diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 44 |
1 files changed, 27 insertions, 17 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 548720021ed..13396eb7f2c 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -3784,7 +3784,7 @@ l2: * overhead would be unchanged, that doesn't seem necessarily * worthwhile. */ - if (PageIsAllVisible(BufferGetPage(buffer)) && + if (PageIsAllVisible(page) && visibilitymap_clear(relation, block, vmbuffer, VISIBILITYMAP_ALL_FROZEN)) cleared_all_frozen = true; @@ -3846,36 +3846,46 @@ l2: * first". To implement this, we must do RelationGetBufferForTuple * while not holding the lock on the old page, and we must rely on it * to get the locks on both pages in the correct order. + * + * Another consideration is that we need visibility map page pin(s) if + * we will have to clear the all-visible flag on either page. If we + * call RelationGetBufferForTuple, we rely on it to acquire any such + * pins; but if we don't, we have to handle that here. Hence we need + * a loop. */ - if (newtupsize > pagefree) - { - /* Assume there's no chance to put heaptup on same page. */ - newbuf = RelationGetBufferForTuple(relation, heaptup->t_len, - buffer, 0, NULL, - &vmbuffer_new, &vmbuffer); - } - else + for (;;) { + if (newtupsize > pagefree) + { + /* It doesn't fit, must use RelationGetBufferForTuple. */ + newbuf = RelationGetBufferForTuple(relation, heaptup->t_len, + buffer, 0, NULL, + &vmbuffer_new, &vmbuffer); + /* We're all done. */ + break; + } + /* Acquire VM page pin if needed and we don't have it. */ + if (vmbuffer == InvalidBuffer && PageIsAllVisible(page)) + visibilitymap_pin(relation, block, &vmbuffer); /* Re-acquire the lock on the old tuple's page. */ LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE); /* Re-check using the up-to-date free space */ pagefree = PageGetHeapFreeSpace(page); - if (newtupsize > pagefree) + if (newtupsize > pagefree || + (vmbuffer == InvalidBuffer && PageIsAllVisible(page))) { /* - * Rats, it doesn't fit anymore. We must now unlock and - * relock to avoid deadlock. Fortunately, this path should - * seldom be taken. + * Rats, it doesn't fit anymore, or somebody just now set the + * all-visible flag. We must now unlock and loop to avoid + * deadlock. Fortunately, this path should seldom be taken. */ LockBuffer(buffer, BUFFER_LOCK_UNLOCK); - newbuf = RelationGetBufferForTuple(relation, heaptup->t_len, - buffer, 0, NULL, - &vmbuffer_new, &vmbuffer); } else { - /* OK, it fits here, so we're done. */ + /* We're all done. */ newbuf = buffer; + break; } } } |