Copy fsync() defines into test_fsync.c, someday place them in an

include.

Propery align for O_DIRECT.

Check for write()/fsync() failures.

diff --git a/src/tools/fsync/test_fsync.c b/src/tools/fsync/test_fsync.c
index 32d3aff003b5250d9e2ba713dc3c5a5760ad4cf6..637d1a6bc16ef131e230695a189e28ef15b89d35 100644 (file)
--- a/src/tools/fsync/test_fsync.c
+++ b/src/tools/fsync/test_fsync.c
@@ -1,10 +1,12 @@
 /*
  * test_fsync.c
- *     tests if fsync can be done from another process than the original write
+ *     test various fsync() methods
  */
 
-#include "../../include/pg_config.h"
-#include "../../include/pg_config_os.h"
+#include "postgres.h"
+
+#include "access/xlog_internal.h"
+#include "access/xlog.h"
 
 #include 
 #include 
@@ -14,29 +16,94 @@
 #include 
 #include 
 #include 
+#include 
 
-#ifdef WIN32
-#define FSYNC_FILENAME "./test_fsync.out"
+/* ---------------------------------------------------------------
+ * Copied from xlog.c.  Some day this should be moved an include file.
+ */
+ 
+/*
+ * Because O_DIRECT bypasses the kernel buffers, and because we never
+ * read those buffers except during crash recovery, it is a win to use
+ * it in all cases where we sync on each write().  We could allow O_DIRECT
+ * with fsync(), but because skipping the kernel buffer forces writes out
+ * quickly, it seems best just to use it for O_SYNC.  It is hard to imagine
+ * how fsync() could be a win for O_DIRECT compared to O_SYNC and O_DIRECT.
+ * Also, O_DIRECT is never enough to force data to the drives, it merely
+ * tries to bypass the kernel cache, so we still need O_SYNC or fsync().
+ */
+#ifdef O_DIRECT
+#define PG_O_DIRECT                O_DIRECT
 #else
-#define FSYNC_FILENAME "/var/tmp/test_fsync.out"
+#define PG_O_DIRECT                0
 #endif
 
-/* O_SYNC and O_FSYNC are the same */
+/*
+ * This chunk of hackery attempts to determine which file sync methods
+ * are available on the current platform, and to choose an appropriate
+ * default method. We assume that fsync() is always available, and that
+ * configure determined whether fdatasync() is.
+ */
 #if defined(O_SYNC)
-#define OPEN_SYNC_FLAG     O_SYNC
+#define BARE_OPEN_SYNC_FLAG        O_SYNC
 #elif defined(O_FSYNC)
-#define OPEN_SYNC_FLAG     O_FSYNC
-#elif defined(O_DSYNC)
-#define OPEN_DATASYNC_FLAG O_DSYNC
+#define BARE_OPEN_SYNC_FLAG        O_FSYNC
+#endif
+#ifdef BARE_OPEN_SYNC_FLAG
+#define OPEN_SYNC_FLAG         (BARE_OPEN_SYNC_FLAG | PG_O_DIRECT)
 #endif
 
+#if defined(O_DSYNC)
 #if defined(OPEN_SYNC_FLAG)
-#if defined(O_DSYNC) && (O_DSYNC != OPEN_SYNC_FLAG)
-#define OPEN_DATASYNC_FLAG O_DSYNC
+/* O_DSYNC is distinct? */
+#if O_DSYNC != BARE_OPEN_SYNC_FLAG
+#define OPEN_DATASYNC_FLAG     (O_DSYNC | PG_O_DIRECT)
+#endif
+#else                          /* !defined(OPEN_SYNC_FLAG) */
+/* Win32 only has O_DSYNC */
+#define OPEN_DATASYNC_FLAG     (O_DSYNC | PG_O_DIRECT)
+#endif
+#endif
+
+#if defined(OPEN_DATASYNC_FLAG)
+#define DEFAULT_SYNC_METHOD_STR "open_datasync"
+#define DEFAULT_SYNC_METHOD        SYNC_METHOD_OPEN
+#define DEFAULT_SYNC_FLAGBIT   OPEN_DATASYNC_FLAG
+#elif defined(HAVE_FDATASYNC)
+#define DEFAULT_SYNC_METHOD_STR "fdatasync"
+#define DEFAULT_SYNC_METHOD        SYNC_METHOD_FDATASYNC
+#define DEFAULT_SYNC_FLAGBIT   0
+#elif defined(HAVE_FSYNC_WRITETHROUGH_ONLY)
+#define DEFAULT_SYNC_METHOD_STR "fsync_writethrough"
+#define DEFAULT_SYNC_METHOD        SYNC_METHOD_FSYNC_WRITETHROUGH
+#define DEFAULT_SYNC_FLAGBIT   0
+#else
+#define DEFAULT_SYNC_METHOD_STR "fsync"
+#define DEFAULT_SYNC_METHOD        SYNC_METHOD_FSYNC
+#define DEFAULT_SYNC_FLAGBIT   0
+#endif
+
+
+/*
+ * Limitation of buffer-alignment for direct IO depends on OS and filesystem,
+ * but XLOG_BLCKSZ is assumed to be enough for it.
+ */
+#ifdef O_DIRECT
+#define ALIGNOF_XLOG_BUFFER        XLOG_BLCKSZ
+#else
+#define ALIGNOF_XLOG_BUFFER        ALIGNOF_BUFFER
 #endif
+
+/* ------------ from xlog.c --------------- */
+
+#ifdef WIN32
+#define FSYNC_FILENAME "./test_fsync.out"
+#else
+/* /tmp might be a memory file system */
+#define FSYNC_FILENAME "/var/tmp/test_fsync.out"
 #endif
 
-#define WAL_FILE_SIZE  (16 * 1024 * 1024)
+#define WRITE_SIZE (16 * 1024)
 
 void       die(char *str);
 void       print_elapse(struct timeval start_t, struct timeval elapse_t);
@@ -49,7 +116,7 @@ main(int argc, char *argv[])
    int         tmpfile,
                i,
                loops = 1000;
-   char       *strout = (char *) malloc(WAL_FILE_SIZE);
+   char       *full_buf = (char *) malloc(XLOG_SEG_SIZE), *buf;
    char       *filename = FSYNC_FILENAME;
 
    if (argc > 2 && strcmp(argv[1], "-f") == 0)
@@ -62,15 +129,20 @@ main(int argc, char *argv[])
    if (argc > 1)
        loops = atoi(argv[1]);
 
-   for (i = 0; i < WAL_FILE_SIZE; i++)
-       strout[i] = 'a';
+   for (i = 0; i < XLOG_SEG_SIZE; i++)
+       full_buf[i] = 'a';
 
    if ((tmpfile = open(filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR)) == -1)
        die("Cannot open output file.");
-   write(tmpfile, strout, WAL_FILE_SIZE);
-   fsync(tmpfile);             /* fsync so later fsync's don't have to do it */
+   if (write(tmpfile, full_buf, XLOG_SEG_SIZE) != XLOG_SEG_SIZE)
+       die("write failed");
+   /* fsync so later fsync's don't have to do it */
+   if (fsync(tmpfile) != 0)
+       die("fsync failed");
    close(tmpfile);
 
+   buf = (char *)TYPEALIGN(ALIGNOF_XLOG_BUFFER, full_buf);
+
    printf("Simple write timing:\n");
    /* write only */
    gettimeofday(&start_t, NULL);
@@ -78,7 +150,8 @@ main(int argc, char *argv[])
    {
        if ((tmpfile = open(filename, O_RDWR)) == -1)
            die("Cannot open output file.");
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
        close(tmpfile);
    }
    gettimeofday(&elapse_t, NULL);
@@ -95,8 +168,10 @@ main(int argc, char *argv[])
    {
        if ((tmpfile = open(filename, O_RDWR)) == -1)
            die("Cannot open output file.");
-       write(tmpfile, strout, 8192);
-       fsync(tmpfile);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (fsync(tmpfile) != 0)
+           die("fsync failed");
        close(tmpfile);
        if ((tmpfile = open(filename, O_RDWR)) == -1)
            die("Cannot open output file.");
@@ -114,12 +189,14 @@ main(int argc, char *argv[])
    {
        if ((tmpfile = open(filename, O_RDWR)) == -1)
            die("Cannot open output file.");
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
        close(tmpfile);
        /* reopen file */
        if ((tmpfile = open(filename, O_RDWR)) == -1)
            die("Cannot open output file.");
-       fsync(tmpfile);
+       if (fsync(tmpfile) != 0)
+           die("fsync failed");
        close(tmpfile);
    }
    gettimeofday(&elapse_t, NULL);
@@ -135,7 +212,8 @@ main(int argc, char *argv[])
        die("Cannot open output file.");
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
-       write(tmpfile, strout, 16384);
+       if (write(tmpfile, buf, WRITE_SIZE) != WRITE_SIZE)
+           die("write failed");
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
    printf("\tone 16k o_sync write   ");
@@ -148,8 +226,10 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
@@ -169,7 +249,8 @@ main(int argc, char *argv[])
        die("Cannot open output file.");
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
    printf("\topen o_dsync, write    ");
@@ -181,7 +262,8 @@ main(int argc, char *argv[])
        die("Cannot open output file.");
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
    printf("\topen o_sync, write     ");
@@ -199,7 +281,8 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
        fdatasync(tmpfile);
    }
    gettimeofday(&elapse_t, NULL);
@@ -217,8 +300,10 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
-       fsync(tmpfile);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (fsync(tmpfile) != 0)
+           die("fsync failed");
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
@@ -235,8 +320,10 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
@@ -254,8 +341,10 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
@@ -271,8 +360,10 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
-       write(tmpfile, strout, 8192);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
        fdatasync(tmpfile);
    }
    gettimeofday(&elapse_t, NULL);
@@ -290,9 +381,12 @@ main(int argc, char *argv[])
    gettimeofday(&start_t, NULL);
    for (i = 0; i < loops; i++)
    {
-       write(tmpfile, strout, 8192);
-       write(tmpfile, strout, 8192);
-       fsync(tmpfile);
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (write(tmpfile, buf, WRITE_SIZE/2) != WRITE_SIZE/2)
+           die("write failed");
+       if (fsync(tmpfile) != 0)
+           die("fsync failed");
    }
    gettimeofday(&elapse_t, NULL);
    close(tmpfile);
@@ -300,6 +394,7 @@ main(int argc, char *argv[])
    print_elapse(start_t, elapse_t);
    printf("\n");
 
+   free(full_buf);
    unlink(filename);
 
    return 0;