aio: Fix crash potential for pg_aios views due to late state update
pgaio_io_reclaim() reset the fields in PgAioHandle before updating the state
to IDLE or incrementing the generation. For most things that's OK, but for
pg_get_aios() it is not - if it copied the PgAioHandle while fields were being
reset, we wouldn't detect that and could call
pgaio_io_get_target_description() with ioh->target == PGAIO_TID_INVALID,
leading to a crash.
Fix this issue by incrementing the generation and state earlier, before
resetting.
Also add an assertion to pgaio_io_get_target_description() for the target to
be valid - that'd have made this case a bit easier to debug. While at it,
add/update a few related assertions.
Author: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/062daca9-dfad-4750-9da8-b13388301ad9@gmail.com
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/0d9114b7040d7503096e2897f4c856b17d461f6a
Modified Files
--------------
src/backend/storage/aio/aio.c | 21 +++++++++++++++------
src/backend/storage/aio/aio_target.c | 12 +++++++++---
2 files changed, 24 insertions(+), 9 deletions(-)
