diff options
| author | Robert Haas | 2024-04-05 17:39:29 +0000 |
|---|---|---|
| committer | Robert Haas | 2024-04-05 17:41:19 +0000 |
| commit | 55a5ee30cd65886ff0a2e7ffef4ec2816fbec273 (patch) | |
| tree | e3384afb0853b27ac43e61e5b0a897414095b298 | |
| parent | 079d94ab3412fdeda637a24b17bde53c576b0007 (diff) | |
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
| -rw-r--r-- | src/common/blkreftable.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/common/blkreftable.c b/src/common/blkreftable.c index bfa6f7ab5d8..845b5d1dc46 100644 --- a/src/common/blkreftable.c +++ b/src/common/blkreftable.c @@ -410,7 +410,11 @@ BlockRefTableEntryGetBlocks(BlockRefTableEntry *entry, if (chunkno == start_chunkno) start_offset = start_blkno % BLOCKS_PER_CHUNK; if (chunkno == stop_chunkno - 1) - stop_offset = stop_blkno % BLOCKS_PER_CHUNK; + { + Assert(stop_blkno > chunkno * BLOCKS_PER_CHUNK); + stop_offset = stop_blkno - (chunkno * BLOCKS_PER_CHUNK); + Assert(stop_offset <= BLOCKS_PER_CHUNK); + } /* * Handling differs depending on whether this is an array of offsets |