct btree_iter bp_iter = { NULL }; + struct printbuf buf = PRINTBUF; + struct bkey_s_c bp_k; + int ret; + + 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 (last_flushed->level != bp.level || + !bpos_eq(last_flushed->pos, orig_k.k->p)) { + last_flushed->level = bp.level; + last_flushed->pos = orig_k.k->p; + + ret = bch2_btree_write_buffer_flush_sync(trans) ?: + -BCH_ERR_transaction_restart_write_buffer_flush; + goto out; + } + goto missing; + } +out: +err: +fsck_err: + bch2_trans_iter_exit(trans, &bp_iter); + 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->sb.version_upgrade_complete < bcachefs_metadata_version_backpointers || + 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, + struct btree_iter *iter, + struct bpos bucket_start, + struct bpos bucket_end, + struct bpos_level *last_flushed) +{ + struct bch_fs *c = trans->c; + struct bkey_ptrs_c ptrs; + const union bch_extent_entry *entry; + struct extent_ptr_decoded p; + struct bkey_s_c k; + int ret; + + k = bch2_btree_iter_peek_all_levels(iter); + ret = bkey_err(k); + if (ret) + return ret; + if (!k.k) + return 0; + + 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, iter->btree_id, iter->path->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 bpos_level *last_flushed) +{ + struct bch_fs *c = trans->c; + struct btree_root *r = bch2_btree_id_root(c, btree_id); + struct btree_iter iter; + struct btree *b; + struct bkey_s_c k; + struct bkey_ptrs_c ptrs; + struct extent_ptr_decoded p; + const union bch_extent_entry *entry; + int ret; + + bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, r->level, 0); + b = bch2_btree_iter_peek_node(&iter); + ret = PTR_ERR_OR_ZERO(b); + if (ret) + goto err; + + BUG_ON(b != btree_node_root(c, b)); + + k = bkey_i_to_s_c(&b->key); + 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, iter.btree_id, b->c.level + 1, + k, p, &bucket_pos, &bp); + + ret = check_bp_exists(trans, bucket_pos, bp, k, + bucket_start, bucket_end, + last_flushed); + if (ret) + goto err; + } +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 bpos_level last_flushed = { UINT_MAX, POS_MIN }; + int ret = 0; + + for (btree_id = 0; btree_id < btree_id_nr_alive(c); btree_id++) { + unsigned depth = btree_type_has_ptrs(btree_id) ? 0 : 1; + + bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, + depth, + BTREE_ITER_ALL_LEVELS| + BTREE_ITER_PREFETCH); + + do { + ret = commit_do(trans, NULL, NULL, + BTREE_INSERT_LAZY_RW| + BTREE_INSERT_NOFAIL, + check_extent_to_backpointers(trans, &iter, + bucket_start, bucket_end, + &last_flushed)); + if (ret) + break; + } while (!bch2_btree_iter_advance(&iter)); + + bch2_trans_iter_exit(trans, &iter); + + if (ret) + break; + + ret = commit_do(trans, NULL, NULL, + BTREE_INSERT_LAZY_RW| + BTREE_INSERT_NOFAIL, + check_btree_root_to_backpointers(trans, btree_id, + bucket_start, bucket_end, + &last_flushed)); + if (ret) + break; + } + return ret; +} + +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); + + if (ret) + 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 btree_iter iter; + struct bkey_s_c k; + 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, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL, + 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); + + if (ret) + bch_err_fn(c, ret); + return ret; +} |