From bade9711e0905eaa99e2ed98fc9642acaf9ba2b5 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sun, 29 Sep 2024 23:40:28 -0400 Subject: [PATCH] bcachefs: Split out check_unreachable_inodes() pass With inode backpointers, we can write a very simple check_unreachable_inodes() pass that only looks for non-unlinked inodes that are missing backpointers, and reattaches them. This simplifies check_directory_structure() so that it's now only checking for directory structure loops, Signed-off-by: Kent Overstreet --- fs/bcachefs/fsck.c | 100 ++++++++++++++++++---------- fs/bcachefs/fsck.h | 1 + fs/bcachefs/recovery_passes_types.h | 1 + 3 files changed, 67 insertions(+), 35 deletions(-) diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c index b8a6ceb0cc7a..257366ec7939 100644 --- a/fs/bcachefs/fsck.c +++ b/fs/bcachefs/fsck.c @@ -1292,6 +1292,58 @@ int bch2_check_inodes(struct bch_fs *c) return ret; } +static int check_unreachable_inode(struct btree_trans *trans, + struct btree_iter *iter, + struct bkey_s_c k) +{ + struct bch_fs *c = trans->c; + 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.bi_subvol) + return 0; + + if (inode.bi_flags & BCH_INODE_unlinked) + return 0; + + if (fsck_err_on(!inode.bi_dir, + trans, inode_unreachable, + "unreachable inode:\n%s", + (printbuf_reset(&buf), + bch2_bkey_val_to_text(&buf, c, k), + 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: + */ +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) { @@ -2450,22 +2502,6 @@ static int check_subvol_path(struct btree_trans *trans, struct btree_iter *iter, if (ret) break; - /* - * We've checked that inode backpointers point to valid dirents; - * here, it's sufficient to check that the subvolume root has a - * dirent: - */ - if (fsck_err_on(!subvol_root.bi_dir, - trans, subvol_unreachable, - "unreachable subvolume %s", - (bch2_bkey_val_to_text(&buf, c, s.s_c), - prt_newline(&buf), - bch2_inode_unpacked_to_text(&buf, &subvol_root), - buf.buf))) { - ret = reattach_subvol(trans, s); - break; - } - u32 parent = le32_to_cpu(s.v->fs_path_parent); if (darray_u32_has(&subvol_path, parent)) { @@ -2526,12 +2562,6 @@ static bool path_is_dup(pathbuf *p, u64 inum, u32 snapshot) return false; } -/* - * Check that a given inode is reachable from its subvolume root - we already - * verified subvolume connectivity: - * - * XXX: we should also be verifying that inodes are in the right subvolumes - */ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c inode_k) { struct bch_fs *c = trans->c; @@ -2545,6 +2575,9 @@ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c ino 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; @@ -2559,21 +2592,15 @@ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c ino bch2_trans_iter_exit(trans, &dirent_iter); if (bch2_err_matches(ret, ENOENT)) { - ret = 0; - if (fsck_err(trans, inode_unreachable, - "unreachable inode\n%s", - (printbuf_reset(&buf), - bch2_bkey_val_to_text(&buf, c, inode_k), - buf.buf))) - ret = reattach_inode(trans, &inode); + 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); - if (!S_ISDIR(inode.bi_mode)) - break; - ret = darray_push(p, ((struct pathbuf_entry) { .inum = inode.bi_inum, .snapshot = snapshot, @@ -2626,9 +2653,8 @@ fsck_err: } /* - * Check for unreachable inodes, as well as loops in the directory structure: - * After bch2_check_dirents(), if an inode backpointer doesn't exist that means it's - * unreachable: + * 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) { @@ -2756,6 +2782,10 @@ static int check_nlinks_find_hardlinks(struct bch_fs *c, 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; diff --git a/fs/bcachefs/fsck.h b/fs/bcachefs/fsck.h index a4ef94271784..1cca31011530 100644 --- a/fs/bcachefs/fsck.h +++ b/fs/bcachefs/fsck.h @@ -9,6 +9,7 @@ int bch2_check_dirents(struct bch_fs *); int bch2_check_xattrs(struct bch_fs *); int bch2_check_root(struct bch_fs *); int bch2_check_subvolume_structure(struct bch_fs *); +int bch2_check_unreachable_inodes(struct bch_fs *); int bch2_check_directory_structure(struct bch_fs *); int bch2_check_nlinks(struct bch_fs *); int bch2_fix_reflink_p(struct bch_fs *); diff --git a/fs/bcachefs/recovery_passes_types.h b/fs/bcachefs/recovery_passes_types.h index 50406ce0e4ef..9d96c06e365c 100644 --- a/fs/bcachefs/recovery_passes_types.h +++ b/fs/bcachefs/recovery_passes_types.h @@ -46,6 +46,7 @@ x(check_dirents, 27, PASS_FSCK) \ x(check_xattrs, 28, PASS_FSCK) \ x(check_root, 29, PASS_ONLINE|PASS_FSCK) \ + x(check_unreachable_inodes, 40, PASS_ONLINE|PASS_FSCK) \ x(check_subvolume_structure, 36, PASS_ONLINE|PASS_FSCK) \ x(check_directory_structure, 30, PASS_ONLINE|PASS_FSCK) \ x(check_nlinks, 31, PASS_FSCK) \