Allow parse_size to return 0.

We will shortly introduce --data-offset= which is allowed to
be zero.  We will want to use parse_size() so it needs to be
able to return '0' without it being an error.

So define INVALID_SECTORS to be an impossible value (currently '1')
and return and test for it consistently.

Signed-off-by: NeilBrown <neilb@suse.de>

3 files changed, 17 insertions, 7 deletions

diff --git a/mdadm.c b/mdadm.c
index 870e5376..51c57c5d 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -372,7 +372,8 @@ int main(int argc, char *argv[])
 				exit(2);
 			}
 			s.chunk = parse_size(optarg);
-			if (s.chunk < 8 || (s.chunk&1)) {
+			if (s.chunk == INVALID_SECTORS ||
+			    s.chunk < 8 || (s.chunk&1)) {
 				pr_err("invalid chunk/rounding value: %s\n",
 					optarg);
 				exit(2);
@@ -426,7 +427,8 @@ int main(int argc, char *argv[])
 				s.size = MAX_SIZE;
 			else {
 				s.size = parse_size(optarg);
-				if (s.size < 8) {
+				if (s.size == INVALID_SECTORS ||
+				    s.size < 8) {
 					pr_err("invalid size: %s\n",
 						optarg);
 					exit(2);
@@ -446,7 +448,8 @@ int main(int argc, char *argv[])
 				array_size = MAX_SIZE;
 			else {
 				array_size = parse_size(optarg);
-				if (array_size <= 0) {
+				if (array_size == 0 ||
+				    array_size == INVALID_SECTORS) {
 					pr_err("invalid array size: %s\n",
 						optarg);
 					exit(2);
@@ -1062,7 +1065,8 @@ int main(int argc, char *argv[])
 		case O(BUILD,BitmapChunk):
 		case O(CREATE,BitmapChunk): /* bitmap chunksize */
 			s.bitmap_chunk = parse_size(optarg);
-			if (s.bitmap_chunk <= 0 ||
+			if (s.bitmap_chunk == 0 ||
+			    s.bitmap_chunk == INVALID_SECTORS ||
 			    s.bitmap_chunk & (s.bitmap_chunk - 1)) {
 				pr_err("invalid bitmap chunksize: %s\n",
 				       optarg);
diff --git a/mdadm.h b/mdadm.h
index 6980bfb8..6db7714a 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1460,4 +1460,10 @@ char *xstrdup(const char *str);
  * In those cases with use MAX_SIZE
  */
 #define MAX_SIZE	1
+
+/* We want to use unsigned numbers for sector counts, but need
+ * a value for 'invalid'.  Use '1'.
+ */
+#define INVALID_SECTORS 1
+
 extern int __offroot;
diff --git a/util.c b/util.c
index fad72cc9..4bd07e1b 100644
--- a/util.c
+++ b/util.c
@@ -194,7 +194,7 @@ unsigned long long parse_size(char *size)
 	 * followed by 'K', 'M', or 'G'.
 	 * Without a suffix, K is assumed.
 	 * Number returned is in sectors (half-K)
-	 * 0 returned on error.
+	 * INVALID_SECTORS returned on error.
 	 */
 	char *c;
 	long long s = strtoll(size, &c, 10);
@@ -215,9 +215,9 @@ unsigned long long parse_size(char *size)
 			break;
 		}
 	} else
-		s = 0;
+		s = INVALID_SECTORS;
 	if (*c)
-		s = 0;
+		s = INVALID_SECTORS;
 	return s;
 }