diff --git a/src/bin/pg_basebackup/pg_receivexlog.c b/src/bin/pg_basebackup/pg_receivexlog.c
index ba533d35978d91ac07a9f02b81e5dc5575d3cff9..9facc198e4e176638e98993ce1183ead18eeb930 100644
--- a/src/bin/pg_basebackup/pg_receivexlog.c
+++ b/src/bin/pg_basebackup/pg_receivexlog.c
@@ -71,33 +71,10 @@ usage(void)
static bool
segment_callback(XLogRecPtr segendpos, uint32 timeline)
{
- char fn[MAXPGPATH];
- struct stat statbuf;
-
if (verbose)
fprintf(stderr, _("%s: finished segment at %X/%X (timeline %u)\n"),
progname, segendpos.xlogid, segendpos.xrecoff, timeline);
- /*
- * Check if there is a partial file for the name we just finished, and if
- * there is, remove it under the assumption that we have now got all the
- * data we need.
- */
- segendpos.xrecoff /= XLOG_SEG_SIZE;
- PrevLogSeg(segendpos.xlogid, segendpos.xrecoff);
- snprintf(fn, sizeof(fn), "%s/%08X%08X%08X.partial",
- basedir, timeline,
- segendpos.xlogid,
- segendpos.xrecoff);
- if (stat(fn, &statbuf) == 0)
- {
- /* File existed, get rid of it */
- if (verbose)
- fprintf(stderr, _("%s: removing file \"%s\"\n"),
- progname, fn);
- unlink(fn);
- }
-
/*
* Never abort from this - we handle all aborting in continue_streaming()
*/
@@ -119,9 +96,8 @@ continue_streaming(void)
/*
* Determine starting location for streaming, based on:
* 1. If there are existing xlog segments, start at the end of the last one
- * 2. If the last one is a partial segment, rename it and start over, since
- * we don't sync after every write.
- * 3. If no existing xlog exists, start from the beginning of the current
+ * that is complete (size matches XLogSegSize)
+ * 2. If no valid xlog exists, start from the beginning of the current
* WAL segment.
*/
static XLogRecPtr
@@ -133,7 +109,6 @@ FindStreamingStart(XLogRecPtr currentpos, uint32 currenttimeline)
bool b;
uint32 high_log = 0;
uint32 high_seg = 0;
- bool partial = false;
dir = opendir(basedir);
if (dir == NULL)
@@ -195,7 +170,7 @@ FindStreamingStart(XLogRecPtr currentpos, uint32 currenttimeline)
disconnect_and_exit(1);
}
- if (statbuf.st_size == 16 * 1024 * 1024)
+ if (statbuf.st_size == XLOG_SEG_SIZE)
{
/* Completed segment */
if (log > high_log ||
@@ -208,37 +183,9 @@ FindStreamingStart(XLogRecPtr currentpos, uint32 currenttimeline)
}
else
{
- /*
- * This is a partial file. Rename it out of the way.
- */
- char newfn[MAXPGPATH];
-
- fprintf(stderr, _("%s: renaming partial file \"%s\" to \"%s.partial\"\n"),
- progname, dirent->d_name, dirent->d_name);
-
- snprintf(newfn, sizeof(newfn), "%s/%s.partial",
- basedir, dirent->d_name);
-
- if (stat(newfn, &statbuf) == 0)
- {
- /*
- * XXX: perhaps we should only error out if the existing file
- * is larger?
- */
- fprintf(stderr, _("%s: file \"%s\" already exists. Check and clean up manually.\n"),
- progname, newfn);
- disconnect_and_exit(1);
- }
- if (rename(fullpath, newfn) != 0)
- {
- fprintf(stderr, _("%s: could not rename \"%s\" to \"%s\": %s\n"),
- progname, fullpath, newfn, strerror(errno));
- disconnect_and_exit(1);
- }
-
- /* Don't continue looking for more, we assume this is the last */
- partial = true;
- break;
+ fprintf(stderr, _("%s: segment file '%s' is incorrect size %d, skipping\n"),
+ progname, dirent->d_name, (int) statbuf.st_size);
+ continue;
}
}
@@ -247,17 +194,11 @@ FindStreamingStart(XLogRecPtr currentpos, uint32 currenttimeline)
if (high_log > 0 || high_seg > 0)
{
XLogRecPtr high_ptr;
-
- if (!partial)
- {
- /*
- * If the segment was partial, the pointer is already at the right
- * location since we want to re-transmit that segment. If it was
- * not, we need to move it to the next segment, since we are
- * tracking the last one that was complete.
- */
- NextLogSeg(high_log, high_seg);
- }
+ /*
+ * Move the starting pointer to the start of the next segment,
+ * since the highest one we've seen was completed.
+ */
+ NextLogSeg(high_log, high_seg);
high_ptr.xlogid = high_log;
high_ptr.xrecoff = high_seg * XLOG_SEG_SIZE;
diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
index 0ca30c425f32559bd50fe55aa7ee944b3d54d014..dea944beb947d42ef4f75b11cf23cc4ef22b66e0 100644
--- a/src/bin/pg_basebackup/receivelog.c
+++ b/src/bin/pg_basebackup/receivelog.c
@@ -27,6 +27,7 @@
#include "receivelog.h"
#include "streamutil.h"
+#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
@@ -41,24 +42,128 @@ const XLogRecPtr InvalidXLogRecPtr = {0, 0};
* Open a new WAL file in the specified directory. Store the name
* (not including the full directory) in namebuf. Assumes there is
* enough room in this buffer...
+ *
+ * The file will be padded to 16Mb with zeroes.
*/
static int
open_walfile(XLogRecPtr startpoint, uint32 timeline, char *basedir, char *namebuf)
{
int f;
char fn[MAXPGPATH];
+ struct stat statbuf;
+ char *zerobuf;
+ int bytes;
XLogFileName(namebuf, timeline, startpoint.xlogid,
startpoint.xrecoff / XLOG_SEG_SIZE);
- snprintf(fn, sizeof(fn), "%s/%s", basedir, namebuf);
- f = open(fn, O_WRONLY | O_CREAT | O_EXCL | PG_BINARY, 0666);
+ snprintf(fn, sizeof(fn), "%s/%s.partial", basedir, namebuf);
+ f = open(fn, O_WRONLY | O_CREAT | PG_BINARY, S_IRUSR | S_IWUSR);
if (f == -1)
+ {
fprintf(stderr, _("%s: Could not open WAL segment %s: %s\n"),
- progname, namebuf, strerror(errno));
+ progname, fn, strerror(errno));
+ return -1;
+ }
+
+ /*
+ * Verify that the file is either empty (just created), or a complete
+ * XLogSegSize segment. Anything in between indicates a corrupt file.
+ */
+ if (fstat(f, &statbuf) != 0)
+ {
+ fprintf(stderr, _("%s: could not stat WAL segment %s: %s\n"),
+ progname, fn, strerror(errno));
+ close(f);
+ return -1;
+ }
+ if (statbuf.st_size == XLogSegSize)
+ return f; /* File is open and ready to use */
+ if (statbuf.st_size != 0)
+ {
+ fprintf(stderr, _("%s: WAL segment %s is %d bytes, should be 0 or %d\n"),
+ progname, fn, (int) statbuf.st_size, XLogSegSize);
+ close(f);
+ return -1;
+ }
+
+ /* New, empty, file. So pad it to 16Mb with zeroes */
+ zerobuf = xmalloc0(XLOG_BLCKSZ);
+ for (bytes = 0; bytes < XLogSegSize; bytes += XLOG_BLCKSZ)
+ {
+ if (write(f, zerobuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+ {
+ fprintf(stderr, _("%s: could not pad WAL segment %s: %s\n"),
+ progname, fn, strerror(errno));
+ close(f);
+ unlink(fn);
+ return -1;
+ }
+ }
+ free(zerobuf);
+
+ if (lseek(f, SEEK_SET, 0) != 0)
+ {
+ fprintf(stderr, _("%s: could not seek back to beginning of WAL segment %s: %s\n"),
+ progname, fn, strerror(errno));
+ close(f);
+ return -1;
+ }
return f;
}
+static bool
+close_walfile(int walfile, char *basedir, char *walname)
+{
+ off_t currpos = lseek(walfile, 0, SEEK_CUR);
+
+ if (currpos == -1)
+ {
+ fprintf(stderr, _("%s: could not get current position in file %s: %s\n"),
+ progname, walname, strerror(errno));
+ return false;
+ }
+
+ if (fsync(walfile) != 0)
+ {
+ fprintf(stderr, _("%s: could not fsync file %s: %s\n"),
+ progname, walname, strerror(errno));
+ return false;
+ }
+
+ if (close(walfile) != 0)
+ {
+ fprintf(stderr, _("%s: could not close file %s: %s\n"),
+ progname, walname, strerror(errno));
+ return false;
+ }
+
+ /*
+ * Rename the .partial file only if we've completed writing the
+ * whole segment.
+ */
+ if (currpos == XLOG_SEG_SIZE)
+ {
+ char oldfn[MAXPGPATH];
+ char newfn[MAXPGPATH];
+
+ snprintf(oldfn, sizeof(oldfn), "%s/%s.partial", basedir, walname);
+ snprintf(newfn, sizeof(newfn), "%s/%s", basedir, walname);
+ if (rename(oldfn, newfn) != 0)
+ {
+ fprintf(stderr, _("%s: could not rename file %s: %s\n"),
+ progname, walname, strerror(errno));
+ return false;
+ }
+ }
+ else
+ fprintf(stderr, _("%s: not renaming %s, segment is not complete.\n"),
+ progname, walname);
+
+ return true;
+}
+
+
/*
* Local version of GetCurrentTimestamp(), since we are not linked with
* backend code.
@@ -178,10 +283,8 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
if (stream_continue && stream_continue())
{
if (walfile != -1)
- {
- fsync(walfile);
- close(walfile);
- }
+ /* Potential error message is written by close_walfile */
+ return close_walfile(walfile, basedir, current_walfile_name);
return true;
}
@@ -360,8 +463,10 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline, char *sysi
/* Did we reach the end of a WAL segment? */
if (blockpos.xrecoff % XLOG_SEG_SIZE == 0)
{
- fsync(walfile);
- close(walfile);
+ if (!close_walfile(walfile, basedir, current_walfile_name))
+ /* Error message written in close_walfile() */
+ return false;
+
walfile = -1;
xlogoff = 0;