diff options
Diffstat (limited to 'src/backend/storage/smgr/smgr.c')
| -rw-r--r-- | src/backend/storage/smgr/smgr.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/src/backend/storage/smgr/smgr.c b/src/backend/storage/smgr/smgr.c index a691aed1f40..b3fb8bc3ea8 100644 --- a/src/backend/storage/smgr/smgr.c +++ b/src/backend/storage/smgr/smgr.c @@ -99,7 +99,7 @@ typedef struct f_smgr BlockNumber blocknum, BlockNumber nblocks); BlockNumber (*smgr_nblocks) (SMgrRelation reln, ForkNumber forknum); void (*smgr_truncate) (SMgrRelation reln, ForkNumber forknum, - BlockNumber nblocks); + BlockNumber old_blocks, BlockNumber nblocks); void (*smgr_immedsync) (SMgrRelation reln, ForkNumber forknum); void (*smgr_registersync) (SMgrRelation reln, ForkNumber forknum); } f_smgr; @@ -697,10 +697,15 @@ smgrnblocks_cached(SMgrRelation reln, ForkNumber forknum) * * The caller must hold AccessExclusiveLock on the relation, to ensure that * other backends receive the smgr invalidation event that this function sends - * before they access any forks of the relation again. + * before they access any forks of the relation again. The current size of + * the forks should be provided in old_nblocks. This function should normally + * be called in a critical section, but the current size must be checked + * outside the critical section, and no interrupts or smgr functions relating + * to this relation should be called in between. */ void -smgrtruncate(SMgrRelation reln, ForkNumber *forknum, int nforks, BlockNumber *nblocks) +smgrtruncate(SMgrRelation reln, ForkNumber *forknum, int nforks, + BlockNumber *old_nblocks, BlockNumber *nblocks) { int i; @@ -728,7 +733,8 @@ smgrtruncate(SMgrRelation reln, ForkNumber *forknum, int nforks, BlockNumber *nb /* Make the cached size is invalid if we encounter an error. */ reln->smgr_cached_nblocks[forknum[i]] = InvalidBlockNumber; - smgrsw[reln->smgr_which].smgr_truncate(reln, forknum[i], nblocks[i]); + smgrsw[reln->smgr_which].smgr_truncate(reln, forknum[i], + old_nblocks[i], nblocks[i]); /* * We might as well update the local smgr_cached_nblocks values. The |