3 files changed, 29 insertions, 10 deletions

diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index f20be82862a..46cb2f36efa 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -25,6 +25,7 @@
 #include "common/logging.h"
 #include "common/relpath.h"
 #include "fe_utils/option_utils.h"
+#include "fe_utils/version.h"
 #include "getopt_long.h"
 #include "pg_getopt.h"
 #include "storage/bufpage.h"
@@ -448,6 +449,8 @@ main(int argc, char *argv[])
 	int			c;
 	int			option_index;
 	bool		crc_ok;
+	uint32		major_version;
+	char	   *version_str;
 
 	pg_logging_init(argv[0]);
 	set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_checksums"));
@@ -543,6 +546,20 @@ main(int argc, char *argv[])
 		exit(1);
 	}
 
+	/*
+	 * Retrieve the contents of this cluster's PG_VERSION.  We require
+	 * compatibility with the same major version as the one this tool is
+	 * compiled with.
+	 */
+	major_version = GET_PG_MAJORVERSION_NUM(get_pg_version(DataDir, &version_str));
+	if (major_version != PG_MAJORVERSION_NUM)
+	{
+		pg_log_error("data directory is of wrong version");
+		pg_log_error_detail("File \"%s\" contains \"%s\", which is not compatible with this program's version \"%s\".",
+							"PG_VERSION", version_str, PG_MAJORVERSION);
+		exit(1);
+	}
+
 	/* Read the control file and check compatibility */
 	ControlFile = get_controlfile(DataDir, &crc_ok);
 	if (!crc_ok)
diff --git a/src/bin/pg_dump/pg_backup_custom.c b/src/bin/pg_dump/pg_backup_custom.c
index f7c3af56304..2226520dffc 100644
--- a/src/bin/pg_dump/pg_backup_custom.c
+++ b/src/bin/pg_dump/pg_backup_custom.c
@@ -624,12 +624,19 @@ _skipData(ArchiveHandle *AH)
 	lclContext *ctx = (lclContext *) AH->formatData;
 	size_t		blkLen;
 	char	   *buf = NULL;
-	int			buflen = 0;
+	size_t		buflen = 0;
 
 	blkLen = ReadInt(AH);
 	while (blkLen != 0)
 	{
-		if (ctx->hasSeek)
+		/*
+		 * Seeks of less than stdio's buffer size are less efficient than just
+		 * reading the data, at least on common platforms.  We don't know the
+		 * buffer size for sure, but 4kB is the usual value.  (While pg_dump
+		 * currently tries to avoid producing such short data blocks, older
+		 * dump files often contain them.)
+		 */
+		if (ctx->hasSeek && blkLen >= 4 * 1024)
 		{
 			if (fseeko(AH->FH, blkLen, SEEK_CUR) != 0)
 				pg_fatal("error during file seek: %m");
@@ -639,8 +646,8 @@ _skipData(ArchiveHandle *AH)
 			if (blkLen > buflen)
 			{
 				free(buf);
-				buf = (char *) pg_malloc(blkLen);
-				buflen = blkLen;
+				buflen = Max(blkLen, 4 * 1024);
+				buf = (char *) pg_malloc(buflen);
 			}
 			if (fread(buf, 1, blkLen, AH->FH) != blkLen)
 			{
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 4b8cd49df09..47913178a93 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -12023,17 +12023,12 @@ dumpExtension(Archive *fout, const ExtensionInfo *extinfo)
 								  .createStmt = q->data,
 								  .dropStmt = delq->data));
 
-	/* Dump Extension Comments and Security Labels */
+	/* Dump Extension Comments */
 	if (extinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
 		dumpComment(fout, "EXTENSION", qextname,
 					NULL, "",
 					extinfo->dobj.catId, 0, extinfo->dobj.dumpId);
 
-	if (extinfo->dobj.dump & DUMP_COMPONENT_SECLABEL)
-		dumpSecLabel(fout, "EXTENSION", qextname,
-					 NULL, "",
-					 extinfo->dobj.catId, 0, extinfo->dobj.dumpId);
-
 	free(qextname);
 
 	destroyPQExpBuffer(q);