From d85e506baa258643ac820b6f21ac3c86247b3cc2 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Fri, 3 Apr 2015 14:28:21 +0900 Subject: [PATCH 2/2] Rework handling of OOM when allocating record buffer in XLOG reader Commit 2c03216 has replaced the memory allocation of the read buffer by a palloc while it was a malloc previously. However palloc fails unconditionally if an out-of-memory error shows up instead of returning NULL as a malloc would do. The broken logic is fixed using palloc_extended which is available for both frontend and backends, a routine able to not fail should an OOM occur when doing an allocation. --- src/backend/access/transam/xlogreader.c | 9 ++++++++- src/backend/replication/logical/logical.c | 5 +++++ src/bin/pg_rewind/parsexlog.c | 6 ++++++ 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c index ba7dfcc..f3cf6a5 100644 --- a/src/backend/access/transam/xlogreader.c +++ b/src/backend/access/transam/xlogreader.c @@ -146,7 +146,14 @@ allocate_recordbuf(XLogReaderState *state, uint32 reclength) if (state->readRecordBuf) pfree(state->readRecordBuf); - state->readRecordBuf = (char *) palloc(newSize); + + state->readRecordBuf = (char *) palloc_extended(newSize, + MCXT_ALLOC_NO_OOM); + if (state->readRecordBuf == NULL) + { + state->readRecordBufSize = 0; + return false; + } state->readRecordBufSize = newSize; return true; } diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c index 30baa45..774ebbc 100644 --- a/src/backend/replication/logical/logical.c +++ b/src/backend/replication/logical/logical.c @@ -163,6 +163,11 @@ StartupDecodingContext(List *output_plugin_options, ctx->slot = slot; ctx->reader = XLogReaderAllocate(read_page, ctx); + if (!ctx->reader) + ereport(ERROR, + (errcode(ERRCODE_OUT_OF_MEMORY), + errmsg("out of memory"))); + ctx->reader->private_data = ctx; ctx->reorder = ReorderBufferAllocate(); diff --git a/src/bin/pg_rewind/parsexlog.c b/src/bin/pg_rewind/parsexlog.c index 0787ca1..3cf96ab 100644 --- a/src/bin/pg_rewind/parsexlog.c +++ b/src/bin/pg_rewind/parsexlog.c @@ -70,6 +70,8 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, TimeLineID tli, private.datadir = datadir; private.tli = tli; xlogreader = XLogReaderAllocate(&SimpleXLogPageRead, &private); + if (xlogreader == NULL) + pg_fatal("out of memory"); do { @@ -121,6 +123,8 @@ readOneRecord(const char *datadir, XLogRecPtr ptr, TimeLineID tli) private.datadir = datadir; private.tli = tli; xlogreader = XLogReaderAllocate(&SimpleXLogPageRead, &private); + if (xlogreader == NULL) + pg_fatal("out of memory"); record = XLogReadRecord(xlogreader, ptr, &errormsg); if (record == NULL) @@ -171,6 +175,8 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, TimeLineID tli, private.datadir = datadir; private.tli = tli; xlogreader = XLogReaderAllocate(&SimpleXLogPageRead, &private); + if (xlogreader == NULL) + pg_fatal("out of memory"); searchptr = forkptr; for (;;) -- 2.3.5