bcachefs: fsck: Fix nested transaction handling

This uses the new trans->restart count to make sure we always correctly
return -BCH_ERR_transaction_restart_nested when we restart a nested
transaction - eliminating some other hacks and preparing for new
assertions.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index ea264421fe8f082f0e66c677d2d2f371109be794..bb8cab7cb405f1994848886c12ae34d9fbb6e416 100644 (file)
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -650,6 +650,7 @@ static int __walk_inode(struct btree_trans *trans,
        struct bch_fs *c = trans->c;
        struct btree_iter iter;
        struct bkey_s_c k;
+       u32 restart_count = trans->restart_count;
        unsigned i;
        int ret;
 
@@ -677,6 +678,10 @@ static int __walk_inode(struct btree_trans *trans,
 
        w->cur_inum             = pos.inode;
        w->first_this_inode     = true;
+
+       if (trans_was_restarted(trans, restart_count))
+               return -BCH_ERR_transaction_restart_nested;
+
 lookup_snapshot:
        for (i = 0; i < w->inodes.nr; i++)
                if (bch2_snapshot_is_ancestor(c, pos.snapshot, w->inodes.data[i].snapshot))
@@ -1115,7 +1120,8 @@ static int check_i_sectors(struct btree_trans *trans, struct inode_walker *w)
 {
        struct bch_fs *c = trans->c;
        struct inode_walker_entry *i;
-       int ret = 0, ret2 = 0;
+       u32 restart_count = trans->restart_count;
+       int ret = 0;
        s64 count2;
 
        darray_for_each(w->inodes, i) {
@@ -1140,13 +1146,16 @@ static int check_i_sectors(struct btree_trans *trans, struct inode_walker *w)
                        ret = write_inode(trans, &i->inode, i->snapshot);
                        if (ret)
                                break;
-                       ret2 = -BCH_ERR_transaction_restart_nested;
                }
        }
 fsck_err:
-       if (ret)
+       if (ret) {
                bch_err(c, "error from check_i_sectors(): %s", bch2_err_str(ret));
-       return ret ?: ret2;
+               return ret;
+       }
+       if (trans_was_restarted(trans, restart_count))
+               return -BCH_ERR_transaction_restart_nested;
+       return 0;
 }
 
 static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
@@ -1182,14 +1191,7 @@ static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
                        goto err;
        }
 
-       if (!iter->path->should_be_locked) {
-               /*
-                * hack: check_i_sectors may have handled a transaction restart,
-                * it shouldn't be but we need to fix the new i_sectors check
-                * code and delete the old bch2_count_inode_sectors() first
-                */
-               return -BCH_ERR_transaction_restart_nested;
-       }
+       BUG_ON(!iter->path->should_be_locked);
 #if 0
        if (bkey_cmp(prev.k->k.p, bkey_start_pos(k.k)) > 0) {
                char buf1[200];
@@ -1336,7 +1338,8 @@ static int check_subdir_count(struct btree_trans *trans, struct inode_walker *w)
 {
        struct bch_fs *c = trans->c;
        struct inode_walker_entry *i;
-       int ret = 0, ret2 = 0;
+       u32 restart_count = trans->restart_count;
+       int ret = 0;
        s64 count2;
 
        darray_for_each(w->inodes, i) {
@@ -1362,13 +1365,16 @@ static int check_subdir_count(struct btree_trans *trans, struct inode_walker *w)
                        ret = write_inode(trans, &i->inode, i->snapshot);
                        if (ret)
                                break;
-                       ret2 = -BCH_ERR_transaction_restart_nested;
                }
        }
 fsck_err:
-       if (ret)
+       if (ret) {
                bch_err(c, "error from check_subdir_count(): %s", bch2_err_str(ret));
-       return ret ?: ret2;
+               return ret;
+       }
+       if (trans_was_restarted(trans, restart_count))
+               return -BCH_ERR_transaction_restart_nested;
+       return 0;
 }
 
 static int check_dirent_target(struct btree_trans *trans,
@@ -1526,10 +1532,7 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
                        goto err;
        }
 
-       if (!iter->path->should_be_locked) {
-               /* hack: see check_extent() */
-               return -BCH_ERR_transaction_restart_nested;
-       }
+       BUG_ON(!iter->path->should_be_locked);
 
        ret = __walk_inode(trans, dir, equiv);
        if (ret < 0)