diff options
Diffstat (limited to 'src/backend')
-rw-r--r-- | src/backend/access/nbtree/nbtree.c | 2 | ||||
-rw-r--r-- | src/backend/access/nbtree/nbtutils.c | 47 | ||||
-rw-r--r-- | src/backend/commands/copyfromparse.c | 2 | ||||
-rw-r--r-- | src/backend/libpq/be-secure-gssapi.c | 6 | ||||
-rw-r--r-- | src/backend/utils/adt/inet_net_pton.c | 3 |
5 files changed, 33 insertions, 27 deletions
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c index 03a1d7b027a..fdff960c130 100644 --- a/src/backend/access/nbtree/nbtree.c +++ b/src/backend/access/nbtree/nbtree.c @@ -417,6 +417,8 @@ btrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys, * way, so we might as well avoid wasting cycles on acquiring page LSNs. * * See nbtree/README section on making concurrent TID recycling safe. + * + * Note: so->dropPin should never change across rescans. */ so->dropPin = (!scan->xs_want_itup && IsMVCCSnapshot(scan->xs_snapshot) && diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c index 29f0dca1b08..86293cba5ab 100644 --- a/src/backend/access/nbtree/nbtutils.c +++ b/src/backend/access/nbtree/nbtutils.c @@ -3323,24 +3323,26 @@ _bt_checkkeys_look_ahead(IndexScanDesc scan, BTReadPageState *pstate, * current page and killed tuples thereon (generally, this should only be * called if so->numKilled > 0). * - * The caller does not have a lock on the page and may or may not have the - * page pinned in a buffer. Note that read-lock is sufficient for setting - * LP_DEAD status (which is only a hint). + * Caller should not have a lock on the so->currPos page, but must hold a + * buffer pin when !so->dropPin. When we return, it still won't be locked. + * It'll continue to hold whatever pins were held before calling here. * - * We match items by heap TID before assuming they are the right ones to - * delete. We cope with cases where items have moved right due to insertions. - * If an item has moved off the current page due to a split, we'll fail to - * find it and do nothing (this is not an error case --- we assume the item - * will eventually get marked in a future indexscan). - * - * Note that if we hold a pin on the target page continuously from initially - * reading the items until applying this function, VACUUM cannot have deleted - * any items on the page, so the page's TIDs can't have been recycled by now. - * There's no risk that we'll confuse a new index tuple that happens to use a - * recycled TID with a now-removed tuple with the same TID (that used to be on - * this same page). We can't rely on that during scans that drop pins eagerly + * We match items by heap TID before assuming they are the right ones to set + * LP_DEAD. If the scan is one that holds a buffer pin on the target page + * continuously from initially reading the items until applying this function + * (if it is a !so->dropPin scan), VACUUM cannot have deleted any items on the + * page, so the page's TIDs can't have been recycled by now. There's no risk + * that we'll confuse a new index tuple that happens to use a recycled TID + * with a now-removed tuple with the same TID (that used to be on this same + * page). We can't rely on that during scans that drop buffer pins eagerly * (so->dropPin scans), though, so we must condition setting LP_DEAD bits on * the page LSN having not changed since back when _bt_readpage saw the page. + * We totally give up on setting LP_DEAD bits when the page LSN changed. + * + * We give up much less often during !so->dropPin scans, but it still happens. + * We cope with cases where items have moved right due to insertions. If an + * item has moved off the current page due to a split, we'll fail to find it + * and just give up on it. */ void _bt_killitems(IndexScanDesc scan) @@ -3353,6 +3355,7 @@ _bt_killitems(IndexScanDesc scan) OffsetNumber maxoff; int numKilled = so->numKilled; bool killedsomething = false; + Buffer buf; Assert(numKilled > 0); Assert(BTScanPosIsValid(so->currPos)); @@ -3369,11 +3372,11 @@ _bt_killitems(IndexScanDesc scan) * concurrent VACUUMs from recycling any of the TIDs on the page. */ Assert(BTScanPosIsPinned(so->currPos)); - _bt_lockbuf(rel, so->currPos.buf, BT_READ); + buf = so->currPos.buf; + _bt_lockbuf(rel, buf, BT_READ); } else { - Buffer buf; XLogRecPtr latestlsn; Assert(!BTScanPosIsPinned(so->currPos)); @@ -3391,10 +3394,9 @@ _bt_killitems(IndexScanDesc scan) } /* Unmodified, hinting is safe */ - so->currPos.buf = buf; } - page = BufferGetPage(so->currPos.buf); + page = BufferGetPage(buf); opaque = BTPageGetOpaque(page); minoff = P_FIRSTDATAKEY(opaque); maxoff = PageGetMaxOffsetNumber(page); @@ -3511,10 +3513,13 @@ _bt_killitems(IndexScanDesc scan) if (killedsomething) { opaque->btpo_flags |= BTP_HAS_GARBAGE; - MarkBufferDirtyHint(so->currPos.buf, true); + MarkBufferDirtyHint(buf, true); } - _bt_unlockbuf(rel, so->currPos.buf); + if (!so->dropPin) + _bt_unlockbuf(rel, buf); + else + _bt_relbuf(rel, buf); } diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c index f5fc346e201..f52f2477df1 100644 --- a/src/backend/commands/copyfromparse.c +++ b/src/backend/commands/copyfromparse.c @@ -1538,7 +1538,7 @@ GetDecimalFromHex(char hex) if (isdigit((unsigned char) hex)) return hex - '0'; else - return tolower((unsigned char) hex) - 'a' + 10; + return pg_ascii_tolower((unsigned char) hex) - 'a' + 10; } /* diff --git a/src/backend/libpq/be-secure-gssapi.c b/src/backend/libpq/be-secure-gssapi.c index 3534f0b8111..5d98c58ffa8 100644 --- a/src/backend/libpq/be-secure-gssapi.c +++ b/src/backend/libpq/be-secure-gssapi.c @@ -121,9 +121,9 @@ be_gssapi_write(Port *port, const void *ptr, size_t len) * again, so if it offers a len less than that, something is wrong. * * Note: it may seem attractive to report partial write completion once - * we've successfully sent any encrypted packets. However, that can cause - * problems for callers; notably, pqPutMsgEnd's heuristic to send only - * full 8K blocks interacts badly with such a hack. We won't save much, + * we've successfully sent any encrypted packets. However, doing that + * expands the state space of this processing and has been responsible for + * bugs in the past (cf. commit d053a879b). We won't save much, * typically, by letting callers discard data early, so don't risk it. */ if (len < PqGSSSendConsumed) diff --git a/src/backend/utils/adt/inet_net_pton.c b/src/backend/utils/adt/inet_net_pton.c index ef2236d9f04..3b0db2a3799 100644 --- a/src/backend/utils/adt/inet_net_pton.c +++ b/src/backend/utils/adt/inet_net_pton.c @@ -115,8 +115,7 @@ inet_cidr_pton_ipv4(const char *src, u_char *dst, size_t size) src++; /* skip x or X. */ while ((ch = *src++) != '\0' && isxdigit((unsigned char) ch)) { - if (isupper((unsigned char) ch)) - ch = tolower((unsigned char) ch); + ch = pg_ascii_tolower((unsigned char) ch); n = strchr(xdigits, ch) - xdigits; assert(n >= 0 && n <= 15); if (dirty == 0) |