Clean up write() return type

and analogously for pg_pwrite() and FileWrite()

Be sure to store the return value in a variable of type ssize_t, not
int.

Some callers of FileWrite() did not have a separate error message for
a short write.  This is okay in practice because FileWriteV() sets
ENOSPC for all non-error returns, so you'll get a reasonable error
message either way.  But callers handled this inconsistently, and this
behavior isn't really prominently documented and commit 871fe4917e
seems to frown upon it, so it seems better to make all callers handle
this consistently by adding the separate error message.

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/f9aab072-0078-49e4-ab93-3b08086a4406@eisentraut.org

src/backend/access/heap/rewriteheap.c

@@ -829,8 +829,8 @@ logical_heap_rewrite_flush_mappings(RewriteState state)
 		char	   *waldata_start;
 		xl_heap_rewrite_mapping xlrec;
 		Oid			dboid;
-		uint32		len;
-		int			written;
+		size_t		len;
+		ssize_t		written;
 		uint32		num_mappings = dclist_count(&src->mappings);
 
 		/* this file hasn't got any new mappings */
@@ -882,10 +882,14 @@ logical_heap_rewrite_flush_mappings(RewriteState state)
 		 */
 		written = FileWrite(src->vfd, waldata_start, len, src->off,
 							WAIT_EVENT_LOGICAL_REWRITE_WRITE);
-		if (written != len)
+		if (written < 0)
 			ereport(ERROR,
 					(errcode_for_file_access(),
-					 errmsg("could not write to file \"%s\", wrote %d of %d: %m", src->path,
+					 errmsg("could not write to file \"%s\": %m", src->path)));
+		else if (written != len)
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not write to file \"%s\": wrote %zd of %zu", src->path,
 							written, len)));
 		src->off += len;
 
@@ -1078,7 +1082,7 @@ heap_xlog_logical_rewrite(XLogReaderState *r)
 	char		path[MAXPGPATH];
 	int			fd;
 	xl_heap_rewrite_mapping *xlrec;
-	uint32		len;
+	size_t		len;
 	char	   *data;
 
 	xlrec = (xl_heap_rewrite_mapping *) XLogRecGetData(r);

src/backend/access/transam/timeline.c

@@ -461,7 +461,7 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
  * to avoid emplacing a bogus file.
  */
 void
-writeTimeLineHistoryFile(TimeLineID tli, const char *content, int size)
+writeTimeLineHistoryFile(TimeLineID tli, const char *content, size_t size)
 {
 	char		path[MAXPGPATH];
 	char		tmppath[MAXPGPATH];
@@ -483,7 +483,7 @@ writeTimeLineHistoryFile(TimeLineID tli, const char *content, int size)
 
 	errno = 0;
 	pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_FILE_WRITE);
-	if ((int) write(fd, content, size) != size)
+	if (write(fd, content, size) != size)
 	{
 		int			save_errno = errno;
 

src/backend/access/transam/twophase.c

@@ -232,7 +232,7 @@ static void ProcessRecords(char *bufptr, FullTransactionId fxid,
 						   const TwoPhaseCallback callbacks[]);
 static void RemoveGXact(GlobalTransaction gxact);
 
-static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len);
+static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, size_t *len);
 static char *ProcessTwoPhaseBuffer(FullTransactionId fxid,
 								   XLogRecPtr prepare_start_lsn,
 								   bool fromdisk, bool setParent, bool setNextXid);
@@ -240,7 +240,7 @@ static void MarkAsPreparingGuts(GlobalTransaction gxact, FullTransactionId fxid,
 								const char *gid, TimestampTz prepared_at, Oid owner,
 								Oid databaseid);
 static void RemoveTwoPhaseFile(FullTransactionId fxid, bool giveWarning);
-static void RecreateTwoPhaseFile(FullTransactionId fxid, const void *content, int len);
+static void RecreateTwoPhaseFile(FullTransactionId fxid, const void *content, size_t len);
 
 /*
  * Register shared memory for two-phase state.
@@ -1417,7 +1417,7 @@ ReadTwoPhaseFile(FullTransactionId fxid, bool missing_ok)
  * similarly to the way WALSender or Logical Decoding would do.
  */
 static void
-XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
+XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, size_t *len)
 {
 	XLogRecord *record;
 	XLogReaderState *xlogreader;
@@ -1747,7 +1747,7 @@ RemoveTwoPhaseFile(FullTransactionId fxid, bool giveWarning)
  * Note: content and len don't include CRC.
  */
 static void
-RecreateTwoPhaseFile(FullTransactionId fxid, const void *content, int len)
+RecreateTwoPhaseFile(FullTransactionId fxid, const void *content, size_t len)
 {
 	char		path[MAXPGPATH];
 	pg_crc32c	statefile_crc;
@@ -1867,7 +1867,7 @@ CheckPointTwoPhase(XLogRecPtr redo_horizon)
 			gxact->prepare_end_lsn <= redo_horizon)
 		{
 			char	   *buf;
-			int			len;
+			size_t		len;
 
 			XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, &len);
 			RecreateTwoPhaseFile(gxact->fxid, buf, len);

src/backend/access/transam/xlog.c

@@ -3541,7 +3541,7 @@ XLogFileCopy(TimeLineID destTLI, XLogSegNo destsegno,
 		}
 		errno = 0;
 		pgstat_report_wait_start(WAIT_EVENT_WAL_COPY_WRITE);
-		if ((int) write(fd, buffer.data, sizeof(buffer)) != (int) sizeof(buffer))
+		if (write(fd, buffer.data, sizeof(buffer)) != sizeof(buffer))
 		{
 			int			save_errno = errno;
 

src/backend/backup/basebackup_server.c

@@ -160,7 +160,7 @@ static void
 bbsink_server_archive_contents(bbsink *sink, size_t len)
 {
 	bbsink_server *mysink = (bbsink_server *) sink;
-	int			nbytes;
+	ssize_t		nbytes;
 
 	nbytes = FileWrite(mysink->file, mysink->base.bbs_buffer, len,
 					   mysink->filepos, WAIT_EVENT_BASEBACKUP_WRITE);
@@ -176,7 +176,7 @@ bbsink_server_archive_contents(bbsink *sink, size_t len)
 		/* short write: complain appropriately */
 		ereport(ERROR,
 				(errcode(ERRCODE_DISK_FULL),
-				 errmsg("could not write file \"%s\": wrote only %d of %zu bytes at offset %lld",
+				 errmsg("could not write file \"%s\": wrote only %zd of %zu bytes at offset %lld",
 						FilePathName(mysink->file),
 						nbytes, len, (long long) mysink->filepos),
 				 errhint("Check free disk space.")));
@@ -253,7 +253,7 @@ static void
 bbsink_server_manifest_contents(bbsink *sink, size_t len)
 {
 	bbsink_server *mysink = (bbsink_server *) sink;
-	int			nbytes;
+	ssize_t		nbytes;
 
 	nbytes = FileWrite(mysink->file, mysink->base.bbs_buffer, len,
 					   mysink->filepos, WAIT_EVENT_BASEBACKUP_WRITE);
@@ -269,7 +269,7 @@ bbsink_server_manifest_contents(bbsink *sink, size_t len)
 		/* short write: complain appropriately */
 		ereport(ERROR,
 				(errcode(ERRCODE_DISK_FULL),
-				 errmsg("could not write file \"%s\": wrote only %d of %zu bytes at offset %lld",
+				 errmsg("could not write file \"%s\": wrote only %zd of %zu bytes at offset %lld",
 						FilePathName(mysink->file),
 						nbytes, len, (long long) mysink->filepos),
 				 errhint("Check free disk space.")));

src/backend/commands/dbcommands.c

@@ -460,7 +460,7 @@ static void
 CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid, bool isRedo)
 {
 	int			fd;
-	int			nbytes;
+	size_t		nbytes;
 	char		versionfile[MAXPGPATH];
 	char		buf[16];
 
@@ -500,7 +500,7 @@ CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid, bool isRedo)
 	/* Write PG_MAJORVERSION in the PG_VERSION file. */
 	pgstat_report_wait_start(WAIT_EVENT_VERSION_FILE_WRITE);
 	errno = 0;
-	if ((int) write(fd, buf, nbytes) != nbytes)
+	if (write(fd, buf, nbytes) != nbytes)
 	{
 		/* If write didn't set errno, assume problem is no disk space. */
 		if (errno == 0)

src/backend/libpq/be-fsstubs.c

@@ -488,8 +488,7 @@ be_lo_export(PG_FUNCTION_ARGS)
 	Oid			lobjId = PG_GETARG_OID(0);
 	text	   *filename = PG_GETARG_TEXT_PP(1);
 	int			fd;
-	int			nbytes,
-				tmp;
+	int			nbytes;
 	char		buf[BUFSIZE];
 	char		fnamebuf[MAXPGPATH];
 	LargeObjectDesc *lobj;
@@ -531,6 +530,8 @@ be_lo_export(PG_FUNCTION_ARGS)
 	 */
 	while ((nbytes = inv_read(lobj, buf, BUFSIZE)) > 0)
 	{
+		ssize_t		tmp;
+
 		tmp = write(fd, buf, nbytes);
 		if (tmp != nbytes)
 			ereport(ERROR,

src/backend/postmaster/fork_process.c

@@ -102,7 +102,7 @@ fork_process(void)
 			if (fd >= 0)
 			{
 				const char *oomvalue = getenv("PG_OOM_ADJUST_VALUE");
-				int			rc;
+				ssize_t		rc;
 
 				if (oomvalue == NULL)	/* supply a useful default */
 					oomvalue = "0";

src/backend/replication/libpqwalreceiver/libpqwalreceiver.c

@@ -70,7 +70,7 @@ static char *libpqrcv_get_option_from_conninfo(const char *connInfo,
 static int	libpqrcv_server_version(WalReceiverConn *conn);
 static void libpqrcv_readtimelinehistoryfile(WalReceiverConn *conn,
 											 TimeLineID tli, char **filename,
-											 char **content, int *len);
+											 char **content, size_t *len);
 static bool libpqrcv_startstreaming(WalReceiverConn *conn,
 									const WalRcvStreamOptions *options);
 static void libpqrcv_endstreaming(WalReceiverConn *conn,
@@ -738,7 +738,7 @@ libpqrcv_endstreaming(WalReceiverConn *conn, TimeLineID *next_tli)
 static void
 libpqrcv_readtimelinehistoryfile(WalReceiverConn *conn,
 								 TimeLineID tli, char **filename,
-								 char **content, int *len)
+								 char **content, size_t *len)
 {
 	PGresult   *res;
 	char		cmd[64];

src/backend/replication/walreceiver.c

@@ -755,7 +755,7 @@ WalRcvFetchTimeLineHistoryFiles(TimeLineID first, TimeLineID last)
 		{
 			char	   *fname;
 			char	   *content;
-			int			len;
+			size_t		len;
 			char		expectedfname[MAXFNAMELEN];
 
 			ereport(LOG,
@@ -913,7 +913,7 @@ static void
 XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr, TimeLineID tli)
 {
 	int			startoff;
-	int			byteswritten;
+	ssize_t		byteswritten;
 	instr_time	start;
 
 	Assert(tli != 0);

src/backend/storage/file/buffile.c

@@ -498,7 +498,6 @@ static void
 BufFileDumpBuffer(BufFile *file)
 {
 	int64		wpos = 0;
-	int64		bytestowrite;
 	File		thisfile;
 
 	/*
@@ -510,6 +509,8 @@ BufFileDumpBuffer(BufFile *file)
 		int64		availbytes;
 		instr_time	io_start;
 		instr_time	io_time;
+		size_t		bytestowrite;
+		ssize_t		rc;
 
 		/*
 		 * Advance to next component file if necessary and possible.
@@ -538,12 +539,12 @@ BufFileDumpBuffer(BufFile *file)
 		else
 			INSTR_TIME_SET_ZERO(io_start);
 
-		bytestowrite = FileWrite(thisfile,
-								 file->buffer.data + wpos,
-								 bytestowrite,
-								 file->curOffset,
-								 WAIT_EVENT_BUFFILE_WRITE);
-		if (bytestowrite <= 0)
+		rc = FileWrite(thisfile,
+					   file->buffer.data + wpos,
+					   bytestowrite,
+					   file->curOffset,
+					   WAIT_EVENT_BUFFILE_WRITE);
+		if (rc <= 0)
 			ereport(ERROR,
 					(errcode_for_file_access(),
 					 errmsg("could not write to file \"%s\": %m",
@@ -555,8 +556,8 @@ BufFileDumpBuffer(BufFile *file)
 			INSTR_TIME_ACCUM_DIFF(pgBufferUsage.temp_blk_write_time, io_time, io_start);
 		}
 
-		file->curOffset += bytestowrite;
-		wpos += bytestowrite;
+		file->curOffset += rc;
+		wpos += rc;
 
 		pgBufferUsage.temp_blks_written++;
 	}

src/backend/storage/ipc/waiteventset.c

@@ -1905,7 +1905,7 @@ latch_sigurg_handler(SIGNAL_ARGS)
 static void
 sendSelfPipeByte(void)
 {
-	int			rc;
+	ssize_t		rc;
 	char		dummy = 0;
 
 retry:

src/backend/storage/smgr/md.c

@@ -488,7 +488,7 @@ mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 		 const void *buffer, bool skipFsync)
 {
 	pgoff_t		seekpos;
-	int			nbytes;
+	ssize_t		nbytes;
 	MdfdVec    *v;
 
 	/* If this build supports direct I/O, the buffer must be I/O aligned. */
@@ -530,9 +530,9 @@ mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 		/* short write: complain appropriately */
 		ereport(ERROR,
 				(errcode(ERRCODE_DISK_FULL),
-				 errmsg("could not extend file \"%s\": wrote only %d of %d bytes at block %u",
+				 errmsg("could not extend file \"%s\": wrote only %zd of %zu bytes at block %u",
 						FilePathName(v->mdfd_vfd),
-						nbytes, BLCKSZ, blocknum),
+						nbytes, (size_t) BLCKSZ, blocknum),
 				 errhint("Check free disk space.")));
 	}
 
@@ -1080,7 +1080,7 @@ mdwritev(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 		struct iovec iov[PG_IOV_MAX];
 		int			iovcnt;
 		pgoff_t		seekpos;
-		int			nbytes;
+		ssize_t		nbytes;
 		MdfdVec    *v;
 		BlockNumber nblocks_this_segment;
 		size_t		transferred_this_segment;

src/backend/utils/error/elog.c

@@ -3027,7 +3027,7 @@ write_eventlog(int level, const char *line, int len)
 static void
 write_console(const char *line, int len)
 {
-	int			rc;
+	ssize_t		rc;
 
 #ifdef WIN32
 
@@ -3917,7 +3917,7 @@ write_pipe_chunks(char *data, int len, int dest)
 {
 	PipeProtoChunk p;
 	int			fd = fileno(stderr);
-	int			rc;
+	ssize_t		rc;
 
 	Assert(len > 0);
 

src/backend/utils/init/miscinit.c

@@ -1522,7 +1522,8 @@ void
 AddToDataDirLockFile(int target_line, const char *str)
 {
 	int			fd;
-	ssize_t		len;
+	ssize_t		nread;
+	size_t		len;
 	int			lineno;
 	char	   *srcptr;
 	char	   *destptr;
@@ -1539,9 +1540,9 @@ AddToDataDirLockFile(int target_line, const char *str)
 		return;
 	}
 	pgstat_report_wait_start(WAIT_EVENT_LOCK_FILE_ADDTODATADIR_READ);
-	len = read(fd, srcbuffer, sizeof(srcbuffer) - 1);
+	nread = read(fd, srcbuffer, sizeof(srcbuffer) - 1);
 	pgstat_report_wait_end();
-	if (len < 0)
+	if (nread < 0)
 	{
 		ereport(LOG,
 				(errcode_for_file_access(),
@@ -1550,7 +1551,7 @@ AddToDataDirLockFile(int target_line, const char *str)
 		close(fd);
 		return;
 	}
-	srcbuffer[len] = '\0';
+	srcbuffer[nread] = '\0';
 
 	/*
 	 * Advance over lines we are not supposed to rewrite, then copy them to

src/backend/utils/probes.d

@@ -85,7 +85,7 @@ provider postgresql {
 	probe smgr__md__read__start(ForkNumber, BlockNumber, Oid, Oid, Oid, int);
 	probe smgr__md__read__done(ForkNumber, BlockNumber, Oid, Oid, Oid, int, long long int, long long int);
 	probe smgr__md__write__start(ForkNumber, BlockNumber, Oid, Oid, Oid, int);
-	probe smgr__md__write__done(ForkNumber, BlockNumber, Oid, Oid, Oid, int, int, int);
+	probe smgr__md__write__done(ForkNumber, BlockNumber, Oid, Oid, Oid, int, long long int, long long int);
 
 	probe wal__insert(unsigned char, unsigned char);
 	probe wal__switch();

src/bin/pg_basebackup/pg_recvlogical.c

@@ -292,10 +292,10 @@ StreamLogicalLog(void)
 	while (!time_to_abort)
 	{
 		int			r;
-		int			bytes_left;
-		int			bytes_written;
+		size_t		bytes_left;
+		size_t		bytes_written;
 		TimestampTz now;
-		int			hdr_len;
+		size_t		hdr_len;
 
 		cur_record_lsn = InvalidXLogRecPtr;
 
@@ -560,7 +560,7 @@ StreamLogicalLog(void)
 
 		while (bytes_left)
 		{
-			int			ret;
+			ssize_t		ret;
 
 			ret = write(outfd,
 						copybuf + hdr_len + bytes_written,
@@ -568,7 +568,7 @@ StreamLogicalLog(void)
 
 			if (ret < 0)
 			{
-				pg_log_error("could not write %d bytes to log file \"%s\": %m",
+				pg_log_error("could not write %zu bytes to log file \"%s\": %m",
 							 bytes_left, outfile);
 				goto error;
 			}
@@ -580,8 +580,8 @@ StreamLogicalLog(void)
 
 		if (write(outfd, "\n", 1) != 1)
 		{
-			pg_log_error("could not write %d bytes to log file \"%s\": %m",
-						 1, outfile);
+			pg_log_error("could not write %zu bytes to log file \"%s\": %m",
+						 (size_t) 1, outfile);
 			goto error;
 		}
 

src/bin/pg_basebackup/receivelog.c

@@ -274,7 +274,7 @@ existsTimeLineHistoryFile(StreamCtl *stream)
 static bool
 writeTimeLineHistoryFile(StreamCtl *stream, const char *filename, const char *content)
 {
-	int			size = strlen(content);
+	size_t		size = strlen(content);
 	char		histfname[MAXFNAMELEN];
 	Walfile    *f;
 
@@ -299,7 +299,7 @@ writeTimeLineHistoryFile(StreamCtl *stream, const char *filename, const char *co
 		return false;
 	}
 
-	if ((int) stream->walmethod->ops->write(f, content, size) != size)
+	if (stream->walmethod->ops->write(f, content, size) != size)
 	{
 		pg_log_error("could not write timeline history file \"%s\": %s",
 					 histfname, GetLastWalMethodError(stream->walmethod));

src/bin/pg_checksums/pg_checksums.c

@@ -237,7 +237,7 @@ scan_file(const char *fn, int segmentno)
 		}
 		else if (mode == PG_MODE_ENABLE)
 		{
-			int			w;
+			ssize_t		w;
 
 			/*
 			 * Do not rewrite if the checksum is already set to the expected
@@ -263,8 +263,8 @@ scan_file(const char *fn, int segmentno)
 					pg_fatal("could not write block %u in file \"%s\": %m",
 							 blockno, fn);
 				else
-					pg_fatal("could not write block %u in file \"%s\": wrote %d of %d",
-							 blockno, fn, w, BLCKSZ);
+					pg_fatal("could not write block %u in file \"%s\": wrote %zd of %zu",
+							 blockno, fn, w, (size_t) BLCKSZ);
 			}
 		}
 

src/bin/pg_combinebackup/backup_label.c

@@ -151,18 +151,19 @@ write_backup_label(char *output_directory, StringInfo buf,
 		if (!line_starts_with(s, e, "INCREMENTAL FROM LSN: ", NULL) &&
 			!line_starts_with(s, e, "INCREMENTAL FROM TLI: ", NULL))
 		{
+			const size_t bytes_left = e - s;
 			ssize_t		wb;
 
-			wb = write(output_fd, s, e - s);
-			if (wb != e - s)
+			wb = write(output_fd, s, bytes_left);
+			if (wb != bytes_left)
 			{
 				if (wb < 0)
 					pg_fatal("could not write file \"%s\": %m", output_filename);
 				else
-					pg_fatal("could not write file \"%s\": wrote %d of %d",
-							 output_filename, (int) wb, (int) (e - s));
+					pg_fatal("could not write file \"%s\": wrote %zd of %zu",
+							 output_filename, wb, bytes_left);
 			}
-			if (pg_checksum_update(&checksum_ctx, (uint8 *) s, e - s) < 0)
+			if (pg_checksum_update(&checksum_ctx, (uint8 *) s, bytes_left) < 0)
 				pg_fatal("could not update checksum of file \"%s\"",
 						 output_filename);
 		}

src/bin/pg_combinebackup/copy_file.c

@@ -179,7 +179,7 @@ copy_file_blocks(const char *src, const char *dst,
 	uint8	   *buffer;
 	const int	buffer_size = 50 * BLCKSZ;
 	ssize_t		rb;
-	unsigned	offset = 0;
+	size_t		offset = 0;
 
 	if ((src_fd = open(src, O_RDONLY | PG_BINARY, 0)) < 0)
 		pg_fatal("could not open file \"%s\": %m", src);
@@ -199,8 +199,8 @@ copy_file_blocks(const char *src, const char *dst,
 			if (wb < 0)
 				pg_fatal("could not write to file \"%s\": %m", dst);
 			else
-				pg_fatal("could not write to file \"%s\", offset %u: wrote %d of %d",
-						 dst, offset, (int) wb, (int) rb);
+				pg_fatal("could not write to file \"%s\", offset %zu: wrote %zd of %zu",
+						 dst, offset, wb, (size_t) rb);
 		}
 
 		if (pg_checksum_update(checksum_ctx, buffer, rb) < 0)

src/bin/pg_combinebackup/reconstruct.c

@@ -755,15 +755,15 @@ static void
 write_block(int fd, const char *output_filename,
 			const uint8 *buffer, pg_checksum_context *checksum_ctx)
 {
-	int			wb;
+	ssize_t		wb;
 
 	if ((wb = write(fd, buffer, BLCKSZ)) != BLCKSZ)
 	{
 		if (wb < 0)
 			pg_fatal("could not write file \"%s\": %m", output_filename);
 		else
-			pg_fatal("could not write file \"%s\": wrote %d of %d",
-					 output_filename, wb, BLCKSZ);
+			pg_fatal("could not write file \"%s\": wrote %zd of %zu",
+					 output_filename, wb, (size_t) BLCKSZ);
 	}
 
 	/* Update the checksum computation. */

src/bin/pg_combinebackup/write_manifest.c

@@ -259,8 +259,8 @@ flush_manifest(manifest_writer *mwriter)
 			if (wb < 0)
 				pg_fatal("could not write file \"%s\": %m", mwriter->pathname);
 			else
-				pg_fatal("could not write file \"%s\": wrote %zd of %d",
-						 mwriter->pathname, wb, mwriter->buf.len);
+				pg_fatal("could not write file \"%s\": wrote %zd of %zu",
+						 mwriter->pathname, wb, (size_t) mwriter->buf.len);
 		}
 
 		if (mwriter->still_checksumming &&

src/bin/pg_dump/parallel.c

@@ -186,7 +186,7 @@ static CRITICAL_SECTION signal_info_lock;
 #define write_stderr(str) \
 	do { \
 		const char *str_ = (str); \
-		int		rc_; \
+		ssize_t	rc_; \
 		rc_ = write(fileno(stderr), str_, strlen(str_)); \
 		(void) rc_; \
 	} while (0)
@@ -1526,7 +1526,7 @@ getMessageFromLeader(int pipefd[2])
 static void
 sendMessageToLeader(int pipefd[2], const char *str)
 {
-	int			len = strlen(str) + 1;
+	size_t		len = strlen(str) + 1;
 
 	if (pipewrite(pipefd[PIPE_WRITE], str, len) != len)
 		pg_fatal("could not write to the communication channel: %m");
@@ -1643,7 +1643,7 @@ getMessageFromWorker(ParallelState *pstate, bool do_wait, int *worker)
 static void
 sendMessageToWorker(ParallelState *pstate, int worker, const char *str)
 {
-	int			len = strlen(str) + 1;
+	size_t		len = strlen(str) + 1;
 
 	if (pipewrite(pstate->parallelSlot[worker].pipeWrite, str, len) != len)
 	{

src/bin/pg_test_fsync/pg_test_fsync.c

@@ -593,7 +593,7 @@ test_non_sync(void)
 static void
 signal_cleanup(SIGNAL_ARGS)
 {
-	int			rc;
+	ssize_t		rc;
 
 	/* Delete the file if it exists. Ignore errors */
 	if (needs_unlink)

src/fe_utils/cancel.c

@@ -61,7 +61,7 @@
 #define write_stderr(str) \
 	do { \
 		const char *str_ = (str); \
-		int		rc_; \
+		ssize_t	rc_; \
 		rc_ = write(fileno(stderr), str_, strlen(str_)); \
 		(void) rc_; \
 	} while (0)

src/include/access/timeline.h

@@ -34,7 +34,7 @@ extern bool existsTimeLineHistory(TimeLineID probeTLI);
 extern TimeLineID findNewestTimeLine(TimeLineID startTLI);
 extern void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
 								 XLogRecPtr switchpoint, const char *reason);
-extern void writeTimeLineHistoryFile(TimeLineID tli, const char *content, int size);
+extern void writeTimeLineHistoryFile(TimeLineID tli, const char *content, size_t size);
 extern void restoreTimeLineHistoryFiles(TimeLineID begin, TimeLineID end);
 extern bool tliInHistory(TimeLineID tli, List *expectedTLEs);
 extern TimeLineID tliOfPointInHistory(XLogRecPtr ptr, List *history);

src/include/replication/walreceiver.h

@@ -309,7 +309,7 @@ typedef void (*walrcv_readtimelinehistoryfile_fn) (WalReceiverConn *conn,
 												   TimeLineID tli,
 												   char **filename,
 												   char **content,
-												   int *size);
+												   size_t *size);
 
 /*
  * walrcv_startstreaming_fn

src/interfaces/libpq/fe-lobj.c

@@ -749,8 +749,7 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
 {
 	int			result = 1;
 	int			fd;
-	int			nbytes,
-				tmp;
+	int			nbytes;
 	char		buf[LO_BUFSIZE];
 	int			lobj;
 	char		sebuf[PG_STRERROR_R_BUFLEN];
@@ -788,6 +787,8 @@ lo_export(PGconn *conn, Oid lobjId, const char *filename)
 	 */
 	while ((nbytes = lo_read(conn, lobj, buf, LO_BUFSIZE)) > 0)
 	{
+		ssize_t		tmp;
+
 		tmp = write(fd, buf, nbytes);
 		if (tmp != nbytes)
 		{

src/test/examples/testlo.c

@@ -151,8 +151,7 @@ exportFile(PGconn *conn, Oid lobjId, char *filename)
 {
 	int			lobj_fd;
 	char		buf[BUFSIZE];
-	int			nbytes,
-				tmp;
+	int			nbytes;
 	int			fd;
 
 	/*
@@ -177,6 +176,8 @@ exportFile(PGconn *conn, Oid lobjId, char *filename)
 	 */
 	while ((nbytes = lo_read(conn, lobj_fd, buf, BUFSIZE)) > 0)
 	{
+		ssize_t		tmp;
+
 		tmp = write(fd, buf, nbytes);
 		if (tmp < nbytes)
 		{

src/test/examples/testlo64.c

@@ -174,8 +174,7 @@ exportFile(PGconn *conn, Oid lobjId, char *filename)
 {
 	int			lobj_fd;
 	char		buf[BUFSIZE];
-	int			nbytes,
-				tmp;
+	int			nbytes;
 	int			fd;
 
 	/*
@@ -200,6 +199,8 @@ exportFile(PGconn *conn, Oid lobjId, char *filename)
 	 */
 	while ((nbytes = lo_read(conn, lobj_fd, buf, BUFSIZE)) > 0)
 	{
+		ssize_t		tmp;
+
 		tmp = write(fd, buf, nbytes);
 		if (tmp < nbytes)
 		{