pgsql: Fix snapshot reference leak if lo_export fails.
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: /messages/by-id/32bf767a-2d65-71c4-f170-122f416bab7e@iki.fi
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/6b1b405ebfdce9da47f59d8d4144b1168709fbce
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(-)
On 3 Nov 2021, at 10:44, Heikki Linnakangas <heikki.linnakangas@iki.fi> wrote:
Fix snapshot reference leak if lo_export fails.
This commit seems to lack the update in largeobject_1 as per hamerkop in:
https://brekka.postgresql.org/cgi-bin/show_log.pl?nm=hamerkop&dt=2021-11-03%2010%3A42%3A37
--
Daniel Gustafsson https://vmware.com/
On 03/11/2021 13:06, Daniel Gustafsson wrote:
On 3 Nov 2021, at 10:44, Heikki Linnakangas <heikki.linnakangas@iki.fi> wrote:
Fix snapshot reference leak if lo_export fails.
This commit seems to lack the update in largeobject_1 as per hamerkop in:
Fixed, thanks!
I'm a bit surprised none of the other Windows systems on the buildfarm
complained. The difference in largeobject_1 output is apparently that
the 'tenk.data' file uses Windows line endings. I guess that on all the
other Windows hosts, git has been configured to use Unix line endings.
- Heikki
On 3 Nov 2021, at 18:47, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
On 03/11/2021 13:06, Daniel Gustafsson wrote:
On 3 Nov 2021, at 10:44, Heikki Linnakangas <heikki.linnakangas@iki.fi> wrote:
Fix snapshot reference leak if lo_export fails.This commit seems to lack the update in largeobject_1 as per hamerkop in:
Fixed, thanks!
I'm a bit surprised none of the other Windows systems on the buildfarm complained. The difference in largeobject_1 output is apparently that the 'tenk.data' file uses Windows line endings. I guess that on all the other Windows hosts, git has been configured to use Unix line endings.
Interesting, so when hamerkop is offline (which it was for a month) we don't
have coverage for Windows line endings? That's worth keeping in mind.
--
Daniel Gustafsson https://vmware.com/
On 11/3/21 13:47, Heikki Linnakangas wrote:
On 03/11/2021 13:06, Daniel Gustafsson wrote:
On 3 Nov 2021, at 10:44, Heikki Linnakangas
<heikki.linnakangas@iki.fi> wrote:Fix snapshot reference leak if lo_export fails.
This commit seems to lack the update in largeobject_1 as per hamerkop
in:Fixed, thanks!
I'm a bit surprised none of the other Windows systems on the buildfarm
complained. The difference in largeobject_1 output is apparently that
the 'tenk.data' file uses Windows line endings. I guess that on all
the other Windows hosts, git has been configured to use Unix line
endings.
no, on drongo this comes up blank:
git config --get --show-origin core.eol
These days I often set:
git config --system core.eol lf
git config --system core.autocrlf input
because it makes repos checked out with Windows native git work nicely
with msys git, but I haven't done that on drongo.
cheers
andrew
--
Andrew Dunstan
EDB: https://www.enterprisedb.com