Reset properly errno before calling write()

michaelpq · michaelpq · commit 5a23c74b63ec · 2018-08-05T05:31:18.000+09:00
6cb3372 enforces errno to ENOSPC when less bytes than what is expected have been written when it is unset, though it forgot to properly reset errno before doing a system call to write(), causing errno to potentially come from a previous system call. Reported-by: Tom Lane Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/31797.1533326676@sss.pgh.pa.us
diff --git a/src/backend/access/heap/rewriteheap.c b/src/backend/access/heap/rewriteheap.c
@@ -1166,6 +1166,7 @@ heap_xlog_logical_rewrite(XLogReaderState *r)
 	len = xlrec->num_mappings * sizeof(LogicalRewriteMappingData);
 
 	/* write out tail end of mapping file (again) */
+	errno = 0;
 	pgstat_report_wait_start(WAIT_EVENT_LOGICAL_REWRITE_MAPPING_WRITE);
 	if (write(fd, data, len) != len)
 	{
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
@@ -1669,6 +1669,7 @@ RecreateTwoPhaseFile(TransactionId xid, void *content, int len)
 				 errmsg("could not recreate file \"%s\": %m", path)));
 
 	/* Write content and CRC */
+	errno = 0;
 	pgstat_report_wait_start(WAIT_EVENT_TWOPHASE_FILE_WRITE);
 	if (write(fd, content, len) != len)
 	{
diff --git a/src/backend/replication/logical/origin.c b/src/backend/replication/logical/origin.c
@@ -576,6 +576,7 @@ CheckPointReplicationOrigin(void)
 						tmppath)));
 
 	/* write magic */
+	errno = 0;
 	if ((write(tmpfd, &magic, sizeof(magic))) != sizeof(magic))
 	{
 		int			save_errno = errno;
@@ -619,6 +620,7 @@ CheckPointReplicationOrigin(void)
 		/* make sure we only write out a commit that's persistent */
 		XLogFlush(local_lsn);
 
+		errno = 0;
 		if ((write(tmpfd, &disk_state, sizeof(disk_state))) !=
 			sizeof(disk_state))
 		{
@@ -641,6 +643,7 @@ CheckPointReplicationOrigin(void)
 
 	/* write out the CRC */
 	FIN_CRC32C(crc);
+	errno = 0;
 	if ((write(tmpfd, &crc, sizeof(crc))) != sizeof(crc))
 	{
 		int			save_errno = errno;
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
@@ -2421,6 +2421,7 @@ ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn,
 
 	ondisk->size = sz;
 
+	errno = 0;
 	pgstat_report_wait_start(WAIT_EVENT_REORDER_BUFFER_WRITE);
 	if (write(fd, rb->outbuf, ondisk->size) != ondisk->size)
 	{
diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
@@ -1609,6 +1609,7 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)
 		ereport(ERROR,
 				(errmsg("could not open file \"%s\": %m", path)));
 
+	errno = 0;
 	pgstat_report_wait_start(WAIT_EVENT_SNAPBUILD_WRITE);
 	if ((write(fd, ondisk, needed_length)) != needed_length)
 	{
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
@@ -1275,6 +1275,7 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel)
 				SnapBuildOnDiskChecksummedSize);
 	FIN_CRC32C(cp.checksum);
 
+	errno = 0;
 	pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_WRITE);
 	if ((write(fd, &cp, sizeof(cp))) != sizeof(cp))
 	{
diff --git a/src/bin/pg_basebackup/walmethods.c b/src/bin/pg_basebackup/walmethods.c
@@ -122,6 +122,7 @@ dir_open_for_write(const char *pathname, const char *temp_suffix, size_t pad_to_
 		zerobuf = pg_malloc0(XLOG_BLCKSZ);
 		for (bytes = 0; bytes < pad_to_size; bytes += XLOG_BLCKSZ)
 		{
+			errno = 0;
 			if (write(fd, zerobuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 			{
 				int			save_errno = errno;
@@ -445,6 +446,7 @@ tar_write_compressed_data(void *buf, size_t count, bool flush)
 		{
 			size_t		len = ZLIB_OUT_SIZE - tar_data->zp->avail_out;
 
+			errno = 0;
 			if (write(tar_data->fd, tar_data->zlibOut, len) != len)
 			{
 				/*
@@ -629,6 +631,7 @@ tar_open_for_write(const char *pathname, const char *temp_suffix, size_t pad_to_
 
 	if (!tar_data->compression)
 	{
+		errno = 0;
 		if (write(tar_data->fd, tar_data->currentfile->header, 512) != 512)
 		{
 			save_errno = errno;
@@ -829,6 +832,7 @@ tar_close(Walfile f, WalCloseMethod method)
 		return -1;
 	if (!tar_data->compression)
 	{
+		errno = 0;
 		if (write(tar_data->fd, tf->header, 512) != 512)
 		{
 			/* if write didn't set errno, assume problem is no disk space */
@@ -901,6 +905,7 @@ tar_finish(void)
 	MemSet(zerobuf, 0, sizeof(zerobuf));
 	if (!tar_data->compression)
 	{
+		errno = 0;
 		if (write(tar_data->fd, zerobuf, sizeof(zerobuf)) != sizeof(zerobuf))
 		{
 			/* if write didn't set errno, assume problem is no disk space */
@@ -933,6 +938,7 @@ tar_finish(void)
 			{
 				size_t		len = ZLIB_OUT_SIZE - tar_data->zp->avail_out;
 
+				errno = 0;
 				if (write(tar_data->fd, tar_data->zlibOut, len) != len)
 				{
 					/*

Original file line number	Diff line number	Diff line change
`@@ -1166,6 +1166,7 @@ heap_xlog_logical_rewrite(XLogReaderState *r)`
`1166`	`1166`	`len = xlrec->num_mappings * sizeof(LogicalRewriteMappingData);`
`1167`	`1167`
`1168`	`1168`	`/* write out tail end of mapping file (again) */`
	`1169`	`+ errno = 0;`
`1169`	`1170`	`pgstat_report_wait_start(WAIT_EVENT_LOGICAL_REWRITE_MAPPING_WRITE);`
`1170`	`1171`	`if (write(fd, data, len) != len)`
`1171`	`1172`	`{`
Original file line number	Diff line number	Diff line change
`@@ -1669,6 +1669,7 @@ RecreateTwoPhaseFile(TransactionId xid, void *content, int len)`
`1669`	`1669`	`errmsg("could not recreate file \"%s\": %m", path)));`
`1670`	`1670`
`1671`	`1671`	`/* Write content and CRC */`
	`1672`	`+ errno = 0;`
`1672`	`1673`	`pgstat_report_wait_start(WAIT_EVENT_TWOPHASE_FILE_WRITE);`
`1673`	`1674`	`if (write(fd, content, len) != len)`
`1674`	`1675`	`{`
Original file line number	Diff line number	Diff line change
`@@ -576,6 +576,7 @@ CheckPointReplicationOrigin(void)`
`576`	`576`	`tmppath)));`
`577`	`577`
`578`	`578`	`/* write magic */`
	`579`	`+ errno = 0;`
`579`	`580`	`if ((write(tmpfd, &magic, sizeof(magic))) != sizeof(magic))`
`580`	`581`	`{`
`581`	`582`	`int save_errno = errno;`
`@@ -619,6 +620,7 @@ CheckPointReplicationOrigin(void)`
`619`	`620`	`/* make sure we only write out a commit that's persistent */`
`620`	`621`	`XLogFlush(local_lsn);`
`621`	`622`
	`623`	`+ errno = 0;`
`622`	`624`	`if ((write(tmpfd, &disk_state, sizeof(disk_state))) !=`
`623`	`625`	`sizeof(disk_state))`
`624`	`626`	`{`
`@@ -641,6 +643,7 @@ CheckPointReplicationOrigin(void)`
`641`	`643`
`642`	`644`	`/* write out the CRC */`
`643`	`645`	`FIN_CRC32C(crc);`
	`646`	`+ errno = 0;`
`644`	`647`	`if ((write(tmpfd, &crc, sizeof(crc))) != sizeof(crc))`
`645`	`648`	`{`
`646`	`649`	`int save_errno = errno;`
Original file line number	Diff line number	Diff line change
`@@ -2421,6 +2421,7 @@ ReorderBufferSerializeChange(ReorderBuffer rb, ReorderBufferTXN txn,`
`2421`	`2421`
`2422`	`2422`	`ondisk->size = sz;`
`2423`	`2423`
	`2424`	`+ errno = 0;`
`2424`	`2425`	`pgstat_report_wait_start(WAIT_EVENT_REORDER_BUFFER_WRITE);`
`2425`	`2426`	`if (write(fd, rb->outbuf, ondisk->size) != ondisk->size)`
`2426`	`2427`	`{`
Original file line number	Diff line number	Diff line change
`@@ -1609,6 +1609,7 @@ SnapBuildSerialize(SnapBuild *builder, XLogRecPtr lsn)`
`1609`	`1609`	`ereport(ERROR,`
`1610`	`1610`	`(errmsg("could not open file \"%s\": %m", path)));`
`1611`	`1611`
	`1612`	`+ errno = 0;`
`1612`	`1613`	`pgstat_report_wait_start(WAIT_EVENT_SNAPBUILD_WRITE);`
`1613`	`1614`	`if ((write(fd, ondisk, needed_length)) != needed_length)`
`1614`	`1615`	`{`
Original file line number	Diff line number	Diff line change
`@@ -1275,6 +1275,7 @@ SaveSlotToPath(ReplicationSlot slot, const char dir, int elevel)`
`1275`	`1275`	`SnapBuildOnDiskChecksummedSize);`
`1276`	`1276`	`FIN_CRC32C(cp.checksum);`
`1277`	`1277`
	`1278`	`+ errno = 0;`
`1278`	`1279`	`pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_WRITE);`
`1279`	`1280`	`if ((write(fd, &cp, sizeof(cp))) != sizeof(cp))`
`1280`	`1281`	`{`
Original file line number	Diff line number	Diff line change
`@@ -122,6 +122,7 @@ dir_open_for_write(const char pathname, const char temp_suffix, size_t pad_to_`
`122`	`122`	`zerobuf = pg_malloc0(XLOG_BLCKSZ);`
`123`	`123`	`for (bytes = 0; bytes < pad_to_size; bytes += XLOG_BLCKSZ)`
`124`	`124`	`{`
	`125`	`+ errno = 0;`
`125`	`126`	`if (write(fd, zerobuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)`
`126`	`127`	`{`
`127`	`128`	`int save_errno = errno;`
`@@ -445,6 +446,7 @@ tar_write_compressed_data(void *buf, size_t count, bool flush)`
`445`	`446`	`{`
`446`	`447`	`size_t len = ZLIB_OUT_SIZE - tar_data->zp->avail_out;`
`447`	`448`
	`449`	`+ errno = 0;`
`448`	`450`	`if (write(tar_data->fd, tar_data->zlibOut, len) != len)`
`449`	`451`	`{`
`450`	`452`	`/*`
`@@ -629,6 +631,7 @@ tar_open_for_write(const char pathname, const char temp_suffix, size_t pad_to_`
`629`	`631`
`630`	`632`	`if (!tar_data->compression)`
`631`	`633`	`{`
	`634`	`+ errno = 0;`
`632`	`635`	`if (write(tar_data->fd, tar_data->currentfile->header, 512) != 512)`
`633`	`636`	`{`
`634`	`637`	`save_errno = errno;`
`@@ -829,6 +832,7 @@ tar_close(Walfile f, WalCloseMethod method)`
`829`	`832`	`return -1;`
`830`	`833`	`if (!tar_data->compression)`
`831`	`834`	`{`
	`835`	`+ errno = 0;`
`832`	`836`	`if (write(tar_data->fd, tf->header, 512) != 512)`
`833`	`837`	`{`
`834`	`838`	`/* if write didn't set errno, assume problem is no disk space */`
`@@ -901,6 +905,7 @@ tar_finish(void)`
`901`	`905`	`MemSet(zerobuf, 0, sizeof(zerobuf));`
`902`	`906`	`if (!tar_data->compression)`
`903`	`907`	`{`
	`908`	`+ errno = 0;`
`904`	`909`	`if (write(tar_data->fd, zerobuf, sizeof(zerobuf)) != sizeof(zerobuf))`
`905`	`910`	`{`
`906`	`911`	`/* if write didn't set errno, assume problem is no disk space */`
`@@ -933,6 +938,7 @@ tar_finish(void)`
`933`	`938`	`{`
`934`	`939`	`size_t len = ZLIB_OUT_SIZE - tar_data->zp->avail_out;`
`935`	`940`
	`941`	`+ errno = 0;`
`936`	`942`	`if (write(tar_data->fd, tar_data->zlibOut, len) != len)`
`937`	`943`	`{`
`938`	`944`	`/*`