From: Karel Zak <kzak@redhat.com>
Date: Wed, 6 Jan 2010 10:12:43 +0000 (+0100)
Subject: fdisk: sleep-after-sync and fsync usage
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e90709421ac86e2e81498143f75734e0b79f76d1;p=util-linux

fdisk: sleep-after-sync and fsync usage

It seems that sleep() after sync() is unnecessary legacy. It's very
probably unnecessary since kernel 1.3.20. For example the libparted
does not to use sleep() at all.

It seems that more important is fsync() usage in fdisks. For more
details see

  http://marc.theaimsgroup.com/?l=linux-kernel&m=105545785306867&w=3
  http://marc.theaimsgroup.com/?l=linux-kernel&m=105545848607353&w=3
  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=276369

Currently we use fsync() in fdisk only. This patch also add fsync() to
sfdisk and cfdisk.

Addresses: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=276369
Addresses: http://bugzilla.redhat.com/show_bug.cgi?id=502639
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/fdisk/cfdisk.c b/fdisk/cfdisk.c
index 0405e126..eec16893 100644
--- a/fdisk/cfdisk.c
+++ b/fdisk/cfdisk.c
@@ -406,9 +406,11 @@ partition_type_text(int i) {
 
 static void
 fdexit(int ret) {
-    if (opened)
+    if (opened) {
+	if (changed)
+		fsync(fd);
 	close(fd);
-
+    }
     if (changed) {
 	fprintf(stderr, _("Disk has been changed.\n"));
 #if 0
@@ -1912,12 +1914,10 @@ write_part_table(void) {
     if (is_bdev) {
 #ifdef BLKRRPART
 	 sync();
-	 sleep(2);
 	 if (!ioctl(fd,BLKRRPART))
 	      changed = TRUE;
 #endif
 	 sync();
-	 sleep(4);
 
 	 clear_warning();
 	 if (changed)
diff --git a/fdisk/fdisk.c b/fdisk/fdisk.c
index af525bad..5ef24f66 100644
--- a/fdisk/fdisk.c
+++ b/fdisk/fdisk.c
@@ -2519,7 +2519,6 @@ reread_partition_table(int leave) {
 	i = fstat(fd, &statbuf);
 	if (i == 0 && S_ISBLK(statbuf.st_mode)) {
 		sync();
-		sleep(2);
 #ifdef BLKRRPART
 		printf(_("Calling ioctl() to re-read partition table.\n"));
 		i = ioctl(fd, BLKRRPART);
@@ -2550,7 +2549,6 @@ reread_partition_table(int leave) {
 
 		printf(_("Syncing disks.\n"));
 		sync();
-		sleep(4);		/* for sync() */
 		exit(!!i);
 	}
 }
diff --git a/fdisk/sfdisk.c b/fdisk/sfdisk.c
index 0652cfa3..6ac91f07 100644
--- a/fdisk/sfdisk.c
+++ b/fdisk/sfdisk.c
@@ -806,14 +806,13 @@ reread_disk_partition(char *dev, int fd) {
     printf(_("Re-reading the partition table ...\n"));
     fflush(stdout);
     sync();
-    sleep(3);			/* superfluous since 1.3.20 */
 
     if (reread_ioctl(fd) && is_blockdev(fd))
       do_warn(_("The command to re-read the partition table failed.\n"
 	        "Run partprobe(8), kpartx(8) or reboot your system now,\n"
 	        "before using mkfs\n"));
 
-    if (close(fd)) {
+    if (fsync(fd) || close(fd)) {
 	perror(dev);
 	do_warn(_("Error closing %s\n"), dev);
     }
@@ -3103,6 +3102,5 @@ do_fdisk(char *dev){
 	 "(See fdisk(8).)\n"));
 
     sync();			/* superstition */
-    sleep(3);
     exit(exit_status);
 }