pgsql: Fix incorrect calculation in BlockRefTableEntryGetBlocks. - Mailing list pgsql-committers

From Robert Haas
Subject pgsql: Fix incorrect calculation in BlockRefTableEntryGetBlocks.
Date
Msg-id E1rsni5-000fUn-Ae@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Fix incorrect calculation in BlockRefTableEntryGetBlocks.

The previous formula was incorrect in the case where the function's
nblocks argument was a multiple of BLOCKS_PER_CHUNK, which happens
whenever a relation segment file is exactly 512MB or exactly 1GB in
length. In such cases, the formula would calculate a stop_offset of
0 rather than 65536, resulting in modified blocks in the second half
of a 1GB file, or all the modified blocks in a 512MB file, being
omitted from the incremental backup.

Reported off-list by Tomas Vondra and Jakub Wartak.

Discussion: http://postgr.es/m/CA+TgmoYwy_KHp1-5GYNmVa=zdeJWhNH1T0SBmEuvqQNJEHj1Lw@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/55a5ee30cd65886ff0a2e7ffef4ec2816fbec273

Modified Files
--------------
src/common/blkreftable.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)


pgsql-committers by date:

Previous
From: Tomas Vondra
Date:
Subject: pgsql: Check HAVE_COPY_FILE_RANGE before calling copy_file_range
Next
From: Andrew Dunstan
Date:
Subject: [MASSMAIL]pgsql: Silence some compiler warnings in commit 3311ea86ed