From aba8943082f1ccbfb19f2e7ff02ba3be0fcb6c9d Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Mon, 6 Jun 2016 06:14:21 -0400
Subject: [PATCH] pg_upgrade: Improve error checking in rewriteVisibilityMap.
In the old logic, if read() were to return an error, we'd silently stop
rewriting the visibility map at that point in the file. That's safe,
but reporting the error is better, so do that instead.
Report by Andres Freund. Patch by Masahiko Sawada, with one correction
by me.
---
src/bin/pg_upgrade/file.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/src/bin/pg_upgrade/file.c b/src/bin/pg_upgrade/file.c
index 5d87408ce93..9b25dc5b284 100644
--- a/src/bin/pg_upgrade/file.c
+++ b/src/bin/pg_upgrade/file.c
@@ -165,6 +165,7 @@ rewriteVisibilityMap(const char *fromfile, const char *tofile, bool force)
int dst_fd = 0;
char buffer[BLCKSZ];
ssize_t bytesRead;
+ ssize_t totalBytesRead = 0;
ssize_t src_filesize;
int rewriteVmBytesPerPage;
BlockNumber new_blkno = 0;
@@ -200,13 +201,23 @@ rewriteVisibilityMap(const char *fromfile, const char *tofile, bool force)
* page is empty, we skip it, mostly to avoid turning one-page visibility
* maps for small relations into two pages needlessly.
*/
- while ((bytesRead = read(src_fd, buffer, BLCKSZ)) == BLCKSZ)
+ while (totalBytesRead < src_filesize)
{
char *old_cur;
char *old_break;
char *old_blkend;
PageHeaderData pageheader;
- bool old_lastblk = ((BLCKSZ * (new_blkno + 1)) == src_filesize);
+ bool old_lastblk;
+
+ if ((bytesRead = read(src_fd, buffer, BLCKSZ)) != BLCKSZ)
+ {
+ close(dst_fd);
+ close(src_fd);
+ return getErrorText();
+ }
+
+ totalBytesRead += BLCKSZ;
+ old_lastblk = (totalBytesRead == src_filesize);
/* Save the page header data */
memcpy(&pageheader, buffer, SizeOfPageHeaderData);
--
GitLab