Grow: fix can't change bitmap type from none to clustered.

Commit a042210648ed ("disallow create or grow clustered bitmap with
writemostly set") introduced this bug. We should use 'true' logic not
'== 0' to deny setting up clustered array under WRITEMOSTLY condition.

How to trigger

```
~/mdadm # ./mdadm -Ss && ./mdadm --zero-superblock /dev/sd{a,b}
~/mdadm # ./mdadm -C /dev/md0 -l mirror -b clustered -e 1.2 -n 2 \
/dev/sda /dev/sdb --assume-clean
mdadm: array /dev/md0 started.
~/mdadm # ./mdadm --grow /dev/md0 --bitmap=none
~/mdadm # ./mdadm --grow /dev/md0 --bitmap=clustered
mdadm: /dev/md0 disks marked write-mostly are not supported with clustered bitmap
```

Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jes Sorensen <jes@trained-monkey.org>

diff --git a/Grow.c b/Grow.c
index 8f5cf07d10d9a22f1545ab85be4cbba76ca508e3..bb5fe45c851cf82c3e476d3063b86c3f2b40c48c 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -429,7 +429,7 @@ int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
                        dv = map_dev(disk.major, disk.minor, 1);
                        if (!dv)
                                continue;
-                       if (((disk.state & (1 << MD_DISK_WRITEMOSTLY)) == 0) &&
+                       if ((disk.state & (1 << MD_DISK_WRITEMOSTLY)) &&
                           (strcmp(s->bitmap_file, "clustered") == 0)) {
                                pr_err("%s disks marked write-mostly are not supported with clustered bitmap\n",devname);
                                free(mdi);