mdadm.c: Fix error handling for --zero-superblock

When Kill() cannot open device or find superblock it return the same
error and mdadm ignores it.
Change error handling in Kill() function. Return error if device is
busy, ignore it only when superblock doesn't exist- assume that metadata
is zeroed.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

2 files changed, 4 insertions, 3 deletions

diff --git a/Kill.c b/Kill.c
index ff52561d..d4767e29 100644
--- a/Kill.c
+++ b/Kill.c
@@ -37,7 +37,8 @@ int Kill(char *dev, struct supertype *st, int force, int verbose, int noexcl)
 	 * Returns:
 	 *  0 - a zero superblock was successfully written out
 	 *  1 - failed to write the zero superblock
-	 *  2 - failed to open the device or find a superblock.
+	 *  2 - failed to open the device.
+	 *  4 - failed to find a superblock.
 	 */
 
 	int fd, rv = 0;
@@ -57,7 +58,7 @@ int Kill(char *dev, struct supertype *st, int force, int verbose, int noexcl)
 		if (verbose >= 0)
 			pr_err("Unrecognised md component device - %s\n", dev);
 		close(fd);
-		return 2;
+		return 4;
 	}
 	st->ignore_hw_compat = 1;
 	rv = st->ss->load_super(st, fd, dev);
diff --git a/mdadm.c b/mdadm.c
index 1cf5c189..25a1abd2 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -1959,7 +1959,7 @@ static int misc_list(struct mddev_dev *devlist,
 					rv |= Kill(dv->devname, NULL, c->force, v, 0);
 					v = -1;
 				} while (rv == 0);
-				rv &= ~2;
+				rv &= ~4;
 			}
 			continue;
 		case 'Q':