From: Matthias Koenig <mkoenig@suse.de>
Date: Wed, 18 Jul 2007 14:15:46 +0000 (+0200)
Subject: disk-utils: let mkfs tools open with O_EXCL
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2018629905d3d881ff3fddf76552b6e79091f2b8;p=util-linux

disk-utils: let mkfs tools open with O_EXCL

Let mkswap, mkfs.bfs, mkfs.minix open with O_EXCL if
used on block devices to prevent writing to the device
even if they are busy (mounted).

Unfortunately, O_EXCL has zero effect for 2.4 kernels where
in-kernel code doesn't use O_EXCL-like access locks. (Tested
on RHEL3.)

Signed-off-by: Matthias Koenig <mkoenig@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/disk-utils/mkfs.bfs.c b/disk-utils/mkfs.bfs.c
index 8221f3b7..557cde48 100644
--- a/disk-utils/mkfs.bfs.c
+++ b/disk-utils/mkfs.bfs.c
@@ -170,7 +170,7 @@ main(int argc, char *argv[]) {
 	if (!S_ISBLK(statbuf.st_mode))
 		fatal(_("%s is not a block special device"), device);
 
-	fd = open(device, O_RDWR);
+	fd = open(device, O_RDWR | O_EXCL);
 	if (fd == -1) {
 		perror(device);
 		fatal(_("cannot open %s"), device);
diff --git a/disk-utils/mkfs.minix.c b/disk-utils/mkfs.minix.c
index 92a6789a..8a81e7ca 100644
--- a/disk-utils/mkfs.minix.c
+++ b/disk-utils/mkfs.minix.c
@@ -699,11 +699,14 @@ main(int argc, char ** argv) {
   tmp += dirsize;
   *(short *)tmp = 2;
   strcpy(tmp+2,".badblocks");
-  DEV = open(device_name,O_RDWR );
+  if (stat(device_name, &statbuf) < 0)
+    die(_("unable to stat %s"));
+  if (S_ISBLK(statbuf.st_mode))
+    DEV = open(device_name,O_RDWR | O_EXCL);
+  else
+    DEV = open(device_name,O_RDWR);
   if (DEV<0)
     die(_("unable to open %s"));
-  if (fstat(DEV,&statbuf)<0)
-    die(_("unable to stat %s"));
   if (!S_ISBLK(statbuf.st_mode))
     check=0;
   else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
diff --git a/disk-utils/mkswap.c b/disk-utils/mkswap.c
index 1fd1f185..6af1ff7b 100644
--- a/disk-utils/mkswap.c
+++ b/disk-utils/mkswap.c
@@ -640,8 +640,16 @@ main(int argc, char ** argv) {
 		usage();
 	}
 
-	DEV = open(device_name,O_RDWR);
-	if (DEV < 0 || fstat(DEV, &statbuf) < 0) {
+	if (stat(device_name, &statbuf) < 0) {
+		perror(device_name);
+		exit(EXIT_FAILURE);
+	}
+	if (S_ISBLK(statbuf.st_mode))
+		DEV = open(device_name, O_RDWR | O_EXCL);
+	else
+		DEV = open(device_name, O_RDWR);
+
+	if (DEV < 0) {
 		perror(device_name);
 		exit(1);
 	}