Stop using O_EXCL by default when opening the device for writing.

gpt.c

Index: gpt.c
diff --git a/gpt.c b/gpt.c
index a09df130c579e2010d99014ccfde961ef7097ff8..c1bf9445c2388cf775a09d414ecd4e5c224a1029 100644
--- a/gpt.c
+++ b/gpt.c
@@ -60,7 +60,7 @@ off_t	mediasz;
 u_int	parts;
 u_int	secsz;
 
-int	readonly, verbose;
+int	readonly, exclusive = O_EXCL, verbose;
 
 static uint32_t crc32_tab[] = {
 	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
@@ -557,7 +557,7 @@ gpt_open(const char *dev)
 	struct stat sb;
 	int fd, mode;
 
-	mode = readonly ? O_RDONLY : O_RDWR|O_EXCL;
+	mode = readonly ? O_RDONLY : O_RDWR|exclusive;
 
 	strlcpy(device_path, dev, sizeof(device_path));
 	device_name = device_path;
@@ -666,7 +666,7 @@ usage(void)
 {
 
 	fprintf(stderr,
-	    "usage: %s [-rv] [-p nparts] command [options] device ...\n",
+	    "usage: %s [-rSv] [-p nparts] command [options] device ...\n",
 	    getprogname());
 	exit(1);
 }
@@ -694,7 +694,7 @@ main(int argc, char *argv[])
 	int ch, i;
 
 	/* Get the generic options */
-	while ((ch = getopt(argc, argv, "+p:rv")) != -1) {
+	while ((ch = getopt(argc, argv, "+p:rSv")) != -1) {
 		switch(ch) {
 		case 'p':
 			if (parts > 0)
@@ -706,6 +706,9 @@ main(int argc, char *argv[])
 		case 'r':
 			readonly = 1;
 			break;
+		case 'S':
+			exclusive = 0;
+			break;
 		case 'v':
 			verbose++;
 			break;