Fix deadlock in GIN vacuum introduced by 218f51584d5 Before 218f51584d5 if posting tree page is about to be deleted, then the whole posting tree is locked by LockBufferForCleanup() on root preventing all the concurrent inserts. 218f51584d5 reduced locking to the subtree containing page to be deleted. However, due to concurrent parent split, inserter doesn't always holds pins on all the pages constituting path from root to the target leaf page. That could cause a deadlock between GIN vacuum process and GIN inserter. And we didn't find non-invasive way to fix this.
This commit reverts VACUUM behavior to lock the whole posting tree before delete any page. However, we keep another useful change by 218f51584d5: the tree is locked only if there are pages to be deleted. Reported-by: Chen Huajun Diagnosed-by: Chen Huajun, Andrey Borodin, Peter Geoghegan Discussion: https://postgr.es/m/31a702a.14dd.166c1366ac1.Coremail.chjischj%40163.com Author: Alexander Korotkov, based on ideas from Andrey Borodin and Peter Geoghegan Reviewed-by: Andrey Borodin Backpatch-through: 10 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/fd83c83d0943a6717dbe521efa10da9dce94e4cd Modified Files -------------- src/backend/access/gin/README | 15 +--- src/backend/access/gin/ginvacuum.c | 148 +++++++++++++++++-------------------- 2 files changed, 73 insertions(+), 90 deletions(-)