Use pg_pwrite() in pg_test_fsync.

For consistency with the PostgreSQL behavior this test program is
intended to simulate, use pwrite() instead of lseek() + write().

Also fix the final "non-sync" test, which was opening and closing the
file for every write.

Discussion: https://postgr.es/m/CA%2BhUKGJjjid2BJsvjMALBTduo1ogdx2SPYaTQL3wAy8y2hc4nw%40mail.gmail.com

diff --git a/src/bin/pg_test_fsync/pg_test_fsync.c b/src/bin/pg_test_fsync/pg_test_fsync.c
index 3eddd983c63ba6c7e761f6cd519e0941dcf9f444..29ee7c7d6f174b8683b66fb14c39b443292eedbc 100644 (file)
--- a/src/bin/pg_test_fsync/pg_test_fsync.c
+++ b/src/bin/pg_test_fsync/pg_test_fsync.c
@@ -290,10 +290,11 @@ test_sync(int writes_per_op)
        for (ops = 0; alarm_triggered == false; ops++)
        {
            for (writes = 0; writes < writes_per_op; writes++)
-               if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+               if (pg_pwrite(tmpfile,
+                             buf,
+                             XLOG_BLCKSZ,
+                             writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
                    die("write failed");
-           if (lseek(tmpfile, 0, SEEK_SET) == -1)
-               die("seek failed");
        }
        STOP_TIMER;
        close(tmpfile);
@@ -315,11 +316,12 @@ test_sync(int writes_per_op)
    for (ops = 0; alarm_triggered == false; ops++)
    {
        for (writes = 0; writes < writes_per_op; writes++)
-           if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+           if (pg_pwrite(tmpfile,
+                         buf,
+                         XLOG_BLCKSZ,
+                         writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
                die("write failed");
        fdatasync(tmpfile);
-       if (lseek(tmpfile, 0, SEEK_SET) == -1)
-           die("seek failed");
    }
    STOP_TIMER;
    close(tmpfile);
@@ -339,12 +341,13 @@ test_sync(int writes_per_op)
    for (ops = 0; alarm_triggered == false; ops++)
    {
        for (writes = 0; writes < writes_per_op; writes++)
-           if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+           if (pg_pwrite(tmpfile,
+                         buf,
+                         XLOG_BLCKSZ,
+                         writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
                die("write failed");
        if (fsync(tmpfile) != 0)
            die("fsync failed");
-       if (lseek(tmpfile, 0, SEEK_SET) == -1)
-           die("seek failed");
    }
    STOP_TIMER;
    close(tmpfile);
@@ -362,12 +365,13 @@ test_sync(int writes_per_op)
    for (ops = 0; alarm_triggered == false; ops++)
    {
        for (writes = 0; writes < writes_per_op; writes++)
-           if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+           if (pg_pwrite(tmpfile,
+                         buf,
+                         XLOG_BLCKSZ,
+                         writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
                die("write failed");
        if (pg_fsync_writethrough(tmpfile) != 0)
            die("fsync failed");
-       if (lseek(tmpfile, 0, SEEK_SET) == -1)
-           die("seek failed");
    }
    STOP_TIMER;
    close(tmpfile);
@@ -393,8 +397,10 @@ test_sync(int writes_per_op)
        for (ops = 0; alarm_triggered == false; ops++)
        {
            for (writes = 0; writes < writes_per_op; writes++)
-               if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
-
+               if (pg_pwrite(tmpfile,
+                             buf,
+                             XLOG_BLCKSZ,
+                             writes * XLOG_BLCKSZ) != XLOG_BLCKSZ)
                    /*
                     * This can generate write failures if the filesystem has
                     * a large block size, e.g. 4k, and there is no support
@@ -402,8 +408,6 @@ test_sync(int writes_per_op)
                     * size, e.g. XFS.
                     */
                    die("write failed");
-           if (lseek(tmpfile, 0, SEEK_SET) == -1)
-               die("seek failed");
        }
        STOP_TIMER;
        close(tmpfile);
@@ -457,11 +461,12 @@ test_open_sync(const char *msg, int writes_size)
        for (ops = 0; alarm_triggered == false; ops++)
        {
            for (writes = 0; writes < 16 / writes_size; writes++)
-               if (write(tmpfile, buf, writes_size * 1024) !=
+               if (pg_pwrite(tmpfile,
+                             buf,
+                             writes_size * 1024,
+                             writes * writes_size * 1024) !=
                    writes_size * 1024)
                    die("write failed");
-           if (lseek(tmpfile, 0, SEEK_SET) == -1)
-               die("seek failed");
        }
        STOP_TIMER;
        close(tmpfile);
@@ -553,16 +558,16 @@ test_non_sync(void)
    printf(LABEL_FORMAT, "write");
    fflush(stdout);
 
+   if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
+       die("could not open output file");
    START_TIMER;
    for (ops = 0; alarm_triggered == false; ops++)
    {
-       if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
-           die("could not open output file");
-       if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
+       if (pg_pwrite(tmpfile, buf, XLOG_BLCKSZ, 0) != XLOG_BLCKSZ)
            die("write failed");
-       close(tmpfile);
    }
    STOP_TIMER;
+   close(tmpfile);
 }
 
 static void