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_13_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/07070c0082aacc9e9bf09d1d08bc3a60c999332e 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(-)
