bcachefs: Issue a transaction restart after commit in repair

transaction commits invalidate pointers to btree values, and they also
downgrade intent locks.

This breaks the interior btree update path, which takes intent locks and
then calls into the allocator.

This isn't an ideal solution: we can't unconditionally issue a restart
after a transaction commit, because that would break other codepaths.

Reported-by: syzbot+78d82470c16a49702682@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 8846daaa116239f939f062a79c56dceb6ffb5472..79af226ca609a0f5fa8c9362460dfab2c557cdeb 100644 (file)
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -1384,7 +1384,7 @@ delete:
        ret =   bch2_btree_bit_mod_iter(trans, iter, false) ?:
                bch2_trans_commit(trans, NULL, NULL,
                        BCH_TRANS_COMMIT_no_enospc) ?:
-               1;
+               -BCH_ERR_transaction_restart_commit;
        goto out;
 }
 

diff --git a/fs/bcachefs/errcode.h b/fs/bcachefs/errcode.h
index a12050e9c1913dc05c529d8a0bec01c5a89c878d..a0cfc0f286f4c125350410ff3c314ee65e3875d9 100644 (file)
--- a/fs/bcachefs/errcode.h
+++ b/fs/bcachefs/errcode.h
@@ -148,6 +148,7 @@
        x(BCH_ERR_transaction_restart,  transaction_restart_split_race)         \
        x(BCH_ERR_transaction_restart,  transaction_restart_write_buffer_flush) \
        x(BCH_ERR_transaction_restart,  transaction_restart_nested)             \
+       x(BCH_ERR_transaction_restart,  transaction_restart_commit)             \
        x(0,                            no_btree_node)                          \
        x(BCH_ERR_no_btree_node,        no_btree_node_relock)                   \
        x(BCH_ERR_no_btree_node,        no_btree_node_upgrade)                  \