amcheck: Allow interrupting the child-level rightlink walk bt_child_highkey_check() walks right along the child level following btpo_next links, reading a page on each iteration, but its loop lacked a CHECK_FOR_INTERRUPTS(). Every other page-traversal loop in verify_nbtree.c already has one.
The loop's existing checks do not guarantee a timely exit on a corrupt index. The in-loop cycle check only fires when a rightlink points back through the block the walk started from, or to a page whose btpo_prev points to itself, so a cycle further downstream can go undetected -- for example a run of pages all flagged P_INCOMPLETE_SPLIT, which skips both the high-key comparison and bt_downlink_missing_check() and so never reaches an error. Such an index, or simply a very long rightlink chain, makes the walk effectively uninterruptible. Since amcheck exists to be run against possibly-corrupt indexes, make this walk respond to query cancellation and shutdown requests like the sibling loops do. Author: Paul Kim <[email protected]> Reviewed-by: shihao zhong <[email protected]> Discussion: https://www.postgresql.org/message-id/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/a846ee9854ee9994935d697e1f9c2a0d70f328f1 Modified Files -------------- contrib/amcheck/verify_nbtree.c | 2 ++ 1 file changed, 2 insertions(+)
