Use O_EXCL when opening component devices to be assembled into an array

In 2.6, this will fail if the device is already in use, so we can detect this error
more easily.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>

1 files changed, 8 insertions, 0 deletions

diff --git a/Manage.c b/Manage.c
index 8835095..b323fd3 100644
--- a/Manage.c
+++ b/Manage.c
@@ -194,6 +194,14 @@ int Manage_subdevs(char *devname, int fd,
 			return 1;
 		case 'a':
 			/* add the device - hot or cold */
+			/* Make sure it isn' in use (in 2.6 or later) */
+			fd = open(dv->devname, O_RDONLY|O_EXCL);
+			if (fd < 0) {
+				fprintf(stderr, Name ": Cannot open %s: %s\n",
+					dv->devname, strerror(errno));
+				return 1;
+			}
+			close(fd);
 			if (ioctl(fd, HOT_ADD_DISK, (unsigned long)stb.st_rdev)==0) {
 				fprintf(stderr, Name ": hot added %s\n",
 					dv->devname);