Fix snapshot reference leak if lo_export fails.
If lo_export() fails to open the target file or to write to it, it leaks
the created LargeObjectDesc and its snapshot in the top-transaction
context and resource owner. That's pretty harmless, it's a small leak
after all, but it gives the user a "Snapshot reference leak" warning.
Fix by using a short-lived memory context and no resource owner for
transient LargeObjectDescs that are opened and closed within one function
call. The leak is easiest to reproduce with lo_export() on a directory
that doesn't exist, but in principle the other lo_* functions could also
fail.
Backpatch to all supported versions.
Reported-by: Andrew B
Reviewed-by: Alvaro Herrera
Discussion: https://www.postgresql.org/message-id/[email protected]
Branch
------
REL_14_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/4ebd740cd3f3afe5523c5947be836edf8cccdc27
Modified Files
--------------
src/backend/libpq/be-fsstubs.c | 146 ++++++++++++++---------------
src/backend/storage/large_object/inv_api.c | 27 +++---
src/test/regress/input/largeobject.source | 11 +++
src/test/regress/output/largeobject.source | 11 +++
4 files changed, 104 insertions(+), 91 deletions(-)
