mdadm/grow: adding a test to ensure resize was required

To fix the commit: 4b74a905a67e
(mdadm/grow: Component size must be larger than chunk size)

array.level > 1 : against the raids which chunk_size is meaningful.
s->size > 0 : ensure that changing component size has required.
array.chunk_size / 1024 > s->size : ensure component size should
be always >= current chunk_size when requires resize, otherwise,
mddev->pers->resize would be set mddev->dev_sectors as '0'.

Reported-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

diff --git a/Grow.c b/Grow.c
index 4d79d832da48331a27b5ba0856bfe5eebe5cada8..0f9e89bcc5bad5ce97c269dee3b1efad2a8992d7 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -1809,8 +1809,8 @@ int Grow_reshape(char *devname, int fd,
                return 1;
        }
 
-       if (array.level > 1 &&
-          (array.chunk_size / 1024) > (int)s->size) {
+       if (array.level > 1 && s->size > 0 &&
+           (array.chunk_size / 1024) > (int)s->size) {
                pr_err("component size must be larger than chunk size.\n");
                return 1;
        }